Abstracts

Rationale: Anatomically, the frontal operculum is associated with the expression of language. Within the dominant hemisphere, a lesion of the operculum may result in a Broca’s aphasia whereas an expressive dysprosody may be seen in lesions of the non dominant hemisphere. The opercular syndrome is described as dysarthria, dysphagia , and facial paresis. Varied manifestations have been observed as ictal phenomenon from seizures arising from the operculum. Here we report the electroclinical findings and outcomes of five cases of lesional opercular epilepsy which proceeded to surgical resection. Methods: Five patients who had failed adequate trials of at least two medications were identified to have frontal opercular lesions (2 with cavernous hemangiomas, two with DNETs, and one with hamartoma). One of five had dual pathology with a cavernous hemangioma in the operculum as well as the superior temporal gyrus. Seizure frequency ranged from two per week to 20 per night. All patients underwent routine evaluation including brain MRI and phase I monitoring. The semiology was varied and ictal manifestions ranged from a transient opercular syndrome with post ictal dysarthria to clonic seizures of the face to mixed seizure types of myoclonic, tonic and generalized tonic clonic. The electrographic onset of the seizures varied from no electrographic change (2/5), nonlateralized fast activity (1/5), to diffuse slowing in (2/5). Results: The five patients proceeded to lesionectomy and were followed for an average of 5.4 years (range 1-8 years). Three patients had a class I outcome, one patient had a class II outcome and one patient had a class IV outcome. Of the patients with a class I and II outcomes (3 were operated on the dominant hemisphere for language, one on the non dominant), one patient was found to have word finding difficulty on neuropsychological testing. One patient reported episodic stuttering that was not an ictal phenomenon. The patient with a class IV outcome (operated on the non dominant hemisphere) was observed to have significant deficits in verbal fluency. Notable were the psychiatric sequalae in 4/5 patients which ranged from behavioral dyscontrol syndromes in three and a delusional disorder in the fourth patient. Conclusions: Lesions within frontal operculum give rise to seizures which are heterogeneous in electroclinical manifestations. Fairly successful results with minimal language deficits can be obtained through surgical resection; however, careful attention to co-morbid psychiatric conditions should optimize the outcome.