| Objective:To investigate the long-term clinical efficacy and adverse reactions of Vagus Nerve Stimulation(VNS)in the treatment of epileptic encephalopathy in children.Methods:From October 2016 to August 2018,15 children with epilepsy and encephalopathy were selected according to the inclusion criteria and exclusion criteria.Clinical data of the 15 children were collected and followed up.Past history,etiology,seizures,course of the disease,treatment,and development are included.The patients were followed up by the outpatient department of neurology and telephone inquiry.The patients were followed up for the first time 2 weeks after VNS was started up,followed up once every 3 months,and followed up once every 6 months after 1 year.The contents include adverse reactions after VNS implantation,frequency of seizures(per month),degree of seizures,improvement of cognitive function,improvement of adverse emotions,and improvement of language function.Urges the child’s parents to record the epilepsy diary in detail.The evaluation scales of language,exercise,attention,and cognitive ability were completed and compared with the evaluation scores before VNS treatment.By comparing and analyzing the frequency reduction rate,effective rate,severity,duration of the seizure,McHugh curative effect classification,language,movement and learning ability changes of different follow-up time.Comparison of rates among VNS treatment groups by chi-square test,P<0.05 was statistically significant.The paired t-test was used to compare the scores of the ability evaluation scale before and after treatment of VNS,and P<0.05 was considered statistically significant.The paired t-test was used to compare the effect of VNS treatment on seizure time and frequency before and after seizures.P<0.05 was considered a statistically significant difference.Spearman correlation test was applied to analyze the correlation and P<0.05 was considered statistically significant.Results:a total of 15 cases were enrolled,including 7 males and 8 females,aged 5-11 years,with an average age of 7.3(±1.76)years.There were 8 cases of LGS,4 cases of Dravet syndrome and 3 cases of Doose syndrome.The course of epilepsy:1-9 years,mean 5.46(±2.19)years.The main types of seizures include atypical absences,atonic,myoclonic,tonic,partial seizures,Generalized tonic-clonic seizures,etc.The number of antiepileptic drugs retained was 2-4,with an average of 3(±0.6).The number of antiepileptic drugs used before was 5.6(±1.1).All the 15 cases were followed up successfully.3 to 4 weeks after VNS implantation,the machine was started up,starting parameter current 0.25ma,pulse width 250uS,frequency 30Hz,duty cycle 30/5min,magnet mode current 0.25ma,pulse width 500uS,frequency 60Hz.After adding 0.25ma of current every 2 weeks and reaching the target current of 1.5ma,the pulse width and duty ratio can be well tolerated.The duty ratio of 2 children with frequent attacks was adjusted to 30/3 min,while that of other children remained unchanged.The mean incidence reduction rate at 2 weeks after VNS treatment was 7.8%,31.81%,42.78%,50.58%,59.39%,63.89%and 62.55%at 3 months,6 months,9 months,12 months,18 months and 24 months,respectively,which were statistically significant compared with that at 2 weeks(P<0.05).Statistical analysis of the incidence reduction rate of the three kinds of epileptic encephalopathy patients showed that the LGS was 6.77%,34.58%,43.54%,50.56%,60.83%,63.44%and 61.53%at 2 weeks,3 months,6 months,9 months,12 months,18 months and 24 months after surgery,respectively.The Dravet syndrome was 11.56%,25.14%,39.31%,51.77%,59.38%,63.70%and 64.58%,respectively.Doose syndrome was found to be 5.93%,33.33%,45.37%,49.07%,55.56%and 66.67%,respectively.The incidence reduction rates of the three kinds of epileptic encephalopathy were statistically significant compared with that at 2 weeks after treatment(P<0.05).The main seizures with a reduction rate of more than 70%were myoclonic seizures(7/7),atypical lapses(6/7)and tonic seizures(4/7).Among them,1 patient’s atypical absence seizures disappeared after treatment,and the number of falls in 2 patients with Doose syndrome was reduced from 2-3 times per day before VNS treatment to 0.5-1 times per day.At 2 weeks of treatment,no patients with reduction rate≥50%,3 months,6 months,9 months,12 months,18 months and 24 months in patients with reduction rate≥50%the proportion of all patients was 20%(3/15),46.67%(7/15),53.33%(8/15),66.67%(10/15),77.78%(7/9),66.67%(4/6),the difference was statistically significant when compared with 2 weeks(P<0.05).At the follow-up time of 12 months,the effective rate of the three kinds of epileptic encephalopathy was 62.5%for LGS,75%for Dravet syndrome and 66.67%for Doose syndrome,respectively.The mean effective rate of the disease course less than 5 years was higher than that of the disease course for more than 5 years,and the difference was statistically significant(P<0.05).The frequency of seizures with a duration greater than 5 minutes before and after VNS treatment was compared and analyzed,and the improvement was statistically significant(P<0.05).After VNS treatment,there was no significant improvement in motor ability(P>0.05),significant improvement in language and learning ability(P<0.05),and no correlation with the reduction of epileptic seizures(P>0.05).The VNS device was well tolerated in 15 children,and no complication was found after the operation.During the phase of increasing the stimulation parameters,12(80%)children developed a cough,5(33%)developed hoarseness,and 6(40%)had transient crying.These adverse reactions disappeared within 1-2 days after the stimulation adjustment.No other significant adverse reactions were observed.In one case,the symptoms of allergic rhinitis disappeared for 3-4 days after each stimulation parameter was added,and disappeared after 12 months of follow-up.Conclusion:1.Vagus nerve stimulation is a safe and effective treatment for children with epilepsy encephalopathy,it can reduce the frequency of seizures,shorten the duration of seizures,reduce the severity of seizures,the most effective form of seizures is atypical absence seizures and drop-attack seizures.VNS treatment has time accumulation effect,the longer the treatment time,the better the seizure control effect.2.With the extension of treatment time,the language ability,attention and cognitive ability were significantly improved,while the motor movement was not significantly improved.3.There is no correlation between the improvement of children’s language and cognitive function and the seizure control situation.That is to say,when the seizure control is not ideal,the children’s language and cognitive function may also be improved. |
PDF Full Text Request