Resistance training with instability is more effective than resistance training in improving spinal inhibitory mechanisms in Parkinson's disease

Physical exercise for people with Parkinson's disease: a systematic review and network meta-analysis

BACKGROUND

Physical exercise is effective in managing Parkinson's disease (PD), but the relative benefit of different exercise types remains unclear.

OBJECTIVES

To compare the effects of different types of physical exercise in adults with PD on the severity of motor signs, quality of life (QoL), and the occurrence of adverse events, and to generate a clinically meaningful treatment ranking using network meta-analyses (NMAs).

SEARCH METHODS

An experienced information specialist performed a systematic search for relevant articles in CENTRAL, MEDLINE, Embase, and five other databases to 17 May 2021. We also searched trial registries, conference proceedings, and reference lists of identified studies up to this date.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) comparing one type of physical exercise for adults with PD to another type of exercise, a control group, or both.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data. A third author was involved in case of disagreements. We categorized the interventions and analyzed their effects on the severity of motor signs, QoL, freezing of gait, and functional mobility and balance up to six weeks after the intervention using NMAs. Two review authors independently assessed the risk of bias using the risk of bias 2 (RoB 2) tool and rated the confidence in the evidence using the CINeMA approach for results on the severity of motor signs and QoL. We consulted a third review author to resolve any disagreements. Due to heterogeneous reporting of adverse events, we summarized safety data narratively and rated our confidence in the evidence using the GRADE approach.

MAIN RESULTS

We included 154 RCTs with a total of 7837 participants with mostly mild to moderate disease and no major cognitive impairment. The number of participants per study was small (mean 51, range from 10 to 474). The NMAs on the severity of motor signs and QoL included data from 60 (2721 participants), and 48 (3029 participants) trials, respectively. Eighty-five studies (5192 participants) provided safety data. Here, we present the main results. We observed evidence of beneficial effects for most types of physical exercise included in our review compared to a passive control group. The effects on the severity of motor signs and QoL are expressed as scores on the motor scale of the Unified Parkinson's Disease Rating Scale (UPDRS-M) and the Parkinson's Disease Questionnaire 39 (PDQ-39), respectively. For both scales, higher scores denote higher symptom burden. Therefore, negative estimates reflect improvement (minimum clinically important difference: -2.5 for UPDRS-M and -4.72 for PDQ-39). Severity of motor signs The evidence from the NMA (60 studies; 2721 participants) suggests that dance and gait/balance/functional training probably have a moderate beneficial effect on the severity of motor signs (dance: mean difference (MD) -10.18, 95% confidence interval (CI) -14.87 to -5.36; gait/balance/functional training: MD -7.50, 95% CI -11.39 to -3.48; moderate confidence), and multi-domain training probably has a small beneficial effect on the severity of motor signs (MD -5.90, 95% CI -9.11 to -2.68; moderate confidence). The evidence also suggests that endurance, aqua-based, strength/resistance, and mind-body training might have a small beneficial effect on the severity of motor signs (endurance training: MD -5.76, 95% CI -9.78 to -1.74; aqua-based training: MD -5.09, 95% CI -10.45 to 0.40; strength/resistance training: MD -4.96, 95% CI -9.51 to -0.40; mind-body training: MD -3.62, 95% CI -7.24 to 0.00; low confidence). The evidence is very uncertain about the effects of "Lee Silverman Voice training BIG" (LSVT BIG) and flexibility training on the severity of motor signs (LSVT BIG: MD -6.70, 95% CI -16.48 to 3.08; flexibility training: MD 4.20, 95% CI -1.61 to 9.92; very low confidence). Quality of life The evidence from the NMA (48 studies; 3029 participants) suggests that aqua-based training probably has a large beneficial effect on QoL (MD -15.15, 95% CI -23.43 to -6.87; moderate confidence). The evidence also suggests that mind-body, gait/balance/functional, and multi-domain training and dance might have a small beneficial effect on QoL (mind-body training: MD -7.22, 95% CI -13.57 to -0.70; gait/balance/functional training: MD -6.17, 95% CI -10.75 to -1.59; multi-domain training: MD -5.29, 95% CI -9.51 to -1.06; dance: MD -3.88, 95% CI -10.92 to 3.00; low confidence). The evidence is very uncertain about the effects of gaming, strength/resistance, endurance, and flexibility training on QoL (gaming: MD -8.99, 95% CI -23.43 to 5.46; strength/resistance training: MD -6.70, 95% CI -12.86 to -0.35; endurance training: MD -6.52, 95% CI -13.74 to 0.88; flexibility training: MD 1.94, 95% CI -10.40 to 14.27; very low confidence). Adverse events Only 85 studies (5192 participants) provided some kind of safety data, mostly only for the intervention groups. No adverse events (AEs) occurred in 40 studies and no serious AEs occurred in four studies. AEs occurred in 28 studies. The most frequently reported events were falls (18 studies) and pain (10 studies). The evidence is very uncertain about the effect of physical exercise on the risk of adverse events (very low confidence). Across outcomes, we observed little evidence of differences between exercise types.

