From Childhood Seizures to Adult Disability: A Case of Dyke–Davidoff–Masson Syndrome

Introduction: Dyke–Davidoff–Masson syndrome (DDMS) is a rare disorder with classical neuroimaging findings. Because of its low prevalence and heterogeneous clinical presentation, DDMS is frequently underrecognized, resulting in delayed diagnosis and suboptimal management. We present a case of DDMS in a young woman with longstanding refractory epilepsy and progressive neurological deficits. Case Presentation: A 21-year-old female, born at full term to nonconsanguineous parents following an uneventful antenatal and perinatal period, presented with breakthrough seizures. She had a 20-year history of recurrent right-sided focal seizures with occasional secondary generalization. Over the years, she developed worsening right-sided weakness, dysarthria, and learning difficulties. Neurological examination demonstrated right upper motor neuron facial palsy, spastic hemiparesis, brisk deep tendon reflexes, and an extensor plantar response on the right. Electroencephalography revealed epileptiform discharges originating from the posterior temporal region. Magnetic resonance imaging demonstrated marked left cerebral hemiatrophy with ex vacuo dilatation of the left lateral ventricle and prominence of the left Sylvian fissure. Despite the treatment with oxcarbazepine and topiramate, the patient continued to experience recurrent seizures and subsequently levetiracetam and clobazam were added in view of seizure exacerbation. Discussion and Conclusion: First described by Dyke, Davidoff, and Masson in 1933, DDMS is broadly classified into congenital and acquired forms. The congenital variant is attributed to fetal vascular insults, whereas the acquired form may result from perinatal hypoxia, intracranial infections, cerebrovascular disorders, or cranial trauma sustained during early childhood. Important differential diagnoses include Sturge–Weber syndrome, Rasmussen encephalitis, intracranial neoplasms, and Fishman syndrome. Management is primarily supportive and focuses on seizure control using antiepileptic therapy along with multidisciplinary rehabilitation. In carefully selected patients with medically refractory epilepsy and severe hemiplegia, hemispherectomy remains a viable therapeutic option, with reported success rates approaching 85%. Publication History Article published online: 15 July 2026 © 2026. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/) Thieme Medical and Scientific Publishers Private Limited A-13A, Graphix Tower 1, 6th floor, Sector 62, Noida 201309, Uttar Pradesh, India