Neuro 2 (Brainstem, PNS) Flashcards Preview

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Flashcards in Neuro 2 (Brainstem, PNS) Deck (120):
1

C1 dermatome

hairline

2

T4 dermatome

nipple line (male)

3

T10 dermatome

umbilicus

4

L1 dermatome

inguinal ligament

5

S1 dermatome

sole of foot

6

S4/5 dermatome

perianal

7

large cells/axons mediate

vibration and joint position sense

8

small cells/axons mediate

pain and temperature sensation

9

monomelic amyotrophy

Wasting in myotome
Self-limited
Electromyographic exam
May see MRI T2 signal

10

location of C6 root

between C5, C6

11

location of C8 root

between C7, T1

12

location of L4 root

between L4, L5

13

central protrusion in lumbar cord

affect descending root

14

lateral protrusion in lumbar cord

affects lateral roots

15

how to know it's a radiculopathy?

Sensory and motor symptoms and signs in same dermatome and myotome

16

C5 radiculopathy = weakness in

Deltoid (C5, axillary)
Biceps (C5, musculocutaneous)
Infraspinatus (C5, suprascapular)
Rhomboid (C5, dorsal scapular)

17

Erb's Palsy

upper plexus injury
Stretch upper roots (C5, C6)
Waiter's tip
Musculocutaneous out

18

Klumpke's Palsy

lower plexus traction injury
Pulling arm away from neck
Or nursemaid's injury
Extensors out

19

How to know it's a plexus injury

® Clinical-sensory, and motor deficits which do not fit a particular dermatoma/myotomal distribution or single nerve distribution
associated pain
usually unilateral

20

Parsonage Turner syndrome

□ Hereditary neuralgic amyotrophy
® Males>>Females
® SEPT9 gene on chromosome 17w
® Septins are involved in formation of cytoskeleton
® Recurrent
Episide precipitated by physical activity

21

neuropraxia

temporary loss of motor and sensory function due to blockage of nerve conduction- focal demyelination

22

axonotmesis

disruption of axon w/ little disruption of CT

23

neurotmesis

disruption of axon and CT

24

Wallerian degeneration

degeneration of axon from distal to proximal. Associated w/ metabolic insufficiency

25

How to know it’s a mononeuropathy?

Sensory and motor symptoms and signs confined to distribution of one nerve

26

most common cause of polyneuropathy in US

diabetes

27

classification of polyneuropathy

vascular
infectious
neoplastic
degenerative
inflammatory
congenital
autoimmune
trauma/toxins
endocrine
something else

28

how do we know it is a polyneuropathy?

Symptoms and signs in multiple nerves

Early neuropathy may not yet show motor or autonomic sxs

Symptoms and signs are length dependent, distal, symmetrical, dying back over time

29

Guillain-Barre syndrome (AIDP)

Bystander mechanism- antibody made against something else cross-reacts w/ myelin
Autoimmune process
Ascending weakness
Attacking the myelin- inflammatory mediators, damage the axon itself

30

Miller Fisher Variant

5% of GBC
Descending paralysis w/ triad: opthalmoplegia, ataxia (gait/trunk), areflexia
Anti GQ1B Ab in 85-90%
Tx: IVIg, PEx

31

Bickerstaff's Encephalitis

Ataxia, cranial neuropathy, opthalmoplegia, altered mental status, hyperreflexia/Babinski
Anti-GQ1B Ab in 66%
Tx w/ steroids, IVIg, PEx

32

asymmetric polyneuropathy

demyelinating mononeuritis

multifocal motor neuropathy
small fiber neuropathy

33

Slow motor unit

Smaller forces
Maintain composure longer- resistant to fatigue due to subcellular anatomy
Important for posture, maintaining position

34

fast fatigable motor unit

Larger forces
Less myoglobin, fatigue easier
i.e. sympathetic response, standing jump (brief large forces)

35

fast fatigue resistant

Intermediate
Good for transition movements

36

2 ways to increase force (motor recruitment)

Enlist more friends --> increase number of motor units firing

Tell your friends to work harder --> increased firing frequency

37

Hallmarks of ALS Diagnosis

Combination of UMN and LMN signs
Can occur in 4 body regions: bulbar, cervical, thoracic, lumbosacral
Research requires 3/4 areas- may delay diagnosis and treatment
Rule out potentially treatable conditions mimicking this disorder

