Neuro 14-Brainstem Iii

Front 1

what part of the brainstem are the superior and inferior colliculi found in?

Back 1

midbrain

Front 2

what nuclei are found in the superior colliculi?

Back 2

oculomotor and red nuclei

Front 3

what nuclei are found in the inferior colliculi?

Back 3

trochlear nuclei

Front 4

all visceral afferents travel to which nucleus?

Back 4

nucleus solitarius

Front 5

what is the usual cause of locked-in syndrome?

Back 5

infarct in the ventral pons affecting the bilateral corticospinal and corticobulbar tracts

Front 6

what controls alertness?

Back 6

pontomesencephalic reticular formation, thalamus, and the cortex

Front 7

what controls attention?

Back 7

pontomesencephalic reticular formation, thalamus, and the frontoparietal association cortex

Front 8

where do lesions cause coma?

Back 8

bilateral pontomesencephalic reticular formation, bilateral DIFFUSE regions of the cortex, and bilateral thalami

Front 9

what are the main functions of ACh in the CNS?

Back 9

alertness, memory, learning

Front 10

where are the ACh cell bodies found?

Back 10

basal forebrain and pontomesencephalic region

Front 11

what would pharmacological blockade of central cholinergic transmission cause?

Back 11

delirium

Front 12

what are the main functions of dopamine in the CNS?

Back 12

movements, initiative, working memory

Front 13

where are the dopamine cell bodies found?

Back 13

midbrain: substantia nigra pars compacta and ventral tegmental area

Front 14

what does the dopamine pathway project to?

Back 14

striatum, limbic cortex, amygdala, nucleus accumbens, prefrontal cortex

Front 15

what would a lesion to the mesostriatal pathway cause?

Back 15

movement disorders such as Parkinson's

Front 16

what would overactivity of the mesolimbic pathway cause?

Back 16

positive symptoms of schizophrenia such as hallucinations

Front 17

what are the main functions of NE in the CNS?

Back 17

attention and mood elevation

Front 18

where are the NE cell bodies found?

Back 18

pons: locus ceruleus and lateral tegmental area

Front 19

what are the main functions of serotonin in the CNS?

Back 19

mood elevation

Front 20

where are the serotonin cell bodies found?

Back 20

raphe nuclei of the midbrain, pons, and medulla

Front 21

what are the projections of the caudal raphe nuclei to the spinal cord and medulla involved in?

Back 21

pain modulation

Front 22

where are the histamine cell bodies found?

Back 22

hypothalamus in the tuberomammillary nucleus

Front 23

what are the main functions of histamine in the CNS?

Back 23

alertness

Front 24

what regions are important for promoting nonREM sleep?

Back 24

medulla, anterior hypothalamus, and basal forebrain

Front 25

describe the process of nonREM sleep

Back 25

GABAergic neurons in the ant. hypothalamus inhibit histaminergic neurons in the post. hypothalamus preventing activation in the forebrain; also inhibits ACh in the brainstem, which leads to a further reduction in arousal

Front 26

where are the nonREM-on cells?

Back 26

anterior hypothalamus

Front 27

where are the REM-on cells?

Back 27

pontine reticular formation

Front 28

describe the process of REM sleep

Back 28

GABAergic REM-on cells inhibit NE and serotonin (5-HT)

Front 29

narcolepsy

Back 29

abnormal tendency to easily enter REM sleep directly from the waking state

Front 30

what is the cause of narcolepsy?

Back 30

deficiency of hypocretins arising from cells in the lateral hypothalamus

Front 31

what is the difference b/w coma and persistent vegetative state?

Back 31

both have brainstem reflexes, but sleep-wake cycles occur in the persistent vegetative state

Front 32

how can you distinguish akinetic mutism from PVS?

Back 32

in akinetic mutism, pt. can visually track the examiner

Front 33

abulia

Back 33

patients sit passively but may occasionally respond to questions or commands after a long delay

Front 34

what is the cause of akinetic mutism, abulia, and catatonia?

Back 34

dysfunction of circuits involving the frontal lobes, diencephalon (thalami), and ascending dopaminergic projections

Front 35

what should be given immediately to a pt. in a coma?

Back 35

IV thiamine, dextrose, and naloxone because thiamine deficiency, hypoglycemia, and opiate overdose are readily treatable causes of coma

Front 36

What is usually the cause of coma in a pt. with normal reactive pupils?

Back 36

toxic or metabolic

Front 37

What is the cause of coma in a pt. with unilateral or bilateral dilated, unresponsive pupils?

Back 37

midbrain compression or transtentorial herniation

Front 38

What is the cause of coma in a pt. with bilateral small, but responsive pupils?

