Brainstem Disorders

Question 1

what is involved in a MEDIAL BS lesion?

Answer 1

motor tracts

MLF

medial lemniscus

motor nuclei (divide into 12)
- CN 3, 4, 6, 12

Question 2

what is involved in a LATERAL (side) BS lesion?

Answer 2

sympathetic (hypothalamospinal) tract -Horner’s syndrome

spinothalamic tract

spinocerebellar tract

sensory nuclei (don’t divide into 12)
- CN 5, 7, 8, 9, 10

Question 3

if there is a lesion to the lateral corticospinal tract or DCML above the caudal medulla, where is the loss? why?

Answer 3

contralateral signs bc the damage is after the decussation

Question 4

if there is a lesion to the lateral cortiocospinal tract or DCML below the caudal medulla, where is the loss? why?

Answer 4

ipsilateral signs bc the damage is b4 the decussation

Question 5

if there is any BS damage to the spinothalamic tract, where is the loss? why?

Answer 5

contralateral signs bc of the immediate decussation so damage is after decussation

Question 6

if there is a lesion of the L rostral anteromedial medulla, what is the loss?

Answer 6

paresis of the R hand and foot

loss of light touch and proprioception on the R side of the body

paresis on the L side of the tongue

Question 7

how do you differentiate the involvement of the motor tract or the motor cranial neurons?

Answer 7

ask the pt to close their eyes

hypertonicity vs hypotonicity

Question 8

what supplies blood to the midbrain?

Answer 8

posterior cerebral artery

basilar artery

Question 9

what supplies blood to the pons?

Answer 9

anterior inferior cerebellar artery (AICA)

basilar artery

Question 10

what supplies blood to the medulla?

Answer 10

posterior inferior cerebellar artery (PICA)

vertebral artery

anterior spinal artery

Question 11

what are the cardinal signs of BS dysfxn? (KNOW THIS)

Answer 11

the 4 Ds:
1) dysphagia
2) dysarthria
3) diploplia
4) dysmetria

disorders of vital fxns

disorders of consciousness

Question 12

why does BS dysfxn cause dysphagia and dysarthria?

Answer 12

the CNs are in the pons and medulla of the BS

Question 13

why does BS dysfxn lead to diploplia?

Answer 13

CN 3, 4, 6 control eye movement and they are in the BS

Question 14

damage to what structure in the BS can cause disorders of consciousness?

Answer 14

reticular formation

Question 15

what is vertebrobasilar artery insufficiency?

Answer 15

causes transient symptoms of BS ischemia reproduced with cervical extension and rotation

Question 16

vertebrobasilar artery insufficiency is characterized by poor blood flow to what part of the brain?

Answer 16

the posterior brain

Question 17

what are the symptoms associated with BS ischemia?

Answer 17

abrupt onset of neurologic symptoms (dizziness, weakness, incoordination, and somatosensory dysfxn)

sustained ischemia=Wallenberg syndrome, loss of consciousness

Question 18

what is the most common BS stroke?

Answer 18

Wallenburg syndrome

lateral medullary lesion

Question 19

what is Wallenburg syndrome?

Answer 19

a LATERAL medullary lesion

PICA affected

very parasympathetic

spinal trigeminal tract: loss of nociception and temp from the ipsilateral face

spinothalamic tract: loss of nociception and temp from contralateral body

spinocerebellar tract: ipsilateral ataxia

descending sympathetic tract: ipsilateral Horner’s syndrome

Question 20

does Wallenburg have contra or ipsi s/s?

Answer 20

both

Question 21

what CNs are involved in Wallenburg syndrome?

Answer 21

5, 7, 8, 9, 10, 12

Question 22

what are the CN s/s associated with Wallenburg syndrome?

Answer 22

vertigo, nystagmus, problems swallowing and speaking, hoarse voice, digestion issues, inability to slow the HR

Question 23

what CNs are involved in AICA syndrome?

Answer 23

5, 7, 8

Question 25

what is AICA syndrome

Answer 25

lateral caudal pons lesion AICA affected spinal trigeminal tract: loss of nociception and temp from the ipsilateral face spinothalamic tract: loss of nociception and temp from contralateral body spinocerebellar tract: ipsilateral ataxia descending sympathetic tract: ipsilateral Horner's syndrome

Question 26

what is the 2nd most common BS stroke?

Answer 26

lateral caudal pons lesion

Question 27

are the s/s of AICA syndrome ipsi or contra?

Answer 27

both

Question 28

what are the CN s/s associated with AICA syndrome?

Answer 28

loss of efferent limb of corneal reflex and stapedius reflex (sounds are louder), lack of tears and salivation, unilateral deafness, vertigo, nystagmus, nausea, vomiting

Question 29

what is an anteromedial midbrain stroke?

Answer 29

the most common midbrain stroke involved the basilar artery contra signs (except CN 3) med lemniscus: contra loss of sensation red nucleus: motor dysfxn obscured by ataxia; pathologic laughing/crying motor tracts (corticopontine): contra cerebellar ataxia; (corticospinal and corticobrainstem): contra paresis of the body and lower face MLF: internuclear opthalmoplegia obscured by CN 3 lesion

Question 30

what is internuclear opthalmoplegia?

Answer 30

damaged connection bw CN 6 and 3

Question 31

what CNs are involved in anteromedial midbrain stroke?

Answer 31

3

Question 32

what are the CN signs associated with an anteromedial midbrain stroke?

Answer 32

pupil dilation from lack of pupillary sphincter innervation inability to focus on near objects unable to move eye up, down, or in double vision

Question 33

what structures may be involved in disorders of consciousness?

Answer 33

cerebrum (thalamic or hypothalamic) and BS (reticular formation)

Question 34

what is a coma?

Answer 34

unarousable state no response to strong stim lost vital fxns (vent is necessary)

Question 35

what is a vegetative state?

Answer 35

cycle of sleeping and waking (can yawn and vocalize) unresponsive wakeful state complete loss of consciousness w/o alteration of vital fxns (don't need a vent)

Question 36

what is a minimally conscious state?

Answer 36

respond to very painful stim and follow very easy instructions some signs of consciousness in and out of consciousness

Question 37

tumors in the cerebellum or BS cause an increase in what?

Answer 37

intracranial pressure

Question 38

what are the symptoms associated with increased ICP?

Answer 38

headache, nausea, vomiting, CN dysfxn, and/or hydrocephalus possible ataxia

Question 39

what is the most common BS tumor?

Answer 39

acoustic neuroma

Question 40

what is an acoustic neuroma?

Answer 40

a benign tumor of the Schwann cells surrounding CN 8 unilateral vestibular lesion