OBJECTIVE: The aim of this study was to determine if insular damage is associated with markers of autonomic dysfunction. METHODS: We studied patients who underwent temporal lobe and/or insular resections for epilepsy surgery between April 2010 and June 2015 at University Hospitals Cleveland Medical Center (UHCMC). Presurgical T1-weighted MPRAGE, standard T1, T2 and FLAIR sequences were compared with postsurgical MRI by a neuroradiologist and classified as type 0 (no involvement of insula), type 1 (minimal involvement of insular margin), type 2 (insular involvement <25%), and type 3 (insular involvement >/=25%). Analysis of heart rate variability (HRV) was carried out in pre- and postoperative video-electroencephalography (vEEG) recording. Time-domain parameters were calculated: (mean of the RR intervals (MNN), root mean square difference of successive RR intervals (RMSSD), standard deviation of the RR intervals (SDNN), and coefficient of variation (CV)). In addition, frequency-domain parameters were calculated: low frequency (LF), high frequency (HF), and low frequency/high frequency (LF/HF). RESULTS: Twenty-one patients (14 females) with mean age of 36.2鈥?/-鈥?4.4鈥痽ears (30; 22-75) were studied. Insular involvement was classified as type 0 (4 patients [19%]), type 1 (9 [43%]), type 2 (7 [33%]), and type 3 (1 [5%]). Significant decrease in RMSSD (p鈥?鈥?.025) and CV (p鈥?鈥?.008) was seen in insular damage types 2 and 3 compared with no or minimal insular involvement (types 0 and 1). Right-sided resections were associated with increase in LF power (p鈥?鈥?.010) and the LF/HF ratio (p鈥?鈥?.017). CONCLUSIONS: This study indicates that insular resection may lead to autonomic function changes.