1404. Neuroethical Issues of Repeated Pre-surgical Functional Brain Mapping as a Tool of Monitoring Brain Plasticity

Authors: Olena Nikolenko, M.D., PhD; Oleg Nikolenko; Andrew Davidson, MD, PhD; Thomas Picht, MD, PhD (Odessa, Ukraine)

Introduction: Neuroethics of neurosurgery addresses ethical decision-making, legal evaluation of opportunities and outcomes of neurosurgical treatment as well as the results of relevant neuroscience research. Last advances in functional brain mapping and resection of tumors located at eloquent cortex require specification of neuroethics in relation to neurosurgery and brain plasticity. Methods: We systematically reviewed the relevant literature concerning neuroethics of neurosurgery, repeated functional brain mapping, operations at eloquent areas and brain plasticity. Results: Neuroethical issues of neurosurgery at eloquent areas differ from the neuroethical problems of neuroscience. Tumor growth, surgical resection and repeated Transcranial Magnetic Stimulation (r-TMS) can induce brain plasticity, particularly - relocation of cortical function from one eloquent area to another, including activation of homologous eloquent areas at the contralateral hemisphere. Such relocation is detected by the longitudinal follow-up with repeated functional brain mapping. Induced brain plasticity makes risk of tumor resection acceptable. Patients with highly eloquent tumor location and high risk of surgical resection rarely been monitored by repeated functional brain mapping. Brain plasticity could not be monitored without repeated functional brain mapping. Insurances usually cover costs of single functional Magnetic Resonance Imaging (fMRI) for brain tumor patients only if fMRI is a part of presurgical mapping for upcoming operation. Neuroethical issue consist in defining pre-conditions for repeated functional brain mapping to detect the relocation of cortical function. It concerning cases when primary mapping has recognized patient as non-suitable for operative intervention. With time tumor growth can induce brain plasticity and patient might require reassessment of eloquent function location and risks of surgical resection of tumor. Conclusion: Neuroethical issues of neurosurgery at eloquent cortex are determined by legal settlement to conduct repeated functional brain mapping for monitoring relocation of cortical function and reassessment of risks for surgical tumor resection.