Metabolic Disorders among Children Presenting with Acute Encephalopathy.

Objective: To study the clinicoetiological profile of children presenting with acute noninfectious encephalopathy (NIE) and identify the proportion of children having inborn errors of metabolism (IEM).

Method: This descriptive cross sectional study was conducted in a tertiary care centre in Northern India. Consecutive children, aged more than 28 d and less than 12 y, with acute encephalopathy were enrolled after ruling out CNS infection. All children were evaluated on an internally validated structured proforma. A sequential pre-decided battery of tests was applied to determine the cause of encephalopathy. IEM suspects were subjected to TMS/GCMS followed by mutation analysis for confirmation.

Results: Fifty children with noninfectious encephalopathy (NIE) were recruited and metabolic causes were detected in 9 of these children (18%), aged 3 to 42 mo, with female preponderance. The IEMs included lactic acidosis (4), glutaric aciduria (3), isovaleric academia (1), and hyperhomocysteinemia (1). History of previously affected siblings and consanguinity between the parents were important indicators of IEM. MS/MS and mutation analysis were the mainstay of diagnosis in these patients. IEMs contributed to the most common cause amongst cases of NIE.

Conclusion: IEMs constitute a significant proportion of NIE in India and a high index of suspicion is required to make the diagnosis.