Peripheral nervous system Flashcards
What is Wallerian degeneration?
disintegration of axons distal to site of injury
What are some of the signs of a lower motor neuron process?
hypotonia, decreased reflexes, areas of numbness next ot normal areas, weak muscles next to strong muscles
What are signs of an upper motor neuron process?
spasticity, hyperreflexia, all muscles in an area are weak, drift
What are the causes of multiple mononeuropathies? (e.g. mononeuropathy multiplex?)
vasculitis
What antibodies are present during GBS?
anti-ganglioside antibodies
What are the typical symptoms of GBS?
rapidly evolving areflexic motor paralysis - tendon reflexes disappear after few days, bulbar muscle weakness, autonomic dysfunction
What is miller fischer syndrome?
variant of GBS with ataxia, areflexia, external opthalmoplegia
What level corresponds to the biceps reflex?
C5/6
What level corresponds to the brachoradialis reflex?
C6
What level corresponds to the triceps reflex?
C7
What level corresponds to the patellar reflex?
L3/L4
What level corresponds to the ankle jerk reflex?
S1
What nerves are test in hip flexion?
testing iliopsoas - L1-L3
What nerves are tested in knee extension?
quads - testing L3-L4
What nerves are tested in knee flexion?
hamstrings - testing L5-S2
What nerves are tested in leg abduction?
gluteus medius - testing superior gluteal nerve L4-S1
What nerves are tested in leg adduction?
obturators and adducturs - testing
What nerves are tested in toe dorsiflexion?
testing extensor hallicus longus - deep peroneal nerve = L5
What nerves are tested in foot dorsiflexion?
tibialis anterior - deep peroneal
What nerves are tested in foot plantar flexion?
gastroc - testing tibial nerve S1-S2
What nerves are tested in foot eversion?
superficial peroneal nerve - L5-S1
What nerves are tested in foot inversion?
tibialis posterior - tibial nerve L4-L5
A diabetic patient has sudden onset weakness of psoas, quads, and adductors. This could be…
microinfarct of a nerve - needs emergent EMG, physical exam, insulin
A patient who uses cocaine and has been using crutches has decreased pin prick sensation on the back of the hand, decreased wrist extension, intact triceps Where did he injure his nerve?
radian nerve below axilla (since triceps in tact)
A patient has shooting wrist pain that is worse at night. This is most likely…
carpal tunnel syndrome
A 75 year old patient comes in with worsening foot numbness and burning pains in a stocking glove pattern. This is…
classic diabetic neuropathy
What medications can induce a polyneuropathy?
amiodarone, chemo drugs, antibiotics (metronidazole), HIV meds
A patient presents with slow evolving weakness, areflexia, weakness of neck flexors and painful paresthesias. CSF has elevated protein. This is..
CIDP - treat with IVIG
A patient is found to have slowly progressive weakness starting in the arms. Serum shows high Igm anti GM1. This is.. (and treat with…)
multifocal motor neuropathy - treat with IVIg
What are the common manifestations of uremic neuropathy?
foot drop and leg weakness
What are the common neurological associations ofporyphoria?
rapidly evolving weakness, paralysis
An adolescent presents with slowly progressive distal musclar atrophy of the legs and feet. She has a hammer toe and pes cavus. What genetic disease could this be?
charcot marie tooth
What is the neuropathy associated with leprosy?
motor and sensory neuropathy
What is the pathogenesis of MG?
antibodies against post synaptic nAChR
What is the difference in presentation between lambert eaten syndrome and myasthenia gravis?
incremental response on fast repetitive nerve stimulation
A child presents with the need to push down on thigns when getting up and proximal muscle weakness. What could this be?
duchenne muscular dystrophy or the less severe Becker’s
What treatment can be offered to patients with DMD or BMD?
glucocorticoids can slow decline
What are some of the findings in labs that you would expect on limb girdle muscular dystrophies?
elevated CK, EMG myopathic
A young teenage patient presents with face, should and upper arm weakness that is progressing. This is..
fascioscapulohumeral muscular dystrophy
A patient has muscle stiffness and weakness distally, percussion myotonia, cataracts, arrhythmia. Suspect…
myotonic dystrophy
A patient presents with joint contractures at the elbows, ankles and cervical spine. She has cardiomyopathy and early involvement that manifests as conduction abnormalities. EMG shows dystrophic changes. This could be…
emery dreifuss disorder
What is the pathophysiology of periodic paralyses?
ion channel dysfunction
What does MELAS stand for?
mitochondrial myopathy, encephalopathy, lactoacidosis, and stroke
A patient presents with proximal muscle weakness especially affecting forearm flexors, knee extensors, and ankle extensors. This is ..
inflammatory myopathy
What distinguishes PM from DM from IBM?
DM often characterized by purplish discoloration of the eyelids. Inclusion body myositis is often characterized by non-reaction to steroids
What are some of the extramuscular manifestations of DM?
cardiac manifestations, interstitial lung disease, mixed connective tissue disease,
What are the characteristic muscle biopsy and EMG findings of PM?
endomysial inflammation, myopathic changes on EMG
What types of drugs can induce myopathy?
steroids, statins, propofol, zidovudine, phenytoin,
What antibodies can cause a peripheral neuropathy?
Anti - Hu (paraneoplastic)
A patient with poorly controlled diabetes presents with pain, muscle wasting, and dennervation of the quads. This is…
Diabetic amytrophy
A patient complains of symmetric bilateral loss of sensation on the Dorsum of the hand from the thumb to digit ii. This is a lesion of…
Superficial radial - handcuffs!
A man who has been confined to bed complains of right leg weakness, right ankle dorsiflexion weakness, eversion and great toe extension weakness. This is …
peroneal nerve
A patient who injured his hand presents with extensive ecchymosis and swelling. He is unable to tolerate light touch or motion of the joints. This is..
complex regional pain syndrome
