Usually preceded by fever and has a relentless course. Psychiatric problems are more common. There is confluent, asymmetric demyelination involving both cerebral and cerebellar hemispheres and brain stem. Has a concentric or lamellar pattern. Is progressive and seen in young people.
Larger lesions have a tendency to coalesce and form confluent lesions.
The plaques usually involve the posterior and lateral segments of the cord and they do not respect boundaries between grey and white matter and specific white matter tracts. The plaques are usually wedge shaped with it's apex pointing to the centre of the cord. The plaques are sharply defined and there is no edema in chronic cord lesions. Spinal cord atrophy may be seen with chronic disease. Contrast enhancement is usually homogenous.