Neuroanatomy Flashcards

Question

While placing DBS electrodes for essential tremor into VIM thalamus, the patient develops persistent paresthesias during test stimulation. Which direction should you move the electrode A. Anterior B. Posterior C. Medial D. Lateral

Answer 1

**A. Anterior** B. Posterior C. Medial D. Lateral ## Footnote VIM thalamus is just anterior to the VPL nucleus of the thalamus, the main sensory relay nucleus of the thalamus. If the electrode is placed correctly into VIM, patients can develop transient paresthesias during test stimulation, but these symptoms often resolve quite quickly. If the patient develops persistent paresthesias, current is likely spreading into VPL thalamus, and the electrode should be moved anteriorly. Further Reading: Israel, Burchiel, Microelectrode Recording in Movement Disorder Surgery, 2004, target selection using microelectrode recording

Answer 2

A. Posterosuperior B. Posteroinferior C. Anterosuperior **D. Anteroinferior** ## Footnote Utilizing the MCA M1 segment to reach the ICA terminus is one technique to expose an ICA terminus aneurysm. The main concern dissecting along the M1 segment of the MCA is preservation of the lateral lenticulostriate perforating arteries, which are located on the posterosuperior aspect of the M1 segment. The safe zone of dissection is on the anteroinferior surface of the vessel. Further Reading: Spetzler, Kalani, Nakaji. Neurovascular Surgery, 2nd edition, 2015, surgical therapies for saccular aneurysms of the internal carotid artery.

Answer 3

A. Medial forebrain bundle **B. Limen insulae** C. Inferior longitudinal fasciculus D. Diagonal band of Broca ## Footnote The limen insula is a structure that connects the temporal and orbital cortical regions. It often marks the MCA bifurcation, and laterally is continuous with the insular cortex. Medially it is bordered by the anterior perforated substance. Further Reading: Starr, Barbaro, Larson, Neurosurgical Operative Atlas: Functional Neurosurgery, 2nd edition, 2009, surgical anatomy of the temporal lobe.

Answer 4

**A. Cingulate gyrus** B. Paracentral lobule C. Supramarginal gyrus D. Precentral gyrus ## Footnote The cingulate gyrus is located immediately superior to the corpus callosum, and must be gently retracted to expose the corpus callosum for division. Care must be taken to avoid damaging the pericallosal arteries, which are also running immediately over the corpus callosum Further Reading: Sekhar, Fessler, Atlas of Neurosurgical Techniques: Brain, Vol. 2, 2016, surgical approaches to lesions located in the lateral, third, and fourth ventricles

Answer 5

A. Precentral cerebellar vein B. Basal vein of Rosenthal C. Internal cerebral vein **D. Thalamostriate vein** ## Footnote The vein of Galen may have numerous supplying veins, but most often it receives the paired internal cerebral veins, the paired basal veins of Rosenthal and the precentral cerebellar vein. The thalamostriate vein of the lateral ventricle drains into the internal cerebral vein at the venous angle near the foramen of Monro, but this vein does not directly drain into the vein of Galen. Further Reading: Spetzler, Kalani, Nakaji. Neurovascular Surgery, 2nd edition, 2015, microsurgical treatment of vein of Galen malformations

Answer 6

**A. Anterior** B. Lateral C. Posterior D. Medial ## Footnote During an endoscopic third ventriculostomy, one of the easiest structures to identify are the paired mammillary bodies. Just anterior to the mammillary bodies is the safe zone for puncture. Care must be taken to not injure the basilar artery or posterior cerebellar arteries, which are just deep and slightly posterior to the puncture location Further Reading: Torres-Corzo, Rangel-Castilla, Nakaji. Neuroendoscopic Surgery, 2016, lateral and third ventricle anatomy

Answer 7

A. Anterior commissure **B. Lamina terminalis** C. Optic chiasm D. Mammillary bodies ## Footnote In the anterior floor of the third ventricle, the lamina terminalis is located superior to the supraoptic recess. It is formed during closure of the anterior neuropore on embryological day 24. Division of the lamina terminalis allows access to the third ventricle for drainage of CSF and brain relaxation if required during anterior fossa aneurysm surgery. Further Reading: Torres-Corzo, Rangel-Castilla, Nakaji. Neuroendoscopic, Surgery, 2016, lateral and third ventricle anatomy.

Answer 8

A. Squamosal B. Coronal **C. Lambdoid** D. Sphenosquamosal ## Footnote The lambdoid suture connects the occipital and parietal bones while descending laterally across the posterior skull. Further Reading: Greenberg. Handbook of Neurosurgery, 8th edition, 2016, gross anatomy, cranial and spine.

Answer 9

A. Sagittal-lambdoid B. Parietomastoid-occipitomastoid C. Squamosal-parietomastoid **D. Coronal-sagittal** ## Footnote The bregma is a midline skull structure that is the location where the coronal and sagittal sutures conjoin. It is the location of the anterior fontanelle, which closes in most pediatric patients around 18 months of age. Further Reading: Greenberg. Handbook of Neurosurgery, 8th edition, 2016, gross anatomy, cranial and spine.

Answer 10

A. Globose B. Fastigial C. Emboliform **D. Vestibular** ## Footnote The deep cerebellar nuclei are the dentate, emboliform, globose and fastigial, going from lateral to medial. A mnemonic to remember is “Don’t Eat Greasy Foods.” Since the deep cerebellar nuclei control all output from the cerebellum, damage to these structures can mimic a complete cerebellar resection and are considered by some to be “eloquent cortex.” Further Reading: Psarros. The Definitive Neurosurgical Board Review. Alberstone, Benzel, Najm, Steinmetz. Anatomic Basis of Neurologic Diagnosis, 2009, cerebellum.

Answer 11

**A. Brachium conjunctivum** B. Restiform body C. Brachium pontis D. Vermis ## Footnote The 4th ventricle has lateral walls formed superiorly by the superior cerebellar peduncle (brachium conjunctivis), and lateral walls formed inferiorly by the inferior cerebellar peduncle (restiform body). The middle cerebellar peduncle (brachium pontis) does not form a lateral wall of the 4th ventricle. The roof of the 4th ventricle is formed by both the superior and inferior medullary velum, and the floor is formed by the brainstem. Further Reading: Psarros. The Definitive Neurosurgical Board Review. Alberstone, Benzel, Najm, Steinmetz. Anatomic Basis of Neurologic Diagnosis, 2009, cerebellum.

Answer 12

A. Brachium conjunctivum **B. Restiform body** C. Brachium pontis D. Vermis ## Footnote The 4th ventricle has lateral walls formed superiorly by the superior cerebellar peduncle (brachium conjunctivis), and lateral walls formed inferiorly by the inferior cerebellar peduncle (restiform body). The middle cerebellar peduncle (brachium pontis) does not form a lateral wall of the 4th ventricle. The roof of the 4th ventricle is formed by both the superior and inferior medullary velum, and the floor is formed by the brainstem. Further Reading: Psarros. The Definitive Neurosurgical Board Review. Alberstone, Benzel, Najm, Steinmetz. Anatomic Basis of Neurologic Diagnosis, 2009, cerebellum

Answer 13

A. Anterior lobe B. Posterior lobe C. Vermis **D. Flocculonodular lobe** ## Footnote The cerebellum can be divided in to three functional segments, the vestibulocerebellum, the spinocerebellum and the cerebrocerebellum. The vestibulocerebellum is formed by the flocculonodular lobe and it receives projections from the vestibular nuclei, the superior colliculi and visual cortex. This system controls head and eye movements as well as postural and balance adjustments. Further Reading: Psarros. The Definitive Neurosurgical Board Review, page 37. Alberstone, Benzel, Najm, Steinmetz. Anatomic Basis of Neurologic Diagnosis, 2009, cerebellum.

Answer 14

A. Anterior lobe **B. Lateral hemisphere** C. Vermis D. Flocculonodular lobe ## Footnote The functional division of the cerebellum known as the cerebrocerebellum is comprised of the lateral hemispheres. It projects to the dentate nucleus of the deep cerebellar nuclei. Further connections include the VL nuclei of the thalamus and red nucleus, followed by motor cortex, and helps to provide feedback to motor cortex regarding accuracy of movement. Further Reading: Psarros. The Definitive Neurosurgical Board Review, page 37. Alberstone, Benzel, Najm, Steinmetz. Anatomic Basis of Neurologic Diagnosis, 2009, cerebellum

Answer 15

A. Anterior lobe B. Lateral hemisphere **C. Vermis** D. Flocculonodular lobe ## Footnote The functional division of the cerebellum known as the spinocerebellum is comprised mainly of the vermis. It projects to the fastigial nucleus of the deep cerebellar nuclei. It receives afferent connections from the spinocerebellar tract. Efferent connections from the fastigial nucleus project to the reticular formation and lateral vestibular nuclei, as well as the contralateral motor cortex via the VL thalamus. Further Reading: Psarros. The Definitive Neurosurgical Board Review, page 37. Alberstone, Benzel, Najm, Steinmetz. Anatomic Basis of Neurologic Diagnosis, 2009, cerebellum

Answer 16

A. Trochlear nucleus **B. Abducens nucleus** C. Oculomotor nucleus D. Facial nucleus ## Footnote The paramedian pontine reticular formation is also known as the lateral gaze center, and it is located near the abducens nucleus. It receives input from the superior colliculus to coordinate vertical eye movements, and from the frontal eye fields via the frontopontine fibers to coordinate lateral gaze. Contralateral eye movement in a conjugate fashion is mediated by crossing fibers from the medial longitudinal fasciculus. Further Reading: Psarros. The Definitive Neurosurgical Board Review, page 33. Alberstone, Benzel, Najm, Steinmetz. Anatomic Basis of Neurologic Diagnosis, 2009, brainstem

Answer 17

A. Right abducens nerve **B. Medial longitudinal fasciculus** C. Left abducens nerve D. Medial lemniscus ## Footnote In this scenario, the patient is not able to adduct the right eye when attempting to look left, while the left eye is able to abduct. This likely represents a lesion of the medial longitudinal fasciculus. Further Reading: Psarros. The Definitive Neurosurgical Board Review, page 32. Alberstone, Benzel, Najm, Steinmetz. Anatomic Basis of Neurologic Diagnosis, 2009, vestibular system.

Answer 18

A. Trochlear nuclei **B. Facial colliculus** C. Stria medullaris D. Middle cerebellar peduncle ## Footnote The paired facial colliculi form noticeable structures on surface of the floor of the 4th ventricle. They are located above the bilateral stria medullari. Care should be taken to not violate the floor of the 4th ventricle. Further Reading: Binder, Sonne, Fischbein. Cranial Nerves: Anatomy, Pathology, Imaging, 2010, facial nerve

Answer 19

A. Medial **B. Lateral** C. Superior D. Inferior ## Footnote There are several observable structures on the surface of the floor of the 4th ventricle. The paired facial colliculi are prominences that can be seen above the laterally projecting fibers of the stria medullari. Below the stria, the hypoglossal trigone is closest to midline, with the vagal trigone located lateral to the hypoglossal trigone. Further Reading: Binder, Sonne, Fischbein. Cranial Nerves: Anatomy, Pathology, Imaging, 2010, vagus nerve

Answer 20

A. Medial longitudinal fasciculus **B. Internal arcuate fibers** C. Pyramids D. Mossy fibers ## Footnote The nuclei gracilis and cuneatus receive sensory input from the dorsal columns of the spinal cord. In the medulla they decussate and form the medial lemniscus. The decussating fibers cross the midline as internal arcuate fibers. Further Reading: Psarros. The Definitive Neurologic Surgery Board Review, page 30. Citow, Macdonald, Refai. Comprehensive Neurosurgery Board Review, 2nd edition, 2010, anatomy.

