Vitamin B(12) deficiency with bilateral globus pallidus abnormalities.

OBJECTIVE To describe a case of vitamin B(12) deficiency with classic and rare clinical features and novel radiographic features. DESIGN Case report. SETTING Johns Hopkins Hospital neurology service. PATIENT Middle-aged man with neuropathy, myelopathy,impaired cognition, and extrapyramidal signs. RESULTS The patient had neurologic and hematologic signs of vitamin B(12) deficiency, with elevated methylmalonic acid and homocysteine levels. Brain magnetic resonance imaging showed signal abnormality in the globi pallidi, as can be seen in inherited methylmalonic acidemia.The clinical and radiographic findings reversed with vitamin B(12) administration. CONCLUSION Vitamin B(12) deficiency can present with extrapyramidal symptoms and reversible bilateral globus pallidus abnormalities.