Subacute sclerosing panencephalitis is a progressive, usually fatal, brain disorder occurring months to usually years after an attack of measles. It produces mental deterioration, myoclonic jerks, and seizures. Diagnosis involves EEG, CT, CSF examination, and measles serology. Treatment is supportive. SSPE is a persistent measles virus infection. Affected patients have measles virus in brain tissue.
SSPE occurs in about 6 to 22 cases per million people who had wild measles and in about 1 case per million people receiving measles vaccine; some cases may be due to unrecognized measles before vaccination. Males are more often affected. Onset is usually before age 20. SSPE is exceedingly rare in the US and Western Europe.
Symptoms and Signs
Often, the first signs are subtle-diminished performance in schoolwork, forgetfulness, temper tantrums, distractibility, and sleeplessness. However, hallucinations and myoclonic jerks may then occur, followed by generalized seizures. There is further intellectual decline and speech deterioration. Dystonic movements and transient opisthotonos occur. Later, muscular rigidity, dysphagia, cortical blindness, and optic atrophy may occur. Focal chorioretinitis and other funduscopic abnormalities are common. In the final phases, hypothalamic involvement may produce intermittent hyperthermia, diaphoresis, and pulse and BP disturbances.
Diagnosis
SSPE is suspected in young patients with dementia and neuromuscular irritability. EEG, CT or MRI scan, CSF examination, and measles serology are obtained. EEG shows periodic complexes with high-voltage diphasic waves occurring synchronously throughout the recording. CT or MRI may show cortical atrophy or white matter lesions. CSF examination usually reveals normal pressure, cell count, and total protein content; however, CSF globulin is almost always elevated, constituting up to 20 to 60% of the CSF protein. Serum and CSF contain elevated levels of measles virus antibodies. Anti-measles IgG appears to increase as the disease progresses. If test results are inconclusive, brain biopsy may be needed.
Prognosis and Treatment
The disease is almost invariably fatal within 1 to 3 yr (often pneumonia is the terminal event), although some have a more protracted course. A few patients have remissions and exacerbations. Antiepileptics and other supportive measures are the only accepted treatments. Isoprinosine, interferon-?, and lamivudine are controversial, and antiviral drugs have generally not proved helpful.
Special thanks for Merck & Co., for permission to use the above article on our website. The above excerpt is copyright protected © 1995-2008 Merck & Co., Inc. Read more) From The Merck Manual of Diagnosis and Therapy, Edition 18,edited by Mark H. Beers. Copyright 2006 by Merck & Co., Inc., Whitehouse Station, NJ. is available online. Please visit all of The Merck Manuals free online.