Quantitative Analysis Of The Non-Motor Symptoms Of Parkinson's Disease After Deep Brain Stimulation

BackgroundNon-motor symptoms of Parkinson's disease are a key determinant of life quality. Deep brain stimulation can dramatically improve the cardinal motor symptoms and therapy related motor complications, but its effects on non-motor symptoms are still a matter of debate. Although certain objective assessments of the effects of STN-DBS on specific NMSs have been done, such as, after STN-DBS sleep architecture has improved obviously on polysomnographic evaluation, and after STN-DBS urodynamic improvement was also noticed, however, other researches have found that the incidence of suicide after STN-DBS has increased. All the researches mentioned above were merely based on a short follow-up of a small population. The research based on long-term all-around follow-up of the NMSs after STN-DBS has not been done.ObjectiveThis study assessed the effects of STN-DBS on NMSs of Parkinson'disease, discussed the possible mechanism, and analyzed the complications of STN-DBS.Methods1. Subjects:We enrolled 30 consecutive STN-DBS patients as the STN-DBS group who were programmed at QiLu Hospital between June 2008 and January 2010. From the patients who visited the neurology clinic at QiLu Hospital between June 2008 and January 2010, we selected 30 primary Parkinson's disease patients as the control group, each of whom was paired with the STN-DBS group on sex and years of disease duration.2. Methods:We collected the basic information of the 60 patients, including name, sex, age, years of disease duration, H-Y staging, medical dosage and DBS parameters. We assessed the non-motor symptoms of the 60 patients using NMSS. The score of each item is the product of the severity(from 0 to 3) and frequency(from 1 to 4).We also scored each individual NMS as being'present'or'absent'in order to analyze the prevalence of each NMS. We collected the complications of STN-DBS, including dyskinesia, abnormal sense, diplopia, blurred vision, eyelid apraxia, dysarthria, muscular spasms and dystonia.3. Statistical analysis:SPSS 17.0 for Windows (Chicago, IL) was used for the statistical analysis. Wilcoxon signed rank test was used to analyze the difference in demographic data (sex, age, years of disease duration, H-Y staging) and madopar equivalent dose (MED). X2 test (fisher's exact test) was used to compare the prevalence of each NMS between STN-DBS group and control group. Wilcoxon signed rank test was also used to analyze the NMS scores between STN-DBS group and control group. The level of statistical significance was set at p<0.05.The p value was bilateral.Results1. The mean madopar equivalent dose in STN-DBS group is (485.48±185.56)mg, the control group (642.18±213.86)mg. The difference was of significance (p=0.006). The mean madopar equivalent dose was reduced by 24.4％compared to control group.2. In STN-DBS group, the mean number of NMSs per subject was 11.53±7.49, while that was 12.53±5.23 in control group. The number of NMSs of each subject between STN-DBS group and control group was of no significance (p=0.162). In STN-DBS group, the mean of the total score of NMSs was 53.70±38.42, while that was 53.43±25.17 in control group. The total scores of NMSs between STN-DBS group and control group were of no significance (p=0.160). The frequency of NMSs in STN-DBS group was significantly lower than control group in the following aspects:sleep disorder (p=0.033), depression (p=0.033) and excessive sweating (p=0.033). The scores of NMSs were significantly lower than control group in the following aspects:sleep disorder (p=0.038), constipation (p=0.012) and excessive sweating (p=0.004).3. In the STN-DBS group,13 patients experienced transient abnormal sense.4 patients experienced muscular spasms. Dystonia appeared in 3 patients, diplopia in 2 patients, dyskinesia in 10 patients and eyelid apraxia in 1 patient. Except for 1 patient got infected, there were no severe complications such as suicide and dementia.ConclusionsThe paired comparison study about the 30 STN-DBS patients and 30 primary Parkinson's disease patients indicated that the non-motor symptoms of Parkinson's disease patients are mostly unchanged after STN-DBS, however, some specific aspects such as, sleep disorder, depressions, constipation and excessive sweating can be significantly ameliorated. Severe complications of STN-DBS are rare, and most complications such as abnormal sense, muscular spasms can be ameliorated by adjusting DBS parameters.