subacute sclerosing panencephalitis
noun
subacute sclerosing pan·en·ceph·a·li·tis -ˌpan-in-ˌse-fə-ˈlī-təs 
: a usually fatal neurological disease of children and young adults caused by infection of the brain by a previously latent measles virus that is marked especially by behavioral changes, myoclonic seizures, progressive deterioration of motor and mental functioning, and coma
Word History
Etymology
panencephalitis from New Latin, from pan- + encephalitis
First Known Use
1950, in the meaning defined above
Medical Definition
subacute sclerosing panencephalitis
noun
: a usually fatal neurological disease of children and young adults that is caused by infection of the brain by a previously latent morbillivirus causing measles and that is marked especially by behavioral changes, myoclonic seizures, progressive deterioration of motor and mental functioning, and coma —abbreviation SSPE