Common and Uncommon Neurological Manifestations as Presenting Symptoms of Vitamin‐B 12 Deficiency

Data on 3 elderly patients with neurological manifestations of vitamin‐B 12 deficiency, without anemia, are presented. In one case the appearance of peripheral neuropathy preceded the onset of speech disturbances and mental changes and the onset of the common syndrome of subacute combined degeneration of the spinal cord. In the other 2 patients, lateral sclerosis in one case and pseudotabes in the other case were the presenting features. Several months after the beginning of cyanocobalamin therapy, the patients were almost cured. Early diagnosis of vitamin‐B 12 deficiency is important in cases of myelopathy, encephalopathy or peripheral neuropathy without hematological changes, because the neurological damage may become completely irreversible if treatment is delayed by failure in early diagnosis.