AUTHORS' CONCLUSIONS

We found evidence of beneficial effects on the severity of motor signs and QoL for most types of physical exercise for people with PD included in this review, but little evidence of differences between these interventions. Thus, our review highlights the importance of physical exercise regarding our primary outcomes severity of motor signs and QoL, while the exact exercise type might be secondary. Notably, this conclusion is consistent with the possibility that specific motor symptoms may be treated most effectively by PD-specific programs. Although the evidence is very uncertain about the effect of exercise on the risk of adverse events, the interventions included in our review were described as relatively safe. Larger, well-conducted studies are needed to increase confidence in the evidence. Additional studies recruiting people with advanced disease severity and cognitive impairment might help extend the generalizability of our findings to a broader range of people with PD.

Mesencephalic Locomotor Region and Presynaptic Inhibition during Anticipatory Postural Adjustments in People with Parkinson's Disease

Individuals with Parkinson's disease (PD) and freezing of gait (FOG) have a loss of presynaptic inhibition (PSI) during anticipatory postural adjustments (APAs) for step initiation. The mesencephalic locomotor region (MLR) has connections to the reticulospinal tract that mediates inhibitory interneurons responsible for modulating PSI and APAs. Here, we hypothesized that MLR activity during step initiation would explain the loss of PSI during APAs for step initiation in FOG (freezers). Freezers (n = 34) were assessed in the ON-medication state. We assessed the beta of blood oxygenation level-dependent signal change of areas known to initiate and pace gait (e.g., MLR) during a functional magnetic resonance imaging protocol of an APA task. In addition, we assessed the PSI of the soleus muscle during APA for step initiation, and clinical (e.g., disease duration) and behavioral (e.g., FOG severity and APA amplitude for step initiation) variables. A linear multiple regression model showed that MLR activity (R2 = 0.32, p = 0.0006) and APA amplitude (R2 = 0.13, p = 0.0097) explained together 45% of the loss of PSI during step initiation in freezers. Decreased MLR activity during a simulated APA task is related to a higher loss of PSI during APA for step initiation. Deficits in central and spinal inhibitions during APA may be related to FOG pathophysiology.

Temporal Investigations of the Changes in Presynaptic Inhibition Associated With Subthalamic Nucleus-Deep-Brain Stimulation

BACKGROUND AND PURPOSE

There are controversies regarding the role of presynaptic inhibition (PSI) in the mechanisms underlying the efficacy of deep-brain stimulation (DBS) in Parkinson's disease (PD). We sought to determine the involvement of PSI in DBS-related mechanisms and clinical correlates.

METHODS

We enrolled PD subjects who had received subthalamic nucleus DBS (STN-DBS) therapy and had been admitted to our clinic between January 2022 and March 2022. The tibial H-reflex was studied bilaterally during the medication-off state, and all tests were repeated 10 and 20 minutes after the simulation was turned off. Simultaneous evaluations based on the Movement-Disorder-Society-sponsored revision of the Unified Parkinson's Disease Rating Scale part III (MDS-UPDRS-III) were performed in all of the patients.

RESULTS

Ultimately we enrolled 18 patients aged 58.7±9.3 years (mean±standard deviation, 10 females). Fifty percent of the patients showed a decrease in the MDS-UPDRS-III score of more than 60% during the stimulation-on period. Comparative analyses of the repeated measurements made according to the stimulation status revealed significant differences only in the left H-reflex/M-response amplitude ratio (H/M ratio). However, no difference in the left H/M ratio was found in the subgroup of patients with a prominent clinical response to stimulation (n=9). Analyses of the less-affected side revealed differences in the H-reflex amplitude and H/M ratio.

