Discussion
Dyke, Davidoff and Masson recognized and reported the first cases of this syndrome in 1933.1 Almost a century later, less than 100 cases reported worldwide but its global incidence is still unknown. DDMS falls in the category of epilepsy with brain structural abnormalities of the International League Against Epilepsy classification (ILAE).12 The clinical manifestations encompass a focal and/or generalized drugs-resistant epilepsy, hemiparesis or hemiplegia, facial or body asymmetry with atrophy and mental retardation as seen in our patient.2, 3 Besides these manifestations, rare cases may include cerebellar atrophy, neuropsychiatric disorders and ear malformations.3However, the disease phenotype can vary from one patient to another, and some may not present epilepsy, mental retardation or body asymmetry.13 The patient was referred for convulsive status epilepticus that led to the diagnosis as seen in previous reports.14 DDMS is usually diagnosed in childhood, mostly in the first decade, but cases of late diagnosis or adults cases were also reported.2 Although the syndrome is easily recognizable by clinical and brain imaging findings, the diagnosis delay was eighteen years in our patient. This is likely due to the limited access to specialists who could further investigate with brain imaging as this was not performed before we saw the patient. A similar case with a long diagnosis odyssey was reported in a patient from Nigeria.11 Brain CT-scan or MRI have contributed to facilitate the diagnosis by typically showing hemi cerebral atrophy, ipsilateral thickening of the skull bone and ipsilateral hyper pneumatization of the frontal and paranasal sinuses.15In our case, the hyper pneumatization of the frontal and paranasal sinuses and the thickening of the skull bone were bilateral. To the best of our knowledge, these brain imaging findings have not been previously reported. This case could be another phenotypic variant of DDMS that might be due to some specific genetic factors as suggested by previous studies2 or to recurring brain. Although our patient fulfilled the diagnosis criteria of DDMS, other diseases such as Rasmussen’s encephalitis (RE), hemiplegia-hemi convulsion epilepsy (HHE) syndrome and Sturge Weber syndrome (SWS) are also possible.15, 16 However, in RE and HHE there is no skull bone thickening or a hyper pneumatization of the sinuses that are pathognomonic radiological findings in DDMS as seen in the patient presented here. In addition, in HHE syndrome, the seizures are in the hemiplegia/hemiparesis side without secondary generalization. SWS is a neurocutaneous syndrome characterized by facial birthmark also called port-wine birthmark and cerebral vascular calcifications which were absent in our patient. The management of DDMS is challenging, especially in resource-limited settings due to the resistance to several antiepileptic drugs (AED). The treatment is based on the use of a combination of AEDs and the surgery with hemispherectomy is an option in the case of refractory epilepsy.14