Clinical, neuro-radiological and prognostic aspects of post-encephalitic catastrophic epilepsies
To determine the prevalence of encephalitis and meningo encephalitis as the causative agents of catastrophic epilepsies (CE) and the incidence of post encephalitic CE, when catastrophic epilepsy is defined as often refractory to treatment and always associated with psychoneurological deterioration. The prevalence of central nervous system (CNS) infections in determining West s syndrome (WS), Lennox Gastaut syndrome (LGS) and HHE syndrome (HHES) was detected in the large series published since 1980 in which the cause was stated. The incidence of CE in the course of meningoencephalitis was deduced from three studies done in the Virgen del Roc o Hospital: study 1 of 1,221 children admitted to hospital with the diagnosis of meningo encephalitis; study 2 of 55 cases of tuberculous meningitis; study 3 of 30 cases of encephalitis. CNS infections causing CE are responsible for from 3 to 11% of all WS, 3 to 8.2% of all LGS and 19% of the HHES with a catastrophic course. The commonest causes are infection due to cytomegalovirus and toxoplasmosis during the prenatal stage and the purulent meningitis, tuberculous meningitis and herpetic encephalitis during the neonatal and postnatal periods. The evidence of CE in meningo encephalitis varies according to the germ, age and severity of the aggression. CNS infections during the neonatal period in 3% of cases cause CE. In babies, newborn and subsequently, tuberculous meningitis (12.7%), measles meningo encephalitis (22%) and herpetic encephalitis (50%) lead to refractory epileptic seizures and very severe psychoneurological deterioration. 1. Encephalitis and meningo encephalitis are commoner than usually thought as a cause of CE. 2. They cause 3 11% of the WS, 3 8% of the LGS and 19% of the HHES. 3. The incidence of CE in the course of meningo encephalitis varies according to the germ involved and the severity of the aggression. 4. CE are very frequent during the course of herpetic encephalitis, measles meningo encephalitis and tuberculous meningo encephalitis. The latter two are becoming much less common. 5. The prognosis is extremely serious