Neurology Anatomy Questions

Question 1

Match the following clinical features of a stroke to either anterior circulation (anterior and middle cerebral arteries), posterior circulation (posterior cerebral, vertebral and basilar arteries) or both.

Ataxia

Answer 1

Ataxia = posterior circulation stroke (vertebral or basilar arteries)
The stroke will affect the vertebral or basilar arteries. The Superior cerebellar arteries and the anterior inferior cerebellar arteries stem from the basilar artery, and the posterior inferior cerebellar arteries originate from the vertebral arteries.

Question 2

Match the following clinical features of a stroke to either anterior circulation (anterior and middle cerebral arteries), posterior circulation (posterior cerebral, vertebral and basilar arteries) or both.

Hemianopia

Answer 2

Hemianopia = posterior circulation stroke; it is a stroke affecting the visual pathways from the optic chiasm onwards to the occipital lobe. A homonymous hemianopia would arise from an occlusion of the posterior cerebral artery.

Question 3

Match the following clinical features of a stroke to either anterior circulation (anterior and middle cerebral arteries), posterior circulation (posterior cerebral, vertebral and basilar arteries) or both.

Motor weakness

Answer 3

Motor weakness = any stroke that affects the motor cortex or motor tracts. The anterior and middle cerebral arteries supply the primary motor cortex, this means that strokes of the anterior circulation will produce motor weakness. However, as the corticospinal tracts have to through the brainstem and spinal cord, a stroke affecting the brainstem could also produce weakness, therefore as the basilar arteries supply the brainstem a posterior circulation stroke could also produce motor weakness

Question 4

Match the following clinical features of a stroke to either anterior circulation (anterior and middle cerebral arteries), posterior circulation (posterior cerebral, vertebral and basilar arteries) or both.

Unable to form words

Answer 4

Unable to form words = expressive aphasia will occur from a stroke of the artery supplying BROCCA’S AREA in the frontal lobe of the brain.
In right handed people, Brocca’s area is almost always on the left and so is supplied by the left middle cerebral artery, so it is an ANTERIOR CIRCULATION STROKE.

Question 5

Match the following clinical features of a stroke to either anterior circulation (anterior and middle cerebral arteries), posterior circulation (posterior cerebral, vertebral and basilar arteries) or both.

Unable to understand speech

Answer 5

Receptive aphasia occurs in strokes involving WERNICKE’S AREA, which is also supplied by the middle cerebral artery, so this is also in the anterior circulation.

Question 6

Match the following clinical features of a stroke to either anterior circulation (anterior and middle cerebral arteries), posterior circulation (posterior cerebral, vertebral and basilar arteries) or both.

Cranial nerve involvement

Answer 6

pons or medulla

posterior circulation

Question 7

Match the following clinical features of a stroke to either anterior circulation (anterior and middle cerebral arteries), posterior circulation (posterior cerebral, vertebral and basilar arteries) or both.

Sensory loss

Answer 7

Sensory loss can occur from any stroke that affects the sensory cortex or sensory tracts of the brain and spinal cord. The anterior and middle cerebral arteries supply the sensory cortex; this means that strokes of the ANTERIOR circulation will produce sensory loss.

However, as the sensory tracts have to travel through the brainstem and spinal cord, a stroke affecting the brainstem could also produce sensory loss, as the basilar arteries supply the brainstem a POSTERIOR circulation stroke could also produce sensory loss.

Question 8

What structure produces CSF and where in the brain is it located?

Answer 8

CSF is produced by the choroid plexus and the majority of the choroid plexus is located on the walls of the lateral ventricles along the choroid fissure. Choroid plexus is also present in the roofs of the 3rd and 4th ventricles.

Question 9

What path does CSF take from where it is formed to where it is reabsorbed?

Answer 9

The CSF travels from the lateral ventricles through the foramen of Munroe to the third ventricle. The fluid then flows through the aqueduct of Sylvius (cerebral aqueduct) into the 4th ventricle where it drains out of the foramen of Lushka and Magendie into the subarachnoid space.

Question 10

How is CSF reabsorbed?

Answer 10

CSF is reabsorbed by the arachnoid villi located in the dural venous sinuses. Aggregrations of arachnoid villi are known as arachnoid granulations.

Question 11

Match the following areas of the brain to their correct lobe

Hippocampus
Amygdala
Primary motor cortex
Primary visual cortex
Primary somatosensory cortex
Primary auditory cortex 
Wernicke's area
Broca's area

Answer 11

Temporal 
Temporal 
Frontal
Occipital 
Parietal 
Temporal 
Parietal 
Frontal

Question 12

What is the blood supply of these areas?

