lissencephaly
Pronunciation: lis-en-SEF-ah-lee
A rare brain malformation characterized by absent or reduced brain folds (gyri), resulting in a smooth brain surface.
Full Definition
Lissencephaly, literally meaning 'smooth brain,' is a severe neurological disorder caused by defective neuronal migration during fetal development. The condition results in a brain surface that lacks the normal convolutions (gyri and sulci), appearing abnormally smooth. This malformation leads to severe developmental delays, intellectual disability, and often intractable seizures. There are several genetic subtypes, most commonly caused by mutations in the LIS1 or DCX genes. The condition is typically diagnosed through brain imaging and requires comprehensive neurological management throughout the patient's life.
Usage
Usage note: Not to be confused with agyria, which is a more severe form of the same spectrum.
In Context
- "The infant's MRI demonstrated classic type 1 lissencephaly with a smooth cortical surface and thick cortex." — Radiology report
- "Genetic testing confirmed lissencephaly secondary to a LIS1 gene deletion." — Genetics consultation note