Answer 21

**A. Area prostrema** B. Subforniceal organ C. Vascular organ of the lamina terminalis D. Subcommissural organ ## Footnote The circumventricular organs are regions of the brain located at the boundaries of the ventricular system and they are regions with an incomplete blood brain barrier. This allows these regions to sense peptide levels within the brain without requiring active transport mechanisms. There circumventricular organs include the median eminence, posterior pituitary, subcommissural organ, subforniceal organ, area prostrema, choroid plexus, vascular organ of the lamina terminalis and pineal gland. The only paired circumventricular organ is the area prostrema. Further Reading: Psarros. The definitive Neurologic Surgery Board Review, page 30. Yaşargil, Adamson, Cravens, Johnson, Reeves, Teddy, Valavanis, Wichmann, Wild, Young. Microneurosurgery IV A, 1994, neurophysiology.

Answer 22

A. Medially B. Anteriorly **C. Laterally** D. Posteriorly ## Footnote The cerebral peduncles contain descending corticospinal tracts organized in a somatotopic organization with the sacral fibers occupying the most lateral aspect of the corticospinal tracts, and fibers controlling the head/arms are the most medial. Further Reading: Psarros. The Definitive Neurologic Surgery Board Review, page 34. Alberstone, Benzel, Najm, Steinmetz. Anatomic Basis of Neurologic Diagnosis, 2009, brainstem.

Answer 23

A. Cerebral peduncles **B. Superior colliculi** C. Inferior colliculi D. Pons ## Footnote The nucleus of the IIIrd nerve, the occulomotor nucleus, is located roughly at the same horizontal level as the superior colliculi. Further Reading: Psarros. The Definitive Neurologic Surgery Board Review, page 34. Alberstone, Benzel, Najm, Steinmetz. Anatomic Basis of Neurologic Diagnosis, 2009, brainstem.

Answer 24

A. Interstitial nucleus of Cajal B. Oculomotor **C. Pretectal** D. Trochlear ## Footnote The pretectal nucleus controls the direct and consensual pupillary light reflex Further Reading: Psarros. The Definitive Neurologic Surgery Board Review, page 34. Alberstone, Benzel, Najm, Steinmetz. Anatomic Basis of Neurologic Diagnosis, 2009, visual system.

Answer 25

**A. Subcommissural organ** B. Subforniceal organ C. Area prostrema D. Pineal gland ## Footnote The subcommissural organ is made of ependymal cells that secrete somatostatin. It is the only circumventricular organ with an intact blood brain barrier. Further Reading: Psarros. The Definitive Neurologic Surgery Board Review, page 34. Yaşargil, Adamson, Cravens, Johnson, Reeves, Teddy, Valavanis, Wichmann, Wild, Young. Microneurosurgery IV A, 1994, neurophysiology

Answer 26

A. IIIrd nerve fibers B. Periacqueductal grey C. Medial longitudinal fasciculus **D. Medial lemniscus** ## Footnote The medial lemniscus appears as a curved structure projecting laterally from the red nucleus on a horizontal section through the midbrain. Further Reading: Psarros. The Definitive Neurologic Surgery Board Review, page 35. Alberstone, Benzel, Najm, Steinmetz. Anatomic Basis of Neurologic Diagnosis, 2009, brainstem.

Answer 27

A. Anterior inferior cerebellar artery B. Posterior inferior cerebellar artery **C. Superior cerebellar artery** D. Posterior cerebral artery ## Footnote The deep cerebellar nuclei are located very close to the superior cerebellar peduncle within the vicinity of the superior lateral wall of the 4th ventricle. The superior cerebellar artery provides blood supply to the superior surface of the cerebellum as well as to the superior cerebellar peduncle and the majority of the deep cerebellar nuclei. Further Reading: Psarros. The Definitive Neurologic Surgery Board Review, page 38. Spetzler, Kalani, Nakaji. Neurovascular Surgery, 2nd edition, 2015, cranial vascular anatomy of the posterior circulation

Answer 28

A. Lateral B. Posterior **C. Medial** D. Anterior ## Footnote At the level of the midbrain, the descending corticospinal tracts are located in the ventral region of the midbrain and are arranged in a somatotopic fashion. The tracts controlling the upper extremity are located medial to tracts controlling lower extremity function. Further Reading: Alberstone, Benzel, Najm, Steinmetz. Anatomic Basis of Neurologic Diagnosis, 2009, brainstem.

Answer 29

**A. Medial** B. Lateral C. Anterior D. Posterior ## Footnote At the level of the medulla, after the internal arcuate fibers have crossed and formed the medial lemniscus, the fibers conveying information from the upper extremity are located dorsal and the fibers from the lower extremity are located ventrally. As these fibers ascend to the level of the midbrain, the medial lemniscus becomes a curve structure extending laterally from the red nucleus. In this region, the fibers from the upper extremity are the most medial, while the lower extremity fibers are located laterally. Further Reading: Alberstone, Benzel, Najm, Steinmetz. Anatomic Basis of Neurologic Diagnosis, 2009, brainstem

Answer 30

A. Frontal nerve B. Trochlear nerve C. Lacrimal nerve **D. Nasociliary nerve** ## Footnote The annulus of Zinn is a structure located in the superior orbital fissure, dividing it into sections. There are multiple structures that pass through the annulus of Zinn, including the oculomotor nerve, the nasociliary nerve, the abducens nerve and roots of the ciliary ganglion. The frontal nerve, trochlear nerve and lacrimal nerve all pass outside of the annulus of Zinn. Further Reading: Citow, Macdonald, Refai. Comprehensive Neurosurgery Board Review, 2nd edition, 2010, anatomy.

Answer 31

A. Lateral rectus palsy B. Medial rectus palsy C**. Superior oblique palsy** D. Monocular visual loss ## Footnote The IVth nerve (trochelar nerve), runs at the edge of the tentorial incisura in the ambient cistern and is at risk during complete division of the tentorium. Further Reading: Binder, Sonne, Fischbein. Cranial Nerves: Anatomy, Pathology, Imaging, 2010, trochlear nerve.

Answer 32

A. Nystagmus to the right **B. Nystagmus to the left** C. Superior nystagmus D. Ocular bobbing ## Footnote Cold calorics involve irrigating cold saline into the patient’s ear and observing the movements of the eyes. The mnemonic COWS (cold-opposite, warm-same) is useful to remember, but it must be noted that this mnemonic refers to the nystagmus portion of the eye movements. In this patient, you irrigate the right ear with cold saline, and you would expect a slow drift of the eyes to the right followed by a fast-jerk nystagmus back to the left. The cold saline decreases the temperature of the tympanic membrane and hyperpolarizes the vestibular cells, tricking the system into thinking the head is moving to the left. Further Reading: Alberstone, Benzel, Najm, Steinmetz. Anatomic Basis of Neurologic Diagnosis, 2009, vestibular system.

Answer 33

**A. Base** B. Apex C. Scala vestibuli D. Scala tympani ## Footnote The cochlea is a coiled organ that process auditory input. It is arranged tonotopically with high frequency sounds processed at the base, and low-frequency sounds processed at the apex. Further Reading: Alberstone, Benzel, Najm, Steinmetz. Anatomic Basis of Neurologic Diagnosis, 2009, auditory system.

Answer 34

**A. Tectorial membrane** B. Basilar membrane C. Scala vestibuli D. Scala tympani ## Footnote As sound travels through the cochlea it causes movement of the basilar membrane, which in turn moves the organ of Corti at specific locations. This movement causes a shearing motion against the tectorial membrane, to which the ciliary processes of the hair cells are connected. This movement causes opening of these processes and depolarization of the hair cells Further Reading: Alberstone, Benzel, Najm, Steinmetz. Anatomic Basis of Neurologic Diagnosis, 2009, auditory system.

Answer 35

**A. Ventral cochlear nucleus–inferior colliculus** B. Ventral cochlear nucleus–medial geniculate body C. Ventral cochlear nucleus–superior olive D. Ventral cochlear nucleus–inferior olive ## Footnote The trapezoid body conveys information from the cochlear nucleus to the superior olive. Fibers then travel to the inferior colliculus and subsequently the medial geniculate body. Further Reading: Alberstone, Benzel, Najm, Steinmetz. Anatomic Basis of Neurologic Diagnosis, 2009, auditory system

Answer 36

A. Medial lemniscus B. Trapezoid body **C. Lateral lemniscus** D. Restiform body ## Footnote The lateral lemniscus connects the dorsal cochlear nucleus to the inferior colliculus via the lateral lemniscus. It is involved in the response to sudden loud noises. Further Reading: Alberstone, Benzel, Najm, Steinmetz. Anatomic Basis of Neurologic Diagnosis, 2009, auditory system.

Answer 37

**A. Spinal trigeminal nucleus** B. Oculomotor nucleus C. Superior olive D. Abducens nucleus ## Footnote The corneal blink reflex pathway involves sensory information from the cornea passing through the trigeminal nerve to the spinal trigeminal nucleus and tract. Further connections include the bilateral facial nuclei which mediate eye closure. Further Reading: Rohkamm. Color Atlas of Neurology, 2007, normal and abnormal function of the nervous system.

Answer 38

A. Spinal trigeminal tract **B. Facial nerve** C. Medial longitudinal fasciculus D. Internal arcuate fibers ## Footnote Fibers traveling from the facial nucleus travel around the abducens nucleus in the brainstem. Further Reading: Binder, Sonne, Fischbein. Cranial Nerves: Anatomy, Pathology, Imaging, 2010, facial nerve.

Answer 39

A. Lateral **B. Ventromedial** C. Paraventricular D. Preoptic ## Footnote The ventromedial nucleus of the hypothalamus controls satiety. A way to remember this is “if the ventromedial nucleus is destroyed, you grow ventrally and medially.” Further Reading: Alberstone, Benzel, Najm, Steinmetz. Anatomic Basis of Neurologic Diagnosis, 2009, hypothalamus.

Answer 40

A. Lateral B. Ventromedial C. Arcuate **D. Supraoptic** ## Footnote The supraoptic nuclei of the hypothalamus are involved in fluid balance regulation. Further Reading: Alberstone, Benzel, Najm, Steinmetz. Anatomic Basis of Neurologic Diagnosis, 2009, hypothalamus.

Answer 41

**A. Central tegmental tract** B. Lateral lemniscus C. Medial lemniscus D. Trapezoid body ## Footnote Gustatory information from the tongue and oropharynx travels through the chorda tympani and VIIth nerve, as well as the IX/X nerves. 1st order neurons synapse in the nucleus of the solitary tract. Then, 2nd order neurons travel via the central tegmental tract to VPM thalamus and 3rd order neurons travel from VPM thalamus to the postcentral gyrus. Further Reading: Greenstein B, Greenstein A. Color Atlas of Neuroscience, 2000, transverse section of medulla oblongata II

Answer 42

A. Inferior colliculus B. Superior colliculus **C. Superior olivary nucleus** D. Inferior olivary nucleus ## Footnote The auditory dampening reflex is mediated by the superior olivary nucleus and involves contraction of the stapedius (VIIth nerve) and tensor tympani (Vth nerve). Further Reading: Psarros. Intensive neurosurgery board review. Greenstein B, Greenstein A. Color Atlas of Neuroscience, 2000, localization of sound.

