Hemodynamic Characteristics Of Cerebral Frontal Cortex And The Effect Of Exercise Intervention In Single And Dual Task Fall-Related Postural Balance In Patients With Parkinson’s Disease

Purpose:Fall is an essential clinical manifestation of impaired motor balance control in patients with Parkinson’s disease（PD）,and it is also the main factor of injury death in PD patients.Studies have shown that motor and cognitive dysfunction are critical factors of falls in PD patients.However,there is still a lack of in-depth understanding of how the two interact to affect falls in PD patients.The cerebral frontal cortex plays a crucial role in motor control and cognitive function.The purposes of this study are to explore the activity characteristics of the frontal cortex of PD patients when they perform single balance tasks such as sitting,standing,posture conversion,walking,turning,as well as simultaneously complete cognitive dual tasks,and also to study the effect of different exercise interventions on the motor balance control function of PD patients,to provide theoretical and empirical basis for clinical intervention.Methods:This paper consists of four studies.Study 1,the translation and cross-cultural adaptation of the English version of the freezing of gait questionnaire（FOGQ）,as well as its reliability and validity of the Chinese version of FOGQ（FOGQ-CH）.Sixty-five PD patients included in this study,Cronbach’s alpha（Cα）and intraclass correlation coefficient（ICC）to evaluate the internal consistency and test-retest reliability of FOGQ-CH.A law that incorporates minimum detectable changes（MDC）and an area under the receiver operating characteristic curve（AUC）to evaluate the convergent and predictive validity of FOGQ-CH,respectively.Study 2,the characteristics of cerebral frontal cortical hemodynamic changes and motor performance in the single-and dual-task postural balance control related to falls in PD patients.Including two experiments,experiment 1 explored center of pressure（COP）shift and frontal cortical hemodynamic changes in PD patients and healthy controls during sit-to-stand test（STS）and sit-to-stand test in cognitive task（cog-STS）.Experiment 2 explored the characteristics of frontal cortical hemodynamic changes in PD patients and healthy controls during timed up and go test（TUGT）and timed up and go test in cognitive task（cog-TUGT）.The subjects in experiment 1 and experiment 2were identical,12 PD patients and 16 healthy control adults were included by sample size calculation.Three factor repeated measure analysis of variance（ANOVA）was used to compare frontal cortical oxyhemoglobin（HbO）concentration and center of pressure（COP）shift in PD patients and healthy controls with different task types and different postural/TUGT periods.T-test was used to analyze the differences of TUGT and cog-TUGT between and within groups.The correlations between HbO concentration and TUGT time,FOGQ-CH and unified Parkinsons disease rating scaleⅢ（UPDRSⅢ）were also analyzed.Study 3,the characteristics of cerebral frontal cortical hemodynamic changes during TUGT and cog-TUGT in PD patients at high risk and low risk of falling.According to the sample size calculation,8 PD patients with high fall risk and 9 PD patients with low fall risk were included.Using the same method as study 2,we compared the frontal cortical hemodynamic changes of PD patients with high risk and low fall risk in four different TUGT periods,and analyzed the correlation between HbO concentration and motor function parameters such as FOGQ-CH and UPDRSⅢ.Study 4,the effects of different exersice interventions on motor function such as postural control and walking in PD patients.42 PD patients were randomly divided into three groups（cognitive-Gongfa group,traditional Gongfa group,self-stretching group）,14 in each group,with 12 weeks intervention,2 times per week（one centralized training,one home training）,60 minutes per time,a total of 38 PD patients completed intervention and curative effect evaluation.The efficacy was evaluated before and after the intervention.The primary outcome measures included postural control（STS,TUGT,Mini-BESTest）and walking ability（stride length,stride speed,time of double support phase,proportion of double support phase,etc.）.Two-way repeated measures ANOVA was used to compare the differences in the main outcome indicators between the three groups before and after intervention.Results:1.FOGQ-CH reliability and validity study:（1）FOGQ-CH had strong internal consistency（Cα=0.823）and good test-retest reliability（ICC=0.469～0.848,P<0.01）.（2）The MDC₉₀ of FOGQ-CH was 4.538,which had good convergent validity.