- - subacute sclerosing p. (SSPE) a rare chronic, progressive encephalitis that affects primarily children and young adults, caused by the measles virus. Characterized by a history of primary measles infection before the age of 2 years, followed by several asymptomatic years, and then gradual, progressive psychoneurological deterioration, consisting of personality change, seizures, myoclonus, ataxia, photosensitivity, ocular abnormalities, spasticity, and coma. Characteristic periodic activity is seen on EEG; pathologically, the white matter of both the hemispheres and brainstem are affected, as well as the cerebral cortex, and eosinophilic inclusion bodies are present in the cytoplasm nuclei of neurons and glial cells. Death usually occurs within 3 years. SYN: Bosin disease, Dawson encephalitis, inclusion body encephalitis, sclerosing leukoencephalitis, subacute inclusion body encephalitis, subacute sclerosing leukoencephalitis, van Bogaert encephalitis.
* * *pan·en·ceph·a·li·tis .pan-in-.sef-ə-'līt-əs n, pl -lit·i·des -'lit-ə-.dēz inflammation of the brain affecting both white and gray matter see SUBACUTE SCLEROSING PANENCEPHALITIS
* * *pan·en·ceph·a·li·tis (pan″ən-sef″ə-liґtis) a type of encephalitis, probably of viral origin, that produces intranuclear or intracytoplasmic inclusion bodies that cause parenchymatous lesions in both gray and white matter of the brain.
Medical dictionary. 2011.