Neuroanatomy Review

Question 1

Bilateral Antonia, areflexia and flaccid paralysis involving the C7-T1 motor dermatomes indicates involvement of which of the following?
A. Anterior horn neurons
B. ANterior white commissure
C. Dorsal roots 
D. Lateral corticospinal tract
E. Posterior limb of internal capsule

Answer 1

A. Anterior horn neurons

Question 2

Hemianalgesia and thermal hemianesthesia (body) indicated involvement of which of the following?
A. Dorsal roots
B. Medial lemniscus
C. Posterior limb of internal capsule
D. Spinal lemniscus
E. Ventral posterior medial nucleus

Answer 2

D. Spinal lemniscus

Question 3

Alternating hemianalgesia indicates involvement of which of the following?
A. Descending tract of V
B. Lateral lemniscus
C. Medial Lemniscus
D. Trigeminal lemniscus 
E. Trigeminal nerve

Answer 3

A. Descending tract of V

Question 4

Bilateral diminution of hearing with a more prominent loss in one ear indicates involvement of which of the following?
A. Lateral geniculate body
B. Lateral lemniscus
C. Posterior limb of internal capsule
D. Superior colliculus
E. Vestibulocochlear nerve

Answer 4

B. Lateral lemniscus

Question 5

A boxer receives 3 direct blows to the left side of his head. After the first blow, he collapsed on the mat then stood back up. He was then hit again before the end of that round, then received a third direct blow to the same region and fell to the mat. He was unconscious and unresponsive, his left pupil was dilated. He was transported to a trauma center and neurosurgery was performed to control the bleeding from some bridging veins. He remained in a persistent vegetative coma state one month later. What is the dx?

Answer 5

subdural hematoma

Question 6

during the neuro exam for the gag reflex, the pt does not sense the tongue depressor touching the oropharyngeal mucosa, but shows palatial elevation when phonating ("ahhhhh) and no dysphonia. These findings indicate involvement of which of the following?
A. Chorda tympani nerve
B. Glossopharyngeal nerve
C. Recurrent laryngeal nerve
D. Trigeminal nerve
E. Vagus nerve

Answer 6

B. glossopharyngeal

• this is a CN question that requires you to distinguish between the sensory (IX) and motor (X) components. This pt can’t sense the stimulus to the back of the throat (oropharynx), but shows normal motor function

Question 7

Spastic hemiplegia indicates involvement of which of the following?
A. Corticospinal tract 
B. lateral reticulospinal tract 
C. Spinal lemniscus
D. Genu of internal capsule 
E. Ventral roots

Answer 7

A. corticospinal tract

• the CST are UMNs. A lesion of the CST results in contralateral spastic hemiplegia: hyperreflexia, hypertonia, paralysis and disuse dystrophy

Question 8

Lesions of the ______ roots of the spinal cord causes a lower motor neuron paralysis of the associated motor dermatome causing atone, areflexia, fasciculation and flaccid paralysis

Answer 8

Ventral roots

Question 9

Supranuclear facial palsy indicates involvement of which of the following?
A. Facial Nerve 
B. Corticobulbar tract 
C. Corticospinal tract 
D. Posterior limb of internal capsule 
E. Rubrospinal tract

Answer 9

B. Corticobulbar tract

• Corticobulbar fibers originate in the head region of pre central gyrus, course through the gene of the internal capsule and cerebral peduncles as uncrossed CBT -> unilateral lesions of UNCROSSED CBT result in contralateral supra nuclear facial palsy

Question 10

Where do corticobulbar tracts decussate, and at which point a unilateral lesion would cause ipsilateral cranial palsies?

