A 57-year-old man presented with three days of nausea/vomiting,mental fogginess, and tremulousness and was found to have hemolytic anemia(hemoglobin 8.6, haptoglobin<8,schistocytes on peripheral smear), thrombocytopenia(platelets 23K) and acute kidney injury(creatinine 8.48,BUN 114,K 5.9).He was started on hemodialysis, treated with 3 cycles of plasmapheresis and steroids followed by Eculizumab for suspected thrombotic microangiopathy.Diagnostic work up revealed positive stool Shiga 2 toxin and normal ADAMST13, suggesting typical HUS.His neurological exam was remarkable for disorientation, inattention, anxiety, agitation, auditory and visual hallucinations, tremor as well as intermittent diffuse myoclonus.VideoEEG showed mild slowing consistent with mild encephalopathy.MRI brain was unremarkable.His neurological symptoms improved after hemodialysis on hospital day(HD) 11, and he was discharged on HD16.Two days after discharge, he returned after having a generalized tonic-clonic seizure without return to baseline.He was intubated and treated with levetiracetam, phenytoin, propofol, and midazolam infusions for possible status epilepticus.After this, his exam was significant for rare clonic movements of bilateral upper extremities, extensor posturing to noxious stimulus, hyperreflexia, sustained clonus, and upgoing toes.VideoEEG showed diffuse attenuated slowing and no epileptiform discharges or seizures.Lumbar puncture revealed WBC 7/μL, RBC 4/μL, glucose 94 mg/dl, protein 40mg/dL.MRI brain and cervical spine were unremarkable.Extensive microbiological work up and autoimmune encephalitis panel were negative.He remained severely encephalopathic and hyperreflexic.Repeat lumbar puncture on HD5 demonstrated WBC 3/μL, RBC 1/μL, protein 88mg/dL, glucose 98mg/dl.His mental status gradually improved and he was extubated on HD14.He had a normal neurological exam on HD27.