Subacute sclerosing panencephalitis (SSPE) is a disease of young children and adults caused by measles virus or a virus very closely related to it. The disease is more frequent in boys as compared to girls and generally starts in patients below the age of 10.
It has insidious onset with a slowly progressive course spread over two to six months. In the first phase of disease there are behavioral disturbances and some intellectual deterioration.
This is shown by the child performing poorly at school. This phase is followed by phase in which there are involuntary movements like ataxia, in-coordination and myoclonic jerks.
Abnormalities of pyramidal and extra-pyramidal tracts develop within a few months. Visual disturbances (cortical blindness, papilloedema, optic atrophy) are common.
The child becomes bed ridden in a period of 6 to 9 months. This is the third and final stage of decortication. There are no signs of meningeal irritation or fever. Death occurs within 1 to 2 years due to inter current pulmonary or urinary infections.
Investigations of Subacute sclerosing panencephalitis
CSF shows increase in oligo-clonal IgG but otherwise is normal. It may show paretic colloidal gold curve. Elevated levels of measles antibody are found in blood and CSF.
BEG shows a “burst suppression” pattern with high voltage slow wave activity followed by electrical inactivity. CT and MRI scans show left ventricular dilatation, cortical, brain stem and cerebellar atrophy.
The lesions occur in the grey and white matter of cerebral hemispheres brain stem and cerebellum. There is lymphocytic and mono-nuclear infiltration around small vessels of the brain along with neuronal cell loss and reactive gliosis.
There is demyelination of medullated nerve fibers. Inclusion bodies containing viral particles are present in the cytoplasm of neurons and glial cells.
It is unsatisfactory. Antiviral drugs like inosiplex, ribavarin and interferon may be tried but their effectiveness is doubtful.
The Subacute sclerosing panencephalitis disease in young children and adults can be prevented by giving measles vaccine in young age.