38

Upper motor neuron signs

Hyperreflexia
□ clonus
Spascicity
Upgoing toes (plantar extensor response)

39

Lower motor neuron signs

Weakness
Muscle atrophy
Fasciculations
Decreased/absent reflexes

40

Important negatives of ALS

Sensory systems in tact
Bowel/bladder dysfunction is spared
Ocular motor problems not effected

41

Poliomyelitis

□ Caused by RNA enterovirus
□ Eventually spreads to alpha motor neurons in spinal cord and brain stem
□ Causes focal atrophy and LMN findings

42

Spinal muscular atrophy

Bucket of autosomal recessive disorders
Survival motor neuron gene- important for alpha motor neuron to live
Looks like a LMN disease
Wernbig-Hoffman disease- huge spectrum of disease

43

muscular dystrophy

disease in muscle membrane or supporting proteins
ongoing muscle degeneration and regeneration

44

Duchenne/Becker MD

x-linked: mytation in dystrophin gene
important for structural integrity of muscles
Duchenne (absent), Beckers (low levels)
eventually lose walking ability
pseudohypertrophy
Gower's sign

45

Myotonic dystrophy Type 1

most common in adults
trinucleotide repeat disease in myotonin protein kinase

46

symptoms of myotonic dystrophy

ptosis, cataracts at early age (slit lamp needed)
Weakness- distal muscles get weak first
hypogonadism (reduced testosterone, testicular atrophy), reduced GH, insulin resistance, frequent loss of pregnancy
Afib, tachyarrhythmia, ectopic beats and cardiomyopathy late
dysphagia, hypokinetic tract w/ pseudo-obstruction, constipation

47

Fascioscapulohumeral MD

face, shoulder, arm
Reduction or deletion of DNA sequence- thought to be activator
70-90% AD inheritance
Highly penetrant- 90% of patients w/ weakness by age 20 w/ sizable deletion

CK values normal (creatine kinase- enzyme in muscles)

48

Fascioscapulohumeral MD Symptoms

Facial weakness early
Horizontal smile, wide palpebral fissures, difficulty burying eyelids and pursing lips
Weakness in arms --> medical attention --> anterior axillary folds
Scapular winging
Triple hump sign- fierce atrophy of deltoid, but trapezius and biceps are in tact
Abdominal laxity
Asymmetry- sometimes.

49

C fibers

nociception
slow conduction velocity
not tested by EMG

50

When to order an EMG

Useful to exclude any peripheral cause of sensory or motor abnormalities on neurological exam when there is a diagnostic uncertainty

51

what is on an NCS report

amplitude
conduction
latency
duration

52

how to diagnose myopathy

EMG
sensory NCS is normal, as it conduction velocity and distal latency

53

target fibers

seen in chronic denervation

54

dysimmune/inflammatory myopathies

polymyositis
dermatomyositis
inclusion body myositis

55

polymyositis

Cell mediated
Adults 40-70 yo
Proximal, symmetrical weakness and myalgia evolving (several months)
Lymphocytes (CD8+ T cells): w/in fascicules, surround, invade, and destroy myofibers

56

dermatomyositis

Children and adults
Microvasculature
Association w/ malignancy
Proximal muscle weakness
Infiltrates B & CD 4+ T lymphocytes in interfascicular distribution
Heliotrope rash

57

inclusion body myositis

mostly men
Pathology: inflammation, rimmed vacuoles
Congo red positive inclusions:
No effective treatment

58

mitochondrial myopathies

ragged-red fiber

59

GSE

somites- efferent

60

GVE

sympathetic/parasympathetic

61

SVE

branchial motor- derived from pharyngeal arch muscles

62

GSA

sensation of external environment

63

GVA

sensation of internal environment
carotid bodies, feedback system.

64

SSA

vision
hearing
vestibular function

65

SVA

chemical transmission:
olfaction, taste

66

lesion on XII in cortex

contralateral tongue deviation

67

lesion on XII nucleus, fascicles, or nerve

ipslateral tongue deviation

68

lesion on XI in R cortex

L trapezius, R SCM weakness
head deviates toward the R

69

lesion on R XI nerve itself

R trapezius, R SCM weakness
if anything, deviation toward R

70

vagus nerve nuclei

Dorsal motor nucleus
Nucleus ambiguus
Solitary tract/nucleus
Spinal trigeminal nucleus

71

Dorsal motor nucleus

parasympathetic

72

Nucleus ambiguus

branchial motor supply (arch 4-6)

