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ARTICLES: V. Dal Bello-Haas, J. M. Florence, A. D. Kloos, J. Scheirbecker, G. Lopate, S. M. Hayes, E. P. Pioro, and H. Mitsumoto A randomized controlled trial of resistance exercise in individuals with ALS Neurology 2007; 68: 2003-2007 [Abstract] [Full text] [PDF]

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A randomized controlled trial of resistance exercise in individuals with ALS

Carmel Armon, M.D., M.H.S.   (25 February 2008)

Reply from the authors

Vanina PM Dal Bello-Haas, Julaine M Florence, Anne D Kloos, Jeanine Scheirbecker, Glenn Lopate, Sheila M Hayes, Erik P Pioro, Hiroshi Mitsumoto   (25 February 2008)

A randomized controlled trial of resistance exercise in individuals with ALS 25 February 2008
Carmel Armon, M.D., M.H.S., Baystate Medical Center 759 Chestnut Street - S4648, Springfield, MA 01199 Send Correspondence to journal: Re: A randomized controlled trial of resistance exercise in individuals with ALS Carmel.Armon{at}bhs.org Carmel Armon, M.D., M.H.S.	I read the report by Dal Bello-Hass et al with interest. [1] However, I have some concerns regarding the efficacy data, based on review of the data in the web-based tables. Two points appear to detract from the original findings. The resistance exercise group started out with a better ALSFRS score and was progressing at a slower rate at the time of randomization. In addition, the resistance exercise protocol weeded out faster progressing patients. An estimated progression rate at the time of randomization, based on the number of ALSFRS points lost (relative to the baseline of 40) divided by duration from disease onset to randomization shows that, at the time of randomization, the mean estimated progression rate for the usual care group was -0.416 ALSFRS points/month. It was -0.235, or 43% slower, for the resistance exercise group. An estimated progression rate similarly defined has been shown to be predictive of survival or disease progression for several measures including the ALSFRS-R, and one based on ALSFRS-R has been used for the purposes of stratification in a clinical trial. [2-5] The resistance exercise protocol weeded out faster progressing patients. The FVC of the resistance exercise group was 97.9+/-5.8 %predicted at randomization (n=13) and 99+/- 3.2 at 6 months (n=8). The apparent improvement in mean values with a smaller standard deviation could have only been achieved by dropping the faster progressing patients. The authors should clarify how the Standard Deviation of FVC %predicted for the resistance exercise group is three to five times smaller than that of the usual care group (14.6 at randomization; 15.2 at 6 months). It would be informative if the authors could provide the readers with the probability that this disparity would occur by chance. It is unsafe to take the efficacy data at face value to conclude that exercise had a beneficial effect. One of the resistance exercise group patients needed triple bypass surgery even though he had been deemed healthy to participate in the study by his cardiologist. Future patients who are influenced by the authors’ suggestion that resistance exercise may be an “essential component of the overall care of patients with this disease” [1] may be undertaking this and other risks. In addition, patients will be disappointed when they find themselves unable to persist in this treatment modality. The eight patients who completed the 6 months of resistance exercise are not representative of most patients with ALS who do not have FVCs of 98-99% predicted 20-26 months into their disease. Resistance exercise may be appropriate for consideration only in the slowest of slowly progressing patients. References 1. Dal Bello-Hass V, Florence JM, Kloos AD et al. A randomized controlled trial of resistance exercise in individuals with ALS. Neurology 2007;68:2003-2007. 2. Armon C, Graves MC, Moses D, et al. Linear estimates of disease progression predict survival in patients with amyotrophic lateral sclerosis. Muscle Nerve. 2000;23:874-882. 3. Czaplinski A, Yen AA, Appel SH. Amyotrophic lateral sclerosis: early predictors of prolonged survival. J Neurol. 2006;253:1428-1436. Epub 2006 Jun 13. 4. Czaplinski A, Yen AA, Simpson EP, Appel SH. Predictability of disease progression in amyotrophic lateral sclerosis. Muscle Nerve. 2006;34:702-708. 5. Kimura F, Fujimura C, Ishida S, et al. Progression rate of ALSFRS-R at time of diagnosis predicts survival time in ALS. Neurology 2006;66:265-267. Disclosure: The author reports no conflicts of interest.
Reply from the authors 25 February 2008
Vanina PM Dal Bello-Haas, School of Physical Therapy, University of Saskatchewan 1121 College Drive, Saskatoon, SK S7N 0W3, Julaine M Florence, Anne D Kloos, Jeanine Scheirbecker, Glenn Lopate, Sheila M Hayes, Erik P Pioro, Hiroshi Mitsumoto Send Correspondence to journal: Re: Reply from the authors vanina.dalbello-haas{at}usask.ca Vanina PM Dal Bello-Haas, et al.	We welcome the opportunity to respond to Dr. Armon's questions probing the validity of our interpretations. The tables comparing control and experimental subjects who completed and those who discontinued is now provided (E-Table 1a and 1b) [see link below]. Using Dr. Armon's methodology [2], the estimated progression rate for those who completed was -0.207 (Usual Care: 16.4 months, ALSFRS = 36.6) and -0.211 (Resistance: 21.8 months, ALSFRS = 35.4). In both groups, subjects who discontinued had faster rates of decline compared to those who completed: Usual Care = -0.375 (12.8 months, ALSFRS = 35.2) and Resistance = - 0.301 (17.3 months, ALSFRS = 34.8). %predicted FVC for Resistance subjects who discontinued was 97.3 (±7.9) and for those who completed was 98.2 (± 5.2) (p = 0.80). Resistance subjects who discontinued had lower FSS scores/higher SF-36 vitality scores (less fatigue) and higher SF-36 RP scores (less physical role problems). Thus, Dr. Armon's argument that "resistance exercise protocol weeded out faster progressing patients" is not supported. The subject who dropped post-bypass surgery had > a 10-year history of cardiac problems, including an MI. He was informed of a blockage (time of the MI), but surgery was not performed. A direct correlation between the resistance protocol and surgery could not be determined in reviewing the medical record. However, this does not negate that fact that, as in any other patient population, exercise may have detrimental effects and needs to be carefully prescribed and monitored. We agree with Dr. Armon, as we illustrated in our Discussion, that a subset of people with ALS may respond more positively to resistance exercises. [1] We clearly had a unique subset of subjects, as we specifically limited enrollment to those with an FVC of > 90% predicted and ALSFRS score > 30.2 Numerous factors influence exercise prescription in the ALS population. [6] Although resistance exercise may not have any ultimate influence on disease progression and mortality, the rationale for prescribing resistance exercise in the broader context of the disease should be considered(especially in the earlier stages before significant muscular atrophy or deconditioning occurs). This need to be articulated to patients who can then make informed decisions. Many questions related to the role of exercise in the ALS population remain unanswered. Any exercise prescription should be individualized and carried out under the supervision of a qualified physical therapist who understands the nature of ALS. E - Tables References 6. Dal Bello-Haas V. A framework for rehabilitation in degenerative diseases: planning care and maximizing quality of life. Neurology Report. 2002; 26:115-129. Disclosure: The author reports no conflicts of interest.