A prolonged altered mental status: is it absence status epilepticus?

To cite: Amin OSM. BMJ Case Rep Published online: [please include Day Month Year] doi:10.1136/bcr-2013009845 DESCRIPTION An 11-year-old girl was admitted to our acute and emergency department with a 12-h history of confusion and non-responsiveness. There was no fever or neck stiffness. The parents denied any history of head trauma. She was diagnosed with grand mal epilepsy at the age of 7 years and completed a 2-year course of oral sodium valproate. The patient’s mother stated that for the last 2 years she was seizure-free. Routine blood tests, toxicology screen, 12-lead ECG and CT brain scanning were unremarkable. Therefore, she was diagnosed with acute psychosis. However, her EEG is shown in figure 1. Intravenous diazepam of 0.2 mg/kg resulted in a profound improvement; note the abrupt termination of the typically symmetrical generalised 3 Hz spike-and-wave discharges (figure 2). Absence status epilepticus (ASE) is a form of non-convulsive status epilepticus (NCSE). Owing to the protean manifestations of this NCSE (confusion, altered mental status, non-responsiveness and dazed stare with blinking), the diagnosis is usually not entertained and therefore frequently missed. The patient is wakeful but is dazed and may have frequent blinking. Patients with ASE usually have a history of generalised seizures, myoclonus or absence epilepsy. Sometimes, the status may start or end with a brief generalised seizure and the whole event may last for days. Well-recognised precipitants are withdrawal of benzodiazepines, head trauma and metabolic derangements. The EEG examination reveals continuous, generalised, symmetrical 3-Hz spike-and-wave discharges. Intravenous diazepam, lorazepam or chlormethiazole usually terminates the status. Therefore, the EEG examination should always be considered in patients who have unexplained and persistent altered consciousness.