Neuromuscular Diseases Flashcards
signs of upper motor neuron lesions
weakness, paralysis, spasticity, hypereflexia, extensor plantar Babinski sign, loss of superficial abdominal reflexes, little if any muscle atrophy
signs of lower motor neuron lesions
weakness, paralysis, wasting and fasciculations, hypotonia/flaccidity, loss of tendon reflexes, normal abdominal and plantar reflexes
clinical presentation of peripheral nerve disease
numbness, impaired vibration perception, atrophy of small muscles of hands and feet, weakness, ataxia, pain, risk for charcot foot
major cranial nerve symptom of myasthenia gravis
diplopia that fluctuates throughout the day, worsens towards the end of the day
diagnostic test used to diagnose myasthenia gravis
tensilon test: inhibits ACh esterase
general principles of ALS
sensory is unaffected, random weakness, CNS involvement, hypereflexia
general principles of polyradiculoneuropathy
sensory impairment involved, distal weakness more than proximal, CNS involvement rare, hyporeflexia
general principles of myasthenia gravis
upper extremities more affected than LE, sensory impairment involved, weakness, variable CNS involvement, normal reflexes
general principles of myopathy
more proximal weakness than distal weakness, normal or declining CNS involvement, normal reflexes
risk factors for sporadic ALS
smoking! military, trauma, physical activity (soccer players), environmental toxins: cycad nuts in Guam
sites of motor neuron loss in ALS
cortex, brainstem, spinal cord
sensory or autonomic changes in ALS?
NO
a way that ALS can be fatal
motor neurons to diaphragm and chest muscles leads to respiratory distress
oral sign of ALS
atrophic tongue
ALS medication, what it does
Riluzole: antiglutamate agent; prolonged survival
diseases that can evolve into ALS
primary lateral sclerosis, progressive bulbar palsy, other motor neuron diseases
most common form of inherited motor neuron disease
spinal muscular atrophy (aut. recessive)
examples of mononeuropathy
carpal tunnel, peroneal palsy at the fibular head
large vs small sensory nerves: myelination level?
large sensory neurons are well myelinated; small sensory neurons are poorly myelinated or unmyelinated
function of large sensory neurons
relay vibration and proprioception info (dorsal column)
function of small sensory neurons
relay pain and temp- form spinothalamic tracts
symptoms of polyneuropathy
start in FEET (tripping), move proximally, hand symptoms appear when LE symptoms are up to the knee (trouble turning keys, opening jars), pins and needles, tingling, burning
autonomic symptoms of polyneuropathy
dry eyes, mouth, changes in sweat, orthostatic hypotension, bladder dysfunction, post prandial diarrhea, constipation, ED
name this acute polyneuropathy: acute progressive neuropathy involving myelin of the peripheral nerves
Guillain-Barre syndrome
this acute polyneuropathy involves axons of nerves; can present as psychiatric disorder or have unexplained GI symptoms
porphyria
most common cause of rapidly progressing weakness, demyelination
Guillain-Barre syndrome
Guillain-Barre syndrome has this type of weakness and this type of hyporeflexia; what type of sensory neuron is lost?
ascending type weakness, symmetric areflexia, large fiber sensory loss
causes of death due to Guillain-Barre syndrome
respiratory failure, autonomic instability, DVT, infection
most common autoimmune disease involving post synaptic ACh receptors
myasthenia gravis
pathology of myasthenia gravis
less number of receptors; weakness; ACh goes right to ACh esterase
50% of myasthenia gravis presenting symptoms is..
ocular symptoms (ptosis, diplopia)
weakness in myasthenia gravis patients is described as..
fatigueable weakness
the antibody found is myasthenia gravis functions to..
bind, block, modulate the ACh receptor
extremity weakness in myasthenia gravis: which is greater, legs or arms?
arms > leg weakness
treatment of myasthenia gravis
ACh esterase inhibitors, plasma exchange, IV Ig’s, thymectomy, immunosuppressants
botulism involves which part of the NMJ?
presynaptic part
pathology of lambert eaton syndrome
voltage gated Ca2+ channel antibodies impede the release of ACh
cancer associated with lambert eaton syndrome and calcium channel antibodies*
lung cancer, or possibly any underlying cancer. antibodies to the lung cancer result in weakness of LE, hyporeflexia
the dystrophy muscle diseases
Duchenne’s MD, myotonic dystrophy
the congenital myopathies
glycogenoses, mitochondrial
the acauired myopathies
polymyositis, dermatomyositis, inclusion body myositis, drug related
Duchenne’s MD is cause dby..
absence of dystrophin protein/ its X-linked recessive
clinical sign of duchenne’s muscular dystrophy
Gower’s maneuver: getting off the floor by placing hands and feet on the floor together first
most common form of adult dystrophy
myotonic dystrophy
describe the myotonia of myotonic dystrophy
failure to relax muscle after contraction (hands get stuck)
1/3 of all cases of inflammatory myopathies are..
polymyositis
30% of polymyositis patients experience
cardiac disturbance: conduction issues, tachyarrhythmia, CHF
treatment of polymyositis
immunosuppression: prednisone, methotrexate, azathioprine
*distinctions for dermatomyositis
more rapid onset, very high CPK’s (creatinine phosphokinase), acute renal failure, skin changes that usually appear first
dermatomyositis is also this type of syndrome..
paraneoplastic
the most common idiopathic inflammatory myopathy in adults
inclusion body myositis
typical pattern of weakness of inclusion body myositis
asymmetric, wrist and finger flexors, quadriceps
inclusion body myositis patients present with this 40-60% of the time
dysphagia (more than dermatomyositis)
Duchenne’s MD CK levels are ____ that of normal
100 times
this family of drugs can cause myopathy
cholesterol agents (statins)
factors that determine whether or not to stop administering statins causing myopathy
if symptoms are intolerable, if CPK > 10 x, if elevation of BUN develops
