Lissencephaly

Lissencephaly, meaning smooth brain, is a set of rare brain malformations in which all or part of the brain's surface lacks its normal folds and grooves, caused by defective migration of neurons to their proper positions in the developing brain during roughly the twelfth to twenty-fourth week of gestation. An MRI of an affected brain typically shows the characteristic smooth cortical surface, with folds absent or greatly reduced and the cortex itself abnormally thickened. Children born with lissencephaly show severe developmental impairment along with difficulty gaining weight, seizures, and muscle stiffness or weakness, and often have unusual facial features, swallowing difficulties and abnormalities of the hands or feet. Historically life expectancy was around two years, but with modern management of seizures and respiratory complications many children now live well beyond age ten, though aspiration and respiratory disease remain the leading causes of death, and most affected children remain developmentally delayed at an early level throughout their lives.