Term
| motor neuron and the group of muscle fibers it innervates |
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Definition
|
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Term
| most diseaes of the motor unit cause what |
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Definition
| weakness and wasting of the skeletal muscles |
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Term
| what are the components of the motor unit that could be affected by disease? (4) |
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Definition
| cell body, axon, neuromuscular junction, muscle fibers it innervates |
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Term
| when a peripheral nerve is cut what happens to the muscles innervated by that nerve immediately |
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Definition
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Term
| when a peripheral nerve is cut what happens to the muscles it innervated later? |
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Definition
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Term
| when a peripheral nerve is cut what happens to DTRs |
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Definition
|
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Term
| when a peripheral nerve is cut what happens to sensatoin |
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Definition
| sensation to the area innervated by the nerve is lost |
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Term
| when a peripheral nerve is cut it is similar to what type of disease? |
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Definition
| neurogenic, effects appear more slowly |
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Term
| main symptoms of myopathic diseases are due to what |
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Definition
| weakness of skeletal muscle |
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Term
| myopathic diseases include other less common symptoms such as (3) |
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Definition
| myotonia, myalgia, cramps |
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Term
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Definition
| inability of the muscle to relax |
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Term
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Definition
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Term
| muscular dystrophies are what kind of disease |
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Definition
|
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Term
| inherited diseases, symptoms caused by weakness which become progressive more severe over time, histological signs of degeneration and regeneration |
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Definition
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Term
| classificiation and differential diagnosis of neurogenic vs myopathic diseases includes what |
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Definition
| clinical and laboratory criteria |
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Term
| distal limb weakness most often indicates what disorder? |
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Definition
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Term
| proximal limb weakness usually indicates what disorder |
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Definition
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Term
| fasciculations are reliable signs as they are only found in what disease |
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Definition
|
|
Term
| visible twitches of muscle that can be as flickers under the skin |
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Definition
|
|
Term
| fasciculations result from what? |
|
Definition
| involuntary but synchronous contractions of all muscle fibers in a motor unit |
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|
Term
| fasciculations are characteristic of what? |
|
Definition
| slowly progressive disease of the motor neuron |
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|
Term
| fasciculations are rarely seen in what |
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Definition
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|
Term
| fibrillations arise from what |
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Definition
| spontaneous activity within single muscle fibers |
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|
Term
| what spontaneous activity of muscle fibers can only be detected by EMG |
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Definition
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Term
| high sarcoplasmic enzyme presence in serum is indicative of what type of disease |
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Definition
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|
Term
| enzyme activity most commonly used for diagnosis myopathy is what |
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Definition
|
|
Term
| what are the 3 specific measurements examined by an EMG |
|
Definition
| spontaneous activity at rest, number of motor units under voluntary control, duration and amplitude of AP's in each motor unit |
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Term
| in normal muscle at rest, what should the EMG read at the end plate |
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Definition
|
|
Term
| in neurogenic disease, what does the resting muscles activity look like |
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Definition
|
|
Term
| why may the amplitude and duration of an individual motor unit potentials increase despite neurogenic disease |
|
Definition
| remaining axons give off small branches that innervate denervated muscle fibers |
|
|
Term
| in which disease is there no muscle activity at rest and no change in the number of motor units firing during a contraction |
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Definition
|
|
Term
| in a myopathic disease what happens to the duration and amplitude of a contraction |
|
Definition
| shorter duration and smaller in amplitude due to fewer surviving muscle fibers |
|
|
Term
| what are the predominant metabolic enzymes present in type I |
|
Definition
|
|
Term
| what are teh predominant metabolic enzymes present in type II |
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Definition
