Dyke-Davidoff-Masson syndrome is a disorder involving hemiatrophy or hypoplasia of 1 cerebral hemisphere secondary to an insult in the developing brain. Often this will manifest with seizures, hemiparesis, mental retardation, and facial changes. Associated with this pathology are the radiologically evident changes, such as thickening of the calvarium, hyperpneumatization of the sinuses, and dilation of the ipsilateral lateral ventricle among others.