Subacute sclerosing panencephalitis

Causes

Ordinarily, the measles virus does not cause brain damage, but an abnormal immune response to measles or, possibly, certain mutant forms of the virus may cause severe illness and death. This leads to brain inflammation (swelling and irritation) that may last for years.

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, a dramatic decrease that followed the nationwide measles immunization program. However, in some countries like India, over 20 cases of SSPE per million people are reported each year.

SSPE tends to occur several years after an individual has measles, even though the person seems to have fully recovered from the illness. Males are more often affected than females, and the disease generally occurs in children and adolescents.

Symptoms

• Bizarre behavior
• Dementia (loss of cognitive (thought), emotional, and social abilities)
• Coma
• Gradual behavioral changes
• Myoclonic jerking (quick muscle jerking or spasms)
• School problems
• Seizures
• Unsteady gait
• Very tense muscles or muscles that lack tone, with weakness in both legs

Exams and Tests

There may be a history of measles in an unvaccinated child. A physical examination may reveal:

• Damage to the optic nerve, which is responsible for sight
• Damage to the retina, the part of the eye that receives light
• Muscle twitching
• Poor performance on motor (movement) coordination tests

The following tests may be performed:

• Electroencephalogram (EEG)
• Brain MRI
• Serum antibody titer to look for signs of previous measles infection
• Spinal tap

Treatment

No cure for SSPE exists. However, certain antiviral drugs may slow the progression of the disease.

Outlook (Prognosis)

Persons with this disease frequently die 1 to 2 years after diagnosis, but some may survive for longer periods. The condition is always deadly.

Possible Complications

Prior to death, there may be:

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

When to Contact a Medical Professional

Call your health care provider if your child has not completed their scheduled vaccines. The measles vaccine is included in the MMR vaccine.

Prevention

Immunization against measles is the only known prevention for SSPE. The measles vaccine has been highly effective in reducing the numbers of affected children.

Measles immunization should be done according to the recommended American Academy of Pediatrics and Centers for Disease Control schedule. See: MMR immunization

Alternative Names

SSPE; Subacute sclerosing leukoencephalitis; Dawson´s encephalitis

References

Maldonado YA. Rubeola virus (measles and subacute sclerosing panencephalitis). In: Long SS, ed. Principles and Practice of Pediatric Infectious Diseases. 3rd ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2008:chap 227.

Update Date: 8/1/2012

Updated by: Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.