Exercise as it relates to Disease/Use it or lose it? Resistance training in ALS patients

This is an analysis of the journal article "The value of muscle exercise in patients with amyotrophic lateral sclerosis" by Drory et al (2001)

What is the background to this research?
Amyotrophic lateral sclerosis (ALS) is a progressive neuromuscular disease that affects almost 4 in every 100,000 people. ALS causes motor neurons, the nerve cells which control movement, to degenerate and die. The death of these neurons hinders the bodies ability to produce movement, which results in muscle waste, weakness and eventually death. At present there is no cure for ALS, however medication and Physical therapy may reduce damage to motor neurons and improve quality of life.

Where was this research from?
This study was undertaken in the following Centres:
 * ALS Clinic, Department of Neurology, Tel-Aviv Sourasky Medical Centre, Tel Aviv, Israel
 * Department of Neurology, Tel-Aviv Sourasky Medical Centre and Sackler Faculty of Medicine, Tel Aviv, Israel
 * Department of Rehabilitation Medicine, Tel-Aviv Sourasky Medical Centre, Tel Aviv, Israel
 * Reuth Medical Centre, Tel Aviv, Israel

What kind of research was this?
This study was a parallel, two group, randomized, controlled trial conducted over 12 months. This study design was used as it allows researchers to determine whether a cause-effect relation exists between treatment and outcome.

What did the research involve?
25 subjects were selected to participate in this study. Subjects met the following criteria: Exclusion criteria for this study were: Patients were assigned randomly to two groups: Measures were taken on 6 assessments at baseline, 3, 6, 9 and 12 months:
 * Probable or definite ALS by the revised El Escorial WFN criteria
 * Attended the Tel-Aviv Sourasky Medical Centre
 * A lost ability to walk (any assistive device allowed)
 * Intermittent or continuous mechanical ventilation
 * Inability to understand and follow instruction
 * Treatment group
 * This group was prescribed a personalized exercise program from an experienced physical therapist to be performed twice daily at home.
 * Control group
 * This group was instructed not to perform any additional physical activity other than their usual daily life requirements.
 * Manual Muscle Strength testing (MMT)
 * The Ashworth spasticity scale (ASH)
 * The ALS functional rating scale (FRS)
 * Fatigue severity scale (FSS)
 * A visual analogue scale for musculoskeletal pain graded from 0 (no pain) to 10 (unbearable pain)
 * 36-Item Short form survey (SF-36)

What were the basic results?
Statistical analysis was not possible at 9 and 12 months due to a high drop-out rate and a marked deterioration of all participants in both groups.
 * MMT
 * All patients in both groups experiences a deterioration of motor performance during follow up period. The treatment group showed a slight trend towards a lesser detriment at 6 months however this was not statistically significant.
 * ASH
 * Spasticity increased with time in the control group and decreased in the treatment group. This reached significance only at 3 months due to the small sample size.
 * FRS
 * Decreased over time in all patients. The decrease was less severe in the treatment group and the difference was statistically significant at 3 and 6 months.
 * FSS
 * The treatment group reported almost no change to fatigue over time, while the control group showed an increase in fatigue-related symptoms. The different was not statistically significant.
 * Pain
 * Both groups reported an increase in pain over time, and no obvious effect on pain was found in the treatment group.
 * SF-36
 * The control group suffered a non-significant trend towards deterioration when compared to the treatment group, however both groups worsened slightly over time.

How did the researchers interpret the results?
Researchers determined that moderate range-of-motion training with light resistance, as performed in this study, has a positive effect on muscular endurance, motor deficit and disability, fatigue and quality of life in ALS patients. The effect however is only mild, and may be temporary. The effect reached significance on disability and spasticity. Researchers believe these positive effects were due to an increase in the oxidative metabolic potential of the muscles.

What conclusions should be taken away from this research?
The study has shown that further research into the area of exercise in ALS patients is necessary. This study hints at an overall positive effect of exercise on ALS symptoms in the short term, however a larger sample size is needed in order to determine efficacy in the long term due to the high drop-out rate. Further research comparing different intensities, durations and types of exercise would aid in the treatment of ALS, as the oxidative potential of muscle can be increased by exercise. A more rigorous exercise regime may lead to an increase in muscle oxidative capacity and therefor a reduction in disability, however this may be negated by the potential for an increase in muscle damage

What are the implications of this research?
This research has shown that moderate range-of-motion training can be beneficial in reducing the impact of ALS on patients in the short term. This research, along with other studies in this area can help shape the ongoing treatment of ALS, especially with regards to the prescription of physical activity.