Broca’s area
Motor cortex of the arm
Sensory cortex of the arm
Auditory area

Answer 12

left middle cerebral
middle cerebral
middle cerebral
middle cerebral

Question 13

For the following components, name their exit and entry point to/from the skull ad in which bones these openings are located:

Internal carotid artery

Answer 13

enters the skull via the carotid canal then travels horizontally through the temporal bone to enter the cranium through the foramen lacerum

Question 14

For the following components, name their exit and entry point to/from the skull ad in which bones these openings are located:

Internal carotid artery

Answer 14

enters the skull via the carotid canal then travels horizontally through the temporal bone to enter the cranium through the foramen lacerum

Question 15

For the following components, name their exit and entry point to/from the skull ad in which bones these openings are located:

Optic nerve

Answer 15

Enters through the optic canal in the lesser wing of the

sphenoid bone

Question 16

For the following components, name their exit and entry point to/from the skull ad in which bones these openings are located:

Facial nerve

Answer 16

exits the cranium through the internal acoustic meatus in the petrous part of the temporal bone and emerges from the skull through the stylomastoid foramina

Question 17

For the following components, name their exit and entry point to/from the skull ad in which bones these openings are located:

spinal cord

Answer 17

passes through the foramen magnum in the occipital bone of the skull

Question 18

Which arteries supply the visual cortex? How could the blood supply explain macular sparing?

Answer 18

The visual cortex is located in the occipital lobe of the brain. The occipital lobe is supplied by the posterior cerebral arteries.

It is thought that the middle cerebral artery can supply part of the visual cortex which is one theory for the macular sparing that is apparent visual field defects.

Question 19

A patient is diagnosed with a lesion to the 3rd cranial nerve (oculomotor). How would this eye appear to the examiner?

Answer 19

The oculomotor nerve supplies all extraocular muscles except superior oblique and lateral rectus. A lesion to the oculomotor nerve would result in unopposed action of superior oblique and lateral rectus forcing the eye to look downwards and outwards. The eye will be fixed in this position.

Question 20

Which muscles are involved in the movement of the eye? When tested clinically what action does each exert on the eyeball?

Answer 20

Medial, lateral inferior, superior rectus and inferior and superior oblique.

Actions performed w H-test:
Medial rectus: Adduction
Lateral rectus: abduction 
Superior r.: elevation
Inferior r.: depression
Superior o.: adduction + depression
Inferior o.: adduction and elevation

Question 21

When considering the middle ear, which of the following is the correct order of components when moving from external to internal ear?

Answer 21

tympanic membrane, malleus, incus, stepes, oval window

Question 22

TRUE OR FALSE
Accomodation reflex (looking at a near object) 

1) The suspensory ligaments tighten
2) The pupils dilate
3) The eyes converge
4) It is abolished in a complete lesion of the oculomotor nerve
5) The light reflex will be present and the accomodation reflex will be abolished in lesions of the pretectal nuclei

Answer 22

1) false - the lens need to be convex
2) false - the pupils constrict to prevent divergent light rays from hitting the periphery of the retina and producing a blurred image
3) true
4) true - lose motor control
5) true - the light reflex involves the pretectal nuclei, whereas the accomodation reflex does not

Question 23

TRUE OR FALSE
Accomodation reflex (looking at a near object) 

1) The suspensory ligaments tighten
2) The pupils dilate
3) The eyes converge
4) It is abolished in a complete lesion of the oculomotor nerve
5) The light reflex will be present and the accomodation reflex will be abolished in lesions of the pretectal nuclei

Answer 23

1) false - the lens need to be convex
2) false - the pupils constrict to prevent divergent light rays from hitting the periphery of the retina and producing a blurred image
3) true
4) true - lose motor control
5) true - the light reflex involves the pretectal nuclei, whereas the accomodation reflex does not

Question 24

Which cranial nerves would a mass lesions in the cavernous sinus affect?

Answer 24

occulomotor
trochlear
abducens
trigeminal

Question 25

Symptoms and/or signs would this produce?: Oculomotor lesion

Answer 25

• isolated oculomotor nerve palsy = the eye on affected side would look down and out due to unopposed action of the lateral rectus and superior oblique
• partial ptosis at loss of innervation to levator palpibrae superioris
• dilated pupil as a lesion will compress parasympathetic fibres on the outside of the nerve

Question 26

Symptoms and/or signs would this produce?: Trochlear lesion

Answer 26

loss of intorsion of affected eye due to loss of innervation to superior oblique

Question 27

Symptoms and/or signs would this produce?: Abducens lesion

Answer 27

loss of lateral movement of affected eye

Question 28

Symptoms and/or signs would this produce?: Trigeminal lesion

Answer 28

loss of sensation over the ophthalmic (and sometimes maxillary) branches. The mandibular branch does not run through the cavernous sinus so will be spared.

