Abstracts

Rationale: Revelation of a spontaneous meningoencephalocele (MEC) during adulthood is unusual. They are revealed mostly by otorhinolaryngological infectious symptoms or neurological deficits. We report seven cases of spontaneous meningoencephalocele revealed by partial seizures as their single manifestation.Methods: A MEC is a herniation of brain tissue covered by meninges through a bony defect of the skull base or cranial vault. It is considered spontaneous in the absence of a medical history of brain or otorhinolaryngological surgery, trauma, infection, neoplasm or metabolic damage of the skull. Results: Patients and clinical data The seven patients we report are aged between 20 and 58. Their epilepsies began between 6 and 16 years before they were addressed in our tertiary epilepsy centre. In six patients the brain herniation involved the temporal lobe, in one patient the lateral aspect of the occipital lobe. The diagnosis is made by MRI and CT scan which are showing the bony defect and the involved cortex. In all the patients the epilepsy was the only clinical manifestation: the seizures were simple and complex partial with clinical features consistent with the MEC anatomical localisation. In three cases the diagnosis of MEC was easily made on the first MRI, in the four other cases the MRI was initially considered as normal, then the epilepsies cryptogenic, because the MEC is very small. Two cases are seizure free after a single medication. One has very rare seizures with medication. Four of these patients developed a drug-resistant epilepsy. Three patients were operated on after a presurgical evaluation including video-EEG seizures recording: in one case the seizures recurred (Engel III); the second patient is seizure free since operation (4 years follow-up); the last operated patient is seizure free but the follow-up is short. Conclusions: The only symptom presented by our seven patients related to the MEC is partial seizures. MEC is a rare aetiology of localisation related epilepsy. The seizures may reveal the MEC. Even the small MEC may lead to drug resistant epilepsy. Surgery may be a treatment of choice in these cases.