Neuro 2

Question 1

what is Huntington’s disease

Answer 1

autosomal dominant neurodegenerative disorder characterized by involuntary choreatic movements with cognitive and behavioral disturbances

Question 2

pathophys of Huntington disease

Answer 2

CAG repeats on chromosome 4

Question 3

when do sx usually begin for huntington

Answer 3

30-50

Question 4

sx huntington

Answer 4

3 hallmarks - mood, movement, memory - behavioral and mood changes, chorea (rapid involuntary movements), dementia

chorea - face, neck, trunk, limbs - may disappear during sleep and worse with stress and voluntary movements

Question 5

PE huntington

Answer 5

restlessness, fragility
quick, involuntary hand movements
brisk DTR

Question 6

dx huntington

Answer 6

clinical sx + FHx + genetic confirmation

CT or MRI - cerebral and striata (caudate nucleus and putamen) atrophy with subsequent widening in the frontal horns of the lateral ventricle (boxcar ventricle sign)

Question 7

tx huntington

Answer 7

no cure - usually fatal within 15-20 years after presentation

tetrabenazine for dyskinesia or chorea

antidopaminergics - typical and atypical antipsychotics

benzos intermittently may help w chorea and sleep, esp during stressful situations

Question 8

what is essential tremor

Answer 8

autosomal dominant disorder
incidence increases w age

Question 9

sx essential tremor

Answer 9

intuitional tremor - postural b/l action tremor most commonly affecting the upper extremities and head (hands, forearms, head, neck, voice)

tremor worsened with action and intentional movement, postural - holding affected body part against gravity, adrenergic activity - stress, anxiety

tremor improved with alcohol ingestion, when body part is supported, at rest

Question 10

PE essential tremor

Answer 10

more pronounced with arms suspended against gravity in a fixed posture

during goal-directed activity (finger to nose testing) the tremor increases at the end of approaching the target or holding a position against gravity

may see cogwheel phenomenon

Question 11

dx essential tremor

Answer 11

dx of exclusion based on history, FHx, physical exam

Question 12

tx essential tremor

Answer 12

no needed if mild

first line - propranolol - first line - or primidone (barb) if no relief w propranolol

Question 13

parkinson disease

Answer 13

neurodegenerative movement disorder due to decreased dopamine resulting from idiopathic loss of dopaminergic neurons in the striatum and substantia nigra and the presence of Lewy bodies

Question 14

pathophys Parkinson

Answer 14

decreased dopamine –> imbalance of dopamine and acetylcholine –> improper movement due to failure of acetylcholine inhibition in basal ganglia

eosinophilic cytoplasmic inclusions (Lewy bodies) and loss of pigment cells in substantia nigra

Question 15

sx parkinson

Answer 15

motor triad - -resting tremor, bradykinesia, muscle rigidity

resting tremor - pill-rolling; worse at rest, emotional stress, excitement, walking; better with voluntary activity, intentional movement, sleep

cogwheel rigidity

postural instability - stooped posture and loss of postural reflexes

loss of smell (anosmia), mood disorders (depression), constipation, excess salivation or drooling (sialorrhea), sleep dysfunction

Question 16

PE parkinson

Answer 16

normal DTRs
no weakness
face involvement - fixed facial expression
myerson’s sign - tapping bridge of nose causes a sustained blink
postural instability - pull test - standing behind patient and pulling the shoulders causes the patient to fall or take steps backwards

Question 17

tx parkinson

Answer 17

levodopa-carbidopa - most effective

dopamine agonists - bromocriptine, pramipexole, ropinirole); can be used to delay use of levodopa in younger patients

Question 18

Guillain barre

Answer 18

group of conditions due to acquired autoimmune-mediated demyelinating polyradiculopathy of the peripheral NS characterized by rapidly evolving muscular weakness

Question 19

most common cause of Guillain barre

Answer 19

campylobacter jejune MC
other antecedent GI or respiratory infections - influenza A and B

Question 20

pathophys Guillain barre

Answer 20

molecular mimicry –> autoantibodies attack schwwann cells

Question 21

sx Guillain barre

Answer 21

symmetric, ascending, progressive, flaccid muscle weakness and sensory changes (paresthesias, pain)

cranial nerve and bulbar sx - cranial nerves 3, 4, 6

weakness of respiratory muscles

sensory involvement - paresthesias, pain, cramps

Question 22

PE Guillain barre

Answer 22

LMN signs - decreased DTR

sensory deficits and cranial nerve palsies (3, 4, 6)

autonomic dysfunction - tachycardia, arrhythmias, hypotension, HTN, breathing difficulties

