Subacute sclerosing panencephalitis

  • Definition
    • Subacute sclerosing panencephalitis (SSPE) is a progressive, debilitating, and deadly brain disorder related to measles (rubeola) infection.

  • Alternative Names
    • SSPE; Subacute sclerosing leukoencephalitis; Dawson's encephalitis

  • 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 response 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. This dramatic decrease 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. The disease generally occurs in children and adolescents.

  • Symptoms
    • Symptoms may include:

      • Bizarre behavior
      • Dementia (loss of mental, 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:

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

  • Outlook (Prognosis)
    • People 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.

  • 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.

      Ropper AH, Samuels MA. Viral infections of the nervous system, chronic meningitis, and prion diseases. In: Ropper AH, Samuels MA, eds. Adams & Victor's Principles of Neurology. 10th ed. New York, NY: McGraw Hill; 2014:chap 33.