|
|
Term
| the histochemical type of the muscle is determined by what |
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Definition
|
|
Term
| in chronic neurogenic diseases, what happens to the muscle innervated by a dying motor neuron |
|
Definition
| becomes atrophic and some muscle fibers disappear |
|
|
Term
| what happens to denervated muscle fibers when their neurons die |
|
Definition
| innervate by axons of surviving neurons |
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|
Term
| due to reinnervation by the surviving neurons what can happen to the muscle fiber |
|
Definition
| its histochemical type can change |
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|
Term
| best known disorder of motor neurons |
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Definition
|
|
Term
| symptoms of ALS usually start with what |
|
Definition
| painless weakess of the arms or legs |
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|
Term
|
Definition
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|
Term
| ALS weakness is associated with what |
|
Definition
| wasting of the small muscles of the hands and feet and fasciculations of the muscles of the arm and forearm |
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|
Term
| ALS exhibits signs of lower motor neuron disease, but is often paradoxically associated with what symptom |
|
Definition
| hyperreflexia (characteristic of upper motor neuron disease) |
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Term
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Definition
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Term
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Definition
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Term
| a variant of motor neuron disease with symptoms being restricted to muscles innervated by cranial nerves would result in what symptoms |
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Definition
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|
Term
| when cranial symptoms of motor neuron disease occur alone, the syndrome is called what |
|
Definition
|
|
Term
| if only lower motor neurons are involved, what is the syndrome called |
|
Definition
| progressive spinal muscular atrophy |
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|
Term
| spinal muscular atrophy is characterized by what (4) |
|
Definition
| weakness, wasting, loss of reflexes, fasciculation |
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|
Term
| Disorders of peripheral nerves usually affect which functions |
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Definition
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|
Term
| patients with neuropathies report pins and needles sensation without an external sensory stimulus, this is called what |
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Definition
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|
Term
| patients with paresethesia usually have impaired perception of what sensations |
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Definition
|
|
Term
| patients with paresthesias may or may not have this sense be involved |
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Definition
|
|
Term
| in neuropathies, this sensation may be lost with loss of cutaneous sensation |
|
Definition
| proprioceptive sensations |
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|
Term
| sensory disordres are usually more prominent where? and are called what? |
|
Definition
| distally, glove and stocking pattern |
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|
Term
| peripheral neuropathy is first manifested by weakness predominantly where in acute cases |
|
Definition
|
|
Term
| peripheral neuropathy is first manifested by weakness predominantly where in chronic disorders |
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Definition
|
|
Term
| what happens to tendon reflexes in peripheral neuropathies |
|
Definition
| usually depressed or lost |
|
|
Term
| best known acute neuropathy |
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Definition
|
|
Term
| guillan-barre syndrome usually follows what |
|
Definition
|
|
Term
| disorder attributed to an autoimmune attack on peripheral nerves by circulating antibodies |
|
Definition
|
|
Term
| how is guillan-barre syndrome treated |
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Definition
|
|
Term
| neuropathies may be acute or chronic, and may be also categorized as what |
|
Definition
|
|
Term
| which neuropathy is more common, demyelinating or axonal |
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Definition
|
|
Term
| what is a result of demyelinating neuropathies |
|
Definition
| conduction velocities are slowed in axons that have lost myelin |
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|
Term
| skeletal muscle diseases are conveniently divided into what |
|
Definition
| inherited, appear to be acquired |
|
|
Term
| what are the two types of muscular dystrophies characterized by weakness alone |
|
Definition
| duchenee, facioscapulohumeral dystrophies |
|
|
Term
| dystrophy that starts in the legs, affects males only, progresses relatively rapidly so that the patient is in wheelchairs by age 12 |
|
Definition
| duchenne's muscular dystrophy |
|
|
Term
| muscular dystrophy that affects both sexes equally, starts usually in adolescence, affects the shoulder girdle and face early |
|
Definition
| facioscapulohumeral muscular dystrophy |
|
|
Term
| what is the 3rd type of inherited muscular dystrophy |
|
Definition
| myotonic muscular dystrophy |
|
|
Term
| myotonic muscular dystrophy is characterized by what |
|
Definition
|
|
Term
| delayed relaxation of muscle after vigorous voluntary contraction, percussion, or electrical stimulation |
|
Definition
|
|
Term
| what is the delayed relaxtion from myotonia caused by |
|
Definition
| repetive firing of muscle aciton potentials and is independent of nerve supply because it persists after nerve block |
|
|
Term
| myotonic muscular dystrophy also involves what muscles |
|
Definition
|
|
Term
| myotonic muscular dystrophy has limb weakness primarily where |
|
Definition
|
|
Term
| what is the 4th type of muscular distrophy |
|
Definition
| limb-girdle muscular dystrophy |
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|
Term
| polymyositis is manifest primarily by what |
|
Definition
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