CONCLUSIONS

We found evidence of PSI recovery on the less-affected side of our PD subjects associated with STN-DBS. We hypothesize that the involvement of this spinal pathway and its contribution to the mechanisms of DBS differ between individuals based on the severity of the disease and which brainstem regions and descending tracts are involved.

Telerehabilitation during social distancing for people with Parkinson's disease: a retrospective study

INTRODUCTION/AIM

Clinical worsening has been common in people with Parkinson's disease (PD) during the social distancing due to pandemic. It is unclear if telerehabilitation applied during social distancing preserves clinical aspects of people with PD who are frequent exercisers before the pandemic. Thus, we compared the effects of 10 months of supervised, home-based, real-time videoconferencing telerehabilitation (SRTT) and nonexercising control on clinical aspects in people with PD who are frequent exercisers before the pandemic.

METHODS

Fifty-seven (SRTT group) and 29 (nonexercising control group) people with PD were retrospectively assessed (Clinical Trials Registry: RBR-54sttfk). Only the SRTT group performed a 60-min online training sessions, 2-3 days per week, for 10 months (April 2020 to January 2021) during social distancing. Quality of life (PD Questionnaire [PDQ-39]), walking (item 28 from the Unified Parkinson's Disease Rating Scale part III [UPDRS-III]), posture (item 29 from the UPDRS-III), and freezing of gait (New-FOG questionnaire [NFOGQ]) were retrospectively assessed before (February-March 2020) and during social distancing (February-March 2021). The assessments were performed in-person and remotely before and during social distancing, respectively.

RESULTS

There were no between-group differences at baseline (p > 0.05). SRTT preserves PDQ-39 and walking scores but not posture and NFOGQ scores, while nonexercising control worsens scores in all variables. In addition, SRTT is more effective than nonexercising control in preserving PDQ-39 and walking scores.

CONCLUSION

During social distancing, long-term SRTT preserves the subjective quality of life and walking, but not subjective posture and FOG in people with PD who are frequent exercisers before the pandemic.

Physical exercise for people with Parkinson's disease: a systematic review and network meta-analysis

BACKGROUND

Physical exercise is effective in managing Parkinson's disease (PD), but the relative benefit of different exercise types remains unclear.

OBJECTIVES

To compare the effects of different types of physical exercise in adults with PD on the severity of motor signs, quality of life (QoL), and the occurrence of adverse events, and to generate a clinically meaningful treatment ranking using network meta-analyses (NMAs).

SEARCH METHODS

An experienced information specialist performed a systematic search for relevant articles in CENTRAL, MEDLINE, Embase, and five other databases to 17 May 2021. We also searched trial registries, conference proceedings, and reference lists of identified studies up to this date.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) comparing one type of physical exercise for adults with PD to another type of exercise, a control group, or both.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data. A third author was involved in case of disagreements.  We categorized the interventions and analyzed their effects on the severity of motor signs, QoL, freezing of gait, and functional mobility and balance up to six weeks after the intervention using NMAs. Two review authors independently assessed the risk of bias using the risk of bias 2 (RoB 2) tool and rated the confidence in the evidence using the CINeMA approach for results on the severity of motor signs and QoL. We consulted a third review author to resolve any disagreements. Due to heterogeneous reporting of adverse events, we summarized safety data narratively and rated our confidence in the evidence using the GRADE approach.