Question 29

You examine a patient who on visual field testing has a right lower homonymous quadrantinopia, where is the lesion?

Answer 29

Left parietal - the fibres of the lower quadrants go through Baum’s loop. And as the left side of the eye goes to the left side of the brain, it must be left parietal.

Question 30

Where do the majority of the descending fibres of the cortico-spinal tract decussate?

Answer 30

80% of the corticospinal tract decussate in the medullary pyramids and travel in the lateral corticospinal tract. 10% join the ipsilateral corticospinal tract and 10% travel in the anterior corticospinal tract and cross in the spinal cord.

Question 31

Acoustic neuromas grow on the 8th (vestibulocochlear nerve) causing nerve compression. Which adjacent cranial nerves could also be compressed by the growing tumour and what symptoms may this cause?

Answer 31

An acoustic neuroma can compress the facial nerve resulting in paralysis of the facial muscles. If the palsy is severe enough taste sensation can be lost to the anterior two thirds of the tongue. Loss of innervation to strapedius can lead to an intolerance of loud noises, assuming the acoustic neuroma hasn’t already caused substantial hearing loss.

Question 32

What are the functional connections between the cerebellum and brainstem?

Answer 32

midbrain - superior peduncle
pons - middle peduncle
medulla - inferior peduncle

Question 33

What pathways do each of the peduncular connections carry?

Answer 33

Superior peduncle = efferent fibres from the dentate, emboliform and globose nuclei. These axons send feedback to the motor cortex in the frontal lobe. Afferent fibres from ventrospinocerebellar tract take ‘unconscious proprioceptive’ information from the lower body.

Middle peduncle = corticopontocerebellar information. A copy of the information from the primary motor cortex which the pyramidal tract is carrying down to lower motor neurones.

Inferior peduncle = vestibulocochlear tract (vestibular impulses from labyrinths, directly and via the vestibular nucleus) Also ‘unconscious proprioceptive’ information from the dorsospinocerebellar tract.

Question 34

What is the blood supply to the cerebellum and from which vessels do these arteries usually arise?

Answer 34

Posterior inferior cerebellar arteries arise from the vertebral arteries

Anterior inferior cerebellar arteries arise from the basilar artery

Superior cerebellar arteries arise from the basilar artery

Question 35

The dentate nuclei are the largest of the paired cerebellar deep nuclei. What role do they play? Where do efferent fibres from the nucleus go?

Answer 35

The dentate nucleus is responsible for:
- planning, initiation and control of voluntary movements.

Efferent fibres travel via the superior cerebellar peduncles through the red nucleus to the thalamus.

Question 36

What part of the spinal cord carries ascending sensory fibres carrying touch, vibration and proprioception from the limbs? These 4 tracts terminate in four nuclei, where are they located?

Answer 36

The dorsal columns are ascending pathways carrying fine touch, vibration and ‘conscious proprioception’ from the limbs. At the level fo the medulla the axons synapse with the gracile and cuneate nuclei which represent information from the lower and upper limbs respectively.

Question 37

A patient is brought in to accident and emergency with a sudden onset of difficulty sitting up or standing? Where in the cerebellum is the lesion most likely to be?

Answer 37

The lesion is most likely to be in the vermis (part of the paleocerebellum) which receives fibres from the dorsal and ventral spinocerebellar tracts carrying information from muscle, joint and cutaneous receptors through the interior and superior cerebellar peduncles respectively.

Question 38

A patient is brought into accident and emergency with a sudden onset of difficulty sitting up or standing. Where in the cerebellum is the lesion most likely to be?

Answer 38

The lesion is most likely to be in the vermis (part of the paleocerebellum) which receives fibres from the dorsal and ventral spinocerebellar tracts carrying information from muscle, joint and cutaneous receptors through the inferior and superior cerebellar peduncles respectively.

Question 39

With regards to cerebellar lobe lesions, answer the following statements as either true or false.

1) Nystgmus may be present
2) Muscle hypertonia may be present
3) A resting tremor may occur
4) Muscle weakness can occur
5) Can be caused by multiple sclerosis

Answer 39

1) true
2 false - hypertonia may be present 
3) false - a cerebellar lesion causes an intention 
4) true 
5) true

Question 40

What term do we use for the white matter that connects the cortex of the cerebral hemisphere to other structures?

Answer 40

internal capsule

Question 41

What are the constituents that comprise the basal ganglia?

Answer 41

The Papez circuit consists of the hippocampus, fornix, mamillary bodies, cingulate gyrus, thalamus, singulum and parahippocampus gyrus

Question 42

How do fibres of the olfactory nerve enter the cranium?

