Can amyotrophic lateral sclerosis patients with respiratory insufficiency exercise?

Therapeutic exercise for people with amyotrophic lateral sclerosis or motor neuron disease

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.

OBJECTIVES

The objective was to systematically review randomised and quasi-randomised studies of exercise for people with ALS or MND.

SEARCH STRATEGY

We searched the Cochrane Neuromuscular Disease Group Trials Register, EMBASE (January 1980 to August 2007), LILACS (January 1982 to August 2007), MEDLINE (January 1966 to August 2007), Cochrane Central Register of Controlled Trials (CENTRAL), PEDro (January 1980 to August 2007), AMED (January 1985 to August 2007), HealthSTAR (January 1975 to August 2007), CINAHL (January 1982 to August 2007). We also searched Dissertation Abstracts, inspected the reference lists of all papers selected for review and contacted the 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 amyotrophic lateral sclerosis, 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.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted the data. The authors of the papers were contacted to obtain information not available in the published articles.

MAIN RESULTS

We identified two randomised controlled trials that met our inclusion criteria. The first examined the effects of a twice-daily exercise program of moderate load, endurance exercise versus "usual activities" in 25 people with ALS. The second 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, there was a significant weighted mean improvement in the Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS) measure of function in the exercise compared with the control groups (3.21, 95% confidence interval 0.46 to 5.96) in favour of the exercise group. No statistically significant differences in quality of life, fatigue or muscle strength were found.

AUTHORS' CONCLUSIONS

The only studies detected 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.

What is orofacial fatigue and how does it affect function for swallowing and speech?

Speech-language pathologists are likely to encounter patients who report symptoms of fatigue, but there are few clinical procedures to assess this phenomenon. Furthermore, it is difficult to determine whether fatigue contributes to a patient's dysphagia or dysarthria. This article reviews orofacial muscles, including the muscles of the tongue, lips, and cheeks, highlighting in particular their role in swallowing and speaking. It provides definitions of fatigue and describes assessment procedures. The author's research has focused on assessing fatigue, especially of the tongue, and elucidating the effects of exercising the tongue on speech and nonspeech tasks. Most of this work involves people who have Parkinson's disease and neurologically normal adults; results generally support heightened fatigue in Parkinson's disease. However, the effect of fatigue on functional activities remains unclear. Literature regarding the effects of orofacial fatigue on swallowing and speaking is notably sparse, but preliminary evidence indicates that these functions are rather robust.

Gene transfer demonstrates that muscle is not a primary target for non-cell-autonomous toxicity in familial amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a fatal, progressive paralysis arising from the premature death of motor neurons. An inherited form is caused by a dominant mutation in the ubiquitously expressed superoxide dismutase (SOD1). SOD1 mutant expression within motor neurons is a determinant of onset and early disease, and mutant accumulation within microglia accelerates disease progression. Muscle also is a likely primary source for toxicity, because retraction of motor axons from synaptic connections to muscle is among the earliest presymptomatic events. To test involvement of muscle in ALS, viral delivery of transcription-mediated siRNA is shown to suppress mutant SOD1 accumulation within muscle alone but to be insufficient to maintain grip strength, whereas delivery to both motor neurons and muscle is sufficient. Use of a deletable mutant gene to diminish mutant SOD1 from muscle did not affect onset or survival. Finally, follistatin expression encoded by adeno-associated virus chronically inhibited myostatin and produced sustained increases in muscle mass, myofiber number, and fiber diameter, but these increases did not affect survival. Thus, SOD1-mutant-mediated damage within muscles is not a significant contributor to non-cell-autonomous pathogenesis in ALS, and enhancing muscle mass and strength provides no benefit in slowing disease onset or progression.

