Recovery of empathetic function following resection of insular gliomas

The insular cortex is located deep within the Sylvian fissure between multi-functional and structurally- compressed cerebral structures, and has been suggested to play an important role in both basic sensorimotor and complex social-emotional functions. Such structural and functional complexity presents a challenge for neurosur- geons to remove tumors within the insula safely. It has therefore not yet been documented how neurosurgical resection of insular gliomas would impact social-emotional functions. In this study, we examined empathy, a high-level social-emotional function, in four patients with localized insular gliomas pre- and post-operatively. The patients completed an empathy-for others pain task in which they viewed another person's hand or foot in painful or non- painful situations and made judgments about either pain (explicit empathy) or laterality of the hand or foot (implicit empathy). They also completed questionnaires assessing general emotional processing and personality. Deficits in both explicit and implicit empathetic pain processing were found in patients before the operations. However, the operations significantly improved their empathetic ability after surgery, accompanied by unchanged personality traits. These results confirmed previous findings that the insula plays a critical role for empathetic pain perception. Importantly, the current results suggest that surgical resection is not only a suitable treatment for insular glio- mas for clinical consideration, but also effective in improving high-level functions such as empathetic pain perception.