Acute encephalitis with refractory, repetitive partial seizures: case reports of this unusual post-encephalitic epilepsy.

ABSTRACT

We report on three acute encephalitis patients with refractory, repetitive partial seizures (AERRPS). All three suffered acute febrile episodes associated with status epilepticus, which necessitated high-dose barbiturate therapy under artificial ventilation for several weeks. Electroencephalography (EEG) revealed a predominance of diffuse epileptiform discharges initially, subsequently developing into periodic bursts of these discharges. Reduction of the barbiturate dosage resulted in clinical and subclinical partial seizures appearing repetitively in clusters. Prolonged fever persisted for 2-3 months, even several weeks after normalization of cell counts in the cerebrospinal fluid. The EEG showed an improvement after resolution of this fever, and seizures became less frequent, although still intractable. Oral administration of high-dose barbiturate and benzodiazepines were partially effective during the acute phase, and a barbiturate dependency, lasting for years, was noted in one patient. Steroid administration was effective in stopping the febrile episodes in one patient, with concurrent improvement in seizure control. Magnetic resonance imaging showed enhancement of bitemporal cortical areas in one patient, and high signal intensity on T2 weighted image in the bilateral claustrum in another patient. Diffuse cortical atrophy appeared within two months after the onset of encephalitis in all patients. The evolution of the seizures and EEG findings suggested a high degree of cortical excitability in AERRPS. In this report, we propose a tentative therapeutic regimen for seizure control in this condition. We also hypothesize that a prolonged inflammatory process exists in the cerebral cortex with AERRPS, and may be pivotal in the epileptogenesis.