Combined Presentation of Acute Confusion and Severe Pancytopenia in Vitamin B12 Deficiency.

Vitamin B12 deficiency is more prevalent in the elderly and can develop as a result of malnutrition, malabsorption, chronic alcoholism, and chronic use of common medications (e.g. metformin, PPI, methotrexate) along with other causes. A wide spectrum of hematological and neuropsychiatric manifestations exist with the most common being Megaloblastic anemia and subacute combined degeneration, respectively. The mechanisms leading to the manifestations specific to these two organ systems are thought to be different. The severity of neuropsychiatric presentation is reported to be inversely proportional to that of hematological presentation, thus making it uncommon for both to be readily apparent simultaneously. Regardless of the severity of the clinical presentation, a good response to vitamin B12 replacement therapy is reported despite the lack of guidelines regarding dosing, frequency, or duration of treatment needed to note improvement in manifestations. The aim of this report is to increase the provider's knowledge that a severe combined hematological and neuropsychiatry manifestation can co-exist and report the management used for recovery.