General description

Sugihiratake mushroom encephalopathy is a form of acute encephalopathy that was reported in Japan in 2004 among primarily middle-aged and elderly patients with advanced kidney disease or chronic renal failure undergoing dialysis. These individuals developed symptoms after consuming the Sugihiratake mushroom (Pleurocybella porrigens) from the Tricholomataceae family, commonly eaten in Japan, especially in mountainous areas, though not widely distributed in supermarkets. The condition typically began with disorientation and unsteady gait, progressing within a few days to involuntary movements, myoclonus, and tonic-clonic seizures, often evolving into status epilepticus.

Though various hypotheses were proposed, including possible accumulation of harmful metals due to renal impairment, the exact cause remains unknown. Public health advisories were issued, urging chronic renal failure patients to avoid consuming Sugihiratake mushrooms, and new cases have since dramatically decreased. However, caution is still advised to prevent future occurrences.

Radiographic features

In the acute phase, MRI shows bilateral T2WI and FLAIR hyperintensity with swelling in the basal ganglia, insular cortex, and hippocampus, often accompanied by swelling.

In the chronic phase, atrophy of the basal ganglia may be observed, along with T1WI hyperintensity reflecting hemosiderin deposition.