Analysis of disease progression rate and related factors in amyotrophic lateral sclerosis patients at initial visit

Abstract

Objective: To find out the relationship of the progression rate of amyotrophic lateral sclerosis (ALS) patients with relevant clinical indicators at initial visit so as to enrich the knowledge of ALS at its early stage. Methods: The clinical data of 282 patients diagnosed with ALS at Neurology Department of the First Medical Center, Chinese PLA General Hospital from June 2016 to March 2021 were collected in order to make a retrospective analysis of the dynamic change of the progression rate (ΔFS) and influencing factors, and thus a classification of the progression rate will be summarized. Results: Among 282 patients, 164 were males and 118 were females. The age of onset was (53±11) years old. The ΔFS had a negative exponential relationship with delay time of diagnosis no matter what kinds of onset the patients experienced (upper limb onset, lower limb onset or bulbar onset). The ΔFS for the limb function sub-group had a similar functional relationship with diagnostic delay in patients with either upper limb onset or lower limb onset. The statistical model indicated that the disease progression rate of ALS at initial visit can be classified into three types (high speed type: ΔFS≥1.0 score/month; moderate speed type: 0.5≤ΔFS<1.0 score/month; low speed type: ΔFS<0.5 score/month). The critical values of the three types in patients with upper limb onset were 8 and 20 months, while 9 and 24 months for lower limb onset patients, and 9 and 36 months for bulbar onset patients. At initial visit, there were significant statistical differences among these three types in age at onset (P=0.008), diagnostic delay (P<0.001), ALS functional rating scale-revised (ALSFRS-R) score (P<0.001) and onset site (P=0.006). The age at onset in moderate speed type was significantly greater than that of the slow speed type [(54.9±10.4) years vs (50.2±9.6) years, P=0.002]. The diagnostic delay in high speed type [6 (4, 10) months] was significantly shorter than that in moderate speed type [12 (8, 19) months, P<0.001] and low speed type [22 (14, 36) months, P<0.001], and the moderate speed type was shorter in comparison with low speed type (P<0.001). As for the ALSFRS-R score, the high speed type [36(32, 39)] was significantly lower than the moderate speed type [39 (36, 42), P<0.001] and low speed type [42 (39, 44), P<0.001], and the moderate speed type was lower in comparison with low speed type (P=0.002). The proportion of cases with upper limb onset in high speed type (20.3%) was significantly lower than that in low speed type (42.2%, P<0.001) and moderate speed type (37.5%, P=0.014). By contrast, the proportion of cases with lower limb onset in high speed type (39.2%) was significantly higher than that in low speed type (28.9%, P=0.023), however no difference was shown between the fast speed type and moderate speed type (32.0%, P=0.061). There was no difference among these three progression types in patients with bulbar onset. Conclusions: The disease progression rate of ALS at initial visit can be classified into three types including high speed, moderate speed and low speed. At early stage of ALS, ΔFS is affected by onset age, onset site, diagnostic delay and ALSFRS-R score.