Most encephalopaties due to an underlying metabolic (inborn error of metabolism) disorders are genetic, present early in life, and disrupt normal metabolic function. Most these disorders are individually rare, but collectively are common and important cause of preventable morbidity and mortality, both are high if missed or not treated early. There are more than 500 biochemically diverse disorders with many significant recent advances in the diagnosis and treatment that substantially improved prognosis. Pediatricians and neonatologists are vital in early identification, particularly given that the diagnosis needs to be established quickly. Collaboration with a specialized unit is needed for timely consultations and referrals. The neonatal period is a time of substantial catabolism, therefore, neonates has limited response to severe overwhelming illness resulting in death or permanent neurological sequelae. The aim of this chapter is to provide a practical approach to the recognition and investigations of metabolic encephalopathy presenting early in life. Guidelines for the stabilization and initial management will be provided.
Keywords: Metabolic, Motor, Development, Regression, White matter, Grey matter, Mitochondria, Lysosomal, Peroxisomal, Decompensation.