[Maple syrup urine disease decompensation - rare but life-threatening].

Introduction: Maple syrup urine disease (MSUD) is a rare inherited metabolic disease. Breakdown of branched-chain amino acids (leucine, isoleucine, valine) is impaired or absent, which results in metabolite accumulation causing neurotoxicity. With strict therapy adherence (protein restricted MSUD-diet and amino acid supplementation), nearly normal plasma leucin levels can be achieved. However, therapy interruption or catabolic conditions (illness, operation, fasting) can rapidly lead to life-threatening metabolic decompensation. In this report we present the case of a 50 year-old woman who was referred to our hospital with impaired level of consciousness due to delayed recognition of MSUD decompensation. The aim is to increase awareness for this condition and repeat the central treatment aspects.