Subacute sclerosing panencephalitis

Definition

Subacute sclerosing panencephalitis is a rare, progressive brain disorder caused by an abnormal immune response to the measles virus.

Description

This fatal condition is a complication of measles, and affects children and young adults before the age of 20. It usually occurs in boys more often than in girls, but is extremely rare, appearing in only one out of a million cases of measles.

Causes & symptoms

Experts believe this condition is a form of measles encephalitis (swelling of the brain), caused by an improper response by the immune system to the measles virus.

The condition begins with behavioral changes, memory loss, irritability, and problems with school work. As the neurological damage increases, the child experiences seizures, involuntary movements, and further neurological deterioration. Eventually, the child starts suffering from progressive dementia. The optic nerve begins to shrink and weaken (atrophy) and subsequently the child becomes blind.

Diagnosis

Blood tests and spinal fluid reveal high levels of antibodies to measles virus, and there is a characteristically abnormal electroencephalogram (EEG), or brain wave test. Typically, there is a history of measles infection two to ten years before symptoms begin.

Treatment

There is no standard treatment, and a number of antiviral drugs have been tested with little success. Treatment of symptoms, including the use of anticonvulsant drugs, can be helpful.

Prognosis

While there may be periodic remissions during the course of this disease, it is usually fatal (often from pneumonia) within one to three years after onset.

Key Terms

Measles encephalitis

A serious complication of measles occurring in about one out of every 1,000 cases, causing headache, drowsiness, and vomiting seven to ten days after the rash appears. Seizures and coma can follow, which may lead to retardation and death.

Further Reading

For Your Information

Books

• Adams, R.D., and M. Victor, eds. Principles of Neurology, 5th ed. New York: McGraw-Hill, 1993.
• Thoene, Jess G., and Nancy P. Coker, eds. Physician's Guide to Rare Diseases, 2nd ed. Montvale, NJ: Dowden Publishing Co., 1997.

  Periodicals

• Frank, J., et al. "SSPE: But We Thought Measles was Gone!" Journal of Pediatric Nursing, 6 (2) (April 1991): 87-92.

  Organizations

• National Organization for Rare Disorders (NORD). PO Box 8923, New Fairfield, CT 06812. (203) 746-6518.
• National Institute of Allergy and Infectious Disease. 9000 Rockville Pike, Bldg. 31, Rm. 7A32, Bethesda, MD 20892. (301) 496-5717.

Gale Encyclopedia of Medicine. Gale Research, 1999.