Term
| what are the 3 questions to ask when considering neurologic problems? |
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Definition
| is the problem neurologic? where is the lesion? what is the lesion? (what type of insurance do they have?) |
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Term
| what are the cardinal manifestations of neurologic problems? |
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Definition
| paresthesias/dysesthesias, motor deficits, reflex abnormalities, sensory loss, and autonomic disorders |
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Term
| what are paresthesias/dysesthesias? |
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Definition
| burning/explosive discomfort, can have electrical quality, shooting, and pins/needles. distribution can assist in making a dx. |
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Term
| what are tools used to evaluate paresthesias? |
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Definition
| q-tip, reflex hammer, tuning fork |
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Term
| what is the monofilament nylon probe used for? |
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Definition
| this is pressed against the skin until it buckles, if the pt still doesn't detect its presence = significant sensory reduction |
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Term
| what are the two categories for the neural source behind parasthesias? |
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Definition
| peripheral cutaneous nerve (like lateral femoral cutanenous nerve = myralgia paresthetica) or a dermatone (damage from spinal cord down to L5, S1) |
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Term
| what characterizes motor deficits? |
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Definition
| these tend to be more distal (if more proximal, want to consider a myopathy) and distribution has localizing value for mononeuropathy |
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Term
| what characterizes reflex abnormalities? |
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Definition
| UMN (brain down to anterior horn): increased DTRs, no atrophy, no fasciculations, increased tone, and pathologic reflexes (babinski, hoffman). LMN (anterior horn or below ): decreased DTRs, atrophy, fasciculations, no increase in tone, and no pathologic reflexes. sometimes the peripheral neuropathy is due to a LMN, but b/c of isolated small fiber involvement, the pt may have preserved reflexes. |
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Term
| what characterizes sensory loss? |
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Definition
| this occurs more commonly in the legs (greater length), and all modalities tend to be affected (impaired or lost). if mononeuropathy, distribution is helpful as is checking for a gradient (distal to proximal). |
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Term
| what characterizes autonomic disorders? |
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Definition
| orthostatic hypotension, anhidrosis, bowel/bladder dysfunction, and impotence. |
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Term
| what characterizes axonal degeneration? |
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Definition
| "dying back phenomenon" from distal to proximal. on EMG: causes decreases amplitude of potential. |
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Term
| what characterizes segmental demyelination? |
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Definition
| the myelin sheath is the *most susceptible part of a nerve fiber. among other things, compression can damage the myelin sheath. in the PNS, schwann cells can be generally or locally injured, which *leads to a "conduction block" (slowing of the nerve). |
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Term
| what is wallerian degeneration? |
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Definition
| when a nerve is interrupted/cut, the distal site of an axon starts to degenerate (isolated from nutrition). |
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Term
| what are some causes of symmetric polyneuropathy? |
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Definition
| DM (most common), uremia, hepatic failure, and myxedema (thyroid problems) |
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Term
| what should be assessed in terms of vitamin deficiency when evaluating symmetric polyneuropathy? |
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Definition
| thiamine, B12, folic acid, and pyridoxine deficiency/OD |
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Term
| what should be assessed in terms of toxicities when evaluating symmetric polyneuropathy? |
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Definition
| alcohol, heavy metals, industrial solvents, and insecticides/herbicides |
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Term
| what should be assessed in terms of recreational drugs when evaluating symmetric polyneuropathy? |
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Definition
| glue sniffing, nitrous oxide, cocaine, and heroin |
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Term
| what should be assessed in terms of medication when evaluating symmetric polyneuropathy? |
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Definition
| phenytoin, vincristine, isoniazid, gold, chloroquine, hydrazine, disulfiram, penicillamine. |
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Term
| what should be assessed in terms of immune processes when evaluating symmetric polyneuropathy? |
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Definition
| guillian-barre syndrome and chronic inflammatory demyelinating polyradiculoneuropathy - associated w/monoclonal proteins and/or amyloidosis |
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Term
| what should be assessed in terms of misc/unusual processes when evaluating symmetric polyneuropathy? |
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Definition
| AIDS-related neuropathy, paraneoplastic neuropathy, inherited neuropathy, lymes disease, leprosy, porphyria, collagen vascular disease, metachromatic leukodystrophy, diphtheria and sarcoidosis |
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Term
| what is gullian barre syndrome? presentation? dx? tx? |
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Definition
| an acute inflammatory demyelinating polyneuropathy (likely autoimmune against myelin sheath *initiated by a virus) which is one of the most frequent and fatal forms of neuropathy seen in the hospital setting. presentation: 20-30 y/o who doesn’t look like self, dizzy, had to drag self out of bed, fatigue quickly - can still function but as day progresses cant move. generally an ascending pattern of *acute reduction/loss of reflexes, predominantly motor w/a several day-couple week course and can lead to a total paralysis w/resp failure. dx: spinal tap looking for *albuminocytologic dissociation (elevated protein w/normal cells). tx: possible ventilator support, NOT steroids, plasmapheresis or IVIg. prognosis: 90% full recovery, 3% mortality (inadequate f/u). |
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Term
| what characterizes neuropathy due to DM? |
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Definition
| most common is distal, symmetric, primarily sensory segmental demyelination = numbness/pain in feet and toes. |
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Term
| what is the most common DM CN palsy? |
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Definition
| CN 3 is the most common DM CN palsy, which spares the pupil (DM affects the inside of the nerve, not autonomic exterior). since LR6SO4, eyes may be looking down+outward = unopposed ptosis. |
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Term
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Definition
| injury of the lumbar plexus due to DM neuropathy = weakness and atrophy involving the pelvic girdle and thigh (hamstring) |
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Term
| what is the etiology behind DM neuropathy? |
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Definition
| vascular w/ischemia to the vaso nervorum and metabolic w/accumulation of byproducts of glucose metabolism. prognosis is variable and tx is strict blood sugar control. |
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Term
| what autonomic involvement is seen w/DM neuropathy? |
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Definition
| gastroparesis (slowing), bladder, impotence, postural hypotension, and diarrhea |
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Term
| what is the most common mononeuropathy? |
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Definition
| carpal tunnel syndrome/median nerve entrapment = compression under the flexor retinaculum: numbness and tingling in the wrist, thumb/2nd/3rd digits (variable distribution). associated w/trauma, pregnancy, arthritis, hypothyroidism (myxedema), DM, and acromegaly. the dominant hand is more commonly affected, 50% is bilateral. |
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Term
| what is tx for carpal tunnel syndrome/median nerve entrapment? |
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Definition
| discontinue activity, tx associated disorder, wrist splint/local injection, and surgical decompression (90% effective). |
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Term
| what is the etiology of peripheral neuropathy due to alcohol? |
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Definition
| deficiency of B vitamins and the direct toxic effect of alcohol. may develop over a period of several weeks and last for a variable period. presentation: pain/numbness in legs. may be associated w/proximal alcoholic myopathy. tx: abstinence from etoh and B vitamin replacement. |
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Term
| what is charcot-marie-tooth? |
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Definition
| an autosomal dominant neuropathy characterized by onset in adolescence w/atrophy of calf muscles (champagne glass appearance of calf). it is associated w/foot-drop and sensory ataxia as well as a mild upper extremity involvement proximal to elbow and knee. |
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Term
| what is tx for charcot-marie-tooth? |
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Definition
| ID any other etiology and tx if possible. symptomatic tx: treat pain (anticonvulsants [tegretol, dilantin, neurontin, lamictal, topamax, trileptal], TCAs, antiarrhythmics, capsaicin cream, TENS, analgesics, acupuncture, antibx) and provide assistive device/physical therapy. |
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