Rasmussen's Encephalitis - Causes and Pathophysiology

Causes and Pathophysiology

In Rasmussen’s encephalitis, there is chronic inflammation of the brain, with infiltration of T lymphocytes into the brain tissue. This affects only one cerebral hemisphere, either the left or the right. This inflammation causes permanent damage to the cells of the brain, leading to atrophy of the hemisphere; the epilepsy that this causes may itself contribute to the brain damage.

The cause of the inflammation is not known: infection by a virus has been suggested, but the evidence for this is inconclusive. In the 1990s it was suggested that auto-antibodies against the glutamate receptor GluR3 were important in causing the disease, but this is no longer thought to be the case. However, more recent studies report the presence of autoantibodies against the NMDA-type glutamate receptor subunit GluRepsilon2 (anti-NR2A antibodies) in a subset of patients with Rasmussen's encephalitis.

Rasmussen's encephalitis has been recorded with a neurovisceral porphyria, acute intermittent porphyria and after ADEM (acute disseminated encephalomyelitis).