Abstracts

Rationale: Herpes simplex virus (HSV) encephalitis can manifest with different clinical presentations including acute monophasic illness and biphasic chronic granulomatous HSV encephalitis. Chronic granulomatous HSV encephalitis is a rare manifestation in children, and rarely late relapses are associated with intractable epilepsy and progressive neurological deficits with or without evidence of HSV presence in CSF. Chronic granulomatous inflammation with multinucleated giant cells, gliosis and multifocal mineralization results in focal destruction of brain parenchyma. Continuous spikes and waves during sleep (CSWS)/ESES is acknowledged as one of the epileptic encephalopathies seen in children. The burden of EEG abnormality outweigh the clinical seizures. Often this syndrome results in neuropsychological regression and behavioral problems associated with, continuous epileptiform activity for more than 85% of non-rapid eye movement (NREM) sleep. Methods: We report herein, an eight-year old girl with a history of treated HSV-1 encephalitis at 13 months of age who subsequently developed seizure disorder and worsening behavioral pattern changes. Her electroencephalography (EEG) at the time of these problems demonstrated focal electrical status epilepticus during slow-wave sleep (ESES) and isolated electrographic seizures in the right temporal and frontal regions. Surgical resection was performed to remove temporal lobe encephalomalacia and tailored based on the ECOG data. Her pathology findings were consistent with "chronic granulomatous encephalitis". Following surgery, focal ESES and seizures were resolved. Results: To best of our knowledge, 11 cases involving pediatric patients with chronic granulomatous herpes simplex encephalitis have been reported until today. Our patient is one of these few reported cases, additionally, this is the first case report of chronic granulomatous HSV encephalitis causing Epileptic Encephalopathy associated with focal ESES. Conclusions: This patient highlights: 1) the role of chronic inflammation and epileptogenesis, 2) reversible course of epileptic encephalopathy following epilepsy surgery. Funding: We confirm that no form of external funding was received for this work from any organization.