Back 38

pontine lesion

Front 39

What is the cause of coma in a pt. with bilateral pinpoint pupils?

Back 39

opiate overdose

Front 40

where are respiratory rhythms controlled?

Back 40

medulla

Front 41

where do the chemoreceptors for blood oxygen and pH project?

Back 41

cardiorespiratory portion of nucleus solitarius

Front 42

where is the pacemaker for respiration located?

Back 42

pre-Botzinger complex in medulla

Front 43

where would a lesion cause apneustic respiration?

Back 43

rostral pons; pt. has brief 2-3 second pauses at full inspiration

Front 44

coughing, hiccuping, sneezing, yawning, shivering, gagging, vomiting, swallowing, laughing, and crying are dependent on

Back 44

circuits in pontomedullary reticular formation

Front 45

where is the chemotactic trigger zone?

Back 45

area postrema, located along the caudal wall of the 4th ventricle in the medulla

Front 46

what is significant about the chemotactic trigger zone?

Back 46

blood-brain barrier is incomplete; toxins can trigger nausea and vomiting

Front 47

what does the PICA supply?

Back 47

lateral medulla and inferior cerebellum

Front 48

the PICA arises from

Back 48

vertebral a.

Front 49

the AICA arises from

Back 49

basilar a.

Front 50

what does the AICA supply?

Back 50

lateral caudal pons

Front 51

what arteries does CN III pass b/w?

Back 51

SCA and PCA

Front 52

the medial medulla is supplied by

Back 52

paramedian branches of vertebral a. (rostrally) and paramedian branches of anterior spinal a. (caudally)

Front 53

the midbrain is supplied by

Back 53

PCA

Front 54

what are signs of midbrain dysfunction?

Back 54

CN III palsy, unilateral or bilateral pupil dilation ataxia, flexor posturing, and impaired consciousness

Front 55

what are signs of pontine dysfunction?

Back 55

bilateral Babinski's signs, generalized weakness, perioral numbness, pins and needles facial tingling, apneustic respirations, ocular bobbing, shivering, palatal myoclonus, abducens palsy, small but reactive pupils, extensor posturing

Front 56

what are signs of medullary dysfunction?

Back 56

vertigo, ataxia, nystagmus, nausea, vomiting, respiratory arrest, autonomic instability, and hiccups

Front 57

what ischemic structures would cause dysarthria or dysphagia?

Back 57

corticobulbar pathways or brainstem CN nuclei

Front 58

what ischemic structures would cause somnolence (drowsiness)?

Back 58

pontomesencephalic reticular formation or bilateral thalami

Front 59

what ischemic structures would cause an occipital HA?

Back 59

posterior fossa meninges and vessels (CN X and cervical roots)

Front 60

what ischemic structures would cause a frontal HA?

Back 60

supratentorial meninges and vessels (CN V; PCA is often CN V1)

Front 61

what ischemic structures would cause a nonlocalized HA?

Back 61

supra and/or infratentorial meninges and vessels

Front 62

what are the clinical features of medial medullary syndrome?

Back 62

contralateral arm or leg weakness, contralateral decreased position and vibration sense, ipsilateral tongue weakness

Front 63

what supplies the medial medulla?

Back 63

paramedian branches of vertebral and anterior spinal arteries

Front 64

what is the most common cause of lateral medullary syndrome?

Back 64

vertebral thrombosis

Front 65

what causes ipsilateral ataxia in lateral medullary syndrome?

Back 65

infarction of the inferior cerebellar peduncle

Front 66

what is the cause of vertigo in lateral medullary syndrome?

Back 66

infarction of the vestibular nuclei

Front 67

what causes ipsilateral facial decreased pain and temp. sense in lateral medullary syndrome?

Back 67

trigeminal nucleus and tract

Front 68

what causes ipsilateral Horner's syndrome in lateral medullary syndrome?

Back 68

descending sympathetic fibers, which run in the lateral tegmentum

Front 69

what causes hoarseness and dysphagia in lateral medullary syndrome?

Back 69

infarction of nucleus ambiguus and CN X

Front 70

what causes ipsilateral decreased taste in lateral medullary syndrome?

Back 70

nucleus solitarius

Front 71

what is the usual cause of unilateral paramedian pontine infarcts?

Back 71

lacunar infarcts resulting from small-vessel lipohyalinosis in the setting of chronic HTN; basilar stenosis may also be a cause

Front 72

what causes dysarthria hemiparesis?

Back 72

lacunar infarct of the posterior limb of the internal capsule

Front 73

Infarction of what arteries cause midbrain syndromes?

Back 73

branches of PCA and top of basilar a.

Front 74

where would an infarct cause somnolence, delirium, or vivid visual hallucinations?

Back 74

midbrain reticular formation