Question 23

dx Guillain barre

Answer 23

electrophysiologic studies - decreased motor nerve conduction velocities and amplitude

CSF analysis - high protein with normal WBC

autoantibodies - anti-GM1, anti-GD1A, anti-GT1A, anti-GQ1B

PFTs - decreased peak inspiratory pressure and forced vital capacity

Question 24

tx Guillain barre

Answer 24

plasmphaeresis or IVIG first line for antibody removal

prednisone not indicated

Question 25

what is myasthenia gravis

Answer 25

autoimmune peripheral nerve disorder of the neuromuscular junction due to autoantibodies against the acetylcholine receptor on the muscles --> weakness

Question 26

epidemiology myasthenia gravis what other abnormality is strongly associated with myasthenia gravis

Answer 26

bimodal distribution - most common in young women < 40 and men > 50 strong associated w an abnormal thymus gland (hyperplasia or thymoma)

Question 27

what type of hypersensitivity rxn is myasthenia gravis

Answer 27

type 2 - autoantibodies against acetylcholine (nicotinic) postsynaptic receptor at the neuromuscular junction

Question 28

sx myasthenia gravis sensation and DTR?

Answer 28

ocular weakness and generalized weakness worsened with repeated use diploma and ptosis; pupils are spared fluctuating skeletal muscle weakness worsened with repeated muscle use throughout the day, often with true muscle fatigue bulbar weakness - weakness w prolonged chewing, dysphagia, dysphonia, dysarthria respiratory muscle weakness may lead to respiratory failure - myasthenic crisis sensation and DTR preserved bedside ice pack test - can be used if ptosis, but not helpful w extra ocular muscle weakness; application of ice for 10 minutes improves ocular sx of MG

Question 29

dx myasthenia gravis

Answer 29

serologic antibody testing - acetylcholine receptor antibodies - initial test of choice - AChR-Ab positive MuSK antibodies obtained if ACR antibodies negative anti-striated muscle antibodies - usual marker for thymoma in early onset MG electrophysiology testing - repetitive nerve stimulation and single finger electromyography are most accurate tests - repetitive nerve stimulation - decrement is > 10% chest imaging - in all patients w MG to detect thymus gland abnormalities

Question 30

tx myasthenia gravis

Answer 30

myasthenic crisis/severe - plasmapheresis or IV immunoglobulin long term - acetylcholinesterase inhibitors (pyridostigmine or neostigmine); glucocorticoid as alternative thymectomy - even if thymus gland is normal can improve sx and removes source of antibodies; useful if no improvement with medical management

Question 31

what meds should ppl w myasthenia gravis avoid

Answer 31

BB aminoglycosides fluoroquinolones

Question 32

what is multiple sclerosis

Answer 32

autoimmune, inflammatory demyelinating disease of the CNS with axon degeneration of white matter (brain and spinal cord)

Question 33

who does MS most commonly affect

Answer 33

women and young adults 20-40

Question 34

3 main types of MS

Answer 34

relapsing-remitting MC - episodic exacerbations progressive disease - progressive decline without acute exacerbations secondary progressive - relapsing-remitting pattern that becomes progressive

Question 35

sx MS

Answer 35

sensory disturbances followed by weakness and visual disturbances (diplopia, optic neuritis) trigeminal neuralgia uhthoff's phenomenon - worsening sx w heat may have bowel or bladder dysfunction

Question 36

PE MS

Answer 36

UMN signs - spasticity, upward babinksi, hyperreflexia lhermittes sign - neck flexion causes lightening shock type pain radiating from spine down the leg Marcus-gunn pupil - during swinging-flashlight test from the unaffected eye into the affected eye, the pupils appear to dilate internuclear ophthalmoplegia - inability to adduct the eye not he side of the lesion w nystagmus on the other cerebellar - Charcot's neurologic triad - nystagmus, staccato speech, intentional tremor bladder, bowel, or sexual dysfunction

Question 37

dx multiple sclerosis

Answer 37

at least 2 distinct episodes of CNS deficits MRI with gadolinium - best initial and most accurate - hyper intense white matter plaques; at least 2 ares of white matter involvement LP if MRI negative - increased IgG and oligoclonal bands

Question 38

tx multiple sclerosis

Answer 38

IV high dose glucocorticoids for acute exacerbation prevention of relapse and progression - beta interferon or glatiramer