Outcomes of physical therapy, speech pathology, and occupational therapy for people with motor neuron disease: a systematic review

This article describes a systematic review and critical evaluation of the international literature on the effects of physical therapy, speech pathology, and occupational therapy for people with motor neuron disease (PwMND). The results were interpreted using the framework of the International Classification of Functioning, Disability and Health. This enabled us to summarize therapy outcomes at the level of body structure and function, activity limitations, participation restrictions, and quality of life. Databases searched included MEDLINE, PUBMED, CINAHL, PSYCInfo, Data base of Abstracts of Reviews of Effectiveness (DARE), The Physiotherapy Evidence data base (PEDro), Evidence Based Medicine Reviews (EMBASE), the Cochrane database of systematic reviews, and the Cochrane Controlled Trials Register. Evidence was graded according to the Harbour and Miller classification. Most of the evidence was found to be at the level of "clinical opinion" rather than of controlled clinical trials. Several nonrandomized small group and "observational studies" provided low-level evidence to support physical therapy for improving muscle strength and pulmonary function. There was also some evidence to support the effectiveness of speech pathology interventions for dysarthria. The search identified a small number of studies on occupational therapy for PwMND, which were small, noncontrolled pre-post-designs or clinical reports.

ALS: a disease of motor neurons and their nonneuronal neighbors

Amyotrophic lateral sclerosis is a late-onset progressive neurodegenerative disease affecting motor neurons. The etiology of most ALS cases remains unknown, but 2% of instances are due to mutations in Cu/Zn superoxide dismutase (SOD1). Since sporadic and familial ALS affects the same neurons with similar pathology, it is hoped that therapies effective in mutant SOD1 models will translate to sporadic ALS. Mutant SOD1 induces non-cell-autonomous motor neuron killing by an unknown gain of toxicity. Selective vulnerability of motor neurons likely arises from a combination of several mechanisms, including protein misfolding, mitochondrial dysfunction, oxidative damage, defective axonal transport, excitotoxicity, insufficient growth factor signaling, and inflammation. Damage within motor neurons is enhanced by damage incurred by nonneuronal neighboring cells, via an inflammatory response that accelerates disease progression. These findings validate therapeutic approaches aimed at nonneuronal cells.

Measurement of decline of functioning in persons with amyotrophic lateral sclerosis: responsiveness and possible applications of the Functional Independence Measure, Barthel Index, Rehabilitation Activities Profile and Frenchay Activities Index

It is important not only to monitor the functional change during the course of ALS, but also to determine whether or not the available help is sufficient. This study was performed to determine which generic assessment instrument is most appropriate. A multicentre cohort of patients with ALS was followed for one year. At baseline, six months, and 1 year four instruments were used: Functional Independence Measure (FIM), Rehabilitation Activities Profile (RAP), Barthel Index (BI), and Frenchay Activities Index (FAI). The responsiveness of the measures was examined using effect sizes and standardized response mean statistics. Seventy-three patients at baseline, 63 after six months and 43 after one year were assessed. If calculated on the group that completed all three assessments, the FIM, BI, and RAP showed moderate effect sizes and standardized response means over a period of six months and large effect sizes over 12 months. Based on their responsiveness FIM, BI, and RAP can be used to evaluate limitations in activities and care needs of persons with ALS and to evaluate treatment results in trials. The FIM was the most responsive instrument, although the BI might be easier to use in clinical practice.

Management of respiration in MND/ALS patients: an evidence based review

This systematic review comprises an objective appraisal of the evidence in regard to the management of respiration in patients with motor neuron disease (MND/ALS). Studies were identified through computerised searches of 32 databases. Internet searches of websites of drug companies and MND/ALS research web sites, 'snow balling' and hand searches were also employed to locate any unpublished study or other 'grey literature' on respiration and MND/ALS. Since management of MND/ALS involves a number of health professionals and care workers, searches were made across multiple disciplines. No time frame was imposed on the search in order to increase the probability of identifying all relevant studies, although there was a final limit of March 2005. Recommendations for patient and carer-based guidelines for the clinical management of respiration for MND/ALS patients are suggested on the basis of qualitative analyses of the available evidence. However, these recommendations are based on current evidence of best practice, which largely comprises observational research and clinical opinion. There is a clear need for further evidence, in particular randomised and non-randomised controlled trials on the effects of non-invasive ventilation and additional larger scale cohort studies on the issues of initial assessment of respiratory symptoms, and management and timing of interventions.