（3）The AUC value of FOGQ-CH for predicting falls in PD patients was 0.777（P=0.036）,the sensitivity and specificity were 100%and 60.7%,respectively;and the cut-off point was 7.5,and the integer was 8.2.The characteristics of cerebral frontal cortical hemodynamic changes and motor performance in the single-and dual-task postural balance control related to falls in PD patients.（1）HbO changes in cerebral frontal cortex:the HbO concentration in frontal cortex decreased successively in the postural transition from standing to sitting,standing,sitting,and sitting to standing in both groups（P<0.05）.During standing,HbO concentration in frontal cortex of PD patients was significantly increased compared with healthy controls（P<0.05）.Compared with healthy controls,the frontal cortex of PD patients during TUGT and cog-TUGT was significantly inactivated initially and then compensatory activated（P<0.05）.However,there was no significant difference between TUGT and cog-TUGT.（2）COP changes:compared with the controls,the COP displacement distance and velocity during standing were significantly increased in PD patients,while the mediao-lateral COP displacement distance and velocity during stand-to-sit were significantly decreased（P<0.05）.In the control group,there were significant differences in COP displacement distance and velocity between STS and cog-STS（P<0.05）,but no significant difference was observed between these two conditions in the PD group.（3）TUGT and cog-TUGT time changes:TUGT and cog-TUGT time in PD patients were significantly higher than those in healthy control population,and cog-TUGT time in control population was significantly higher than TUGT time.（4）Correlation between HbO concentration and motor performance:there was a moderate to strong linear relationship between HbO concentration and COP displacement distance（especially the anteroposterior displacement distance）at different postures（P<0.05）.During TUGT and cog-TUGT,there was a significant negative correlation between HbO concentration and FOGQ-CH in PD patients.During TUGT,HbO concentration was negatively correlated with the disease duration of PD（P<0.05）.3.The characteristics of cerebral frontal cortical hemodynamic changes during TUGT and cog-TUGT in PD patients at high risk and low risk of falling:（1）During cog-TUGT,HbO concentration in frontal cortex of PD patients with high fall risk was significantly lower than that in PD patients with low fall risk,and HbO concentration in the left frontal cortex was significantly higher than that in the right（P<0.05）.（2）In PD patients with low fall risk,HbO concentration in the frontal cortex during cog-TUGT was significantly higher than that during TUGT（P<0.05）.（3）There was a significant positive correlation between HbO concentration in the frontal cortex and FOGQ-CH score during TUGT,and a significant negative correlation between HbO concentration in the frontal cortex and UPDRSⅢduring cog-TUGT（P<0.05）.4.The effects of different exercise interventions on motor function such as postural control and walking in PD patients:both cognitive Gongfa and traditional Gongfa intervention significantly decreased the time of STS and TUGT（P<0.05）,and significantly increased Mini-BESTest score,stride velocity and length（P<0.05）.Moreover,cognitive Gongfa intervention significantly decreased the proportion of double support phase in subtraction walking（P<0.05）.The improvement of stride length and velocity of the two groups before and after intervention was significantly different from that of the self-streching group（P<0.05）.Conclusions:1.FOGQ-CH has good intra-group reliability,test-retest reliability and convergent validity,which can accurately predict recurrent falls in PD patients,and it is recommended to be widely used in clinical practice.2.During STS and TUGT,HbO concentration in the frontal cortex in PD patients is significantly correlated with STS and TUGT performance,suggesting that HbO concentration can be used as an indicator to evaluate motor function in PD patients.3.This study found that the cognitive-motor dual task test did not reflect differences between groups,so it is not recommended to use it as a specific test in clinic.4.Competitive input can enhance neuroplasticity of the brain,so dual-task training can be used as a rehabilitation program to improve balance or prevent falls in PD patients without freezing of gait.5.Both cognitive Gongfa intervention and traditional Gongfa intervention can significantly improve the postural control and walking ability in PD patients,but cognitive Gongfa intervention has no significant additional efficacy benefit compared with traditional Gongfa intervention.