Reversible isolated sensory axonal neuropathy due to cobalamin deficiency.

Vitamin B(12) deficiency causes a wide range of hematological, gastrointestinal, and neurological manifestations. The most common neurological complication is subacute combined degeneration, sometimes associated with polyneuropathy. Isolated peripheral neuropathy due to cyanocobalamin deficiency is less frequent, and thus it may be overlooked. We describe 2 patients with isolated sensory axonal neuropathy secondary to vitamin B(12) deficiency who had complete clinical and electrophysiological recovery after cyanocobalamin replacement. Testing for serum vitamin B(12) and its metabolites should be done in any distal symmetric neuropathy.