Management strategies for patients with amyotrophic lateral sclerosis from diagnosis through death

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a progressive neuromuscular disorder that is inevitably fatal. There are no effective treatments to stop or reverse the natural course of the disease. The role of the physician is to provide comfort and optimize quality of life.

REVIEW SUMMARY

Management of patients with ALS is a process extending over months to years. It begins with breaking the news of the diagnosis and extends through the terminal phase. Medication may extend lifespan by a small amount. However, most efforts are centered around symptom management. Areas of importance include respiration, nutrition, secretions, communication, pseudobulbar affect, therapy and exercise, spasticity and cramps, pain, depression and suicide, spirituality and religion, cognitive changes, the development of advance directives, and care at the end of life. Multidisciplinary ALS clinics provide much-needed support for patients with ALS and their caregivers.

CONCLUSION

Although physicians cannot cure ALS or even halt progression, there is much that can be done to manage the physical and emotional symptoms, thereby maintaining or enhancing quality of life.

Synergy of insulin-like growth factor-1 and exercise in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease of the neuromuscular system resulting in paralysis and ultimately death. Currently, no effective therapy is prescribed for patients; however, several therapeutic strategies are showing promise. Either exercise or treatment with adeno-associated virus/insulin-like growth factor-1 alone has therapeutic benefits in an amyotrophic lateral sclerosis transgenic mouse model. We show here that activity duration affects the therapeutic benefit associated with exercise, with 6- and 12-hour exposure to a running wheel providing significant motor function benefits and increased survival. Remarkably, a combination of insulin-like growth factor-1 gene delivery and exercise has profound effects on survival and function, indicative of synergistic effects with exercise and insulin-like growth factor-1. Our results indicate that a drug treatment in combination with appropriate exercise may provide the most promising therapy for amyotrophic lateral sclerosis to date.

Effects of high-intensity endurance exercise training in the G93A mouse model of amyotrophic lateral sclerosis

The G93A transgenic mouse has a mutation in copper/zinc superoxide dismutase (CuZnSOD) that results in oxidative stress and motor neuron loss. Endurance exercise training is known to increase antioxidant capacity in skeletal muscle. Therefore, we hypothesized that endurance training may extend onset of disease or survival in the G93A mouse. We examined the effects of high-intensity endurance exercise training (45 min/day, 5 times/week, progressive increase from 9 to 22 m/min) on disease onset and survival in G93A mice. Endurance training did not affect clinical onset, although it hastened death in male mice (P < 0.05). Endurance-trained males had a statistically significant decrease in rotarod performance at 112 days (P < 0.05), whereas sedentary males decreased at 119 days (P < 0.05). Endurance-trained and sedentary females decreased at 126 days and 129 days, respectively (P < 0.05). Female mice lived longer than males (P < 0.05), and there was a trend for hastened clinical onset in males (P = 0.062). We conclude that high-intensity endurance exercise training does not affect onset of clinical symptoms in G93A mice but hastens a decrease in motor performance and death following onset of clinical symptoms in male mice only. In light of a recent report describing increased survival following low-intensity endurance training, it appears that training intensity is an important determinant of survival in the G93A mouse.

Sexual differences in onset of disease and response to exercise in a transgenic model of ALS

Transgenic mice that overexpress the mutant human SOD1 gene (hSOD1) serve as an animal model for amyotrophic lateral sclerosis (ALS). Age and sex are recognized as risk factors for ALS, but physical activity remains controversial. Therefore, we investigated the effect of exercise on the phenotype of male and female hSOD1 mice. Onset of disease, progression of disease and survival were measured in low-copy and high-copy hSOD1 mice that were randomized to an exercise or sedentary group. We found that onset of disease was different for the two sexes: significantly earlier in male than in female hSOD1 mice. Exercise delayed the onset of disease in female but not in male hSOD1 mice. Also, exercise delayed the total survival time in female high-copy hSOD1 mice. Muscle morphometry and motor neuron counts were similar in all experimental groups at the end of training. Sedentary female hSOD1 mice showed more frequently irregular estrous cycles suggesting a higher estrogen exposure in exercising female mice. These results suggest a possible neuroprotective effect of female sex hormones and support the view that ALS patients should not avoid regular exercise.

