Patients with lower limb-onset ALS who have a longer duration from onset to diagnosis have a better prognosis

Background: Useful and plain prognostic markers for amyotrophic lateral sclerosis (ALS) progression are desired to propose a suitable living setting for patients and their caregivers and to archive appropriate clinical trials. Aim: To archive an additional prognostic marker for ALS progression, we evaluated the usefulness of duration from onset to diagnosis (DOD) as a prognostic factor by stratifying patients with onset sites. Methods: We retrospectively enrolled 200 patients. The cutoff period for DOD was set to 12 months, which was derived from ROC curve. The patients were divided into two groups by DOD. We analyzed the differences in the time from onset to the endpoint in the two groups. The endpoint was defined as their death due to ALS progression or the application of invasive positive pressure ventilation. Results: We found that patients in short DOD group had significantly shorter survival rate than patients in the long DOD group. When divided by onset sites, the time from onset to the endpoint was significantly different among each group. Particularly, the prognosis of patients in the long DOD group with lower limb onset was extremely better than other groups. A significant positive correlation was detected between DOD and the time from onset to the endpoint. Moreover, DOD was negatively correlated with changes in body mass index and ALS functional rating scale-revised, both of which were reported as the prognostic markers of ALS. Conclusion: DOD might become a simple and useful indicator for the prognosis of ALS.