Ischemic strokes secondary to vitamin B12 deficiency-induced hyperhomocystinemia

A 45-year-old woman sustained two ischemic cerebral infarctions 16 years after ileal resection for Crohn's disease. Her evaluation showed an elevated random serum homocystine level, a low serum vitamin B-12 level, and an increased mean corpuscular volume (MCV) without anemia. A methionine-loading test resulted in a marked increase in the homocystine levels 2, 4, and 6 hours after the load. A Schilling test demonstrated a malabsorption of vitamin B-12. Vitamin B-12 injections normalized her fasting homocystine level and her MCV. She has had no recurrent strokes during a year follow-up.