[A case of combined central and peripheral demyelination]

A 22-year-old man had had difficulty running fast since about he was 10 years old. In June 2011, he was referred to us because of worsened unsteady gait. A neurological examination revealed mild ataxic speech, weakness of the four limbs, with spasticity, and pes cavus. Magnetic resonance T2-weighted images showed multiple high-intensity lesions in the bilateral periventricular white matter, brainstem, and thoracic spinal cord. Peripheral nerve conduction studies revealed marked motor conduction velocities were markedly reduced and sensory nerve velocities were not evoked in the upper and lower limbs. A sural nerve biopsy showed highly active demyelinating lesions. The patient was treated with high-dose steroid therapy (intravenous methylprednisolone, 1,000 mg/day × 3 days) followed by self-injection of interferon β. With these treatments, his symptoms gradually improved. In this case, we could not detect the causative factors, and all autoantibodies tested, except for the anti-neurofascin antibody, were negative. The anti-neurofascin antibody might induce demyelination in the central and peripheral nervous systems. However, in the literature, the evidence of an association between this antibody and these clinical characteristics is not conclusive. We need more studies on the pathogenesis of combined central and peripheral demyelination to establish more effective therapies.