Answer 10

Decussate in lower pons (between V and VI)

Question 11

Proprioceptive and 2-point tactile discrimination loss below the L3 dermatome indicates involvement of which of the following?
A. dorsal roots
B. fasciculus gracilis 
C. Medial lemniscus
D. Spinal lemniscus
E. Ventral posterior medial nucleus

Answer 11

B. Fasciculus Gracilis

Question 12

On horizontal gaze to the right, the left eye does not adduct and the right eye shows nystagmus. This indicates involvement of which of the following?
A. Abducens nerve 
B. Medial longitudinal fasciculus
C. Oculomotor nerve
D. Superior colliculus 
E. vestibulocochlear nerve

Answer 12

B. Medial longitudinal fasciculus

Question 13

Left homonymous hemianopia indicates involvement of which of the following?
A. Loop of meyer 
B. Medial geniculate body
C. optic chiasma
D. Optic tract 
E. Primary visual cortex

Answer 13

D. Optic tract

Contralateral homonymous hemianopia. Unilateral lesions of the lateral geniculate body, complete optic radiations or visual cortex result in contralateral homonymous hemianopsia. This is a left homonymous hemianopia, which would indicate lesions on the right visual pathway, i.e optic tract, lateral geniculate body or complete optic radiations

Question 14

Internal strabismus indicates involvement of which of the following?
A. Abducens nerve
B. Oculomotor nerve
C. Trochlear nerve
D. Superior colliculus
E. Medial longitudinal fasciculus

Answer 14

A. Abducens nerve

**External strabismus would be CN III

Question 15

When you see the “bat-wing” on an MRI of the brain, what level of the brainstem are you at?

Answer 15

Metencephalon

**The bat-wing appearance is of the pons and middle cerebellar peduncle

Question 16

When you see the “mickey mouse” appearance on MRI of the brain, what level of the brainstem are you at?

Answer 16

Mesencephalon

The mickey mouse appearance is of the midbrain. His eyes represent the red nucleus and mouth represents the cerebral aqueduct; also described as a panda bear appearance

Question 17

Acoustic neuromas are common tumors of the posterior cranial fossa in adults. This mass may cause what syndrome?

Answer 17

Cerebellopontine angle (CPA) syndrome

Question 18

What are the symptoms seen with lateral medullary syndrome (AKA wallenberg’s syndrome)?

Answer 18

• Alternating hemianalgesia (ipsilateral loss of pain and ten from face and contralateral loss of pain and temp from body)
• destruction of glossopharyngeal and vagus nerves
• ipsilateral loss of taste from 1/2 of tongue and pharynx
• nystagmus

Question 19

What are the symptoms of cerebellopontine angle (CPA) syndrome?

Answer 19

• deafness and vestibular disturbances (destruction CN VIII)
• Alternating hemianalgesia
• Bells palsy (destruction of CN VII)
• cerebellar ataxia (destruction of peduncles)

Question 20

Benedikt’s syndrome is due to a lesion where?

Answer 20

Of the midbrain tegmentum

Question 21

What are the symptoms of benedikt’s syndrome?

Answer 21

• CN III palsy
• contralateral loss of proprioo and 2-point tactile from body and limbs (destruction of medial lemniscus)
• contralateral motor dysfunction

Question 22

What is parinaud’s syndrome?

Answer 22

• due to lesion of superior colliculus which contains a center for controlling upward gaze
• sx = paralysis of upward gaze
• may be due to a pineal tumor or varix of great vein of Galen
• may also destroy posterior commissure and cause loss of consensual light reflex

Question 23

What is thalamic syndrome?

Answer 23

• usually due to thrombosis of posterior choroidal or thalamogeniculate branches of the posterior cerebral arteries
• Sx = constant spontaneous pain without appropriate external stimulus, extreme mood swings within short period of time, contralateral hemihypalgesia (“crawling ant” sensations), hemiparesis, homonymous hemianopia or auditory deficits

Question 24

Pt presents with oculomotor palsy on the right, loss of pain and temp sensations on the left side of face, loss of proprioception on the left side of body, loss of pain and temp on left side of body and a resting tremor of the left limbs. What is the dx?

Answer 24

Resting tremors are characteristic of benedikts syndrome which is a lesion of the midbrain tegmentum

Question 25

What are the sx of millard Gublers syndrome?