MAIN RESULTS

We included 156 RCTs with a total of 7939 participants with mostly mild to moderate disease and no major cognitive impairment. The number of participants per study was small (mean 51, range from 10 to 474). The NMAs on the severity of motor signs and QoL included data from 71 (3196 participants), and 55 (3283 participants) trials, respectively. Eighty-five studies (5192 participants) provided safety data. Here, we present the main results. We observed evidence of beneficial effects for most types of physical exercise included in our review compared to a passive control group. The effects on the severity of motor signs and QoL are expressed as scores on the motor scale of the Unified Parkinson Disease Rating Scale (UPDRS-M) and the Parkinson's Disease Questionnaire 39 (PDQ-39), respectively. For both scales, higher scores denote higher symptom burden. Therefore, negative estimates reflect improvement (minimum clinically important difference: -2.5 for UPDRS-M and -4.72 for PDQ-39). Severity of motor signs The evidence from the NMA (71 studies; 3196 participants) suggests that dance has a moderate beneficial effect on the severity of motor signs (mean difference (MD) -10.32, 95% confidence interval (CI) -15.54 to -4.96; high confidence), and aqua-based, gait/balance/functional, and multi-domain training might have a moderate beneficial effect on the severity of motor signs (aqua-based: MD -7.77, 95% CI -13.27 to -2.28; gait/balance/functional: MD -7.37, 95% CI -11.39 to -3.35; multi-domain: MD -6.97, 95% CI -10.32 to -3.62; low confidence). The evidence also suggests that mind-body training and endurance training might have a small beneficial effect on the severity of motor signs (mind-body: MD -6.57, 95% CI -10.18 to -2.81; endurance: MD -6.43, 95% CI -10.72 to -2.28; low confidence). Flexibility training might have a trivial or no effect on the severity of motor signs (MD 2.01, 95% CI -4.82 to 8.98; low confidence). The evidence is very uncertain about the effects of strength/resistance training and "Lee Silverman Voice training BIG" (LSVT BIG) on the severity of motor signs (strength/resistance: MD -6.97, 95% CI -11.93 to -2.01; LSVT BIG: MD -5.49, 95% CI -14.74 to 3.62; very low confidence). Quality of life The evidence from the NMA (55 studies; 3283 participants) suggests that aqua-based training probably has a large beneficial effect on QoL (MD -14.98, 95% CI -23.26 to -6.52; moderate confidence). The evidence also suggests that endurance training might have a moderate beneficial effect, and that gait/balance/functional and multi-domain training might have a small beneficial effect on QoL (endurance: MD -9.16, 95% CI -15.68 to -2.82; gait/balance/functional: MD -5.64, 95% CI -10.04 to -1.23; multi-domain: MD -5.29, 95% CI -9.34 to -1.06; low confidence). The evidence is very uncertain about the effects of mind-body training, gaming, strength/resistance training, dance, LSVT BIG, and flexibility training on QoL (mind-body: MD -8.81, 95% CI -14.62 to -3.00; gaming: MD -7.05, 95% CI -18.50 to 4.41; strength/resistance: MD -6.34, 95% CI -12.33 to -0.35; dance: MD -4.05, 95% CI -11.28 to 3.00; LSVT BIG: MD 2.29, 95% CI -16.03 to 20.44; flexibility: MD 1.23, 95% CI -11.45 to 13.92; very low confidence). Adverse events Only 85 studies (5192 participants) provided some kind of safety data, mostly only for the intervention groups. No adverse events (AEs) occurred in 40 studies and no serious AEs occurred in four studies. AEs occurred in 28 studies. The most frequently reported events were falls (18 studies) and pain (10 studies). The evidence is very uncertain about the effect of physical exercise on the risk of adverse events (very low confidence). Across outcomes, we observed little evidence of differences between exercise types.

AUTHORS' CONCLUSIONS

We found evidence of beneficial effects on the severity of motor signs and QoL for most types of physical exercise for people with PD included in this review, but little evidence of differences between these interventions. Thus, our review highlights the importance of physical exercise regarding our primary outcomes severity of motor signs and QoL, while the exact exercise type might be secondary. Notably, this conclusion is consistent with the possibility that specific motor symptoms may be treated most effectively by PD-specific programs. Although the evidence is very uncertain about the effect of exercise on the risk of adverse events, the interventions included in our review were described as relatively safe. Larger, well-conducted studies are needed to increase confidence in the evidence. Additional studies recruiting people with advanced disease severity and cognitive impairment might help extend the generalizability of our findings to a broader range of people with PD.

Investigation of the changes in the presynaptic inhibition in association with the subthalamic nucleus stimulation in Parkinson's disease

BACKGROUND AND PURPOSE

Presynaptic inhibition (PSI) is a critical spinal inhibitory mechanism for modulating muscle coordination by adjusting both supraspinal motor commands and sensory feedback at the spinal level. The literature data regarding the role of PSI in the efficiency of STN-DBS therapy in Parkinson's disease (PD) are limited. We aimed to investigate the possible alteration in this pathway in association with the STN stimulation (STIM) within the very early period after the STIM is off.

METHODS

We performed the H-reflex investigation on 8 PD subjects with STN-DBS who applied to our polyclinic for routine clinical evaluations. The investigations were initially performed at the STIM-on period and repeated after the STIM set is off for 5 min. A within-subjects ANOVA was used to test for a significant difference between the STIM-on and -off states for the variables of (repeated measures) H-latency, H amplitude, M amplitude, H/M amplitude, H threshold, and M threshold.