Answer 42

The fibres of the olfactor nerve enter the anterior cranial fossa through the foramina of the cribiform plate of the ethmoid bone

Question 43

A 72 year old man present with a gradual onset over years of asymmetrical resting tremor, increased tone and slow movements. When he walks into clinic he is hunched over and walking with shuffled steps with no arm swing.
What is the likely diagnosis?
What part of the brain is affected?
What other symptoms may have?

Answer 43

Parkinson’s

Substantia nigra is affected in this disease process which results from a loss of neuromelanin containing cells

• rigidity of the flexor muscles of the neck trunk and limbs
• mask like expressionless face
• reduction in size of the patients handwriting
• difficulting in initiating lower limb movement
• loss of ocular convergence and upwards gaze
• autonomic features such as postural hypotension and constipation
• depression

Question 44

You see a patient in clinic who has left sided hemiballismus (violent flinging movements).
What does hemiballismus result from?

Answer 44

hemiballismus results from a lesion of the contralateral subthalmic nucleus so in this case it would be right subthalmic nucleus as the involuntary movements are on the left hand side.

Question 45

What is an epidural and how does it differ from a lumbar puncture?

Answer 45

An epidural involves the injection of a substance (analgesia/anaesthesia) into the epidural space anywhere along the vertebral column. Whereas in a lumbar puncture a hollow needle is inserted below the level of the spinal cord into the subarachnoid space in order to remove CSF for diagnostic purposes.

Question 46

John is a 60 year old gentleman who presents with multiple scars and healing lesions on his fingers and forearms. He undergoes a cervical MRI. He is diagnosed with syringomyelia. What is syrngomyelia? Which fibres will be affected first? What sensory impairment will this produce?

Answer 46

Syingomyelia = progressive expansion of the central canal of the spinal cord with CSF possible due to altered CSF dynamics. This may be due to congenital abnormality such as Chiari malformation (elongated cerebellar tonsils protrude through the foramen magnum compressing the medulla) or a tumour or trauma.

Signs = dissociated sensory loss (Absent pain and temperature sensation - spinothalamic tracts; with preserved light touch, vibration and proprioception - dorsal columns) due to pressure from the syrinx (cyst) on the decussating spinothalamic pathway.

Question 47

Rachel is a 40 year old lady with no significant past medical history. She attends her GP due to sudden onset lower back pain. She is extremely concerned as that morning she passed water unexpectedly. What other questions would you like to ask her? What diagnosis should you be concerned with?

Answer 47

Take a history about the pain and also focused neurological questions.

Pain: site/onset/character/radiation/associated symptoms/timing/exacerbating and relieving factors/severity

Neurological:
Trauma, or previous injury to back?
Leg weakness, if so rate of progression? Sensory loss? Loss of spincter control (bowels, bladder)?

With these symptoms one would worry about CORD COMPRESSION.

Question 48

What is meant by the term dermatome?

Answer 48

A dermatome is that area of skin supplied by a single spinal cord level, or on one side, by a single spinal nerve. During development cells from a specific somite develop into the dermis in a precise location and somatic sensory fibres associated with that somite become part of one spinal nerve.

Question 49

Which dermatome?

Thumb
Nipple line
Umbilicus
Knee
Big toe

Answer 49

C6
T4
T10
L3
L5

Question 50

What is the arterial blood supply to the spinal cord?

Answer 50

anterior and posterior spinal
The anterior spinal arteries supply the cord in front of the posterior grey column.

The posterior spinal arteries supply the posterior grey columns and the dorsal columns. These arteries are reinforced by radicular arteries at segmental levels from vertebral, ascending cervical, posterior intercostals, lumbar and sacral arteries.

Question 51

What are the two parts of the intervertebral disc and how do they relate to each other?

Answer 51

The 2 parts are the nucleus pulposus and the annulus fibrosus (surrounds the nucleus pulpopsus and resists its expansion)

Question 52

What structures make up the intervertebral foramina through which the spinal nervous pass?

Answer 52

The IF are on the lateral aspect of the vertebral column and lie between the pedicles of adjoining vertebrae
They are bounded anteriorly by the vertebral bodies and the disc and posteriorly by the facet joints.

Question 53

A 31 year old female is involved in a fight and is stabbed in the back. Examination reveals a single penetrating wound at the level of T12 marginally to the right of the midline, her vital signs are stable. Further neurological examination leads you to suspect she has a right sided hemisection of the spinal cord (Brown-Sequard syndrome)

What features of the examination would suggest this diagnosis?

Using your knowledge of the spinal tracts, what is the anatomical basis for this distinct set of features?

Answer 53

Ipsilateral UMN weakness below the level of the lesion (severed corticospinal tract causing spastic paraparesis, brisk reflexes, extensor plantars)

Ipsilateral loss of propriception and vibration = 1 dorsal column severed

Contralateral loss of pain and temperature sensation (Severed spinothalamic tract which has crossed over)