Myoclonic seizure typically seen in: (PGI Nov 2011)
Subacute Sclerosing Panencephalitis (SSPE)
1). SSPE is a chronic complication of measles with a delayed onset and an outcome that is nearly always fatal
2). This is considered a 'slow virus infection' and is believed to result from persistent infection with an altered measles virus that is harboured intracellularly in CNS for several years.
Note: Stage II of SSPE - Massive Myoclonus Is Characteristic - Nelson 18h /1335