Abstracts

Rationale: It is important to have accurate information of functional anatomy for tailor-made resection in intractable epilepsy patients. Wada test and electrical stimulation were used for functional mapping as direct evaluation methods by stimulating or suppressing brain tissue. But in the real clinical practice we had problems in their “size.” Compared to the estimated resection area, electrical stimulation tests the much smaller area and Wada test tests the much larger area. For the evaluation of functions of estimated resection area in appropriate size, we applied the super-selective Wada test (S-Wada) with microcathetel technique in endovascular neurosurgery.Super-selective injection of propofol from the target vessel of intracranial artery that perfuse the anterior language area of Broca, posterior language area of Wernicke and hippocampal formations.In this study we report the real procedure technique of S-Wada and the clinical results of the patients evaluated by S-Wada. Methods: Case series of consecutive 11 patients applied S-Wada from 2018 to 2019 in our institute for the presurgical evaluation of drug-resistant epilepsy. The indication of S-Wada was as belows; expected multilober resection surgery, bilateral epileptic foci and/or preserved neurocognitive functions in comprehensive presurgical evaluation. The patients’ characteristics were as belows; five female patients, aged mean 29.9 (16-39) years old. All patients were right-handed and one patient was left temporal lobe epilepsy without hippocampal atrophy. S-Wada was performed in endovasucular neurosurgical suite. Patients were punctured the femoral artery and introduced guiding catheter to the cervical segement of dominant vertebral artery. Super-selective catheterization leaded the tip of microcathetel to the M2-M3, A2, P2 segment of intracranial artery which perfuse the expected resection area. The target vessel was determined with the consideration of vascular and functional anatomy by endovascular neurosurgeon and cognitive neurologist. The 5-10 mg of propofol prepared 1mg/ml was infused in 1ml/sec infusion rate during the evaluation of electroencephalography (EEG). Immediately after the confirmation of slowing in EEG and neurological deficit that mean the propofol distribution to the territory of target vessel, the neuro-cognitive task was performed within the minutes by behavioral neurologist. The test was tried from bilateral side of middle cerebral artery, anterior cerebral artery and posterior cerebral artery, then we decided the the dominancy of language function and memory function. Results: In all of the cases S-Wada were executed every task without conscious disturbance and confirmed hemianopsia after the injection of propofol. No complication with the procedure was occured.Laterality of the language function domiancy could be decided in all the cases. Four (36%) cases showed atypical functional localization that could not decide the clear laterality of language and recent memory function. These results influenced the surgical procedure with its resection area or intracranial electrode placement in two (18%) cases and surgical indication turned to resective surgery from the contraindication assumed before S-Wada in two (18%) cases.In ten cases functional mapping with intracranial electrode were executed and the results were concordant to S-Wada in all cases. Conclusions: S-Wada enables to evaluate the brain function with appropriate size for expected resection area in epilepsy surgery. Funding: No funding