Vitamin B12 Deficiency-Induced Neuropathy and Cognitive and Motor Impairment in the Elderly: A Case Study.

Vitamin B12 deficiency can present with a variety of neurological and cognitive symptoms. Especially in elderly patients, vitamin B12 deficiency can be easily overlooked because symptoms may be attributed to comorbid conditions or solely to the aging process. In this case study, we present two patients, a 71-year-old man and a 74-year-old female, with vitamin B12 deficiency. The male patient had a history of (partial) resection of the ileum/jejunum/colon because of intestinal ischemia. The female patient had a history of hypothyroidism, type 2 diabetes with complications (including peripheral neuropathy), mitochondrial myopathy, and chronic lymphocytic leukemia. Both patients presented with severe fatigue, cognitive impairment, and impaired walking. Next to this, the male patient suffered from depressive symptoms and mild disorientation, and the female patient experienced neuropathic pain. She also mentioned a positive family history for B12 deficiency. The first patient had normal to high B12 levels because he was already on B12 injections (once every three weeks) because of an earlier diagnosed B12 deficiency. The female patient had B12 levels within normal range (holotranscobalamin 54 pmol/L) and her diagnosis was confirmed by elevated homocysteine and methylmalonic acid levels. Treatment with frequent hydroxocobalamin injections and other supplements significantly improved their cognitive, emotional, and motor functions. These cases underscore the need for a high level of clinical suspicion in elderly patients, also in cases of normal B12 levels but with clinical signs of deficiency and a positive risk factor, such as stomach or small bowel surgery or positive family history.