Answer 43

A. Frontal bone **B. Ethmoid bone** C. Zygomatic bone D. Nasal bone ## Footnote The cribiform plate is a bony structure that is part of the ethmoid bone in the anterior cranial fossa. It supports the olfactory bulb and has numerous foramina through which the olfactory nerves pass to reach the nose. Further Reading: Wanibuchi, Friedman, Fukushima. Photo Atlas of Skull Base Dissection, 2009, craniofacial anatomy

Answer 44

A. Frontal nerve **B. Maxillary nerve** C. Trochlear nerve D. Abducens nerve ## Footnote The maxillary nerve, or V2, does not pass through the superior orbital fissure. Further Reading: Di Ieva, Lee, Cusimano. Handbook of Skull Base Surgery, 2016, clinical and neurologic findings in skull base pathology

Answer 45

A. Pars nervosa of the jugular foramen **B. Pars vascularis of the jugular foramen** C. Foramen lacerum D. Foramen ovale ## Footnote The vagus nerve exits the skull through the jugular foramen, which is divided into two regions by the jugular spine, the pars nervosa (carrying the glossopharyngeal nerve and inferior petrosal sinus) and the pars vascularis (carrying the jugular bulb, vagus nerve and spinal accessory nerve). Further Reading: Binder, Sonne, Fischbein. Cranial Nerves: Anatomy, Pathology, Imaging, 2010, vagus nerve

Answer 46

A. Foramen ovale B. Foramen rotundum **C. Foramen spinosum** D. Foramen lacerum ## Footnote The middle meningeal artery is the most common offending artery in cases of epidural hematoma. It enters the skull as a branch from the internal maxillary artery through the foramen spinosum. Further Reading: Wanibuchi, Friedman, Fukushima. Photo Atlas of Skull Base Dissection, 2009, middle fossa rhomboid approach (anterior petrosectomy)

Answer 47

A. Carotid artery B. Internal maxillary artery C. Sphenopalatine artery **D. Ophthalmic artery** ## Footnote The anterior and posterior ethmoidal arteries give blood supply to the mucosal surfaces of the ethmoid bone, and they are both branches from the ophthalmic artery. Further Reading: Spetzler, Kalani, Nakaji. Neurovascular Surgery, 2nd edition, 2015, microsurgical anatomy of the internal carotid and vertebral arteries

Answer 48

A. Anterior ethmoid artery B. Posterior ethmoid artery C. Kesselbach’s plexus **D. Sphenopalatine artery** ## Footnote The sphenopalatine artery gives blood supply to the middle turbinate, which can be removed by an access surgeon to allow expanded access for endoscopic approaches to the sella and anterior skull base. Further Reading: Stamm. Transnasal Endoscopic Skull Base and Brain Surgery, 2011, anatomy of the nasal cavity and paranasal sinuses.

Answer 49

**A. Optic strut** B. Anterior clinoid process C. Carotid process D. Lateral opticocarotid recess ## Footnote The optic strut joins the lesser wing of the sphenoid to the body of the sphenoid bone. It forms the inferior and lateral wall of the optic canal. It separates the optic canal from the superior orbital fissure. From an endonasal approach, it is located inferior to the optic protuberence, superiomedial to the carotid protuberence, and medial to the lateral opticocarotid recess. Further Reading: Laws, Sheehan. Sellar and Parasellar Tumors, 2012, anatomy of the sellar and parasellar region.

Answer 50

A. Optic strut **B. Planum sphenoidale** C. Anterior clinoid process D. Pterygoid plate ## Footnote Just anterosuperior to the sella turcica is the planum sphenoidale. This can be a site of meningioma growth, and tumors in this region can be accessed via an expanded endonasal approach. Further Reading: Di Ieva, Lee, Cusimano. Handbook of Skull Base Surgery, 2016, anatomy of the skull base and related structures: elements of surgical anatomy.

Answer 51

A. Lesser superficial petrosal nerve **B. Greater superficial petrosal nerve** C. Nervus intermedius D. Chorda tympani ## Footnote The vidian nerve is continuous with the greater superficial petrosal nerve and passes through the vidian canal lateral to the ethmoid air cells. The vidian nerve carries sensory fibers from the facial nerve supplying the soft palate. It is an important landmark in endoscopic endonasal surgery as it leads directly to the carotid artery. Further Reading: Di Ieva, Lee, Cusimano. Handbook of Skull Base Surgery, 2016, anatomy of the skull base and related structures: elements of surgical anatomy.

Answer 52

A. Optic canal **B. Foramen rotundum** C. Foramen ovale D. Foramen spinosum ## Footnote The foramen rotundum is just lateral to the vidian canal and contains the maxillary nerve. Both the vidian canal and foramen rotundum are openings in the greater wing of the sphenoid bone. In this location they connect the middle cranial fossa to the pterygopalatine fossa. Further Reading: Di Ieva, Lee, Cusimano. Handbook of Skull Base Surgery, 2016, anatomy of the skull base and related structures: elements of surgical anatom

Answer 53

A. Oculomotor nerve B. Trochlear nerve C. Ophthalmic nerve **D. Abducens nerve** ## Footnote The cavernous sinus contains several nerves, including CN III, IV, V1, and VI. All nerves run in the lateral wall of the cavernous sinus except for the abducens nerve, which runs with the carotid artery through the cavernous sinus. Further Reading: Di Ieva, Lee, Cusimano. Handbook of Skull Base Surgery, 2016, anatomy of the skull base and related structures: elements of surgical anatomy.

Answer 54

**A. Glasscock’s triangle** B. Kawase’s traingle C. Infratrochlear triangle D. Trigeminal triangle ## Footnote The posterolateral triangle of the skull base is bordered by V3 (mandibular nerve), the greater superficial petrosal nerve, and a line drawn between the foramen spinosum and the arcuate eminence. This triangle can be important during skull base neurosurgery given that it allows for the exposure of the horizontal segment of the petrous internal carotid artery by drilling out bone inferior to the border of V3. Further Reading: Further Reading: Di Ieva, Lee, Cusimano. Handbook of Skull Base Surgery, 2016, anatomy of the skull base and related structures: elements of surgical anatomy.

Answer 55

A. Glasscock’s triangle **B. Kawase’s traingle** C. Infratrochlear triangle D. Trigeminal triangle ## Footnote The posteromedial triangle of the skull base is bordered by V3 (mandibular nerve), the greater superficial petrosal nerve (inferiorly), and the superior petrosal sinus. This triangle can be important during skull base neurosurgery given that drilling in this region allows for an anterior petrosectomy, connecting the middle and posterior cranial fossae. It contains the petrous corner of the ICA and in its lateral aspect contains the cochlea. Further Reading: Further Reading: Di Ieva, Lee, Cusimano. Handbook of Skull Base Surgery, 2016, anatomy of the skull base and related structures: elements of surgical anatomy

Answer 56

A. Glasscock’s triangle B. Kawase’s traingle **C. Infratrochlear triangle** D. Trigeminal triangle ## Footnote The infratrochlear triangle (Parkinson’s triangle) of the skull base is bordered by the trochlear nerve (superior), V1, and the tentorial edge. This triangle can be important during skull base neurosurgery as it contains the horizontal segment of the cavernous carotid, the abducens nerve and the meningohypophyseal trunk. It has been described as the original access location to the cavernous sinus. Further Reading: Further Reading: Di Ieva, Lee, Cusimano. Handbook of Skull Base Surgery, 2016, anatomy of the skull base and related structures: elements of surgical anatomy

Answer 57

A. Facial nerve–cochlear nerve **B. Superior vestibular nerve–inferior vestibularvnerve** C. Facial nerve–superior vestibular nerve D. Cochlear nerve–inferior vestibular nerve ## Footnote Bill’s bar is a vertically oriented bone within the IAC that separates the Facial nerve (anterosuperior) from the superior vestibular nerve (posterosuperior). The cochlear nerve is located anteroinferior, and the inferior vestibular nerve is located posteroinferior. Further Reading: Di Ieva, Lee, Cusimano. Handbook of Skull Base Surgery, 2016, anatomy of the skull base and related structures: elements of surgical anatomy

Answer 58

A. Posterior cerebral artery B. Superior cerebellar artery **C. Anterior inferior cerebellar artery** D. Posterior inferior cerebellar artery ## Footnote The posterior fossa can be thought of as three distinct neurovascular regions. The superior region contains CN III, IV, and V, and is associated with the superior cerebellar artery. The middle neurovascular region consists of CN VI, VII, and VIII as well as the anterior inferior cerebellar artery. The inferior neurovascular region contains CN IX, X, XI, and XII, and is associated with the posterior inferior cerebellar artery. Further Reading: Di Ieva, Lee, Cusimano. Handbook of Skull Base Surgery, 2016, anatomy of the skull base and related structures: elements of surgical anatomy

Answer 59

A. Bregma B. Inion C. Pterion **D. Asterion** ## Footnote The asterion is located where the squamous and parietomastoid sutures join. It is a rough landmark for the transverse sigmoid sinus, and can be an important marker for burr hole location in retrosigmoid craniectomies. Further Reading: Di Ieva, Lee, Cusimano. Handbook of Skull Base Surgery, 2016, anatomy of the skull base and related structures: elements of surgical anatomy.

Answer 60

A. Oculomotor **B. Trochlear** C. Vagus D. Hypoglossal ## Footnote The trochlear nerve is the only cranial nerve to exit from the dorsal aspect of the brainstem. Further Reading: Binder, Sonne, Fischbein. Cranial Nerves: Anatomy, Pathology, Imaging, 2010, trochlear nerve.

Answer 61

A. Ectoderm **B. Mesoderm** C. Endoderm D. Somites ## Footnote The meninges of the skull base arise from the mesoderm of the embryo. This differs from telencephalic meninges which arise from neural crest cells. Further Reading: Di Ieva, Lee, Cusimano. Handbook of Skull Base Surgery, 2016, skull base embryology

Answer 62

A. Posterior inferior cerebellar artery B. Calcarine artery C. Splenial artery **D. Labyrinthine artery** ## Footnote The labyrinthine artery is most commonly a branch from the anterior inferior cerebellar artery, and it follows the vestibulocochlear nerve into the IAC. Further Reading: Di Ieva, Lee, Cusimano. Handbook of Skull Base Surgery, 2016, anatomy of the skull base and related structures: elements of surgical anatomy

Answer 63

A. Meningohypophyseal trunk **B. Ophthalmic artery** C. Superior hypophyseal artery D. Posterior communicating artery ## Footnote The ophthalmic artery originates from the internal carotid just distal to the distal dural ring, making it the first intradural branch of the internal carotid artery. Further Reading: Di Ieva, Lee, Cusimano. Handbook of Skull Base Surgery, 2016, anatomy of the skull base and related structures: elements of surgical anatomy.

