Pachygyria, also known as lissencephaly type II, is a rare brain malformation characterized by a thickened, smooth cerebral cortex with abnormally formed sulci and gyri. It is most commonly caused by genetic mutations and can result in developmental delays, seizures, and other neurological abnormalities. Synonyms for pachygyria include broadgyria, polymicrogyria with abnormal gyration, agyria-pachygyria complex, and lissencephaly type II with agyria. While there is no known cure for pachygyria, early diagnosis and interventions such as medications and therapy can help manage symptoms and improve quality of life. Research on this condition is ongoing, with the hope of discovering new treatment options in the future.