Rinsho Shinkeigaku (Clinical Neurology)

Original Article

Clinical characteristics of elderly Japanese patients with amyotrophic lateral sclerosis; with special reference to the development of respiratory failure

Shin-ichi Terao, M.D.1), Naofumi Miura, M.D.1), Yutaka Osano, M.D.1), Koshin Adachi, M.D.1) and Gen Sobue, M.D.2)

1)Division of General Medicine, Department of Internal Medicine, Aichi Medical University School of Medicine
2)Department of Neurology, Nagoya University Graduate School of Medicine

Objective: To clarify the characteristics of elderly-onset amyotrophic lateral sclerosis (ALS).
Subjects and Methods: We analyzed the pattern of progression of clinical symptoms and respiratory dysfunction in 26 sporadic ALS patients (19 men, 7 women; mean age 73.2±6.0 years) with onset at age 65 years or older (E-ALS). We compared the results with those of 28 ALS patients (20 men, 8 women; 53.7±7.6 years) with younger onset ALS (Y-ALS).
Results: Among E-ALS patients, the bulbar palsy type (BP) was the most common (11 patients, 42%) followed by the respiratory failure type (RF) (7 patients, 27%). In contrast, upper extremity type (UE) was the most common (14 patients, 50%) in Y-ALS patients. Mean vital capacity percentage (%VC) at the initial examination was 71.1±20.4% (vital capacity (VC): 2.12±0.85 L) in all E-ALS patients, 64.5±14.5% in BP, 58.1±5.1% in RF, 94.4±11.1% in lower extremity type (LE), and 73.9±30.2% in UE. In all Y-ALS patients, %VC was 90.1±14.0% (2.94±0.57 L). The initial %VC value in E-ALS was significantly lower than that in Y-ALS (p<0.01). VC was lower in RF and BP among E-ALS patients. It was also lower in BP E-ALS patients than in BP Y-ALS patients. Mean period from initial symptom until first examination was significantly shorter in RF in both groups, followed by BP. Twenty-two patients with E-ALS and 26 with Y-ALS died from respiratory failure. Four patients with E-ALS and 2 with Y-ALS required a mechanical ventilator. The mean period until death or ventilation support was 20.9±10.4 months in E-ALS, and 38.8±21.1 months in Y-ALS. Significantly shorter survival was observed in E-ALS than Y-ALS (p<0.01). In E-ALS patients, the mean period until death or ventilation support was 21.4±9.1 months with BP, 10.3±7.6 months with RF, 29.8±4.0 months with LE, and 29.3±5.4 months with UE. This period was significantly shorter in RF patients in both groups, followed by BP patients (p<0.05, 0.01). Time until death or ventilation support was significantly shorter in BP and UE patients with E-ALS than in those with Y-ALS (p<0.05).
Conclusion: In regard to the progression of respiratory function deterioration, early %VC was lower in E-ALS than in Y-ALS patients, and the period until VC fell below 1 L was shorter. The period until death was particularly short in elderly BP and RF patients, suggesting the possibility that the duration until death from respiratory failure is shorter in E-ALS, because of a decrease in respiratory reverse capacity that accompanies age.

(CLINICA NEUROL, 46: 381－389, 2006)
key words: amyotrophic lateral sclerosis, elderly, natural course, aging, respiratory function

(Received: 29-Sep-05)