Herpes simplex virus (HSV) is a common cause of viral encephalitis. They presented with relatively mild clinical disease but despite treatment with acyclovir (10 mg/kg/day for three days in case 1 and 10 days in case 2) they developed dramatic, progressive changes (shown on brain CT) that mimicked space occupying lesions of the temporal lobes. Contiguous spread from the brain to the eyes may have occurred via the optic nerves. 99mTc-HMPAO SPECT showed an increased accumulation of the tracer in this lesion. Yet, there are no randomized controlled trials for the management of acute seizures, preventive measures or the ideal duration of antiepileptic treatment. Hence, concepts for the medical treatment of seizures during the acute phase of HSE and postencephalitic epilepsy are eagerly awaited. Epilepsy surgery is a potential treatment option for the latter, but only promising in a subgroup of patients suffering from unilateral mesio-temporal lobe epilepsy and congruent neuropsychological impairment.
Relapsing HSE and post-infectious autoimmune conditions can lead to seizures in the aftermath of acute HSE. These conditions need to be kept in mind in order to promptly assure the initiation of accurate diagnostic steps and respective treatment. The purpose of this review is to summarize the current pathogenetical understanding, clinical and diagnostic considerations, and treatment options of seizures in acute HSE and postencephalitic epilepsy.