Background: The insula is a small but complex structure located in the depth of the sylvian fissure, covered by the frontal, parietal and temporal operculum. Ischemic strokes limited to the insula are rare and have not been well studied. Our objective is to better define the clinical presentation and outcome of insular ischemic strokes (IIS). Methods: We reviewed the institutional prospective, consecutive stroke database from two centers to identify patients with IIS seen between 2008 and 2010. We also searched the Medline database using the keywords insula(r), infarction and stroke to identify previously published IIS cases confirmed by MRI. Minimal extension to an adjacent operculum or subinsular area was accepted. Clinicoradiological correlation was performed by distinguishing IIS involving the anterior (AIC) or posterior insular cortex (PIC). We collected clinical, demographic and radiological data. The outcome was determined using the modified Rankin Scale (mRS). Results: We identified 7 patients from our institutions and 16 previously published cases of IIS. Infarcts were limited to the AIC (n = 4) or the PIC (n = 12) or affected both (n = 7). The five most frequent symptoms were somatosensory deficits (n = 10), aphasia (n = 10), dysarthria (n = 10), a vestibular-like syndrome (n = 8) and motor deficits (n = 6). A significant correlation was found between involvement of the PIC and somatosensory manifestations (p = 0.04). No other statistically significant associations were found. IIS presentation resembled a partial anterior circulation infarct (n = 9), a lacunar infarct (n = 2) or a posterior circulation infarct (n = 2). However, most cases presented findings that did not fit with these classical patterns (n = 10). At the 6 month follow up, mRS was 0 in 8/23 (35%) patients, 1–2 in 7/23 (30%) and unknown in 8/23 (35%). Conclusions: IIS presentation is variable. Due to the confluence of functions in a restricted region, it results in multimodal deficits. It should be suspected when vestibular-like or motor but especially somatosensory, speech or language disturbances are combined in the same patient. The outcome of IIS is often favorable. Larger prospective studies are needed to better define the clinical presentation and outcome of IIS.

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

No abstract