Dyke-Davidoff-Masson syndrome in a young adult: Lifelong hemiparesis and characteristic MRI findings.

Dyke-Davidoff-Masson syndrome (DDMS) is a rare disorder characterized by cerebral hemiatrophy and compensatory calvarial changes. We report a 22-year-old male with lifelong left-sided spastic hemiparesis and developmental delay, with a history of prematurity, neonatal meningitis, and childhood head trauma. Brain MRI demonstrated right cerebral hemiatrophy, exvacuo dilatation of the lateral ventricle, ipsilateral sulcal prominence, calvarial thickening, frontal sinus enlargement, and Wallerian degeneration of the corticospinal tract. This case is notable for the coexistence of multiple early-life insults contributing to acquired DDMS and the clear demonstration of classic imaging findings in adulthood. The report highlights the importance of correlating clinical history with imaging for accurate diagnosis and long-term management.