Value In Prognosis Of Seizure And Cognition Protection Of SEEG And Neurophysiological Monitoring Assistant Staged RF Therapy Of Epileptic Network

ObjectiveTo discuss the staged thermoradiofrequency(RF)therapy and protection of recognition guided by stereotactic intracranial electroencephalogram(SEEG)and neuroelectrophysiological index in the treatment of refractory epilepsy.MethodThe clinical features,neuroimaging findings,neuroelectrophysiological results and preoperative neuropsychological evaluation data of 18 patients with refractory epilepsy treated with ROSA robot assisted surgery from 2018-02-01 to 2021-02-01 in neurosurgery of the first affiliated Hospital of Fujian Medical University were retrospectively analyzed.Detailed surgical information of SEEG was recorded,including electrode targets,stimulation and thermal radio frequency lesions,and neuroelectrophysiological evaluation.Postoperative complications,seizure control(Engel grade),adjustment of antiepileptic drugs,neuroimaging,neuroelectrophysiological result and postoperative neuropsychological evaluation were concluded in following up.By analysing decline in typical spikes during interictal period before and after RF as the curative effect index,meanwhile the size of RF leisions was calculated.The verbal memory task was evaluated during hippocampus being stimulating,exploring whether the transient damage to hippocampus has a significant impact on verbal memory.ResultsThrough preoperative evaluation,According to the seizure and classification method of the International Antiepileptic Alliance 2017,All 18 patients had focal origin.In 4 cases,MRI reported no significant leisions,8 cases showing that the lesion was not corresponded to the location of electroencephalogram,4 cases requiring minimally invasive treatment,since that 18 cases choose SEEG operation.A total of 161 SEEG electrodes were implanted,average 8.94 electrodes.Deep intracranial electrode stimulation was performed average 7.17 days after SEEG.A total of 16 patients underwent SEEG recepted further thermal radiofrequency therapy,on average 2.31 days after electrical stimulation.Pre-destructive parameter(2 W,30 s)was selected initially,destroy parameter(3.5 W,60 s)was then selected.RF was performed on average of 2.05 times.2 cases experienced transient aphasia after thermal RF,all recovered in 1 month.1 case experienced intracranial abscess after RF,and recovered after standard antibacterial treatment.On average of 315.61 days postoperative follow-up,among 14 patients only recieved RF treatemt,8 cases showed seizure free(Engel Ⅰ grade),2 cases Engel showed>75%decline in seizure frequency(Engel Ⅱ grade),4 cases still under follow-up.After 3 months follow-up after RF,2 underwent epileptic focus resection(Engel Ⅰ grade).2 cases without RF were treated with palliative operation after electrode removal(Engel grade Ⅳ).The decrease rate of typical spikes during interictal stage over 60%was defined as the curative effect of RF.The contacts referred to rapid propagation of discharge and interval frequent discharge were included in the selection of RF target.There was a significant correlation between spikes decrease over 60%and better prognosis of seizure control(p<0.05).RF targets involved the ipsilateral hippocampus that significantly damage verbal memory during stimulation showed strong correlation with postoperative memory damage(p<0.05).ConclusionSEEG is suitable for localizing epileptic foci and functional areas in magnetic resonance negative and drug-resistant epilepsy cases.RF target is selected based on the discharge during seizure period.While in patients without seizure over 14 days of monitoring,RF target was selected based on interictal typical spikes.The interictal typical spikes decrease over 60%after RF is defined as the therapeutic index.It can not only be used as a reference for staged RF treatment,but also can effectively predict the seizure control agter RF therapy.In order to explore whether the damage of the hippocampus has obvious effect on verbal memory,effective verbal memory task is suggested duting the hippocampus stimulation.Patients with multiple origin epileptogenic network,unknown origin epileptogenic network,epileptic focus involving functional area have indications for RF therapy,which of important application value of therapeutic diagnosis,functional protection and improvement of prognosis.