Abstract
Background
Despite the high incidence of muscle weakness in individuals with amyotrophic lateral sclerosis (ALS) or motor neuron disease (MND), the effects of exercise in this population are not well understood. This is an update of a review first published in 2008.
Objectives
To systematically review randomised and quasi-randomised studies of exercise for people with ALS or MND.
Search methods
We searched The Cochrane Neuromuscular Disease Group Specialized Register (2 July 2012), CENTRAL (2012, Issue 6 in The Cochrane Library), MEDLINE (January 1966 to June 2012), EMBASE (January 1980 to June 2012), AMED (January 1985 to June 2012), CINAHL Plus (January 1938 to June 2012), LILACS (January 1982 to June 2012), Ovid HealthSTAR (January 1975 to December 2012). We also searched ProQuest Dissertations & Theses A&I (2007 to 2012), inspected the reference lists of all papers selected for review and contacted authors with expertise in the field.
Selection criteria
We included randomised or quasi-randomised controlled trials of people with a diagnosis of definite, probable, probable with laboratory support, or possible ALS, as defined by the El Escorial criteria. We included progressive resistance or strengthening exercise, and endurance or aerobic exercise. The control condition was no exercise or standard rehabilitation management. Our primary outcome measure was improvement in functional ability, decrease in disability or reduction in rate of decline as measured by a validated outcome tool at three months. Our secondary outcome measures were improvement in psychological status or quality of life, decrease in fatigue, increase in, or reduction in rate of decline of muscle strength (strengthening or resistance studies), increase in, or reduction in rate of decline of aerobic endurance (aerobic or endurance studies) at three months and frequency of adverse effects. We did not exclude studies on the basis of measurement of outcomes.
Data collection and analysis
Two review authors independently assessed trial quality and extracted the data. We collected adverse event data from included trials. The review authors contacted the authors of the included studies to obtain information not available in the published articles.
Main results
We identified two randomised controlled trials that met our inclusion criteria, and we found no new trials when we updated the searches in 2012. The first, a study with overall unclear risk of bias, examined the effects of a twice-daily exercise program of moderate load endurance exercise versus “usual activities” in 25 people with ALS. The second, a study with overall low risk of bias, examined the effects of thrice weekly moderate load and moderate intensity resistance exercises compared to usual care (stretching exercises) in 27 people with ALS. After three months, when the results of the two trials were combined (43 participants), there was a significant mean improvement in the Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS) measure of function in favour of the exercise groups (mean difference 3.21, 95% confidence interval 0.46 to 5.96). No statistically significant differences in quality of life, fatigue or muscle strength were found. In both trials adverse effects, investigators reported no adverse effects such as increased muscle cramping, muscle soreness or fatigue
Authors’ conclusions
The included studies were too small to determine to what extent strengthening exercises for people with ALS are beneficial, or whether exercise is harmful. There is a complete lack of randomised or quasi-randomised clinical trials examining aerobic exercise in this population. More research is needed.
Plain language summary
Therapeutic exercise for people with amyotrophic lateral sclerosis or motor neuron disease
Muscle weakness is very common in people with amyotrophic lateral sclerosis (ALS), which is also known as motor neuron disease (MND). A weak muscle can be damaged if overworked because it is already functioning close to its maximal limits. Because of this, some experts have discouraged exercise programs for people with ALS. However, if a person with ALS is not active, deconditioning (loss of muscle performance) and weakness from lack of use occurs, on top of the deconditioning and weakness caused by the disease itself. If the reduced level of activity persists, many organ systems can be affected and a person with ALS can develop further deconditioning and muscle weakness, and muscle and joint tightness may occur leading to contractures (abnormal distortion and shortening of muscles) and pain. These all make daily activities harder to do. This review found only two randomised studies of exercise in people with ALS. The trials compared an exercise program with usual care (stretching exercises). Combining the results from the two trials (43 participants), exercise produced a greater average improvement in function (measured using an ALS-specific measurement scale) than usual care. There were no other differences between the two groups. There were no reported adverse events due to exercise. The studies were too small to determine to what extent exercise for people with ALS is beneficial or whether exercise is harmful. We found no new trials when we updated the searches in 2012. More research is needed.