Answer 64

Special visceral afferent fibers from which cranial nerve do not synapse within the thalamus? A. Facial nerve B. Hypoglossal nerve **C. Olfactory nerve** D. Trigeminal nerve ## Footnote Special visceral afferent fibers conveying sense of smell travel through the olfactory nerve directly to the primary olfactory areas via the medial and lateral olfactory striae. Further Reading: Psarros. The Definitive Neurosurgical Board Review. Binder, Sonne, Fischbein. Cranial Nerves: Anatomy, Pathology, Imaging, 2010, olfactory nerve.

Answer 65

**A. Ganglion cells** B. Bipolar cells C. Horizontal cells D. Amacrine cells ## Footnote Within the retina, the bioplar cells are the primary sensory neurons. The ganglion cells receive input from bipolar cells, and the axons of the ganglion cells make up the optic nerve. Further Reading: Psarros. The Definitive Neurosurgical Board Review. Binder, Sonne, Fischbein. Cranial Nerves: Anatomy, Pathology, Imaging, 2010, optic nerve

Answer 66

**A. Levator palpebrae** B. Inferior oblique C. Medial rectus D. Inferior rectus ## Footnote The oculomotor nerve begins within the oculomotor nucleus at the level of the superior colliculus. It travels between the PCA and SCA and enters the orbit through the superior orbital fissure. Notably, it does travel within the annulus of Zinn. It separates into a superior division and inferior division, with the superior division innervating the levator palpebrae and superior rectus, while the inferior division innervates the medial/inferior rectus and the inferior oblique. Further Reading: Psarros. The Definitive Neurosurgical Board Review. Binder, Sonne, Fischbein. Cranial Nerves: Anatomy, Pathology, Imaging, 2010, oculomotor nerve

Answer 67

A. Left oculomotor nucleus B. Right oculomotor nucleus **C. Left trochlear nucleus** D. Right trochlear nucleus ## Footnote The trochlear nerve innervates the superior oblique muscle, and patients tend to tilt their head to the contralateral side of nerve injury to compensate. Also, the trochlear nerve is the only nerve to deccusate outside of the CNS, and the only cranial nerve to exit dorsally from the brainstem. This patient tilts her head to the left, meaning she would have sustained damage to either the right trochlear nerve (postdecussation), or the left trochlear nucleus (predecussation) Further Reading: Psarros. The Definitive Neurosurgical Board Review. Binder, Sonne, Fischbein. Cranial Nerves: Anatomy, Pathology, Imaging, 2010, trochlear nerve.

Answer 68

**A. Trigeminal nerve** B. Facial nerve C. Vestibulocohclear nerve D. Vagus nerve ## Footnote The trigeminal nerve has a portio major (sensory afferents from the face) and a portio minor (motor efferents) that travels with V3. The motor branch of the trigeminal nerve innervates the muscles of mastication, including the tensor veli palatini, masseter, pterygoids, temporalis and anterior belly of the digastric. It also innervates the tensor tympani, which dampens sudden loud noises in the efferent arm of the auditory reflex. Further Reading: Psarros. The Definitive Neurosurgical Board Review. Binder, Sonne, Fischbein. Cranial Nerves: Anatomy, Pathology, Imaging, 2010, trigeminal nerve

Answer 69

A. Left oculomotor nerve B. Left oculomotor nucleus C. Right abducens nerve **D. Right abducens nucleus** ## Footnote The abducens nerve innervates the lateral rectus muscle and mediates lateral gaze of the ipsilateral eye. It is important to note that the abducens nucleus plays an important role in conjuage movement of the eyes. Signals initially reach the ipsilateral PPRF, which synapses on the ipsilateral abducens nucleus to mediate lateral gaze. The abducens nucleus also sends fibers to the contralateral oculomotor nucleus via the MLF to mediate conjugate medial deviation of the contralateral eye. Since this patient cannot cross midline with the left eye, the lesion must be within the abducens nucleus. Further Reading: Psarros. The Definitive Neurosurgical Board Review. Binder, Sonne, Fischbein. Cranial Nerves: Anatomy, Pathology, Imaging, 2010, abducens nerve.

Answer 70

**A. Efferent arm of the corneal reflex** B. Parasympathetic efferents to the lacrimal gland C. Parasympathetic efferents to the submandibular gland D. Taste from the anterior two-thirds of the tongue ## Footnote The facial nerve contains a large motor branch as well as a smaller branch known as the nervus intermedius. The motor branch controls muscles of facial expression and forehead. The nervus intermedius carries parasympathetic fibers to the lacrimal gland through the GSPN and pterygopalatine ganglion, parasympathetic fibers to the submandibular gland via the submandibular ganglion, and taste afferents via the chorda tympani. The efferent arm of the corneal reflex is mediated by muscles of facial expression and is carried in the motor branch of the facial nerve. Further Reading: Psarros. The Definitive Neurosurgical Board Review. Binder, Sonne, Fischbein. Cranial Nerves: Anatomy, Pathology, Imaging, 2010, facial nerve.

Answer 71

A. Spiral–vestibular nuclei **B. Spiral–cochlear** C. Scarpa’s–cochlear D. Scarpa’s–vestibular nuclei ## Footnote Hair cells from the organ of Corti within the cochlea synapse on the spiral ganglion, which in turn connects to the cochlear nucleus in the brainstem via the cochlear nerve. Scarpa’s ganglion receives input from the receptors in the labyrinth of the saccule, utricle and semicircular canals. In turn, these fibers are transmitted to the vestibular nuclei of the brainstem via the vestibular nerve. Some fibers from Scarpa’s ganglion travel to the flocculonodular lobe of the cerebellum as mossy fibers, where they mediate balance. Further Reading: Psarros. The Definitive Neurosurgical Board Review. Binder, Sonne, Fischbein. Cranial Nerves: Anatomy, Pathology, Imaging, 2010, vestibulocochlear nerve.

Answer 72

**A. Lesser superficial petrosal nerve** B. Greater superficial petrosal nerve C. Vidian nerve D. Chorda tympani ## Footnote The glossopharyngeal nerve innervates the parotid gland via branches that form the lesser superficial petrosal nerve. The lesser superficial petrosal nerve contains preganglionic parasympathetic nerves from the inferior salivatory nucleus of the brainstem that synapse in the otic ganglion. In turn, postganglionic parasympathetic nerves leave the otic ganglion and travel to the parotid gland via the auriculotemporal nerve (traveling with V3). Further Reading: Psarros. The Definitive Neurosurgical Board Review. Binder, Sonne, Fischbein. Cranial Nerves: Anatomy, Pathology, Imaging, 2010, glossopharyngeal nerve.

Answer 73

A. Transverse arytenoid B. Thyroepiglottic C. Posterior cricoarytenoid **D. Cricothyroid** ## Footnote The recurrent laryngeal nerve is a branch from the vagus nerve that passes anterior to the subclavian artery on the right, and adjacent to the aorta on the left. Its recurrent route traverses in the tracheoesophageal groove. It innervates all intrinsic muscles of the larynx with the exception of the cricothyroid muscle. Further Reading: Psarros. The Definitive Neurosurgical Board Review. Binder, Sonne, Fischbein. Cranial Nerves: Anatomy, Pathology, Imaging, 2010, vagus nerve

Answer 74

A. Anterior B. Medial **C. Posterior** D. Lateral ## Footnote The spinal accessory nerve has both a cranial and spinal point of origination. It innervates the sternocleidomastoid and trapezius muscles. The spinal portion passes posterior to the dentate ligament. Further Reading: Psarros. The Definitive Neurosurgical Board Review. Binder, Sonne, Fischbein. Cranial Nerves: Anatomy, Pathology, Imaging, 2010, spinal accessory nerve.

Answer 75

**A. Palatoglossus** B. Styloglossus C. Genioglossus D. Hyoglossus ## Footnote The hypoglossal nerve exits the brainstem between the inferior olive and the pyramids. It exits the skull via the hypoglossal canal and innervates all intrinsic and extrinsic muscles of the tongue except for the palatoglossus, which is innervated by the vagus nerve. Further Reading: Psarros. The Definitive Neurosurgical Board Review. Binder, Sonne, Fischbein. Cranial Nerves: Anatomy, Pathology, Imaging, 2010, hypoglossal nerve.

Answer 76

A. Caudal B. Posterior C. Lateral **D. Rostral** ## Footnote The motor root of the trigeminal nerve most often arises rostral to the main sensory root of the trigeminal nerve. Further Reading: Binder, Sonne, Fischbein. Cranial Nerves: Anatomy, Pathology, Imaging, 2010, trigeminal nerve.

Answer 77

A. Apical ligament B. Posterior atlanto-occipital membrane C. Tectorial membrane **D. Anterior atlanto-occipital membrane** ## Footnote The anterior atlanto-occipital membrane connects the anterosuperior border of C1 to the foramen magnum. Further Reading: Baaj, Mummaneni, Uribe, Vaccaro, Greenberg. Handbook of Spine Surgery, 2016, craniovertebral junction

Answer 78

A. Alar plate **B. Notochord** C. Basal plate D. Neural tube ## Footnote The apical ligament is a single structure connecting the dens to the foramen magnum. It is a weak ligament that is an embryological remnant of the notochord. Further Reading: Baaj, Mummaneni, Uribe, Vaccaro, Greenberg. Handbook of Spine Surgery, 2016, embryology of the spine.

Answer 79

**A. Alar** B. Apical C. Transverse D. Cruciate ## Footnote The alar ligaments are paired ligaments that connect the tip of the dens to the foramen magnum near the occipital condyles. They are strong ligaments that limit rotation of the head. Further Reading: Baaj, Mummaneni, Uribe, Vaccaro, Greenberg. Handbook of Spine Surgery, 2016, craniovertebral junction.

Answer 80

A. Alar ligament B. Apical ligaments **C. Transverse ligament** D. Cruciate ligament ## Footnote The transverse ligament is a strong ligament that is very important in stability of the atlanto-axial joint. When the atlanto-dental interval is > 3 mm, this is highly suggestive of transverse ligament disruption and instability of the C1-2 joint. Surgical stabilization or prolonged collar immobilization will likely be required. Further Reading: Baaj, Mummaneni, Uribe, Vaccaro, Greenberg. Handbook of Spine Surgery, 2016, craniovertebral junction

Answer 81

A. Anterior longitudinal ligament **B. Posterior longitudinal ligament** C. Intertransverse ligament D. Supraspinous ligament ## Footnote The tectorial membrane is a broad ligament connecting the axis to the clivus/foramen magnum, and is a superior extension of the posterior longitudinal ligament. Further Reading: Baaj, Mummaneni, Uribe, Vaccaro, Greenberg. Handbook of Spine Surgery, 2016, craniovertebral junction

Answer 82

A. Carotid artery **B. Vertebral artery** C. C2 nerve root D. Recurrent laryngeal nerve ## Footnote The vertebral artery can have variant anatomy within the C2 vertebrae. Certain patients can have a “high-riding vertebral artery” where the vessel passes in close proximity to the C2 pedicle. In these patients it can be dangerous to attempt pedicle screws at C2, and pars screws or interlaminar screws should be considered. In most cases, a high riding vertebral artery can be discovered with a standard, non-contrast CT of the cervical spine in the pre-operative period. Further Reading: Baaj, Mummaneni, Uribe, Vaccaro, Greenberg. Handbook of Spine Surgery, 2016, craniovertebral junction

Answer 83

A. Split anterior arch of atlas B. Split posterior arch of atlas **C. Os odontoideum** D. Klippel-Feil syndrome ## Footnote Os odontoideum is either a congenital failure of fusion of the dens to the C2 vertebral body, or an unrecognized fracture at a young age. When the pseudoarthrosis is present inferior to the transverse ligament, atlantoaxial instability can result. Further Reading: Baaj, Mummaneni, Uribe, Vaccaro, Greenberg. Handbook of Spine Surgery, 2016, Craniovertebral Junction

Answer 84

A. 6 weeks **B. 9 weeks** C. 12 weeks D. 15 weeks ## Footnote The first ossification centers of the spine tend to occur at the cervicothoracic junction, and begin to appear at 9 weeks in utero. Further Reading: Baaj, Mummaneni, Uribe, Vaccaro, Greenberg. Handbook of Spine Surgery, 2016, embryology of the spine

Answer 85

A. 6 months B. 1 year **C. 3 years** D. 6 years ## Footnote The atlas is composed of three main ossification centers, one anteriorly, and two posteriorly. It is common for the posterior ossification centers to persist until 3 years of age, while the anterior ossification center can persist even until 7 years of age. These ossification centers can easily be mistaken for acute fractures. Further Reading: Lustrin et al. 2003, Pediatric Cervical Spine: Normal Anatomy, Variants, and Trauma. Baaj, Mummaneni, Uribe, Vaccaro, Greenberg. Handbook of Spine Surgery, 2016, embryology of the spine.

