Characteristics and Prognosis of Oldest Old Subjects with Amyotrophic Lateral Sclerosis

Background: Amyotrophic Lateral Sclerosis (ALS) is an age-related neurodegenerative disease with unclear characteristics and prognosis in the oldest old (80 years and over). The aim of this study was to compare the oldest old and younger ALS patients in terms of clinical and socio-demographic characteristics, and prognosis.

Methods: ALS incident cases from the register of ALS in Limousin (FRALim), diagnosed between January 2000 and July 2013, were included. Descriptive and comparative analyses by age group were carried out. For time to event univariate analysis, Kaplan-Meier estimator and log rank test were used. Univariate and multivariate survival analyses were carried out with Cox's proportional hazard model.

Results: Out of 322 patients, 50 (15.5%) were aged 80 or over ("oldest old" ALS) at the time of diagnosis. Among them, the male:female gender-ratio was 1.27, and 32.6% had a bulbar onset (not different from subjects aged less than 80 years). With increasing age, there was a worsening of the clinical state of the patients at time of diagnosis in terms of weight loss, forced vital capacity, ALSFRS-R and manual muscular testing. Access to ALS referral centres decreased with age, and the use of riluzole tended to be lower in the oldest old group. The median survival of oldest old patients appeared to be 10 months shorter than that of subjects aged less than 80 years (7.4 vs. 17.4 months).

Conclusion: The survival of oldest old ALS patients is particularly short. It relates to prognostic features at baseline and to an independent effect of advanced age.