Key results from the network meta‐analysis are also available as an interactive summary of findings table, produced in collaboration with MAGIC.
Background
Parkinson's disease (PD) is a progressive disorder of the nervous system that mostly affects people over 60. Symptoms begin gradually and include movement issues, such as trembling, stiffness, slowness of movement and balance, and coordination issues. People with PD can also have emotional and mood problems, fatigue, sleep problems, and thinking difficulties. The disorder cannot be cured, but the symptoms can be relieved, for example, with medicine or surgery. Moreover, people with PD may benefit from physiotherapy or other forms of physical exercise, such as dancing. But it remains unclear if some of these exercise types work better than others.
What was our aim?
We wanted to find out what type of physical exercise works best to improve movement and quality of life for people with PD. We also wanted to find out what type of exercise causes the least unwanted effects.
What did we do?
We searched for studies that compared physical exercise with no physical exercise or with another physical exercise type. We compared and summarized their short-term results, and rated our confidence in the evidence, based on factors such as study methods and number of people included. We only studied short-term results.
What did we find?
We found 154 studies on different physical exercise types for people with PD. The studies included a total of 7837 people. The smallest study was conducted with 10 people and the biggest with 474 people. The average participant age was between 60 and 74 years. The studies were conducted in countries around the world, with the highest number (34) in the USA. Of the included studies, 60 (2721 people) provided information on movement; 48 (3029 people) provided information on quality of life, and 85 (5192 people) provided information on unwanted effects.
What are the key results?
Many types of physical exercise worked well for people with PD compared to no physical exercise.
Dance and gait/balance/functional training probably have a moderate beneficial effect on movement. Training that consists of several exercise types (i.e. multi-domain training) probably has a small beneficial effect on movement. Endurance, aqua-based, strength/resistance, and mind-body training (e.g. tai chi or yoga) might have a small beneficial effect on movement. We are very uncertain about the effects of the PD-specific physical therapy "Lee Silverman Voice training BIG" (LSVT BIG) and flexibility training on movement.
Aqua-based training probably has a large beneficial effect on quality of life. Mind-body, gait/balance/functional, and multi-domain training and dance might have a small beneficial effect on quality of life. We are very uncertain about the effects of gaming, strength/resistance, endurance, and flexibility training on quality of life.
Our confidence in the effects ranged from moderate to very low. When our confidence was reduced, it was often because of two reasons. First, not all of the studies provided information on movement or quality of life from all the people who participated. Second, studies were very small.
Only 85 studies provided some information about unwanted effects, and mostly only for the physical exercise groups, not the groups who did not do exercise. No unwanted effects were reported in 40 studies. No serious unwanted effects were reported in four studies. Unwanted effects were reported in 28 studies. The unwanted effects reported most frequently were falls (18 studies) and pain (10 studies). We could not say what type of exercise causes the least unwanted effects because studies did not provide information about everything we needed. That is why we are very uncertain about the results on unwanted effects.
What does this mean?
We found that many types of physical exercise can help improve movement and quality of life for people with PD. We found scant evidence that certain exercise types work better than others. Therefore, for movement and quality of life, we think physical exercise is important, but the exact exercise type might be less important. Still, it is possible that some symptoms may be relieved best with specific types of training made for people with PD. The types of training we included seemed to be quite safe.
Larger, well-designed studies are needed to increase our confidence in the evidence. Also, more research is required to understand the features that influence the effects of exercise. More studies involving people who have worse symptoms could help extend the results to more people with PD.
How up to date is this review?
The evidence is up to date to May 2021.
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.
Physical exercise is effective in managing Parkinson's disease (PD), but the relative benefit of different exercise types remains unclear.
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).
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.
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.
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.
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.