Pernicious anemia presenting as catatonia: correlating vitamin B12 levels and catatonic symptoms.

Pernicious anemia has been associated with various psychiatric manifestations, such as depression, mania and psychosis. Psychiatric symptoms can sometimes occur without hematological and neurological abnormalities and can be prodromal of vitamin B12 deficiency. We report a case of autoimmune B12 deficiency presenting as catatonia without signs of anemia or macrocytosis, in which a correlation was found between the patient's B12 blood levels and catatonic symptoms over time. This catatonic episode was successfully treated with only lorazepam and adequate doses of cyanocobalamin.