Exercise in neuromuscular disease

In the past, patients with neuromuscular diseases were advised not to exercise because of the fear that too much exercise might produce "overuse weakness." No controlled studies have demonstrated that the phenomenon of overuse weakness actually exists. Most studies of exercise training in patients with neuromuscular disease, despite methodologic limitations, suggest that strength and aerobic capacity gains can occur in patients with slowly progressive disorders. Four forms of exercise training are relevant to patients with neuromuscular disorders: flexibility, strengthening, aerobic, and balance exercises. The literature regarding these forms of exercise in patients with neuromuscular disorders is summarized in this article, and recommendations are made regarding the direction future research on exercise in this population should take.

Regular exercise is beneficial to a mouse model of amyotrophic lateral sclerosis

We tested whether a regular exercise regimen was associated with a change in the life span of G93A-SOD1 transgenic mice, a model of familial ALS. Regular treadmill running for 10 weeks led to a significant increase in the life span of G93A-SOD1 mice. The effect was stronger in male mice, whereas there was only a trend between exercised and sedentary female G93A-SOD1 mice. The data suggest that regular exercise has a beneficial effect on the progression of ALS.

The value of muscle exercise in patients with amyotrophic lateral sclerosis

The role of physical activity for patients with amyotrophic lateral sclerosis (ALS) is controversial. Twenty-five ALS patients were randomized to receive a moderate daily exercise program (n=14) or not to perform any physical activity beyond their usual daily requirements (n=11). At baseline and after 3, 6, 9 and 12 months, patients were assessed by manual muscle strength testing, the Ashworth spasticity scale, ALS functional rating scale (FRS), fatigue severity scale, a visual analogue scale for musculoskeletal pain and the quality-of-life scale (SF-36). At 3 months, patients who performed regular exercise showed less deterioration on FRS and Ashworth scales, but not on other parameters. At 6 months, there was no significant difference between groups, although a trend towards less deterioration in the treated group on most scales was observed. At 9 and 12 months, there were too few patients in each group for statistical evaluation. Our results show that a regular moderate physical exercise program has a short-lived positive effect on disability in ALS patients and should be recommended.

Respiratory disorders in ALS: sleep and exercise studies

Sleep disruption in ALS/MND is related to hypoventilation and nocturnal O(2) saturation. Maximal inspiratory pressure (PI(max)) proved sensitive in predicting nocturnal O(2) saturation. However, PI(max) is highly dependent on patient collaboration; on the other hand Mouth Occlusion Pressure (MOP) is a reliable, non-volitional parameter index of central respiratory drive. Since exercise testing (ET) is also part of the assessment of ventilatory regulation the authors aimed to determine whether MOP and ET are sensitive and reliable parameters predictive of nocturnal O(2) saturation and clinical evolution. We conducted a Polysomnographic (PSG) study in two groups of 14 patients, selected according to their MOP level. Patients performed at admission an ET, Respiratory Function tests (RFT) and clinical evaluation with Norris spinal and bulbar scores (SNS and BNS). All patients in Group I (Low MOP) had decreased O(2) saturation during ET (P<0.001). Correlation study showed correlation between ET and MOP (R=0.6); PI(max) slope and PE(max) slope correlated with ET (R=-0.4; -0.6), respectively. ET also correlated with nocturnal O(2) saturation and SNS slope (R=0.8; -0.5), respectively. SNS and BNS slopes correlated with nocturnal O(2) saturation (R=-0.4; -0.7), respectively. The best correlations found were between MOP slope and BNS slope and SNS slope (R=0.8; 0.7), respectively. The high predictive values of MOP and ET at admission to nocturnal O(2) saturation (predicted value=80%) suggested the need of nocturnal pulse oximetry as a standard procedure. MOP and ET should also be used in evaluation protocols of ALS/MND.