ANESTHESIA PARESTHETICA - NITROUS OXIDE-INDUCED COBALAMIN DEFICIENCY

A man with a subclinical cobalamin deficiency developed syncope, verti go, paresthesias, and ataxia after two exposures to nitrous oxide anes thesia. Patients with unrecognized cobalamin deficiency may be particu larly susceptible to brief exposures to nitrous oxide, which inactivat es the cobalamin-dependent enzyme methionine synthase and may cause a myeloneuropathy. Clinicians should consider this entity when confronte d with patients with neuropathic symptoms after surgical or dental pro cedures.