Effects of insular involvement on functional outcome after intracerebral hemorrhage

Ischemic stroke, as well as intracerebral hemorrhage (ICH), involving the insular cortex tends to be more severe. The impact of insular involvement on outcome of ICH remains enigmatic.

We analyzed 159 patients with supratentorial ICH. Depending on insular involvement the patients were classified into two groups (ICH_non-insular vs. ICH_insular ). Volume and symptom severity of ICH were assessed. Electrocardiography, chest X-ray, and laboratory examinations including myocardial enzymes and inflammatory markers were made. In-hospital death and outcome at discharge from hospital were assessed on the modified Rankin scale (mRS).

The main finding was an association of insular involvement of ICH with worse short-term outcome as measured by mRS (common odds ratio: 4.08 (95% CI: 2.09-7.92); p < .001). This association survived adjustment to relevant covariates such as age, sex, ICH volume, intraventricular hemorrhage, pneumonia, and length of stay (adjusted common odds ratio: 2.51 (95% CI: 1.21-5.21); p = .014) but had no predictive value for side of ICH or rate of atrial fibrillation. There was no association of ICH localization with in-hospital death rate.

Insular localization of ICH lesions predicts worse short-term functional outcome independent of side of bleeding or cardiac dysfunction such as new AF. These findings need clarification in larger prospective cohorts assessed by detailed autonomic/cardiac testing, as well as neuroimaging sub-localization of ICH within the insular region.