subacute sclerosing panencephalitis

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 and 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.

Resources

Organizations

National Institute of Allergy and Infectious Disease. Building 31, Room 7A-50, 31 Center Drive MSC 2520, Bethesda, MD 20892-2520. (301) 496-5717. http://www.niaid.nih.gov/default.htm.

National Organization for Rare Disorders. P.O. Box 8923, New Fairfield, CT 06812-8923. (800) 999-6673. http://www.rarediseases.org.

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subacute sclerosing panencephalitis

n. Abbr. SSPE

An often fatal degenerative disease of the central nervous system occurring chiefly in young people, caused by slow infection with a measles virus and characterized by progressive loss of mental and motor functions ending in dementia and paralysis.

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subacute sclerosing panencephalitis,

a rare progressive neurologic disorder occurring with primary measles infection in children 2 years of age or younger, with a period of latency for 2 to 10 years. The condition occurs in children and in adolescents who have had measles at a very early age. It is characterized by diffuse inflammation of brain tissue, personality change, seizures, ataxia myoclonus, visual disturbances, dementia, fever, and death. Live measles virus can be cultured from brain tissue. No effective therapy is known; however, some antiviral drugs can slow the progression of the disease. A combination of oral Isoprinosine and interferon alfa injected into ventricles of the brain appears to be the most effective treatment. See also slow virus.

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subacute sclerosing panencephalitis

Dawson's encephalitis, SSPE Neurology A slow virus-induced inflammation evoked by the measles virus or its vaccines Clinical Onset in childhood, with mental dysfunction, dyskinesia, myoclonus, hypotonia, emotional lability; it is usually fatal in 1-3 yrs Lab Paretic gold curve with ↑ CSF Igs Management None. Cf Prion.