title: The role of folate deficiency in the development of peripheral neuropathy caused by anticonvulsants.
abstract: To investigate the role of folate deficiency in neuropathy caused by anticonvulsants, electrophysiological studies of peripheral nerve function were carried out on 29 epileptic patients on long-term anticonvulsant therapy. All but three patients showed abnormalities in one or more electrophysiological measurements, the main abnormality being in amplitude of sensory nerve action potential--this was reduced or absent in 76% of patients. All patients had low concentrations of folate in serum and CSF, these being below the normal ranges in 19 patients. These 19 patients were treated with folate, either 5-formyltetrahydrofolate (10 patients) or folic acid (9 patients), over a period of one month. After therapy all patients had normal levels of folate in serum and CSF, slightly higher levels in CSF being obtained in those receiving 5-formyltetrahydrofolate. Folate therapy significantly reversed abnormalities in motor and sensory nerve distal latencies; the effect was greater with 5-formyltetrahydrofolate, apparently because this produced higher CSF folate concentrations than folic acid. We conclude that folate deficiency may be involved in the development of peripheral neuropathy due to anticonvulsants.
mesh_terms: D000328:Adult; D000368:Aged; D000927:Anticonvulsants / Q000009:adverse effects* / Q000627:therapeutic use; D004827:Epilepsy / Q000188:drug therapy; D005260:Female; D005492:Folic Acid / Q000134:cerebrospinal fluid / Q000627:therapeutic use; D005494:Folic Acid Deficiency / Q000150:complications* / Q000188:drug therapy; D005575:Formyltetrahydrofolates / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D009431:Neural Conduction / Q000187:drug effects; D010523:Peripheral Nervous System Diseases / Q000139:chemically induced*
chemical_list: D000927:Anticonvulsants; D005575:Formyltetrahydrofolates; D005492:Folic Acid