Pernicious anemia in the demented patient without anemia or macrocytosis. A case for early recognition.

It is well known that the neurologic manifestations of vitamin B12 deficiency can occur in the absence of anemia. The authors recently observed two elderly patients who presented to a chronic care institution with the diagnosis of dementia, and in both individuals low serum B12 levels were found in conjunction with abnormal Schilling tests. In neither of these two patients was there anemia or macrocytosis. After receiving parenteral B12 injections there was improvement noted in cognitive functions as well as in activities of daily living. The authors are reporting these patients to alert clinicians to the fact that pernicious anemia in the elderly can first present with low serum B12 levels and neurologic abnormalities in the absence of anemia or macrocytosis.