Measles virus usually doesn't cause brain damage, but certain mutant forms can invade the brain, causing severe illness and death. SSPE has been reported in all parts of the world, but in western countries it is considered a rare disease.

Fewer than 10 cases per year are reported in the United States, decreasing the frequency of this disease dramatically, following the nationwide measles immunization program. However, in some countries like India, over 20 cases of SSPE per million people are annually reported.

SSPE tends to occur several years after having measles (rubeola), even though recovery from the illness appears to have been normal. More males are affected than females, and the disease generally occurs in children and adolescents.

Affected individuals frequently die one to two years after being diagnosed with this condition, but some may survive for longer periods.

SSPE is due to the direct invasion of brain cells by the mutant measles virus, which provokes brain inflammation (swelling and irritation with presence of extra immune cells) that can last for years.

• Gradual onset of behavioral changes
• School problems
• Bizarre behavior
• Myoclonic jerking (quick muscle jerking or spasms)
• Seizures
• Dementia (loss of cognitive, emotional, and social abilities)
• Unsteady gait
• Coma
• Patients may be rigid or flaccid, with weakness on both legs

There may be a history of measles in an unvaccinated child. Physical examination may show signs of optic nerve damage, damage to the retina (the part of the eye that perceives light and looks red when a photograph is taken with flash), poor motor cordination tests, and muscle twitching.

Tests:

• Electro-encephalogram (EEG): is a test of the electrical activity of the brain, which may show a wave pattern which is typical of SSPE
• Brain MRI, which provides high-quality pictures of the brain
• Serum antibody titer (concentration of the antibody), measles (rubeola) shows elevated titer to measles virus
• Spinal tap for analysis of the protein (immunoelectrophoresis) in the collected fluid
• Anti-measles virus antibodies

No cure for SSPE exists. However, certain anti-viral drugs can slow the progression of the disease. A combination of oral isoprinosine and interferon alfa injected directly into the brain ventricles, appears to be the most effective treatment.

Ribavirin and Amantadine are other anti-viral medications that have been used with limited success. Patients responding to treatment need to receive it for the rest of their lives. Effective immunization against measles to prevent development of this condition is the only solution presently available.

• Behavior changes
• Dementia
• Stupor and coma
• Seizures and subsequent injuries