Thiamine deficiency and unexplained encephalopathy in hemodialysis and peritoneal dialysis patients

Patients with end-stage renal disease undergoing regular dialysis are prone to encephalopathy, but the cause is often unclear. Dialysis patients are a t risk for thiamine deficiency, which may mimic many uremic complications, including encephalopathy. To determine whether unexplained encephalopathy i n regular dialysis patients is associated with thiamine deficiency, we cond ucted a prospective study that enrolled 30 consecutive dialysis patients wi th altered mental status admitted to a referred hospital during a 1-year pe riod. A complete history, physical and neurological examinations, laborator y investigations, and computed tomographic scans or magnetic resonance imag ing of the brain were obtained for each subject. In 10 of the 30 patients, diagnoses remained obscure after the initial workup. Manifestations include d confusion, chorea, acute visual loss, rapidly progressive dementia, myocl onus, convulsions, and coma. Intravenous thiamine was administered to these 10 patients. All 10 patients had thiamine deficiency confirmed by a marked response to thiamine supplementation and/or a low serum thiamine concentra tion (35.3 +/- 6.0 nmol/L; normal, >50 nmol/L). Nine patients recovered, bu t one patient failed to respond because of delayed treatment. We conclude t hat in regular dialysis patients, unexplained encephalopathy can be mainly attributed to thiamine deficiency, This condition is fatal if unrecognized and can be successfully treated with prompt thiamine replacement. (C) 2001 by the National Kidney Foundation, Inc.