E.O. was a 5 year old boy who was treated in January for an upper respiratory infection. About 6 months later he had his first grand mal seizure. He then began experiencing partial seizures where the right side of his body would jerk uncontrollably. He was started on medication but it did not stop the seizures. A number of other medications were tried without success. Over the next 2 years, he started having slurred speech and weakness of the right side of his body. IVIG helped his seizures temporarily but then the seizures came back. He had a functional hemispherectomy one year later. He is now seizure free and able to walk after months of physical therapy. He cannot use his right hand but has learned to write with his left hand.
Rasmussen syndrome usually begins between 14 months and 14 years of age and is associated with slowly progressive neurologic deterioration and seizures. Seizures are often the first problem to appear. Simple partial motor seizures are the most common type, but in one-fifth of these children, the first seizure is an episode of partial or tonic-clonic status epilepticus.
Although Rasmussen syndrome is rarely fatal, its effects are devastating. Progressive weakness on one side (hemiparesis) and mental handicap are common, and language disorder (aphasia) often occurs if the disorder affects the side of the brain that controls most language functions, which is usually the left side. Mild weakness of an arm or leg is the most common initial symptom besides seizures. The weakness and other neurologic problems often begin 1 to 3 years after the seizures start. CT and MRI scans of the brain show evidence of a slow loss (atrophy) of brain substance. 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.
Treatment of this disease with antiepileptic drugs is disappointing. Steroids may be effective, but additional studies are needed. Immunologic therapies (gamma globulin, plasmapheresis, prednisone) may be helpful in some cases. In children with severe weakness and loss of touch sensation and vision on the side of the body opposite to the involved hemisphere of the brain, a surgical procedure called a functional hemispherectomy may be successful.