RESULTS

The results of the analyses did not reveal marked changes in the variables of the H-reflex between the STIM-on and -off states.

CONCLUSION

PSI do not alter in the very early period after the STIM is off. Taken together with the related literature data and our study results, it can be hypothesized that the PSI might involve in the DBS efficiency in the later phase of the STIM as a compensatory mechanism. Further prospective studies including a larger number of patients with serial electrophysiological recordings to investigate the temporal course of the underlying dynamics are required to clarify these discussions.

Parkinson's disease and intensive exercise therapy - An updated systematic review and meta-analysis

In 2015, Uhrbrand et al. published the first review on Parkinson´s disease (PD) and exercise entirely based on randomized controlled trials (RCT) applying strict exercise definitions. The present review aimed to update the PD literature by assessing the effects of different intensive exercise modalities: resistance training (RT), endurance training (ET), and other intensive exercise modalities (OITM). An updated systematic literature search identified 33 new RCTs. Qualitative and quantitative analyses were performed. A total of 18 RT, 14 ET, and 1 OITM studies were identified (adding to the 8 RT, 6 ET, and 4 OITM studies identified by Uhrbrand et al. in 2015). RT, ET, and OITM were feasible, safe, and did not worsen PD symptoms. Furthermore, RT, ET, and OITM may positively affect functional outcomes (e.g., balance) and depressive symptoms in PD but inconsistencies across these findings warrant cautious conclusions. Meta-analyses showed that RT had a positive impact on muscle strength (standardized mean difference (SMD) = 0.83 [95% CI;0.54, 1.12]), functional capacity (Timed Up and Go Test (TUG): SMD = -0.62 [-1.01, -0.24]), and quality of life (SMD = -0.41 [-0.72, -0.09]), while ET had a positive impact on cardiorespiratory fitness (SMD = 0.27 [0.07, 0.47]) and functional capacity (TUG: SMD = -0.21 [-0.46, 0.04], 6-Min Walk Test: SMD = 0.89 [0.17, 1.62]), and a potentially positive impact on "on-medication" UPDRS-III (SMD = -0.15 [-0.38, 0.09]) and "off-medication" UPDRS-III (SMD = -0.19 [-0.41, 0.04]). In conclusion, RT, ET, and OITM all represent safe, feasible, and beneficial adjunct rehabilitation strategies in PD, with particularly RT and ET showing solid effects.

Physical Therapist Management of Parkinson Disease: A Clinical Practice Guideline From the American Physical Therapy Association

A clinical practice guideline on Parkinson disease was developed by an American Physical Therapy Association volunteer guideline development group that consisted of physical therapists and a neurologist. The guideline was based on systematic reviews of current scientific and clinical information and accepted approaches for management of Parkinson disease. The Spanish version of this clinical practice guideline is available as a supplement (Suppl. Appendix 1).

Effects of resistance training on metabolic and cardiovascular responses to a maximal cardiopulmonary exercise test in Parkinson`s disease

Objective:

To evaluate the effects of resistance training on metabolic and cardiovascular responses during maximal cardiopulmonary exercise testing in patients with Parkinson’s disease.

Methods:

Twenty-four patients with Parkinson’s disease (modified Hoehn and Yahr stages 2 to 3) were randomly assigned to one of two groups: Control or Resistance Training. Patients in the Resistance Training Group completed an exercise program consisting of five resistance exercises (two to four sets of six to 12 repetitions maximum per set) twice a week. Patients in the Control Group maintained their usual lifestyle. Oxygen uptake, systolic blood pressure and heart rate were assessed at rest and during cycle ergometer-based maximal cardiopulmonary exercise testing at baseline and at 12 weeks. Assessments during exercise were conducted at absolute submaximal intensity (slope of the linear regression line between physiological variables and absolute workloads), at relative submaximal intensity (anaerobic threshold and respiratory compensation point) and at maximal intensity (maximal exercise). Muscle strength was also evaluated.

Results:

Both groups had similar increase in peak oxygen uptake after 12 weeks of training. Heart rate and systolic blood pressure measured at absolute and relative submaximal intensities and at maximal exercise intensity did not change in any of the groups. Muscle strength increased in the Resistance Training but not in the Control Group after 12 weeks.

