Neurológia pre prax 6/2013

Neurological disorders in vitamin B12 deficiency

Vitamin B12 plays an important role in organism as cofactor of important enzymes of intermediary metabolism. Lack of vitamin B12 is caused by malabsorption in the gastrointestinal tract, insufficient nourishment by food or genetic deficiency of methylmalonyl-CoA mutase enzyme. Vitamin B12 deficiency usually presents with various haematological, neurological and psychiatric manifestations. Neurological manifestations include myelopathy, neuropathy and, rarely, optic nerve atrophy. Myelopathy in vitamin B12 deficiency presents as subacute combined degeneration of spinal cord (funicular myelosis), characterised by degeneration of the lateral and posterior columns. Neuropathy usually presents as polyneuropathy with predominantly sensory symptoms, sometimes are combined also with motor symptoms. Optic atrophy is rare condition, chracterized by slow progressive worsening of vizus. The aim of our work is to highlight the issue of neurological diseases caused by vitamin B12 deficiency, identified the need to include these diseases in the differential diagnostic considerations.

Keywords: vitamin B12 deficiency, subacute combined degeneration of spinal cord, polyneuropathy, long-term parenteral or oral substitution of vitamin B12.