Evaluation of neuronavigation in lesional and non-lesional epilepsy surgery.

OBJECTIVE: For many patients, surgery for intractable epilepsy provides not only freedom or substantial relief from seizures, but also functional improvement and increased quality of life. Precise intraoperative localization of the underlying structural and functional processes is crucial in this regard. The aim of this study was to clinically evaluate whether neuronavigation leads to an improvement in the precision and safety of epilepsy surgery. In this paper, we also attempt to assess the navigation workstation as a platform for the integration of multimodal information (multimodal information guidance).

PATIENTS: Out of a series of 223 epilepsy surgery procedures, 140 were performed with the aid of neuronavigation. Patient and surgical data were prospectively collected.

METHODS: We used the neuronavigation device as a common platform to merge complementary information modalities. Correlation of anatomic and structural details with functional information contributed to the surgical script in non-lesional and localization-related epilepsy surgery. At least two different information modalities contributed to planning and surgical guidance in every patient. Immediately following the operative procedure, the surgeon answered a set of questions on the reasons for the application of neuronavigation, and the efficiency and safety of navigation. Detailed analysis of the location of the operative procedure, histopathological findings and outcome was performed.

RESULTS: The main benefits of neuronavigation in epilepsy surgery were precision of targeting even in small and deep-seated targets, safe manipulation in critical brain areas, accurate placement of electrodes, and correlation of electro-clinical information modalities with underlying structures. Furthermore, navigation provided individual tailoring of craniotomy and corticotomy. It was less reliable for verification of resection boundaries in the case of underlying glioma. Neuronavigational localization and its combination with image fusion and functional investigations greatly improved discussion within the epilepsy surgery team.

CONCLUSION: The neuronavigation concept proved its value in epilepsy surgery by linking anatomic, pathologic and functional data of the individual patient. Enhanced by the integration of multimodal information, neuronavigation significantly improved the available treatment options.