Answer 86

A. 7 years B. 9 years **C. 11 years** D. 13 years ## Footnote The axis undergoes complicated ossification in 4 different ossification centers. The subdental synchondrosis, or the region where the dens attaches to the body of the axis is usually the last center to be visible on CT scans. It should be completely closed and no longer significantly visible by 11 years of age. Further Reading: Lustrin et al., 2003, Pediatric Cervical Spine: Normal Anatomy, Variants, and Trauma. Baaj, Mummaneni, Uribe, Vaccaro, Greenberg. Handbook of Spine Surgery, 2016, embryology of the spine

Answer 87

A. Median eminence **B. Sulcus limitans** C. Neural groove D. Henson’s node ## Footnote The developing embryo has both a basal plate and an alar plate. The basal plate develops into motor neurons, while the alar plate develops into sensory neurons. The structure dividing them is the sulcus limitans. Further Reading: Psarros. The Definitive Neurological Surgery Board Review. Baaj, Mummaneni, Uribe, Vaccaro, Greenberg. Handbook of Spine Surgery, 2016, embryology of the spine.

Answer 88

**A. Dermal sinus tract** B. Myelomeningocele C. Split-cord malformation D. Spinal cord lipoma ## Footnote During embryologic development, disjunction occurs when the surface ectoderm separates from the neural ectoderm. Failure of disjunction can lead to the development of dermal sinus tracts. Premature disjunction can lead to the development of spinal cord lipomas. Further Reading: Psarros. The definitive neurological surgery board review. Baaj, Mummaneni, Uribe, Vaccaro, Greenberg. Handbook of Spine Surgery, 2016, congenital and neuromuscular scoliosis.

Answer 89

A. 15 to 17 **B. 19 to 21** C. 23 to 25 D. 27 to 29 ## Footnote Somites form from paraxial mesoderm adjacent to the notocord. They begin initially in the cervical region and progress caudally. They begin forming between days 19 to 21 of development. Further Reading: Psarros. The Definitive Neurological Surgery Board Review Baaj, Mummaneni, Uribe, Vaccaro, Greenberg. Handbook of Spine Surgery, 2016, embryology of the spine.

Answer 90

A. Motor neurons B. Sympathetic ganglia **C. Vertebral column and spinal musculature** D. Intervertebral discs ## Footnote Somites form from paraxial mesoderm adjacent to the notocord. They begin initially in the cervical region and progress caudally. They begin forming between days 19 to 21 of development. Ultimately they develop into the vertebral column and dorsal spinal musculature. Their rate of growth exceeds that of the spinal cord, which is why the cord ascends in the canal during development. Further Reading: Psarros. The Definitive Neurological Surgery Board Review. Baaj, Mummaneni, Uribe, Vaccaro, Greenberg. Handbook of Spine Surgery, 2016, embryology of the spine.

Answer 91

A. Primary neurulation **B. Secondary neurulation** C. Disjunction D. Cell migration ## Footnote The sacral spinal cord (distal to S2) is formed during secondary neurulation. Failure of this process can lead to caudal regression syndromes. Further Reading: Psarros. The Definitive Neurological Surgery Board Review. Baaj, Mummaneni, Uribe, Vaccaro, Greenberg. Handbook of Spine Surgery, 2016, embryology of the spine.

Answer 92

**A. Fasciculus cuneatus** B. Fasuculus gracilis C. Ventral corticospinal tract D. Dorsal spinocerebellar tract ## Footnote The fibers carrying sensory information travel within the dorsal columns. Fibers entering above T6 travel within the fasciculus cuneatus, just lateral to the fasciculus gracilis, which carries fibers from below T6. Further Reading: Psarros. The Definitive Neurological Surgery Board Review. Citow, Macdonald, Refai. Comprehensive Neurosurgery Board Review, 2nd edition, 2010, an

Answer 93

A. Lamina II B. Lamina V **C. Lamina VII** D. Lamina IX ## Footnote Lamina VII (Zona intermedia) is the rexed lamina located between the dorsal and ventral horns. The dorsal horn contains lamina I-IV, which V and VI at its base. The ventral horn contains VIII-X. Further Reading: Psarros. The Definitive Neurological Surgery Board Review. Greenstein B, Greenstein A. Color Atlas of Neuroscience, 2000, Sensory Fibers and Dorsal Roots.

Answer 94

**A. Lamina II** B. Lamina V C. Lamina VII D. Lamina IX ## Footnote The substantia gelatinosa is located in rexed lamina II and due to its lower density of myelinated fibers, it has a gelatinous appearance. It is one of two locations (the nucleus proprius being the other) where first order neurons of the spinothalamic tract synapse. Further Reading: Psarros. The Definitive Neurological Surgery Board Review. Greenstein B, Greenstein A. Color Atlas of Neuroscience, 2000, sensory fibers and dorsal roo

Answer 95

A. Lamina II B. Lamina V **C. Lamina VII** D. Lamina IX ## Footnote Lamina VII (Zona intermedia) is the rexed lamina located between the dorsal and ventral horns. Lamina VII contains the interomediolateral cell column and dorsal nucleus of Clarke. Further Reading: Psarros. The Definitive Neurological Surgery Board Review. Greenstein B, Greenstein A. Color Atlas of Neuroscience, 2000, sensory fibers and dorsal roots.

Answer 96

A. Lamina II B. Lamina V **C. Lamina VII** D. Lamina IX ## Footnote Renshaw cells are special inhibitory interneurons of the spinal cord. They are mainly located in rexed laminae VII and VIII and they use glycine as a neurotransmitter. Further Reading: Psarros. The definitive neurological surgery board review. Greenstein B, Greenstein A. Color Atlas of Neuroscience, 2000, sensory fibers and dorsal roots.

Answer 97

A. Lamina II B. Lamina V C. Lamina VII **D. Lamina IX** ## Footnote Primary somatic motor neurons are located in lamina IX and are composted of medial and lateral groups. The medial group innervates axial musculature while the lateral group innervates appendicular musculature. Further Reading: Greenstein B, Greenstein A. Color Atlas of Neuroscience, 2000, sensory fibers and dorsal roots.

Answer 98

A. Anterior spinothalamic tract **B. Lateral spinothalamic tract** C. Dorsal spinocerebellar tract D. Lateral corticospinal tract ## Footnote Pain and temperature information is transmitted to the CNS via the lateral spinothalamic tract, while the anterior spinothalamic tract conveys information about light touch. Further Reading: Citow, Macdonald, Refai. Comprehensive Neurosurgery Board Review, 2nd edition, 2010, anatomy

Answer 99

A. Anterior spinothalamic tract B. Lateral spinothalamic tract **C. Dorsal spinocerebellar tract** D. Ventral spinocerebellar tract ## Footnote The dorsal spinocerebellar tract contains sensory information originating in group Ia, Ib and II afferent fibers of the peripheral system. They synapse in the dorsal nucleus of Clarke (C8-L2) and travel to the cerebellum through the dorsal spinocerebellar tract where they enter the cerebellum via the inferior cerebellar peduncle and synapse within the vermis. They are involved in unconscious balance and proprioception mechanisms. Further Reading: Psarros. The Definitive Neurological Surgery Board Review. Citow, Macdonald, Refai. Comprehensive Neurosurgery Board Review, 2nd edition, 2010, anato

Answer 100

A. Lateral reticulospinal tract **B. Spinotectal tract** C. Lateral corticospinal tract D. Ventral corticospinal tract ## Footnote The spinotectal tract has its origins from lamina I and V of the dorsal horn and projects to the superior colliculus and periacqueductal grey in close proximity to the spinothalamic system. It is involved in reflexive head turning to focus on a source of painful stimulus. Further Reading: Psarros. The Definitive Neurological Surgery Board Review. Citow, Macdonald, Refai. Comprehensive Neurosurgery Board Review, 2nd edition, 2010, anatom

Answer 101

**A. 3%** B. 10% C. 30% D. 100% ## Footnote Only 3% of the corticospinal tract fibers originate from the giant pyramidal Betz cells in the motor cortex. Roughly 40% originate in the parietal lobe, roughly 30% originate in the supplementary motor area, and 30% originate in the primary motor cortex. Further Reading: Psarros. The Definitive Neurological Surgery Board Review. Citow, Macdonald, Refai. Comprehensive Neurosurgery Board Review, 2nd edition, 2010, anatomy.

