| OBJECTIVES: Vagal nerve stimulation is an palliative method for the treatment of drug-refractory epilepsy.It is mainly used for patients who are not suitable for resection of epileptic foci or who have poor efficacy after resection..At present,Vagus Nerve Stimulation(VNS)is already a ripe treatment for refractory epilepsy.The basic research focuses on the mechanism of action,while clinicians focus on the following aspects: First,the therapeutic effect of VNS after implantation.Although most effective,the rate of seizure free is only 10%.Some experts consider the nearly seizure free is 30% after surgery.Most patients still only partially improve,and even a few patients have no improvement.Secondly,some patients will have varying degrees of side reactions,mainly concentrated in the throat,which affects the parameter settings of vagus nerve stimulation,which affects the final efficacy.In addition,there are few reports on the application strategy of AEDs after VNS and whether there is synergy between VNS and AEDs.So,Single-center follow-up of patients in this study to observe postoperative efficacy,stimulation intensity,side effects,and explore the relevant factors that cause differences in efficacy,anti-epileptic drugs(AEDs)adjustment and the effect of VNS combined with drug treatment,to improve the effect of clinical application of VNS.METHODS:A retrospective analysis of 19 patients with refractory epilepsy who underwent VNS treatment was performed in the Department of Functional Neurosurgery,Tianjin Huanhu Hospital,2011.5-2017.1.All operations were performed by the same surgeon according to standard procedures.There were 17 males and 2 females with an average age of 19.7 years,an average age of 10.2 years,and an average duration of 9.5 years.Four of them were partial seizures and 15 were generalized seizures.Etiology: 2 cases of dystocia hypoxia,2 cases of traumatic brain injury,3 cases of intracranial tumor or vascular malformation surgery,3 cases of infantile spasm,3 cases of viral encephalitis,and 6 cases without obvious cause.Preoperative nuclear magnetic examination: 2 cases of bilateral hippocampus symmetry,1 case of local ventricular dilatation,1 case of corpus callosum,1 case of tuberous sclerosis,1 case of right iliac crest,1 case of double anomaly There were 1 case of signal,7 cases of postoperative brain injury,and 5 cases of no obvious abnormality.Preoperative video electroencephalogram(VEEG)report: 15 cases of bilateral epileptic wave were distributed,2 cases of unilateral epileptic wave were distributed,and 2 cases were not detected.Before the operation,18 cases of anti-epileptic drugs of 2 kinds or more were taken,and 1 case of single anti-epileptic drugs was taken.The patient was routinely started after 2-3 weeks,and then the stimulation parameters were individually adjusted according to the patient's specific conditions,and the patients were followed up regularly(3 months,6 months,12 months,24 months,48 months after surgery).The follow-up content mainly focused on the severity of seizures and the frequency of seizures.The frequency of seizures before and after VNS was recorded by a modified version of the recording method.The adjustment of stimulation parameters,the adjustment of the symptoms and the side effects of the larynx were also recorded.(using a questionnaire)and direct laryngoscopy for partially tolerated patients.The evaluation of the postoperative effect was performed using the McHugh classification RESULTS:There were no serious complications and deaths after operation.The average follow-up time was 47.6 months(15-93 months),and the frequency of seizures decreased by an average of 57.6%.Evaluation of VNS efficacy(McHugh classification): McHugh I in 8 case(8/19,42.1%),McHugh II in 4 case(4/19,21.1%),McHugh III in 3 case(3/19,15.8%),McHugh IV in 3 case(3/19,15.8%)and McHugh V in 1 case(1/19,5.3%).After operation,12 patients achieved McHugh grade I and grade II,and the stimulation intensity was 1.38±0.56 mA.Among them,4 patients had zero-stimulus stimulation intensity of 1.06±0.85 mA;the remaining 7 patients were McHugh III-V grade,and the stimulation intensity was It is 1.61 ± 0.38 mA.9/19 patients had at least one anti-epileptic drug reduced in the number of original drugs,4 of which were reduced to single-drug control;10/19 postoperative medications were the same as before surgery,and 4 of them were replaced on the original basis.Or partial replacement of the drug.Twelve patients developed adverse reactions after starting up,including 4 patients with cough,1 with brief shortness of breath,and 9 with hoarseness.These side effects mainly occurred in the first few days after the first start-up or adjustment of parameters,and most of them were transient symptoms during stimulation.During follow-up,7 patients underwent laryngoscopy,6 had vocal cords showing normal bilateral symmetry,and 1 had left vocal cord paralysis.However,all patients showed a fixed median vocal cord fixation on the left side and good vocal cord activity on the right side.CONCLUSION: This study introduces a modified method to record the frequency of seizures,which makes the recording of seizure frequency more standardized,simple and easy to grasp,and is conducive to the comparison of seizure frequency before and after VNS surgery.VNS is effective for drug-refractory epilepsy and increases efficacy with prolonged stimulation time.The selection of stimulation parameters should be individualized.Sensitive patients can achieve better effects even under lower stimulation parameters.For the patients with better tolerance,try to gradually increase the stimulation parameters,and also achieve better results.In general,the stimulation parameters are not standardized,and the parameter settings according to the patient's specific conditions.Patients with refractory epilepsy may have a transient laryngeal reaction after receiving VNS.Among them,hoarseness is the most common,which are transient symptoms during stimulation,and does not affect work and life,so VNS surgery is safe.The AEDs' adjustment is mainly based on the postoperative effect,but also the length of postoperative onset,the sensitivity of the patient to the drug and the side effects of the drug.In addition,after the vagus nerve stimulation to reduce seizures,it can also reduce the side effects of drugs by reducing the drug.Patients with poor results after VNS may also achieve better results by adjusting the drug. |
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