73

Solitary nucleus

visceral sensation, taste

74

Uvular deviation

deviates towards the good side (away from the lesion)

Dysphagia: cortical lesion
Focal swallowing dysfunction/hoarseness: nerve lesion

75

rostral part of nucleus solitarius

gustatory nucleus- taste

76

caudal part of nucleus solitarius

cardiorespiratory nucleus- chemo and baroreceptors

from aortic arch, cardiorespiratory system, digestive tract

77

big difference between IX and X

parasympathetics:
IX: from inferior salivatory nucleus to parotid gland. Sympathetics synapse in otic ganglion

78

area postrema

open BBB
center for vomiting, closely related to CN X

79

CN VIII- type of fibers

all SSA

80

pathway of sound

cochlear nuclei
decussation in trapezoid body
superior olivary nucleus
lateral lemniscus
inferior colliculus
medial geniculate body of thalamus
auditory cortex- frontal lobe

81

nuclei of facial nerve

spinal trigeminal
solitary nucleus
superior salivatory nucleus

82

VII: branchial motor

facial motor nucleus and nerve fascicle
to muscles of facial expression, posterior belly of digastric, stylohyoid, stapedius

83

upper face innervation

ipslateral and contralateral contribution

84

lower face innervation

only contralateral side

85

VII lesion in UMN

contralateral weakness of lower face only

86

VII lesion in LMN

all fibers to one side of face (upper and lower face)

87

VII parasympathetics

from superior salivatory nucleus
via greater petrosal nerve
synapse in sphenopalatine ganglion
all salivary glands except for parotid

88

IX parasympathetics

inferior salivatory nucleus

89

VII taste

nucleus solitarius (rostral)--> geniculate ganglion--> central tegmental tract --> thalamus --> insularr cortex -->...

90

VII GSA

cell bodies in geniculate ganglion

91

exit of CN VI

superior orbital fissure

92

does V have parasympathetics?

no, just motor and sensory

93

location of VI, 2, 3 cell bodies

trigeminal ganglion

94

V1 exit

superior orbital fissure

95

V2 exit

foramen rotundum

96

V3 exit

foramen ovale

does NOT pass through cavernous sinus

97

what is alone in the cavernous sinus?

VI

98

SVE of VII

to muscles of mastication, a nterior belly of digastric, tensor tympani, tensor velli palatini

99

lesion in V3

jaw deviation toward the weak side (due to pterygoids)

100

V for proprioception

GVA for fine touch- mesencephalic nucleus and tract

101

where is the cell body for V proprioceptive neurons?

mesencephalic nucleus

102

corneal reflex

in on V --> blinking VII

103

types of fibers in IV

GSE

104

parasympathetic nucleus for III

edinger-westphall

105

DRG history

Pain and numbness in dermatomal distribution
Decreased sensation in dermatomal distribution
Trouble with balance/coordination
No weakness- no motor

106

APD

○ Damage to the optic nerve or bad retinal disease
○ Not seen with cataracts, vitreous or corneal disease, refractive error
○ Not seen in functional (non-organic disease)

107

cocaine test

blocks reuptake of NE. Dilation is normal.

with Horner's syndrome, nothing happens.

108

apraclonidine

alpha adrenergic agonist
reversal of Horner's syndrome
denervation supersensitivity

109

Adie's Pupil

Occurs in young woman, benign, probably viral
Unlike pharm blockage, you constrict to near
Also reacts to dilute pilocarpine (1/8%) unlike the normal pupil
no response to light, but response to near
absent reflexes

110

binocular vision

sign of issue on efferent side, likely ocular misalignment

111

worse diplopia at a distance

VI

112

worse diplopia near

III, medial rectus

113

vertical diplopia

III, IV
myasthenia gravis
thyroid eye disease

114

benign positional vertigo

last less than a minute- positional

115

Meniere's disease

lasts hours usually with tinnitus (ringing noise) and hearing loss

116

Vestibular neuritis

inflammation of the inner ear- last days to weeks

117

Acoustic neuroma

evolves over weeks to months

118

pathologic nystagmus characteristics

amplitude greater than 4 degrees
asymmetry
commonly caused by drugs and anti-seizure meds
doesn't fatigue with prolonged gaze

119

peripheral nystagmus

beats in one direction regardless of gaze

120

central nystagmus

vertical component, direction changing