Rinsho Shinkeigaku (Clinical Neurology)

Brief Clinical Note

A case of alcoholic with vitamin B12 deficiency presenting central pontine and extrapontine myelinolysis on MRI

Akiko Nagaishi, M.D.1)2), Motohiro Yukitake, M.D.2), Makoto Eriguchi, M.D.2) and Yasuo Kuroda, M.D.2)

1)Department of Internal Medicine, Karatsu Red Cross Hospital
2)Division of Neurology, Department of Internal Medicine, Faculty of Medicine, Saga University

A 55-year-old man with chronic alcoholism was first referred to us in 1992 because of spastic quadriparesis. T2-weighted images of MRI showed pontine and extracapsule lesions as central pontine and extrapontine myelinolysis (CPM/EPM). He had macrocytic anemia with normal serum level of vitamin B12 (B12). Gait disturbance was progressively worsened from the end of 2004 and dysuria appeared from June, 2005. Neurological examination on admission in November, 2005, showed mild impairment of recent memory, spastic paraparesis with hyperreflexia in all limbs, loss of deep sensations in lower limbs and urinary disturbance. The low serum level of B12 with marked macrocytic anemia was noted. On MRI, the pontine lesion extended to the midbrain but no abnormality was found in the spinal cord. We intramuscularly administered B12, resulting in marked improvement of both anemia and neurological symptoms. The brainstem lesion on MRI, however, was unchanged. We assume that B12 deficiency was involved in the formation of CPM/EPM and the neurological symptoms in our patient.

(CLINICA NEUROL, 47: 173－176, 2007)
key words: vitamin B12, central pontine myelinolysis, extrapontine myelinolysis, subacute combined degeneration of the spinal cord, homocystein

(Received: 3-Jul-06)