We report a 56 years old male who developed a transverse myelopathy with cuadriparesis, neurogenic bladder and a sensitive level at C4. Cerebral and spinal cord magnetic resonance imaging showed only one demyelinative lesion at the cervical level. Post mortem neuropathological study showed segmental myelin loss without anatomical limits and with axonal preservation in the involved spinal cord segment. This lesion had the classical features of multiple sclerosis. The isolated lesion, the pathological findings and the delayed age of onset allow the definition of this case as an isolated nervous system demyelinative syndrome.