Rasmussen subacute encephalitis is a rare neurological disorder characterized by inflammation of the brain. It is a progressive disorder that typically affects only one hemisphere of the brain and can cause seizures, motor and cognitive deficits, and language problems. It is most common in children and is often associated with a poor prognosis. Treatment typically involves a combination of medications, physical therapy, and surgery.

The symptoms of Rasmussen subacute encephalitis include:

- Seizures
- Motor Weakness or Paralysis on one side of the body (hemiparesis)
- Cognitive decline
- Speech and language difficulties
- Visual disturbances
- Behavioral changes
- Fatigue
- Headaches
- Fever

The exact cause of Rasmussen subacute encephalitis is unknown. However, it is believed to be an autoimmune disorder, meaning that the body's immune system mistakenly attacks healthy cells in the brain. Other possible causes include genetic factors, viral infections, and environmental triggers.

The treatment for Rasmussen subacute encephalitis typically involves a combination of medications, surgery, and rehabilitation. Medications may include corticosteroids, anticonvulsants, and immunomodulators. Surgery may involve hemispherectomy, a procedure in which one half of the brain is removed, or a hemispherectomy-like procedure, in which a portion of the brain is disconnected from the rest of the brain. Rehabilitation may include physical, occupational, and speech therapy.

1. Age: Rasmussen encephalitis is most commonly seen in children between the ages of 5 and 15.

2. Gender: Rasmussen encephalitis is more common in males than females.

3. Genetics: Rasmussen encephalitis is believed to be caused by a genetic mutation.

4. Immunological factors: Rasmussen encephalitis is believed to be caused by an autoimmune response.

5. Viral infections: Certain viral infections, such as measles, mumps, and rubella, have been linked to Rasmussen encephalitis.

There is no known cure for Rasmussen subacute encephalitis. Treatment typically involves a combination of medications, including corticosteroids, anticonvulsants, and immunomodulatory drugs. Surgery may also be recommended in some cases.