Answer 102

A. Lamina II B. Lamina V **C. Lamina VII** D. Lamina IX ## Footnote The majority of lateral corticospinal tract fibers snyapse primarily on interneurons in lamina VII. Only a minority of fibers synapse directly on alpha motor neurons of the anterior horn. Further Reading: Psarros. The Definitive Neurological Surgery Board Review. Citow, Macdonald, Refai. Comprehensive Neurosurgery Board Review, 2nd edition, 2010, anatom

Answer 103

A. Vestibulospinal tract **B. Rubrospinal tract** C. Reticulospinal tract D. Medial longitudinal fasciculus ## Footnote The rubrospinal tract contains fibers descending from the red nucleus and mediates flexor tone in the response to deep painful stimulus to the extremities. In a patient with decorticate (flexor) posturing, the red nucleus remains intact and flexor tone is maintained. Further Reading: Psarros. The Definitive Neurological Surgery Board Review. Citow, Macdonald, Refai. Comprehensive Neurosurgery Board Review, 2nd edition, 2010, anat

Answer 104

**A. Vestibulospinal tract** B. Rubrospinal tract C. Reticulospinal tract D. Medial longitudinal fasciculus ## Footnote The vestibulospinal tract begins in Dieter’s nucleus (vestibular nucleus) and descends to rexed lamina VII, VIII, and IX. Occasionally, fibers will synapse directly on alpha motor neurons. This nucleus and tract mediate extensor tone of the extremities and is usually under tonic inhibition by higher brain centers. With a lesion between the superior and inferior colliculi, the vestibular nucleus is released from its inhibition and extensor posturing (decerebrate) is observed. Further Reading: Psarros. The Definitive Neurological Surgery Board Review. Citow, Macdonald, Refai. Comprehensive Neurosurgery Board Review, 2nd edition, 2010, anat

Answer 105

A. Vestibulospinal tract B. Rubrospinal tract C. Reticulospinal tract **D. Tectospinal tract** ## Footnote The tectospinal tract carries information from the superior colliculus to all levels of the cervical cord. It mediates postural reflexes and movement of the upper body in response to visual and auditory stimuli. Further Reading: Psarros. The Definitive Neurological Surgery Board Review Citow, Macdonald, Refai. Comprehensive Neurosurgery Board Review, 2nd edition, 2010, anatom

Answer 106

A. Lateral corticospinal tract B. Anterolateral corticospinal tract **C. Anterior corticospinal tract** D. Vestibulospinal tract ## Footnote 90% of descending pyramidal tract fibers travel in the lateral corticospinal tracts. A small number of uncrossed fibers travel in the anterior corticospinal tract, which is located near the median fissure of the cervical spinal cord. In the upper cervical levels they decussate via the anterior commissure and synapse within lamina VII. Further Reading: Psarros. The Definitive Neurological Surgery Board Review. Citow, Macdonald, Refai. Comprehensive Neurosurgery Board Review, 2nd edition, 2010, anatomy

Answer 107

A. Lateral **B. Medial** C. Superior D. Inferior ## Footnote The dorsal columns of the spinal cord receive blood supply from the paired posterior spinal arteries, which lie medial to the dorsal roots, and generally originate from multiple posterior radicular arteries. Further Reading: Psarros. The Definitive Neurological Surgery Board Review. Citow, Macdonald, Refai. Comprehensive Neurosurgery Board Review, 2nd edition, 2010, anatom

Answer 108

A. Anterior radicular arteries B. Posterior radicular arteries **C. Vertebral arteries** D. Carotid arteries ## Footnote The anterior spinal arteries originate from the vertebral arteries and fuse in the midline to form the single anterior spinal artery traversing the cervical cord in the median fissure. It supplies the majority of the cervical spinal cord. Further Reading: Psarros. The Definitive Neurological Surgery Board Review. Citow, Macdonald, Refai. Comprehensive Neurosurgery Board Review, 2nd edition, 2010, anatomy

Answer 109

A. C3-C7 **B. T1-T4** C. L1-L4 D. Conus medullaris ## Footnote The upper thoracic region (T1-T4) is the most susceptible region of the spinal cord to ischemic injury. It is followed by the first lumbar segment, which is the next most susceptible. Further Reading: Psarros. The Definitive Neurological Surgery Board Review. Citow, Macdonald, Refai. Comprehensive Neurosurgery Board Review, 2nd edition, 2010, anatom

Answer 110

A. Left T2 B. Right T2 **C. Left T10** D. Right T10 ## Footnote The artery of Adamkiewicz is a large lower thoracic/upper lumbar anterior radicular artery that supplies the anterior spinal artery and the anterior spinal cord of the thoracic/lumbar regions. Injury to this artery can result in an anterior spinal artery infarct and paraplegia. Further Reading: Psarros. The Definitive Neurological Surgery Board Review. Citow, Macdonald, Refai. Comprehensive Neurosurgery Board Review, 2nd edition, 2010, anatom

Answer 111

A. Ipsilateral paraplegia, contralateral loss of pinprick sensation, ipsilateral loss of pain/temperature sensation B. Preserved strength, bilateral loss of pinprick sensation, preserved pain/temperature sensation C. Paraplegia, ipsilateral loss of pinprick sensation, contralateral loss of pain/temperature sensation **D. Paraplegia, preserved pinprick sensation, bilateral loss of pain/temperature sensation** ## Footnote The artery of Adamkiewicz is a large lower thoracic/upper lumbar anterior radicular artery that supplies the anterior spinal artery and the anterior spinal cord of the thoracic/lumbar regions. Injury to this artery can result in an anterior spinal artery syndrome which includes paraplegia and loss of pain/temperature sensation with preserved pinprick sensation as the dorsal columns are supplied by the posterior spinal arteries. Further Reading: Psarros. The Definitive Neurological Surgery Board Review. Citow, Macdonald, Refai. Comprehensive Neurosurgery Board Review, 2nd edition, 2010, anat

Answer 112

A. L2-3 **B. L3-4** C. L4-5 D. L5-S1 ## Footnote Pain to the knee and weakness of the quadriceps is usually due to a herniated lumbar disc at L3-4. These symptoms are 99% specific for a disc at this level. Further Reading: Greenberg. Handbook of Neurosurgery, 8th edition, 2016, lumbar and thoracic intervertebral disk herniation/radiculopathy

Answer 113

A. L2-3 B. L3-4 **C. L4-5** D. L5-S1 ## Footnote Pain to the ankle and weakness of ankle dorsiflexion is usually due to a herniated lumbar disc at L4-5, and this constellation of symptoms is 70% specific for a disc at this level. Further Reading: Greenberg. Handbook of Neurosurgery, 8th edition, 2016, lumbar and thoracic intervertebral disk herniation/radiculopathy

Answer 114

A. L2-3 B. L3-4 C. L4-5 **D. L5-S1** ## Footnote Pain to the ankle and weakness of ankle plantarflexion is usually due to a herniated lumbar disc at L5-S1, and this constellation of symptoms is 95% specific for a disc at this level. Further Reading: Greenberg. Handbook of Neurosurgery, 8th edition, 2016, lumbar and thoracic intervertebral disk herniation/radiculopathy.

Answer 115

A. Paracentral L3-4 **B. Paracentral L4-5** C. Far lateral L2-3 D. Far lateral L3-4 ## Footnote This constellation of symptoms is suggestive of L5 nerve root impingement. This is possible with a paracentral disc at L4-5, compressing the traversing root, or possible with a far lateral L5-S1 disc, compressing the exiting nerve root. Further Reading: Greenberg. Handbook of Neurosurgery, 8th edition, 2016, lumbar and thoracic intervertebral disk herniation/radiculopathy.

Answer 116

A. Paracentral L3-4 B. Far lateral L4-5 C. Paracentral L5-S1 **D. Far lateral L5-S1** ## Footnote This constellation of symptoms is suggestive of L5 nerve root impingement. This is possible with a paracentral disc at L4-5, compressing the traversing root, or possible with a far lateral L5-S1 disc, compressing the exiting nerve root. Further Reading: Greenberg. Handbook of Neurosurgery, 8th edition, 2016, lumbar and thoracic intervertebral disk herniation/radiculopathy

Answer 117

A. C2-3 B. C3-4 **C. C4-5** D. C5-6 ## Footnote You must remember that in the cervical spine, nerve roots exit above the corresponding vertebral body, with the exception of C8, which exits under the C7 vertebral body. This patient has symptoms suggestive of a disc herniation compressing the C5 nerve root, meaning the herniation is likely to be located at the C4-5 space. Further Reading: Greenberg. Handbook of Neurosurgery, 8th edition, 2016, cervical disc herniatio

Answer 118

A. Right shoulder **B. Right thumb** C. Right third finger D. Right 5th finger ## Footnote In this patient with a herniated disc at the C5-6 space, there should be compression of the exiting C6 nerve root. The sensory distribution of C6 includes the radial forearm and thumb as well as the 2nd finger. Further Reading: Greenberg. Handbook of Neurosurgery, 8th edition, 2016, cervical disc herniatio

Answer 119

A. Right shoulder **B. Right wrist flexion** C. Right wrist extension D. Right finger extension ## Footnote In this patient with a herniated disc at the C6-7 space, there should be compression of the exiting C7 nerve root. C7 compression can lead to triceps weakness as well as weakness of wrist flexion. Further Reading: Greenberg. Handbook of Neurosurgery, 8th edition, 2016, cervical disc herniation

Answer 120

A. Right interossei B. Right wrist flexion C. Right wrist extension **D. Right distal finger flexion** ## Footnote In this patient with a herniated disc at the C6-7 space, there should be compression of the exiting C8 nerve root. C8 compression can lead to weakness of the distal finger flexors as well as parasthesias of the 4th and 5th digits. Further Reading: Greenberg. Handbook of Neurosurgery, 8th edition, 2016, cervical disc herniation

Answer 121

A. L4-5 decompressive laminectomy B. Lower extremity EMG **C. Cervical MRI** D. Physical therapy and pain control ## Footnote This patient presents with symptoms suggestive of pseudoclaudication, with leg pain/weakness when upright as well as evidence of spinal stenosis at L4-5 on MRI. On exam, he has the above mentioned weakness, but also has a positive Hoffman’s sign, a reflex suggestive of cervical compression. This patient should undergo cervical MRI to rule out presence of tandem stenosis. It may be that his symptoms are generated from cervical stenosis, and further workup is required. Further Reading: Harbaugh, Shaffrey, Couldwell, Berger. Neurosurgery Knowledge Update, 2015, pathophysiology of axial spinal pain, radiculopathy, and myelopathy.

Answer 122

A. Lumbar nerve roots **B. Batson’s plexus** C. Thoracic duct D. Artery of Adamkiewicz ## Footnote Batson’s plexus is a venous plexus in the epidural spinal compartment that is continuous with pelvic venous systems. It is unique in that this venous system does not contain valves. It is theorized that the lack of valves allow for easier transfer of both bacterial infections as well as metastatic lesions to affect the spine and spinal cord. Further Reading: Spetzler, Kalani, Nakaji. Neurovascular Surgery, 2nd edition, 2015, spinal vascular anatom

Answer 123

A. Somites B. Neural crest cells **C. Notochord** D. Neural tube ## Footnote The nucleus pulposus of the intervertebral disc is an embryological remnant of the notochord Further Reading: Baaj, Mummaneni, Uribe, Vaccaro, Greenberg. Handbook of Spine Surgery, 2016, embryology of the spine

Answer 124

**B. Ligamentum flavum** ## Footnote The ligamentum flavum is a non-contiguous ligament that connects laminae between segments. It helps to provide tension when the spine is in flexion, to avoid flexion injuries under normal loads. It has a high proportion of elastin, and over time loses its elasticity, causing buckling and encroachment of the thecal sac. Further Reading: Baaj, Mummaneni, Uribe, Vaccaro, Greenberg. Handbook of Spine Surgery, 2016, lumbar laminectomy

Answer 125

A. T1 **B. T4** C. T7 D. L1 ## Footnote On average, T4 has the narrowest pedicle diameter and the shortest pedicle length Further Reading: Citow, Macdonald, Refai. Comprehensive Neurosurgery Board Review, 2nd edition, 2010, anatomy

Answer 126

**A. Type I** B. Type II C. Type III D. Type IV ## Footnote The annulus fibrosus is comprised of obliquely oriented type I collagen fibers. The nucleus pulposus is primarily comprised of type II collagen. Further Reading: Kraemer. Intervertebral Disk Diseases, 3rd Edition, 2009, general anatomy, physiology, and biomechanics.

