Structural Abnormalities in Patients with Insular/Peri-insular Epilepsy: Spectrum, Frequency, and Pharmacoresistance

Abstract

SUMMARY:Between 2002 and 2010, a total of 48 patients were seen at our epilepsy clinic with insular/peri-insular cortex epilepsy. Review of their MR imaging scans revealed a neoplastic lesion in 27% of patients, a malformation of cortical development in 21%, a vascular malformation in 19%, and atrophy/gliosis from an acquired insult in 17%. MR imaging results were normal in 4 patients. Other miscellaneous findings included a case of Rasmussen encephalitis, a nonspecific insular millimetric T2 signal abnormality, a neuroepithelial cyst, and hippocampal sclerosis without MR imaging evidence of dual insular pathologic features (despite depth electrode-proven insular seizures). Refractoriness to antiepileptic drug treatment was present in 56% of patients: 100% for patients with malformations of cortical development (1.0; 95% CI, 0.72-1.0), 50.0% (0.5; 95% CI, 0.21-0.78) in the presence of atrophy/gliosis from acquired insults, 39% (0.39; 95% CI, 0.14 -0.68) for neoplastic lesions, and 22.2% (0.22; 95% CI, 0.06 -0.55) for vascular malformations. ABBREVIATIONS:IPICE ϭ insular/peri-insular cortex epilepsy; MCD ϭ malformation of cortical development

Ictal semiology, functional anatomy and multimodal diagnostic in patients with insular epilepsies

“…In case 1 an FCD is detected in MRI. Causes mostly detected are low grade tumors (27%), focal cortical dysplasia (FCD)(21%), vascular malformation, cavernomas (19%), atrophy/ gliosis (17%) and normal tissue (8%) [19]. Genetic defects were described in operculo-insular epilepsy cases, including mutations in the CHRNB2 and CHRNA4 genes in patients with sleep-related hyperkinetic seizures [20].…”

Proton MR Spectroscopy in Patients with Nonlesional Insular Cortex Epilepsy Confirmed by Invasive EEG Recordings

“…Epilepsy is a chronic condition characterized by recurrent seizures as a result of abnormal and excessive neuronal discharges. While magnetic resonance imaging (MRI) may identify a cause in many patients (eg, tumors, traumatic scars, and vascular malformations), nearly one‐third have no clear epileptogenic lesions (i.e., are MRI‐negative or nonlesional) . The latter are thought to have an underlying genetic defect and/or an occult malformation of cortical development.…”

“…While magnetic resonance imaging (MRI) may identify a cause in many patients (eg, tumors, traumatic scars, and vascular malformations), nearly one-third have no clear epileptogenic lesions (i.e., are MRI-negative or nonlesional). 1,2 The latter are thought to have an underlying genetic defect and/or an occult malformation of cortical development. In patients with drug-resistant epilepsy, surgical resection of the epileptogenic zone (an area of cortex necessary and sufficient for the initiation and organization of the epileptic seizures) can lead to seizure-freedom.…”

Insular epilepsy etiology: clinical manifestation and management tactics for cerebral cavernous angiomas

“…Этиологическое специфическое лечение эпилепсии в современных услови-ях становится актуальной задачей. Инсу-лярная эпилепсия (островковая) в последние годы находится в сфере особого интереса как практической, так и фундаментальной науки [2,3].…”

“…Несмотря на длительный период ис-следований, данная форма относится к не-достаточно изученным разновидностям фокальной эпилепсии [2][3][4]. Начало иссле-дований было положено в конце 40-х -на-чале 50-х годов XX века.…”