Answer 25

• alternating abducens hemiplegia plus a lesion of the VII
• destruction of the facial nerve results in ipsilateral Bell’s palsy, loss of taste sensations from the anterior 2/3 of the tongue, decreased lacrimation and hyperacusis

Question 26

Pt presents with internal strabismus of the right eye, bell’s palsy on the right, and hemiparesis of the left limbs with a positive babinski. What is the level of the lesion and what syndrome is most likely?

Answer 26

The level of this lesion is right at the pontomedullary junction; this is characteristic of a millard gublers syndrome

Question 27

A pt presents with sudden onset of dysesthesia over the entire left side of the body associated with dizziness. What is the most likely syndrome?

Answer 27

Thalamic syndrome -> weird sensations on one half of th body

Question 28

Pt presents with sudden high pitched tinnitus in right ear, dizziness and right facial pain. Neuro exam shows partial ptosis of right eye, constriction of right pupil, right deafness, loss of pain and temp on right side of face and left side of body, intention tremor and dysmetria on right and positive romberg sign to the right. What is the most likely syndrome?

Answer 28

Cerebellopontine angle (CPA) syndrome

Question 29

Pt presents with clumsiness and difficulty walking, which had progressively worsened over the last few years. He passed the romberf test but demonstrated a broad ataxic gait. Other findings include dysdiadochokinesia. What is the likely diagnosis?

Answer 29

Alcoholic cerebellar degeneration may be due to its direct toxic effect to the cerebellum and the consequences of vitamin B1 (thiamine) deficiency. Alcohol produces toxic effect on purkinje cells

Question 30

Pt presents with loss of proprioception, 2-pt tactile discrimination and vibratory sensations in all limbs, paresis of the lower limbs with hypotonia and hyporeflexia and bilateral babinski signs. What is the most likely dx?

Answer 30

Friedrichs ataxia -> demyelination of the proprioceptive neurons in the dorsal roots, posterior columns, medial lemniscus, spinocerebellar tracts and CST

Question 31

71yo female suffered from acute mountain sickness at an altitude of about 12,136ft and became comatose. After coming down from the altitude she recovered from the sx but her family began to notice her personality changes in daily life. She became apathetic, uncommunicative, expressionless, less interested in hobbies and less sociable. What dx is most likely?

Answer 31

Globus pallidus syndrome -> in mountain sickness, pts may have acute onset of HA, changes in consciousness and ataxia. After the pt has recovered from acute sx, executive function should be evaluated. In these cases, hypobaric hypoxia at high elevation induced a neurobehavioral syndrome: globes pallid us syndrome, which is clinically indistinguishable from frontal lobe syndrome

Globus pallidus is very sensitive to hypoxia

Question 32

Pt presents with hemianalgesia and thermal hemianesthesia on the left side of body and face, proprio loss on left side, left spastic hemiplegia with hyperreflexia and babinski, inability to smile on left, and left homonymous hemianopsia, whats the most likely dx?

Answer 32

this is a case of infarct in the cerebrum -> majority of these occur in the posterior limb of the internal capsule

**There are no cranial nerve defects presented here

Question 33

Where is the common location for a parasagittal meningioma?

Answer 33

Paracentral lobule

Question 34

What is the location of a lesion resulting in left superior homonymous quadrantanopia?

Answer 34

loop of meyer

Question 35

What is Gerstmann syndrome?

Answer 35

• due to a lesion of the dominant parietal lobe

- characterized by finger agnosia, right-left disorientation, dysgraphia and dyscalculia

Question 36

63yo male came to his physician complaining that he was no longer able to read or write. PE revealed no defect in visual fields or eye movements. He could recognize and identify objects in both eye fields but couldn’t read. He seemed to understand everything said to him and responded fluently but occasionally misused a word or 2. When handed a pencil and told to draw a picture he couldn’t figure out how to hold the pencil or what hand to use. He also had difficulty working arithmetic problems despite his prior ability to do so. What syndrome does he most likely have?

Answer 36

Gerstmann syndrome