Answer 127

A. Lamina **B. Ligamentum flavum** C. Dura D. Interspinous ligament E. Disc fragment ## Footnote his image is a tubular discectomy and the blunt hook is elevating the yellow ligament, or ligamentum flavum, under which the dura can be seen. Further Reading: Fessler, Sekhar. Atlas of Neurosurgical Techniques: Spine and Peripheral Nerves, 2nd edition, 2016, figure 99.3, MIS posterior lumbar decompression of stenosis.

Answer 128

A. C4 B. C5 **C. C6** D. C7 E. T1 ## Footnote The vertebral artery enters the foramen transversarium at C6 in most patients. In some, with aberrant vertebral anatomy, it can enter at C5. Further Reading: Spetzler, Kalani, Nakaji. Neurovascular Surgery, 2nd edition, 2015, microsurgical anatomy of the internal carotid and verteb

Answer 129

C. C6 ## Footnote The anterior tubercle of the sixth cervical vertebra is known as the carotid tubercle or Chassaignac tubercle. This separates the carotid artery from the vertebral artery and the carotid artery can be massaged against this tubercle to relieve the symptoms of supraventricular tachycardia. Further Reading: An, Singh. Synopsis of Spine Surgery, 2016, anatomy and surgical appro

Answer 130

A. C4 B. C5 **C. C6** D. C7 E. T1 ## Footnote The filum terminale is a fibrous band extending inferiorly from the conus medullaris. It is often seen to have serpiginous vessels running along its course. It is often seen running through myxopapillary ependymomas. It is pictured in the intraoperative image above. Further Reading: Fessler, Sekhar. Atlas of Neurosurgical Techniques: Spine and Peripheral Nerves, 2nd edition, 2016, resection of cauda equina

Answer 131

A. Dentate ligament B. Nerve root C. Artery of Adamkiewicz **D. Filum terminale** ## Footnote The dentate ligaments of the spine extend laterally in between the dorsal and ventral nerve roots. It is an extension of the pia mater which extends to the arachnoid and dura laterally. It provides stability to the spinal cord within the spinal canal. Further Reading: Bambakidis, Dickman, Spetzler, Sonntag. Surgery of the Craniovertebral Junction, 2nd edition, 2013, anatomical basis of surgical approaches to the region of the foramen magnu

Answer 132

A. Cruciate ligament B. Apical ligament C. Alar ligament **D. Transverse ligament** ## Footnote The ligament depicted is the transverse ligament of the atlas. It is very important to assist with atlantoaxial stability. If there is a significant increase in atlantodental interval (> 3 mm), there is a high chance of transverse ligament injury and subsequent atlantoaxial instability. Further Reading: Bambakidis, Dickman, Spetzler, Sonntag. Surgery of the Craniovertebral Junction, 2nd edition, 2013, radiological evaluation of the craniovertebral junction.

Answer 133

A. 0.5 cm B. 1.0 cm **C. 1.5 cm** D. 2.0 cm ## Footnote On average, the vertebral artery is 14.6 mm from midline on the superior aspect of the C1 posterior arch Further Reading: Cacciola et al. Vertebral artery in relationship to C1-C2 vertebrae: An anatomical study. 2004. Citow, Macdonald, Refai. Comprehensive Neurosurgery Board Review, 2nd edition, 2010, anatomy

Answer 134

**A. Pars interarticularis** B. Pedicle C. Spinous process D. Superior articulating process ## Footnote This CT scan depicts a defect of the pars interarticularis, a major structure of the posterior spinal elements that provides stability within a spinal level. The pars interarticularis is the region of bone between the superior articulating process/pedicle and inferior articulating process. It is a good marker for the location of the exiting nerve root. During a laminectomy, care should be taken not to take the bone work too laterally as iatrogenic violation of the pars can lead to instability. Further Reading: Fessler, Sekhar. Atlas of Neurosurgical Techniques: Spine and Peripheral Nerves, 2nd edition, 2016, spondylolysis and spondylolisthesis in childre

Answer 135

A. Zygapophyseal joint **B. Uncinate process** C. Facet joint D. Costovertebral joint ## Footnote The uncovertebral joints are located laterally on each cervical vertebral body. They are formed by the uncinate processes and they help to provide stability to the cervical spine by limiting lateral movement. Further Reading: Forsting, Jansen. MR Neuroimaging: Brain, Spine, Peripheral Nerves, 2017, anato

Answer 136

A. Atlas **B. Axis** C. C3 D. C4 ## Footnote The vertebral body depicted here is the axis, or C2. It is the underside of the C2 body. Hints that this is C2 and not C1 include the presence of a formed vertebral body, as well as a spinous process. Further Reading: Goel, Cacciola. The Craniovertebral Junction: Diagnosis, Pathology, Surgical Techniques, 2011, image-guided surgery in the craniovertebral junction and upper cervical spine.

Answer 137

A. Roots B. Trunks **C. Divisions** D. Cords ## Footnote Each segment of the brachial plexus (roots, trunks, divisions, cords, branches) gives off a branch that innervates the upper extremity except the divisions, which do not have any individual branches. Further Reading: Psaaros. The Definitive Neurosurgical Board Review, page 60 Mackinnon, Yee. Nerve Surgery, 2015, brachial plexus injuries

Answer 138

D. Hand sensation ## Footnote The lateral cord is formed by the anterior divisions from the upper and middle trunks. The lateral cord divides into the musculocutaneous nerve and the lateral root of the median nerve. It is often described that the lateral cord contributions to the median nerve contain mostly sensory fibers traveling to the hand, while the medial cord contributions to the median nerve contain motor nerves controlling intrinsic hand function. Further Reading: Psaaros. The Definitive Neurosurgical Board Review, page 60. Russell. Examination of Peripheral Nerve Injuries: An Anatomical Approach, 2015, brachial plexus anatomy

Answer 139

A. Long thoracic nerve **B. Dorsal scapular nerve** C. Nerve to the subclavius D. Suprascapular nerve ## Footnote The first branch off the brachial plexus is the dorsal scapular nerve, branching off the C5 nerve root, which supplies the rhomboids and the levator scapulae. Next, the long thoracic nerve branches to innervate the serratus anterior. Diminished function in these muscles can represent a clinical confirmation of proximal root injury to the plexus. Further Reading: Psaaros. The definitive neurosurgical board review, page 60. Russell. Examination of Peripheral Nerve Injuries: An Anatomical Approach, 2015, brachial plexus anatomy.

Answer 140

A. Axillary nerve B. Musculocutaneous nerve C. Dorsal scapular nerve **D. Suprascapular nerve** ## Footnote The suprascapular nerve branches off the upper trunk and innervates the supraspinatous and infraspinatous muscles, responsible for initial shoulder abduction and external rotation. The patient likely has idiopathic brachial plexitis, or Parsonage-Turner syndrome. Further Reading: Psaaros. The definitive neurosurgical board review, page 60. Russell. Examination of Peripheral Nerve Injuries: An Anatomical Approach, 2015, brachial plexus anatomy

Answer 141

A. Coracobrachialis B. Biceps brachii **C. Brachioradialis** D. Brachialis ## Footnote Innervation from the musculocutaneous nerve can be remembered as “BBC” Biceps, brachialis, and coracobrachialis. The brachioradialis is innervated by C6 through the radial nerve. The musculocutaneous nerve also gives a sensory branch to the lateral forearm via the lateral antebrachial cutaneous nerve. Further Reading: Psaaros. The definitive neurosurgical board review, page 60. Russell. Examination of Peripheral Nerve Injuries: An Anatomical Approach, 2015, brachial plexus anatomy

Answer 142

A. Anterior division B. Medial pectoral nerve C. Medial brachial cutaneous nerve **D. Medial antebrachial cutaneous nerve** ## Footnote The medial cord has 5 total branches, the medial pectoral nerve (supplying the pectoralis minor and some of the pectoralis major), the medial brachial cutaneous nerve (sensory information from medial upper arm), the medial antebrachial cutaneous nerve (sensory information from medial forearm), and the final two branches, the ulnar nerve and medial contribution to the median nerve. In the options listed above, the medial antebrachial cutaneous nerve (MABC) is the most distal along the medial cord. Further Reading: Psaaros. The Definitive Neurosurgical Board Review, page 60. Russell. Examination of Peripheral Nerve Injuries: An Anatomical Approach, 2015, brachial plexus anatomy.

Answer 143

A. Lateral cord **B. Posterior cord** C. Medial cord D. Ventral roots ## Footnote The thoracodorsal nerve supplies the latissimus dorsi, and it branches as one of the five branches from the posterior cord (upper subscapular nerve, thoracodorsal nerve, lower subscapular nerve, axillary nerve, radial nerve). Further Reading: Psaaros. The Definitive Neurosurgical Board Review, page 61. Russell. Examination of Peripheral Nerve Injuries: An Anatomical Approach, 2015, brachial plexus anatomy.

Answer 144

**A. Teres minor** B. Teres major C. Infraspinatous D. Supraspinatous ## Footnote The axillary nerve branches from the posterior cord and mainly supplies the deltoid muscle. It also innervates the teres minor as well as a patch of skin overlying the shoulder Further Reading: Psaaros. The Definitive Neurosurgical Board Review, page 61. Russell. Examination of Peripheral Nerve Injuries: An Anatomical Approach, 2015, brachial plexus anatomy.

Answer 145

A. Anterior interosseous nerve **B. Posterior interosseous nerve** C. Superficial branch D. Dorsal digital branch ## Footnote The posterior interosseous nerve is a pure motor branch of the radial nerve in the forearm. It innervates the abductor pollicis longus, the extensor pollicis longus/brevis, extensor indices, extensor carpi ulnaris, extensor digitorum and extensor digit minimi. Further Reading: Psaaros. The definitive neurosurgical board review, page 61. Russell. Examination of Peripheral Nerve Injuries: An Anatomical Approach, 2015, brachial plexus anatomy.

Answer 146

**A. Anterior interosseous nerve** B. Posterior interosseous nerve C. Superficial branch D. Dorsal digital branch

Answer 147

A. Volar carpal ligament **B. Transverse carpal ligament** C. Ligament of Struthers D. Arcade of Frohse ## Footnote The patient is experiencing symptoms of carpal tunnel syndrome, where compression of the distal median nerve by the transverse carpal ligament causes the classic syndrome. Symptoms are worsened by the Phalen test (flexion of the wrist for extended periods of time), and there may be a positive Tinel’s sign over the carpal tunnel. Further Reading: Psaaros. The Definitive Neurosurgical Board Review, page 61. Russell. Examination of Peripheral Nerve Injuries: An Anatomical Approach, 2015, median nerve

Answer 148

**A. Volar carpal ligament** B. Transverse carpal ligament C. Ligament of Struthers D. Arcade of Frohse ## Footnote The patient is experiencing symptoms of ulnar tunnel syndrome, where compression of the distal ulnar nerve by the volar carpal ligament within Guyon’s canal. Note that the dorsal ulnar cutaneous nerve, which provides sensory innervation to the dorsum of the ulnar aspect of the hand branches approximately 6cm proximal to Guyon’s canal, so if sensory disturbance is present here, look more medially for compression, such as in the cubital tunnel. Further Reading: Psaaros. The Definitive Neurosurgical Board Review, page 61. Russell. Examination of Peripheral Nerve Injuries: An Anatomical Approach, 2015, ulnar nerve.

