Effects of Strokes and Brain Stem Lesions EC

Question 1

Contralateral hemiparesis of the lower limbs and decreased contralateral proprioception. Tongue deviates ipsilaterally.

What artery was occluded? What tracts were lesioned?

Answer 1

Anterior spinal artery occlusion (medial medullary syndrome)

Lesioned:
Lateral corticospinal tract (hemiparesis)
Medial lemniscus (proprioception)
Hypoglossal nerve (ipsilateral tongue deviation)

Question 2

Vomiting, vertigo, nystagmus.
Decreased pain and temperature sensation to contralateral limbs and ipsilateral face.
Dysphagia/hoarseness, decreased gag reflex
Ipsilateral Horner’s, ataxia, dysmetria.

What artery was occluded? What tracts were lesioned?

Answer 2

PICA (Lateral medullary syndrome)

Vestibular nuclei (nystagmus, vomiting, vertigo
Spinothalamic tract (contralateral p/t from body)
Spinal trigeminal (ipsilateral p/t from face) 
Nucleus ambiguus (dysphagia, hoarseness, decreased gag reflex)
Sympathetic tract (ipsilateral Horner's)
Inferior cerebellar peduncle (ataxia, dysmetria)

Question 3

Contralateral spastic hemiparesis.
Contralateral loss of tactile sensation in trunk and extremities
Ipsilateral eye turned in.

What artery was occluded? What tracts were lesioned?

Answer 3

Paramedian branches of basilar artery (medial inferior pontine syndrome)

Corticospinal tract (contralateral hemiparesis)
Medial lemniscus (contralateral tactile sensation)
Abducent nerve roots (ipsilateral lateral rectus paralysis)

Question 4

Vomiting, vertigo, nystagmus.
Ipsilateral paralysis of face, decreased lacrimation/salivation, decreased taste from anterior 2/3 of tongue, decreased corneal reflex.
Decreased p/t in face, ipsilateral hearing loss and Horner’s.
Ataxia and dysmetria

What artery was occluded? What tracts were lesioned?

Answer 4

AICA (Lateral Pontine Syndrome)

Lateral pons:
Cranial nerve nuclei (ipsilateral facial paralysis, ant. 2/3 tongue loss of taste, loss of salivation/lacrimation, loss of corneal and stapedial reflexes)
Cochlear nuclei (ipsilateral deafness)
Vestibular nuclei (vomiting, vertigo, nystagmus)
Sympathetic fibers (Horner’s)
Middle/Inferior cerebellar peduncles (ataxia, dysmetria)

Question 5

Upon left gaze, impaired adduction in right eye and nystagmus in left eye.

Answer 5

Internuclear ophthalmoplegia (MLF syndrome)

Lesion to right MLF (demyelination in MS)

When looking left, the left nucleus of CN VI fires which contracts the left lateral rectus and stimulates the contralateral nucleus of CN III via the right MLF to contract the right medial rectus (cannot contract R medial rectus if MLF lesioned)

Question 6

Contralateral hemianopia with macular sparing

Answer 6

PCA occlusion

Occipital/visual cortex infarcted.

Question 7

Visual defects due to aneurysm

Artery affected

Answer 7

Anterior communicating artery (Berry aneurysm)

Question 8

Eye down and out with ptosis and pupil dilation due to aneurysm

Artery affected

Answer 8

Posterior communicating artery (berry aneurysm)

Aneurism results in CN III palsy

Question 9

Contralateral paralysis of upper limb and face
Contralateral loss of sensation of upper limb and face
Aphasia if dominant hemisphere/Hemineglect if nondominant

Artery affected and areas affected

Answer 9

MCA occlusion

Motor cortex - upper limb and face (contralateral paralysis)
Sensory cortex-upper limb and face (contralateral loss)
Temporal lobe-Aphasia if dominant, hemineglect if nondominant

Question 10

Contralateral paralysis of lower limb
Contralateral loss of sensation of lower limb

Artery and areas of brain affected

Answer 10

ACA occlusion

Motor cortex-lower limb (contralateral paralysis)
Sensory cortex-lower limb (contralateral loss of sensation)

Question 11

Contralateral hemiparesis/hemiplegia

Artery and areas affected

Answer 11

Lateral striate artery (lacunar infarcts due to hypertension)

Striatum and internal capsule damaged

Question 12

Paralysis of upward gaze, pupil disturbances, absence of convergence.

Answer 12

Lesion in superior colliculi (ie pinealoma)

Parinaud syndrome