Management of acute metabolic decompensation in maple syrup urine disease: a multi-center study

Therapeutic modalities in acute metabolic decompensation in maple syrup urine disease (MSUD) are variable, and outcomes of each therapeutic measure have been known only individually. Factors that affect neurological outcome are not clear.

A questionnaire was sent throughout Japan to each pediatrician treating any of the 42 MSUD patients.

Necessary information was available for 13 patients through the questionnaire, and through a publication for one patient. In nine of the 14 patients episodes of metabolic decompensation developed in the neonatal period. In the other five, the onset of disease was delayed until infancy or later. In the nine patients with neonatal onset, a pretreatment level of plasma leucine greater than 40 mg/100 mL or a duration of altered level of alertness longer than 10 days was associated with a poor neurological outcome. The therapeutic measures employed included intravenous infusion of glucose and electrolyte solution or hypertonic glucose and electrolyte solution, exchange transfusion, peritoneal dialysis, a large dose of thiamine and intravenous hyperalimentation. All patients had survived the episodes and were alive at the time of the survey. Five of the nine patients with neonatal onset have developed neurological sequelae to varying degrees. Episodes of metabolic decompensation in infancy or thereafter did not affect, or only minimally affected, the neurological outcome.

Therapeutic goals to improve neurological outcome are to shorten the duration of the altered level of consciousness, and to minimize the peak plasma leucine level as much as possible.