Conclusion:

Resistance training increases muscle strength but does not change metabolic and cardiovascular responses during maximal cardiopulmonary exercise testing in patients with Parkinson’s disease without cardiovascular comorbidities.

Strength Training versus Stretching for Improving Range of Motion: A Systematic Review and Meta-Analysis

(1) Background: Stretching is known to improve range of motion (ROM), and evidence has suggested that strength training (ST) is effective too. However, it is unclear whether its efficacy is comparable to stretching. The goal was to systematically review and meta-analyze randomized controlled trials (RCTs) assessing the effects of ST and stretching on ROM (INPLASY 10.37766/inplasy2020.9.0098). (2) Methods: Cochrane Library, EBSCO, PubMed, Scielo, Scopus, and Web of Science were consulted in October 2020 and updated in March 2021, followed by search within reference lists and expert suggestions (no constraints on language or year). Eligibility criteria: (P) Humans of any condition; (I) ST interventions; (C) stretching (O) ROM; (S) supervised RCTs. (3) Results: Eleven articles (n = 452 participants) were included. Pooled data showed no differences between ST and stretching on ROM (ES = -0.22; 95% CI = -0.55 to 0.12; p = 0.206). Sub-group analyses based on risk of bias, active vs. passive ROM, and movement-per-joint analyses showed no between-protocol differences in ROM gains. (4) Conclusions: ST and stretching were not different in their effects on ROM, but the studies were highly heterogeneous in terms of design, protocols and populations, and so further research is warranted. However, the qualitative effects of all the studies were quite homogeneous.

Effect of the combination of automated peripheral mechanical stimulation and physical exercise on aerobic functional capacity and cardiac autonomic control in patients with Parkinson's disease: a randomized clinical trial protocol

BACKGROUND

Automated peripheral mechanical stimulation (AMPS) has been proposed as a new complementary therapy with potential for improving motor and cardiovascular abnormalities in Parkinson's disease (PD). However, AMPS long-term effects and its combination with physical exercise are unknown. Thus, this study aims to compare the effects of a program of 12 weeks of physical exercise with a 12-week intervention program combining physical exercise and AMPS on the aerobic capacity, cardiac autonomic control, and gait parameters in patients with PD.

METHODS

A randomized, controlled clinical trial will be conducted. Older volunteers with PD will be randomly assigned to one of the two groups studied: (1) exercise or (2) AMPS + exercise. Both groups will undergo an exercise program of 24 sessions, for 12 weeks, performed twice a week. Before exercise sessions, the group AMPS + exercise will receive a session of active AMPS, while the group exercise will receive an AMPS sham intervention. Shapiro-Wilk's and Levene's tests will be used to check for data normality and homogeneity, respectively. In case parametric assumptions are fulfilled, per-protocol and intention-to-treat analyses will be performed using a mixed model analysis of variance to check for group*time interaction. Significance level will be set at 5%.

DISCUSSION

Several non-pharmacological treatment modalities have been proposed for PD, focusing primarily on the reduction of motor and musculoskeletal disorders. Regular exercise and motor training have been shown to be effective in improving quality of life. However, treatment options in general remain limited given the high prevalence and adverse impact of these disorders. So, developing new strategies that can potentiate the improvement of motor disabilities and also improve non-motor symptoms in PD is relevant. It is expected that the participants from both groups will improve their quality of life, gait parameters, and their cardiac autonomic control, with greater improvements being observed in the group combining active AMPS and physical exercise.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04251728 . Registered on February 05, 2020.

Age-Related Changes in Presynaptic Inhibition During Gait Initiation

Age-related changes in presynaptic inhibition (PSI) have not been observed during gait initiation, which requires anticipatory postural adjustment (APA). As APA is centrally modulated and is impaired in older compared to young adults, here we aimed to study the presynaptic control and co-contraction levels in the ankle muscles during gait initiation in older compared to young adults. Fifteen older (age range 65-80 years) and 15 young adults (age range 19-30 years) performed a gait initiation task on a force platform under 3 conditions: (i) without electrical stimulation; (ii) test Hoffman reflex (H-reflex); and (iii) conditioned H-reflex. H-reflexes were evoked on the soleus muscle when the APA amplitude exceeded 10%-20% of the average baseline mediolateral force. Participants also performed quiet stance as a control task. Results showed that both age groups presented similar PSI levels during quiet stance (p = .941), while in the gait initiation older adults presented higher PSI levels, longer duration, and lower amplitude of APA than young adults (p < .05). Older adults presented higher co-contraction ratio in both tasks than young adults (p < .05). Correlations between the PSI levels and the APA amplitude (r = -0.61, p = .008), and between the PSI levels and the co-contraction ratio during gait initiation (r = -0.64, p = .005) were found for older adults only. APA amplitude explained 49% of the variance of the PSI levels (p = .003). Our findings suggest that older compared to young adults have increased presynaptic control to compensate for the decreased supraspinal modulation on impaired APAs during gait initiation.

