Subacute dementia in elderly due to vitamin B12 deficiency

Dementia is a commonly encountered problem in the aging population. The cardinal manifestations of Vitamin B12 deficiency are dementia, delirium, cognitive impairment, confusion, memory losses, depression, acute psychosis, and rarely mania or schizophrenia. The neuropsychiatric manifestations due to Vitamin B12 deficiency are often accompanied by hematological abnormalities. We report a 68-year-old female who presented with complaints of behavioral changes, intermittent episodes of acute confusional state, memory deficits, inability to identify family members, lethargy and easy generalized fatigability. The laboratory investigations of the patient revealed macrocytic anemia with decreased Serum Vitamin B12 levels, Normal folate levels and elevated Serum Homocysteine levels based on which the patient was diagnosed with Hypovitaminosis of Vitamin B12 with Hyperhomocysteinemia. The patient showed dramatic improvement in the neuropsychiatric manifestations after receiving adequate supplementation of cobalamin.