Hemolytic Uremic Syndrome Complicated by Severe Neuropsychiatric Symptoms: A Case Report and Review of the Literature.

Hemolytic uremic syndrome (HUS) is a thrombotic microangiopathy (TMA) characterized by microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury (AKI). Adult-onset cases that initially manifest with predominantly neuropsychiatric symptoms are uncommon and may delay diagnosis. We describe the case of a 57-year-old female who developed acute cognitive decline, psychomotor retardation, and tremor following the recent use of a compound chlorzoxazone preparation. Laboratory evaluation revealed thrombocytopenia, hemolysis, and renal impairment, while imaging demonstrated reversible white matter abnormalities. Infectious causes and thrombotic thrombocytopenic purpura (TTP) were excluded, and persistently low complement C3 levels supported complement activation. The clinical course and Naranjo probability score suggested a probable association between drug exposure and HUS. The patient improved with comprehensive supportive management, without complement inhibitor therapy. This report highlights the diagnostic challenge of HUS with predominant neuropsychiatric manifestations and underscores the importance of maintaining a high index of suspicion for TMA in patients with unexplained neurological symptoms and concurrent renal or hematologic abnormalities.