Drugs, in particular Isoniazide and ethambutol used to treat TB, vincristine used in cancer chemotherapy and some antibiotics, can produce significant neuropathies. Cancer Factors producing neuropathies in cancer patients include nutritional deficiency, chemotherapeutic agents and concurrent metabolic disorders. Myeloma and macroglobulinemia are accompanied by neuropathy. The most common picture is of a distal sensori-motor polyneuropathy sometimes preceding diagnosis of the Ca. Connective Tissue Disorders Vasculitides generally produce a mononeuropathy characterized by infarction of fasciculi within nerves.
Diagnosis is made by demonstrating porphobilinogen in the urine.
Fabry's disease is X-linked, presenting in males, and is due to ceramide Trihexosidase deficiency. Curiously sensory action potentials are retained in spite of painful paresthesias. Refsum's disease, accompanied by hypertrophic neuropathy, ataxia, deafness atypical retinitis pigmentosa, ichthyosis results from a failure to break down phytanic acid. Treatment consists of elimination of leafy vegetables and animal fats from the diet. Dejerine-Sottas recessive disorder produces severe neuropathy.