Prognostic Factors and Epidemiology of Amyotrophic Lateral Sclerosis in Southeastern United States

Abstract

Objective: To assess the performance of known survival predictors and evaluate their stratification capability in patients with amyotrophic lateral sclerosis (ALS). Patients and Methods: We analyzed demographic and clinical variables collected at the Mayo Clinic, Florida ALS center during the first clinical visit of 1442 (100%) patients with ALS. Results: Our cohort had a median (interquartile range [IQR]) age at diagnosis of 64.8 (57-72) years; 1350 (92%) were non-Hispanic White; and 771 (53.5%) were male. The median (IQR) diagnostic delay was 10.1 (6-18) months, body mass index was 25.4 (23-49), and forced vital capacity was 72% (52%-87%). Approximately 12% of patients tested carried a pathologic C9orf72 hexanucleotide repeat expansion. Median (IQR) ALS functional rating scale-revised score was 35 (29-40) and ALS cognitive behavioral screen score was 15 (12-17). The median (IQR) survival after diagnosis was 17.2 (9-31) months, and survival from symptom onset was 30 (20-48) months. We found that older age decreased forced vital capacity, and fast-progressing ALS functional rating scale-revised scores significantly (P<.0001) influence survival curves and associated hazard risk. Conclusion: Although results obtained from our cohort are consistent with other reports (eg, men with spinal onset experience a longer survival than women with bulbar onset), they remind us of the complexity of the disease’s natural history and the limited prognostic power of the most common clinical predictors.