Operculo insular epilepsy case series

Thirteen patients with operculo insular epilepsy and negative MRI who were identified by presurgical evaluation and underwent resective surgery from January 2011 to June 2015 were included and analysed in the study of Yu et al., from the Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, China.

In presurgical evaluation, the ictal symptoms looked reliable enough to characterise operculo-insular seizures in four patients. MEG spike sources were shown in the operculo-insular region in 11 of 13 (84.6%) patients, including cluster spike sources in 7 patients and scatter spike sources in 4 patients. After MEG examination, the original plan of intracranial electrode implantation was changed in five patients. In these patients, electrodes exploring the operculo-insular cortex were not part of the original plan. The pathological examination showed focal cortical dysplasia (FCD) in 12 patients and FCD with heterotopia in 1 patient. Nine (69.2%)patients were seizure-free in 2-6 years' follow-up.

MEG played an additional and valuable role in the localisation of operculo-insular epilepsy for patients with a negative MRI finding ¹⁾.