This syndrome is a very rare brain malfunction which may happen during any time of childhood, although it commonly affects those aged between 3 to 11 years. This syndrome causes brain cells in one hemisphere (half) of the brain to become inflamed and swollen.
Recent studies suggest that the cause of Rasmussen’s syndrome is an autoimmune disorder (antibodies are produced against the body’s own tissues) directed against receptors on the brain cells. The process may be triggered by a viral infection, and possibly other triggering causes. Seizures are often the first symptom of the syndrome, which generally increase in frequency and may become continuous. Over time progressive weakness on one side of the body, and thinking/memory/language impairment is generally experienced.
For more information about Rasmussen’s syndrome visit the Epilepsy Foundation USA