Dementia caused by vitamin B12 deficiency.: Report of one case

Cyanocobalamin (vitamin 1312) de polyneuropathy, myelopathy, blindness, confusion, psychosis and dementia. Nonetheless, its difficulties as the sole cause of dementia is infrequent. We report a 59 years old man with a 6 months history of progressive loss of memory, disorientation, apathy, paranoid delusions, gait difficulties with falls, and urinary incontinence. He bad suffered a similar episode 3 years before, with a complete remission. On examination there was frontal type domentia with Korsakoff syndrome, a decrease in propioception and ataxic gait. Cerebrospinal fluid examination showed a protein of 0.42 g/L. Brain computed tomography showed seqnelae of a frontal le fit trauma. Brain single photon computed tomography (SPECT) was normal, Complete blood count showed a macrocytic anemia with a hematocrit 29% and a mean corpuscular-volume of 117 mu3. Plasma vitamin B12 levels were undetectable, erythrocyte folate levels were 3.9 ng/ml and plasma folate was normal, The myelogram showed megaloblastosis and The gastric biopsy showed atrophic gastritis. Treatment with parenteral B12 vitamin and folic acid reverted the symptoms, with normalization of the neuropsychological tests and reintegration to work.