The value of muscle exercise in patients with Amyotrophic Lateral Sclerosis (ALS)

Posted on 20th January 2014 by Kat Long

Introduction

Amyotrophic Lateral Sclerosis (ALS) is a progressive disease involving degeneration of motor neurons in the brain and spinal cord. As a result of the death of these neurons, patients with ALS experience various signs and symptoms, including progressive muscle weakness that effects movements of the arms and legs, swallowing, speech, and breathing. ALS is a rapidly progressive neurodegenerative disease that results in death within an average of 3-5 years after onset of symptoms. The drastic impact that ALS has on a patient’s life and function makes it critical to find options to maintain function and independence for as long as possible. One method proposed to improve and maintain strength and function for patients with ALS is physical exercise. However, there is an ongoing debate regarding whether or not exercise for patients with ALS could potentially worsen the already weakened muscles by causing further damage to the muscle fibers. As a result, it is critical for a physical therapist to investigate all research literature available regarding the effects of exercise on patients with ALS before making a clinical decision regarding the safety and appropriate exercise intervention for a patient with ALS. However, the rapid progression of the disease poses difficulties to conducting research studies on individuals with ALS due to the significant drop-outs caused by declines in health status. This characteristic of the patient population causes there to be limited research evidence available regarding the benefits and safety of exercise in patients with ALS. Below I have reviewed one of the few research studies that is available regarding exercise for patients with ALS.

Drory VE, Goltsman E, Reznik JG, Mosek A, Korczyn AD. The value of muscle exercise in patients with amyotrophic lateral sclerosis. J Neurol Sci. 2001;191(1-2):133-137.

Article Summary

In this randomized clinical trial, 25 patients with ALS were randomly assigned to an exercise or non-exercise group. The exercise group performed an endurance exercise program for 15 minutes twice a day at home and the control group was instructed to perform only the activities of daily life and no additional physical activity. The outcome measures were assessed at baseline, 3, 6, 9, and 12 months and included the following measures:

• Manual Muscle Test (MMT): a standardized assessment measuring muscle strength with scores given between 0-5. 0=No muscle contraction and 5=normal strength.
• Ashworth spasticity scale (ASH): assesses muscle spasticity with scores given ranging from 0=no increase in tone to 5=limb in rigid flexion or extension.
• ALS functional rating scale (ALSFRS): which is a disability self-report questionnaire that evaluates functional status and change in patients with ALS over time. Test items include categories assessing: speech, salivation, swallowing, handwriting, cutting food and handling utensils, dressing and hygiene, turning in bed and adjusting bed clothes, walking, climbing stairs, and breathing. Scores range from 0-40 with higher scores indicating higher function. 
• Fatigue severity scale (FSS): which is a 9-item self-report questionnaire measuring severity of fatigue and how much fatigue interferes with daily activities. Scores range from 9-63 with higher scores indicating greater severity of fatigue. 
• Visual analogue scale for musculoskeletal pain: Assesses pain using a continuous scale.
• SF-36 (MOS 36-Item Short Form Survey): self-report questionnaire assessing quality-of-life.

After 3 months, the data indicated a significant difference between the control group and the exercise group in both FRS measures and ASH with both measures having less deterioration in the exercise group. However, there was no difference between the groups in MMT scores, fatigue, or quality of life. At the 6-month follow-up assessment, there were no differences between groups on any of the outcome measures.At the 9- and 12-month follow-up assessments, there were too few patients remaining in each group to perform statistical analysis. The high rate of dropouts was due to the rapid decline of the patients in both groups, which is consistent with the typical pattern of ALS disease progression.

Strengths and Weaknesses

The researchers provide a clear and concise rationale for the selection of the dependent variables proposed to benefit from exercise. In addition, the outcomes are measures that encompass all aspects of the International Classification of Function, Disability and Health (ICF): body function, activity, and participation.

However, this study has a large number of weaknesses that limit its overall strength and its capacity to be used in guiding clinical decision-making. First, the entire methods section of the article lacks the inclusion of details required for replication. For example, the researchers did not include the parameters of the exercise program used as the intervention for the exercise group. The researchers vaguely suggest that the program was individualized for each patient and included modest loads with the goal to improve muscle endurance. Although, every patient likely had a different program depending on his/her individual needs and deficits, the researchers could have improved the reproducibility and clinical applicability of the study by including an appendix with diagrams of all exercise performed, and, even, a table with the number of repetitions, sets, and intensity for each patient or, perhaps, the average for each of these exercise parameters. Without further details regarding the intervention program used, it is impossible to translate this article into clinical practice. Additionally, without specifics regarding the treatment utilized in the study, it is impossible to draw any clear conclusions from the results obtained.

‘Take Home Message’

The lack of clear parameters of the exercise program severely weakens the study and the ability to use the findings to guide clinical practice in establishing specific exercise programs for patients for ALS. I would not use this study alone to support my decision to use endurance exercise to manage fatigue symptoms in a patient with ALS and would seek  further evidence of higher quality strength and detail before making my clinical decision.

Reference:

Drory VE, Goltsman E, Reznik JG, Mosek A, Korczyn AD. The value of muscle exercise in patients with amyotrophic lateral sclerosis. J Neurol Sci. 2001;191(1-2):133-137.

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