Answer 149

A. Dorsal scapular nerve **B. Long thoracic nerve** C. Thoracodorsal nerve D. Lateral pectoral nerve ## Footnote The correct answer is the long thoracic nerve, which innervates the serratus anterior. Winged scapulae on exam suggests injury to this nerve, and can be an important exam finding that suggests proximal brachial plexus injury. Further Reading: Russell. Examination of Peripheral Nerve Injuries: An Anatomical Approach, 2015, brachial plexus anatomy

Answer 150

A. Ulnar nerve B. Median nerve C. Radial nerve **D. Musculocutaneous nerve** ## Footnote This sensory territory is that of the lateral antebrachial cutaneous nerve, a branch off the musculocutaneous nerve. Further Reading: Russell. Examination of Peripheral Nerve Injuries: An Anatomical Approach, 2015, brachial plexus anatomy

Answer 151

A. Lateral pectoral nerve **B. Thoracodorsal nerve** C. Long thoracic nerve D. Medial brachial cutaneous nerve ## Footnote This test evaluates the strength of the latissimus dorsi, which is innervated by the thoracodorsal nerve, a branch from the posterior cord. Further Reading: Russell. Examination of Peripheral Nerve Injuries: An Anatomical Approach, 2015, brachial plexus anatomy

Answer 152

**A. Dorsal scapular nerve** B. Medial antebrachial cutaneous nerve C. Upper subscapular nerve D. Lower subscapular nerve

Answer 153

A. Dorsal scapular nerve B. Nerve to subclavius **C. Suprascapular nerve** D. Lateral pectoral nerve ## Footnote This test examines the supraspinatous muscle, which is innervated by the suprascapular nerve. This muscle abducts the arm for the first 15 degrees from a straight hanging position. Further Reading: Russell. Examination of Peripheral Nerve Injuries: An Anatomical Approach, 2015, brachial plexus anatomy

Answer 154

A. Dorsal scapular nerve B. Nerve to subclavius **C. Suprascapular nerve** D. Lateral pectoral nerve ## Footnote This test examines the strength of the infraspinatous muscle, which primarily externally rotates the arm. It is innervated by the suprascapular nerve. Further Reading: Russell. Examination of Peripheral Nerve Injuries: An Anatomical Approach, 2015, brachial plexus anatomy

Answer 155

A. Musculocutaneous nerve **B. Radial nerve** C. Median nerve D. Ulnar nerve ## Footnote This image depicts the quadrangular space on the back of the arm. The nerve that passes through this space is the axillary nerve as it travels to innervate the deltoid muscle. Further Reading: Russell. Examination of Peripheral Nerve Injuries: An Anatomical Approach, 2015, brachial plexus anatomy

Answer 156

A. Musculocutaneous nerve B. Radial nerve **C. Median nerve** D. Ulnar nerve ## Footnote This sensory innervation of the hand is provided by the median nerve. You can see the common digital branches as well as the palmar cutaneous branch, which branches prior to the carpal tunnel. Further Reading: Russell. Examination of Peripheral Nerve Injuries: An Anatomical Approach, 2015, median nerve

Answer 157

A. Superficial gluteal B. Superior gluteal **C. Inferior gluteal** D. Obturator ## Footnote The gluteus maximus is innervated by the inferior gluteal nerve. The superior gluteal nerve innervates the gluteus minimus/medius and the tensor fascia lata. Further Reading: Russell. Examination of Peripheral Nerve Injuries: An Anatomical Approach, 2015, lumbosacral plexus

Answer 158

A. Sensory loss over the anterior thigh/groin **B. Sensory loss over the buttocks** C. Gluteus maximus D. Gluteus minimus/medius ## Footnote The superior cluneal nerve traverses the iliac crest to provide sensory innervation to the sacral area and superior two-thirds of the buttocks. It is at risk during iliac crest bone harvest. Further Reading: Psaaros. The definitive neurosurgical board review, page 62. Russell. Examination of Peripheral Nerve Injuries: An Anatomical Approach, 2015, lumbosacral plexus

Answer 159

A. Ilioinguinal nerve **B. Lateral femoral cutaneous nerve** C. Iliohypogastric nerve D. Genitofemoral nerve ## Footnote This overweight police officer (wears a tight fitting belt all day), likely has meralgia parasthetica, a compressive condition affecting the lateral femoral cutaneous nerve. It classically presents in overweight patients as patchy sensory loss/pain over the anterolateral thigh. Further Reading: Russell. Examination of Peripheral Nerve Injuries: An Anatomical Approach, 2015, lumbosacral plexus. Psaaros. The definitive neurosurgical board review, page 62.

Answer 160

A. Anterior B. Posterior C. Medial **D. Lateral** ## Footnote The sciatic nerve is the largest nerve in the body and it has both tibial and common peroneal components. The lateral aspect of the sciatic nerve contains the common peroneal portion of the sciatic nerve. Further Reading: Russell. Examination of Peripheral Nerve Injuries: An Anatomical Approach, 2015, sciatic nerve.

Answer 161

**A. Sural nerve** B. Saphenous nerve C. Superficial peroneal nerve D. Deep peroneal nerve ## Footnote The sural nerve receives contributions from both the tibial and common peroneal nerves. It supplies sensory innervation to the lateral aspect of the lower leg and ankle. Further Reading: Russell. Examination of Peripheral Nerve Injuries: An Anatomical Approach, 2015, sciatic nerve.

Answer 162

A. Superficial peroneal nerve **B. Deep peroneal nerve** C. Tibial nerve D. Sural nerve ## Footnote The tibialis anterior is innervated by the deep branch of the common peroneal nerve. The superficial peroneal nerve innervates the muscles involved in foot eversion, the peroneus longus and brevis. Further Reading: Russell. Examination of Peripheral Nerve Injuries: An Anatomical Approach, 2015, sciatic nerve.

Answer 163

A. Interomediolateral nucleus B. Marginal nucleus C. Substantia gelatinosa **D. Onuf’s nucleus** ## Footnote Onuf’s nucleus is located within the conus medullaris and it is a grouping of motor neurons that send projections through the pudendal nerve, controlling urinary and fecal continence. Further Reading: Alberstone, Benzel, Najm, Steinmetz. Anatomic Basis of Neurologic Diagnosis, 2009, spinal cord.

Answer 164

**A. Impaired foot eversion** B. Impaired foot inversion C. Impaired foot dorsiflexion D. Impaired foot plantarflexion ## Footnote The superficial branch of the common peroneal nerve innervates the peroneus longus and brevis and controls foot eversion. Further Reading: Russell. Examination of Peripheral Nerve Injuries: An Anatomical Approach, 2015, sciatic nerve.

Answer 165

A. Tibial nerve B. Flexor hallicus longus tendon C. Tibialis posterior tendon **D. Flexor digitorum brevis tendon** ## Footnote The tarsal tunnel contains the tibial nerve, posterior tibial artery, posterior tibial vein, flexor hallicus longus tendon, flexor digitorum longus tendon and the tibialis posterior tendon. Further Reading: Russell. Examination of Peripheral Nerve Injuries: An Anatomical Approach, 2015, sciatic nerve.

Answer 166

A. Superficial peroneal nerve **B. Deep peroneal nerve** C. Tibial nerve D. Sural nerve ## Footnote The extensor hallicus longus is innervated by the deep branch of the common peroneal nerve. Remember that the superficial branch, while providing sensory information to the majority of the dorsum of the foot, only innervates muscles involved in foot eversion (peroneus longus/brevis). The deep branch innervates the remaining foot extensors. Further Reading: Russell. Examination of Peripheral Nerve Injuries: An Anatomical Approach, 2015, sciatic nerve

Answer 167

A. Gluteus minimus/medius and tensor fascia lata **B. Gluteus maximus** C. Gracilis D. Adductor magnus ## Footnote The gluteus maximus muscle is innervated by the inferior gluteal nerve, and it extends the hip with the assistance of the hamstrings. Further Reading: Russell. Examination of Peripheral Nerve Injuries: An Anatomical Approach, 2015, lumbosacral plexus

Answer 168

**A. Pudendal nerve** B. Superior gluteal nerve C. Inferior gluteal nerve D. Obturator nerve ## Footnote Onuf’s nucleus is located within the conus medullaris and contains motor neurons that control urinary and fecal continence. Fibers are carried through the pudendal nerve. Further Reading: Russell. Examination of Peripheral Nerve Injuries: An Anatomical Approach, 2015, inguinal complex of nerves.

Answer 169

A. Femoral nerve B. Obturator nerve **C. Sciatic nerve** D. Tibial nerve ## Footnote Fibers that innervate the peroneus longus originate in the peroneal component of the sciatic nerve. Further Reading: Russell. Examination of Peripheral Nerve Injuries: An Anatomical Approach, 2015, sciatic nerve.

Answer 170

A. Femoral nerve B. Obturator nerve **C. Sciatic nerve** D. Peroneal nerve ## Footnote The flexor hallicus is innervated by the tibial nerve. Fibers innervating the flexor hallicus longus travel within the sciatic nerve before separating to become the tibial nerve. Further Reading: Russell. Examination of Peripheral Nerve Injuries: An Anatomical Approach, 2015, sciatic nerve.

Answer 171

**A. Sural nerve** B. Sciatic nerve C. Tibial nerve D. Saphenous nerve ## Footnote This image depicts the sensory innervation of the sural nerve. Further Reading: Russell. Examination of Peripheral Nerve Injuries: An Anatomical Approach, 2015, sciatic nerve.

Answer 172

A. Ilioinguinal nerve B. Genitofemoral nerve **C. Lateral femoral cutaneous nerve** D. Obturator nerve ## Footnote Sensory innervation from the anterolateral thigh is provided by the lateral femoral cutaneous nerve. Further Reading: Russell. Examination of Peripheral Nerve Injuries: An Anatomical Approach, 2015, inguinal complex of nerves.

Answer 173

A. Obturator nerve B. Sciatic nerve **C. Femoral nerve** D. Ilioinguinal nerve ## Footnote This examiner is evaluating the strength of the quadriceps muscle, which is innervated by the femoral nerve. Further Reading: Russell. Examination of Peripheral Nerve Injuries: An Anatomical Approach, 2015, inguinal complex of nerves

Answer 174

**A. Obturator nerve** B. Sciatic nerve C. Femoral nerve D. Ilioinguinal nerve ## Footnote The obturator nerve innervates the adductors longus, brevis and magnus. Further Reading: Russell. Examination of Peripheral Nerve Injuries: An Anatomical Approach, 2015, inguinal complex of nerves.

Answer 175

A. Above B. Below **C. Both** D. Neither ## Footnote This sensory innervation is from the genitofemoral nerve which supplies two regions as depicted in the image above. The femoral triangle region is innervated by the nerve branch that passes below the inguinal ligament, while the groin region is innervated by the branch that passes through the spermatic cord. Further Reading: Russell. Examination of Peripheral Nerve Injuries: An Anatomical Approach, 2015, inguinal complex of nerves.

Answer 176

A. Sciatic nerve **B. Sacral plexus** C. Psoas muscle D. Rectus fascia ## Footnote The lumbosacral trunk provides the connection between the lumbar plexus and the sacral plexus. It travels on the psoas muscle. It contributes to multiple sacral plexus nerves, including the superior and inferior gluteal nerves. Further Reading: Russell. Examination of Peripheral Nerve Injuries: An Anatomical Approach, 2015, inguinal complex of nerves.

Neuroanatomy Flashcards

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