Lissencephali

Lissencephaly is a rare congenital brain malformation characterized by a smooth brain surface, meaning the characteristic folds and grooves (gyri and sulci) that are normally present in a developed brain are absent or greatly reduced. This condition is caused by a disruption in neuronal migration, the process by which neurons travel to their correct positions in the developing brain during fetal development. The absence of these folds leads to a thickened cerebral cortex.

The severity of lissencephaly can vary. In some cases, it is a complete absence of gyri, known as agyria, while in others, there may be some shallow grooves, termed pachygyria. Lissencephaly is associated with a range of neurological problems, often severe, including intellectual disability, developmental delays, seizures, and motor impairments. The prognosis depends on the specific genetic cause and the extent of brain malformation.

Diagnosis is typically made through neuroimaging, such as ultrasound or MRI, during pregnancy or after birth. Genetic testing can often identify the underlying cause, as lissencephaly can be caused by mutations in various genes, including LIS1 and DCX. There is no cure for lissencephaly, and management focuses on addressing the symptoms, such as anti-epileptic medications for seizures and supportive therapies for developmental challenges.