Binary dance rhythm or Quaternary dance rhythm which has the greatest effect on non-motor symptoms of individuals with Parkinson's disease?

This study aimed to compare the effect of a binary and quaternary rhythm protocol on cognition, mental activity, daily life, and quality of life among individuals with Parkinson's Disease. A two-arm randomized clinical trial with 31 individuals diagnosed with Parkinson's disease, who were allocated to the binary group or quaternary group. Both groups underwent a 12-week intervention. The following variables were analyzed: personal and clinical information; MoCA; UPDRSI and II; PDQ-39. Both intervention groups improved cognition, mental activity, activities of daily living, and quality of life. In addition, there were intergroup differences in total UPDRSII, writing, and hygiene where the quaternary group was superior to the binary group. It concludes that the binary and quaternary rhythm positively influenced and presented similar effects on the complementary treatment of individuals with Parkinson's disease on the studied variables. Thus, it is believed that both interventions are possible and feasible for the health professionals involved in the area.

Functional Recovery in Parkinson's Disease: Current State and Future Perspective

Parkinson’s disease (PD) is one of the most frequent neurodegenerative disorders, affecting not only the motor function but also limiting the autonomy of affected people. In the last decade, the physical exercises of different intensities carried out by kinetic therapeutic activities, by robotic technologies or with the participation of sensory cues, have become increasingly appreciated in the management of Parkinson’s disease impairments. The aim of this paper was to evaluate the impact of physical exercises with and without physical devices on the motor and cognitive variables of PD patients. In order to achieve our objectives, we performed a systematic review of available original articles based on the impact of kinetic therapeutic activity. Through the search strategy, we selected original papers that were laboriously processed using characteristics related to physical therapy, or the tools used in physiological and psychological rehabilitation strategies for PD patients. In this study, we presented the most current intervention techniques in the rehabilitation programs of patients with Parkinson’s disease, namely the use of assisted devices, virtual imagery or the performing of physical therapies that have the capacity to improve walking deficits, tremor and bradykinesia, to reduce freezing episodes of gait and postural instability, or to improve motor and cognitive functions.

Loss of presynaptic inhibition for step initiation in parkinsonian individuals with freezing of gait

KEY POINTS

Individuals with freezing of gait (FoG) due to Parkinson's disease (PD) have small and long anticipatory postural adjustments (APAs) associated with delayed step initiation. Individuals with FoG ('freezers') may require functional reorganization of spinal mechanisms to perform APAs due to supraspinal dysfunction. As presynaptic inhibition (PSI) is centrally modulated to allow execution of supraspinal motor commands, it may be deficient in freezers during APAs. We show that freezers presented PSI in quiet stance (control task), but they presented loss of PSI (i.e. higher ratio of the conditioned H-reflex relative to the test H-reflex) during APAs before step initiation (functional task), whereas non-freezers and healthy control individuals presented PSI in both the tasks. The loss of PSI in freezers was associated with both small APA amplitudes and FoG severity. We hypothesize that loss of PSI during APAs for step initiation in freezers may be due to FoG.

