Neurodegenerative diseases in children.

The detection of neurodegenerative and neurometabolic diseases in children relies on a high index of suspicion as most will present as common paediatric problems such as recurrent vomiting, feeding problem, failure to thrive, sepsis, or developmental delay. Alternatively, children may present with an acute encephalopathy or with a chronic progressive encephalopathy. Clinical clues suggestive of neurometabolic disorders include encephalopathic features such as microcephaly, macrocephaly, developmental regression, developmental arrest, change in sensorium, seizures, hypotonia, hypertonia, abnormal eye signs; also extrapyramidal or cerebellar signs and systemic features like abnormal respiration, hepatosplenomegaly, abnormal hair, liver dysfunction, renal tubular dysfunction, cardiomyopathy, and feeding difficulties or growth problems. Initial screening include tests for acidosis, ketosis, hyperlacticemia, and hyperammonemia. Further investigations should amino acid chromatography, assays of organic acids, specific enzyme assay of white cell or fibroblast culture, and histopatholgy of cell and tissue biopsy (white blood cell, skin, muscle, conjunctiva, bone marrow, liver, rectum, or brain). The correct diagnosis holds implications for targeted therapeutic intervention, genetic counselling, and possibly, prenatal diagnosis.