Effect of muscle strengthening exercise and time since onset in patients with amyotrophic lateral sclerosis: A 2-patient case series study

Exercise for patients with amyotrophic lateral sclerosis (ALS) can be expected to improve function at the early stage of disease, but improvement cannot be expected at the late stage. However, no report has investigated the correlation between the effect of exercise and time since onset. This study examined the relevance between the effect of muscle strengthening exercise and time since onset in patients with ALS. This study is a retrospective nonconsecutive case series study at a single university hospital. We included 2 patients with ALS who were admitted twice. Case 1 was a 60-year-old man with the bulbar type. He was hospitalized 10 months (ALS functional rating scale-revised, 42 points) and 1 year and 8 months (33 points) after onset. Case 2 was a 52-year-old man with the lower limb type. He was hospitalized 1 year and 3 months (44 points) and 1 year and 8 months (33 points) after onset. Physical therapy was implemented daily on weekdays for approximately 30 minutes. The intervention period was 2 weeks. Lower limb muscle strengthening exercises were mainly performed and exercise intensity was adjusted to a modified Borg Scale score of 5 (lower limbs). The study investigated knee extension muscle strength (KEMS) by using a hand-held dynamometer and Functional Ambulation Categories (FAC) at the start and end of physical therapy during each hospitalization. KEMS improved during the initial hospitalization in both patients, and FAC improved in Case 2; neither KEMS nor FAC improved during rehospitalization in either patient. In Case 1, KEMS was maintained for 10 months. The current results suggest that the positive effect of muscle strengthening exercise is greater at the early stage and may be maintained in patients with bulbar type ALS. In addition, improvement can be achieved approximately 1 year after onset and in patients with an ALSFRS-R score of 40 points or more. Therefore, it is necessary to initiate and continue exercise earlier after onset.