Tuesday, August 29, 2006

Miscellany on neuropathy & tests

from Saperstein
B12--may cccur suddenly, 11% hands, 75 % hands and feet, 42 % PN. In evaluating, recall that MMA is increased in renal disease and volume depletion, homocystein in hypothyroidism, age, genetic syndromes, pyridoxine deficiency.

MGUS incidence of monoclonal proteins in population above 50 is 1 %, above 70 is 3 %, in patients with PN is 10 %. SPEP misses 10 percent caught by SIFE. 30 % of MGUS patients eventually develop something (MM, WM, Amyloid). Quantify M protein should be less than 3 g/dl. +/- BM biopsy. Axonal EMG not as bad. DADS also called demyelinating PN, "CIDP" (wrong) IGM neuropathy and anti MAG neuropathy. Usually occurs in older males (> 60). Sensory ataxia, PROLONGED LATENCIES ON NCS are typical. Consider fat biopsy if cardiac,renal, or disease is present.

Celiac disease-- note there are cases with negative duodenal biopsies. Antigliadin antibodies are present in 5-12 percent of normals, but transglutaminase antibodies are more specific. No response to IVIG or poor response to gluten free diet but do it anyway.

antiHU antibodies are best saved for patients with cerebellar ataxia or encephalopathy. NCS show sensorimotor pattern. Less known antibody is CD@ also known as CRMP (collapsing response mediator protein 5). Consider lung cancer, thymoma.

GM1 antibody associates with multifocal motor neuropathy, or at low titers other AI neuropathies not seen in MADSAM.

antiMAG-- small pct dont have igm

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