Treatment responsive executive and behavioral dysfunction associated with Vitamin B12 deficiency.

Vitamin B12 deficiency can manifest with various neuropsychiatric symptoms. We report a case of an individual with vitamin B12 deficiency presenting with personality, emotional and behavioral changes. Neuropsychological tests revealed disproportionate disturbance of executive functions. Single photon emission tomography (Tc99m HMPAO) showed right fronto-temporo-parietal hypoperfusion. After vitamin B12 injections, the patient's executive and behavioral dysfunction disappeared and performance on neuropsychological tests was once again in the normal range.