A novel type of encephalopathy associated with mushroom Sugihiratake ingestion in patients with chronic kidney diseases

Background. The etiology of encephalopathy in uremic patients is multiple. We recently encountered a novel type of encephalopathy which occurred exclusively in patients with chronic kidney diseases after ingestion of a mushroom called Sugihiratake. While the exact etiology of this encephalopathy remained mysterious, we aimed to describe its clinical features. Methods. A total of 32 patients with chronic kidney diseases who had presented with encephalopathy following ingestion of Sugihiratake were enrolled from seven prefectures in Japan., with 24 of the 32 patients undergoing regular hemodialysis. The patient's clinical data were from surveillance by The Japanese Society of Nephrology. Results. There was a significant association between Sugihiratake ingestion and the occurrence of encephalopathy in 524 hemodialysis patients questioned for a recent ingestion of this mushroom (P= 0.0006). The latent asymptomatic period before the onset of symptoms varied from 1 to 31 days (mean 9.1 +/- 7.3) days. The patient's symptoms consisted of disturbed consciousness in 30 patients (93.8%), convulsions in 25 (78.1%), myoclonus in 15 (46.9%), dysarthria in ten (31.3%), ataxia in eight (25.0%), paresis or paralysis in seven (21.9%), and skin parasthesia in two patients (6.3%). Nine (27.2%) patients died, mostly due to respiratory failure. The other patients were either discharged or still in hospitals with various degrees of clinical improvement. Conclusion. Patients with chronic kidney diseases are at risk of having serious encephalopathy following Sugihiratake ingestion and must refrain from eating it. Physicians, in those parts of the world, where this mushroom harvesting is common, should be aware of this complication.