Abstract

Background: Dyke–Davidoff–Masson syndrome (DDMS) is a rare condition characterized by cerebral hemiatrophy with compensatory ipsilateral calvarial thickening and hyperpneumatization of the paranasal sinuses and mastoid air cells, clinically associated with seizures, contralateral hemiparesis and intellectual disability.

Case presentation: A 34-year-old man presented with focal clonic seizures of the left upper limb, occurring about once a week and sometimes evolving to bilateral tonic-clonic seizures, despite carbamazepine and phenobarbital. Born at term with an uneventful perinatal period and normal psychomotor development until the age of 3 years, he was then admitted to the intensive care unit for status epilepticus revealing meningoencephalitis, and was discharged with residual left hemiparesis and epilepsy. Examination showed left spastic hemiparesis, facial asymmetry, and cognitive impairment (MMSE 18/30). MRI revealed right cerebral hemiatrophy with ex vacuo ventricular dilatation, ipsilateral calvarial thickening and sinus hyperpneumatization, and contralateral cerebellar atrophy. EEG showed right-sided slowing with right temporal interictal discharges activated by sleep. The diagnosis of DDMS had never been made and was established only at the age of 34 years, 31 years after symptom onset. After phenobarbital was tapered off and replaced by lacosamide, seizure frequency decreased from about one per week to one per month.

Conclusion: This case illustrates the acquired form of DDMS after childhood meningoencephalitis and emphasizes the long diagnostic delay that may occur in this syndrome. Neuroimaging should be performed in any patient with childhood-onset hemiparesis and epilepsy, as early diagnosis allows timely recognition of drug resistance and optimization of management.

Keywords

Dyke–Davidoff–Masson syndrome, cerebral hemiatrophy, crossed cerebellar atrophy, delayed diagnosis, meningoencephalitis, drug-resistant epilepsy