ABSTRACT

Freezing of gait (FoG) in Parkinson's disease involves deficient anticipatory postural adjustments (APAs), resulting in a cessation of step initiation due to supraspinal dysfunction. Individuals with FoG ('freezers') may require functional reorganization of spinal mechanisms to perform APAs. As presynaptic inhibition (PSI) is centrally modulated to allow execution of supraspinal motor commands, here we hypothesized a loss of PSI in freezers during APA for step initiation, which would be associated with FoG severity. Seventy individuals [27 freezers, 22 non-freezers, and 21 age-matched healthy controls (HC)] performed a 'GO'-commanded step initiation task on a force platform under three conditions: (1) without electrical stimulation, (2) test Hoffman reflex (H-reflex) and (3) conditioned H-reflex. They also performed a control task (quiet stance). In the step initiation task, the H-reflexes were evoked on the soleus muscle when the amplitude of the APA exceeded 10-20% of the mean baseline mediolateral force. PSI was quantified by the ratio of the conditioned H-reflex relative to the test H-reflex in both the tasks. Objective assessment of FoG severity (FoG-ratio) was performed. Freezers presented lower PSI levels during quiet stance than non-freezers and HC (P < 0.05). During step initiation, freezers presented loss of PSI and lower APA amplitudes than non-freezers and HC (P < 0.05). Significant correlations were only found for freezers between loss of PSI and FoG-ratio (r = 0.59, P = 0.0005) and loss of PSI and APA amplitude (r = -0.35, P < 0.036). Our findings suggest that loss of PSI for step initiation in freezers may be due to FoG.

Short-term resistance training with instability reduces impairment in V wave and H reflex in individuals with Parkinson's disease

This study had two objectives: 1) to compare the effects of 3 wk of resistance training (RT) and resistance training with instability (RTI) on evoked reflex responses at rest and during maximal voluntary isometric contraction (MVIC) of individuals with Parkinson's disease (PD) and 2) to determine the effectiveness of RT and RTI in moving values of evoked reflex responses of individuals with PD toward values of age-matched healthy control subjects (HCs) (z-score analysis). Ten individuals in the RT group and 10 in the RTI group performed resistance exercises twice a week for 3 wk, but only the RTI group included unstable devices. The HC group (n = 10) were assessed at pretest only. Evoked reflex responses at rest (H reflex and M wave) and during MVIC [supramaximal M-wave amplitude (M_sup) and supramaximal V-wave amplitude (V_sup)] of the plantar flexors were assessed before and after the experimental protocol. From pretraining to posttraining, only RTI increased ratio of maximal H-reflex amplitude to maximal M-wave amplitude at rest (H_max/M_max), M_sup, V_sup/M_sup, and peak torque of the plantar flexors (P < 0.05). At posttraining, RTI was more effective than RT in increasing resting H_max and V_sup and in moving these values to those observed in HCs (P < 0.05). We conclude that short-term RTI is more effective than short-term RT in modulating H-reflex excitability and in increasing efferent neural drive, approaching average values of HCs. Thus short-term RTI may cause positive changes at the spinal and supraspinal levels in individuals with PD. NEW & NOTEWORTHY Maximal H-reflex amplitude (H_max) at rest and efferent neural drive [i.e., supramaximal V-wave amplitude (V_sup)] to skeletal muscles during maximal contraction are impaired in individuals with Parkinson's disease. Short-term resistance training with instability was more effective than short-term resistance training alone in increasing H_max and V_sup of individuals with Parkinson's disease, reaching the average values of healthy control subjects.

Balance and fear of falling in subjects with Parkinson's disease is improved after exercises with motor complexity

Resistance training with instability (RTI) uses exercises with high motor complexity that impose high postural control and cognitive demands that may be important for improving postural instability and fear of falling in subjects with Parkinson's disease (PD). Here, we hypothesized that: 1) RTI will be more effective than resistance training (RT) in improving balance (Balance Evaluation Systems Test [BESTest] and overall stability index [Biodex Balance System^®]) and fear of falling (Falls Efficacy Scale-International [FES-I] score) of subjects with Parkinson's disease (PD); and 2) changes in BESTest and FES-I after RTI will be associated with changes in cognitive function (Montreal Cognitive Assessment [MoCA] score - previously published) induced by RTI. Thirty-nine subjects with moderate PD were randomly assigned to a nonexercising control, RT, and RTI groups. While RT and RTI groups performed progressive RT twice a week for 12 weeks, the RTI group added progressive unstable devices to increase motor complexity of the resistance exercises. There were significant group × time interactions for BESTest, overall stability index, and FES-I scores (P < 0.05). Only RTI improved BESTest, overall stability index and FES-I scores, and RTI was more effective than RT in improving biomechanical constraints and stability in gait (BESTest sections) at post-training (P < 0.05). There were strong correlations between relative changes in BESTest and MoCA (r = 0.72, P = 0.005), and FES-I and MoCA (r = -0.75, P = 0.003) after RTI. Due to the increased motor complexity in RTI, RTI is recommended for improving balance and fear of falling, which are associated with improvement in cognitive function of PD.