Coma and confirmed epileptiform activity induced by Amanita pantherina poisoning

Amanita pantherina poisoning is a rare event poorly described. The clinical picture is usually associated with the one of A. muscaria, but A. pantherina contains more muscimol causing more often coma. We describe a case of severe coma and seizures after A. pantherina ingestion. A woman of 56 years old was found at home unresponsive with miosis, clonic movements of four limbs, normal respiratory and cardiovascular functions and without cerebral ischemic symptoms. Her husband reported mushrooms ingestion 4 hours earlier that were picked up in the home garden and believed to be Macrolepiota procera. Unenhanced brain CT and cerebral CT angiography were normal. Blood tests were within normal range, including troponin I, creatine phosphokinase and lactate. Toxicological screening was negative for methadone, ecstasy, amphetamines, barbiturate, cannabinoids, cocaine, opioids and benzodiazepines. Suspecting ingestion of A. pantherina, gastrointestinal decontamination was done. Mycological examination of residual stems of the ingested mushrooms identified A. pantherina, and evaluation of photos of the same mushrooms growing in their garden confirmed the species. Electroencephalogram confirmed epileptiform activity and levetiracetam 3.000 mg/day was started. The patient was always hemodynamically stable but daily neurologic wake-up test highlighted the presence of agitation and clonic movements of the limbs up to the 7th day of hospitalization. Levetiracetam was tapered and stopped after two months based on neurological improvement. The patient recovered without sequelae. Amanita pantherina poisoning is a rare event and clinical picture of convulsions and coma often guides the diagnosis towards organic pathologies. The latter should be excluded first but an accurate anamnesis should also consider mushrooms consumption. Gastrointestinal decontamination may be the only therapy for reducing toxins absorption and clinical severity. Our patient had acute severe neurological effects lasted many days, but she completely recovered with intensive treatment and levetiracetam administration.