lecture 19 - organisation of the cranial nerves

Question 1

Which of the motor and sensory nuclei of the brainstem are found more medially?

Answer 1

Motor

Question 2

What divides the motor and sensory nuclei of the brain stem?

Answer 2

Sulcus limitans

Question 3

What are the 3 types of brain stem motor nuclei, found medial to lateral?

Answer 3

General somatic, branchial efferent, general visceral

Question 4

What are the 3 types of brain stem sensory nuclei, found medial to lateral?

Answer 4

general visceral, general somatic, special somatic

Question 5

Which cranial nerve is found at the level of the superior colliculus in the midbrain?

Answer 5

Oculomotor nerve

Question 6

Which nuclei are found at the level of the superior colliculus in the midbrain?

Answer 6

Oculomotor, Edinger Westphal

Question 7

Where do fibres of the trochlear nerve exit the midbrain?

Answer 7

They cross over then exit dorsally

Question 8

Which brainstem nucleus is found at the level of the inferior colliculus in the midbrain?

Answer 8

Trochlear nucleus

Question 9

Which brain stem nuclei are found at the level of the mid pons?

Answer 9

Motor nucleus of trigeminal nerve, chief/pontine/main nucleus of trigeminal nerve (sensory)

Question 10

Where is the motor nucleus of CNV found in relation to the sensory nuclei of CNV?

Answer 10

Found in the mid pons, medial to where the pontine/chief sensory nucleus of V is also found

Question 11

Which cranial nerves exit the brain stem at the caudal pons?

Answer 11

CNVI, CNVII, CNVIII

Question 12

Which brainstem nuclei are found at the level of the caudal pons? (medial to lateral)?

Answer 12

Abducens nucleus, facial motor nucleus, vestibulocochlear nucleus

Question 13

What is the path of the facial nerve from its nucleus to exiting the brain stem?

Answer 13

It wraps around the abducens nucleus medially at the dorsal part of the caudal pons, before travelling laterally to the abducens and facial nuclei to exit the brain stem ventrally

Question 14

What features of a cross section of the medulla are useful in identifying it?

Answer 14

The olives and pyramids

Question 15

What features of a cross section of the midbrain are useful in identifying it?

Answer 15

‘Mickey mouse’ shape - with ears representing the cerebral peduncles

Question 16

What features of a cross section of the pons are useful in identifying it?

Answer 16

horse shoe/arch shape

Question 17

Which cranial nerve nuclei are found at the open/upper medulla? (medial to lateral)?

Answer 17

hypoglossal nucleus, motor vagal nucleus, vestibulocochlear nucleus, nucleus ambiguous, nucleus of tractus solitarius

Question 18

What is the location of the median longitudinal fasciculus in the brain stem?

Answer 18

travels medially down the midline of the brain stem

Question 19

What are the 3 sensory nuclei of the trigeminal nerve? (superior to inferior)

Answer 19

Mesencephalic nucleus, pontine/chief nucleus, spinal tract nucleus

Question 20

Which arteries supply the midbrain?

Answer 20

Posterior cerebral

Question 21

Which arteries supply the pons?

Answer 21

Superior cerebellar artery, anterior inferior cerebellar artery, basilar artery (via pontine arteries)

Question 22

Which arteries supply the open medulla?

Answer 22

Posterior inferior cerebellar artery, vertebral artery, anterior spinal artery

Question 23

What are some of the general signs and symptoms of a brain stem stroke?

Answer 23

Cranial nerve disturbance (visual disturbance, vertigo, dysphagia, facial numbness, etc.), hemiparesis, hemi or bilateral sensory loss, ataxia

Question 24

What are signs/symptoms of a stroke/lesion to the medial midbrain at the superior-colliculus level of the brainstem?

Answer 24

ipsilateral CNIII dysfunction (ptosis, dilated pupil, eye turned down/out), contralateral hemiparesis, contralateral lower face weakness due to damage to CNVII fibres of the corticobulbar tract.

Question 25

What are signs/symptoms of a stroke/lesion to the medial midbrain at the superior-colliculus level of the brainstem?

Answer 25

ipsilateral CNIII dysfunction (ptosis, dilated pupil, eye turned down/out), contralateral hemiparesis, contralateral lower face weakness due to damage to CNVII fibres of the corticobulbar tract.

Question 26

What are signs/symptoms of a stroke/lesion to the lateral midbrain at the superior-colliculus level of the brainstem?

Answer 26

contralateral hemiparesis, loss of contralateral discriminative sensation (medial leminscus), loss of contralateral pain/temperature (spinothalamic tract), loss contralateral VTTT sensory modalities to the face

Question 27

What are signs/symptoms of a stroke/lesion to the medial zone of the mid pons of the brainstem?

Answer 27

contralateral hemiparesis, loss of contralateral discriminative sensation and pain/temperature, loss of contralateral VTTT pain/temperature facial sensation

Question 28

What are signs/symptoms of a stroke/lesion to the lateral zone of the mid pons of the of the brainstem?

Answer 28

contralateral pain/temperature sensory loss, ipsilateral ataxia, ispilateral CNV palsy (paralysis of muscles of mastication), ipsilateral CNV sensory loss

Question 29

What are signs/symptoms of a stroke/lesion to the medial zone of the caudal pons of the brainstem?

Answer 29

contralateral hemiparesis, contralateral discriminative sensation loss, contralateral pain/temperature sensory loss, contralateral VTTT pain/temperature sensory loss to the face, ipsilateral CNVI damage (medially deviating eyes), ipsilateral CNVII palsy (paralysis of muscles of facial expression)

Question 30

What are signs/symptoms of a stroke/lesion to the medial zone of the caudal pons of the brainstem?

Answer 30

contralateral hemiparesis, contralateral discriminative sensation loss, contralateral pain/temperature sensory loss, contralateral VTTT pain/temperature sensory loss to the face, ipsilateral CNVI damage (medially deviating eyes), ipsilateral CNVII palsy (paralysis of muscles of facial expression)

Question 31

What are signs/symptoms of a stroke/lesion to the medial medulla of the brainstem?

Answer 31

contralateral hemiparesis, contralateral discriminative sensation loss, ipsilateral CNXII palsy (deviating tongue)

Question 32

What are signs/symptoms of a stroke/lesion to the lateral medulla of the brainstem?

Answer 32

contralateral pain-temperature sensory loss, ipsilateral spinal trigeminal tract damage (Loss of pain/temperature to the face), ipsilateral nucleus ambiguus damage (CNIX, X, XI signs), cerebellar dysfunction, ipsilateral vestibular nucleus dysfunction (vertigo, nausea, nystagmus)

Question 33

What vessel is occluded in a lesion of the medial zone of the midbrain at the level of the superior colliculus?

Answer 33

Posterior cerebral artery (medial branch)

Question 34

What vessel is occluded in a lesion of the later zone of the midbrain at the level of the superior colliculus?

Answer 34

Posterior cerebral artery, lateral branch

Question 35

What vessel is occluded in a lesion of the medial zone of the mid pons?

Answer 35

Medial pontine artery

Question 36

What vessel is occluded in a lesion of the lateral zone of the mid pons?

Answer 36

Anterior inferior cerebellar artery

Question 37

What vessel is occluded in a lesion of the caudal pons?

Answer 37

Medial pontine artery

Question 38

What vessel is occluded in a lesion of the medial medulla?

Answer 38

Anterior spinal artery

Question 39

What vessel is occluded in a lesion of the lateral medulla?

Answer 39

PICA (posterior inferior cerebellar artery)