Objective: To define changes of clinical features in amyotrophic lateral sclerosis (ALS) over the past 20 years and prognostic indicators of ALS from a single hospital-based retrospective survey.
Background: One of the important tasks in ALS research is to determine differences between patients who progress at different rates. Predicting survival time in ALS helps both physicians and patients to make decisions regarding assisted ventilation.
Patients/methods: A total of 100 patients (61 men, 39 women) hospitalized between 1980 and 2000 were investigated in the study. Subjects were divided into Groups A and B (Group A: n = 50, diagnosed between 1990 and 2000; Group B: n = 50, diagnosed between 1980 and 1990). Group C comprised 34 patients supported by artificial ventilation between 1980 and 2000. Information was obtained for all patients regarding time of individual primary end-point (PEP, time of death or required ventilation support), secondary end-point (SEP, time of death after artificial ventilation) or being alive with or without ventilation support. Combined type of ALS was defined as two or more regions presenting simultaneously at initial onset. Progression rate was calculated as the time (months) required for a 1-point loss on the ALS functional rating scale (ALS-FRS), using 1/delta FS:1/delta FS = duration (months) from onset to diagnosis/(48-ALSFRS at diagnosis)
Results: Mean age at onset has increased in the past 20 years from 59.4 years (group B) to 62.5 years (group A). An increased incidence has been observed in the patients over 70 years with ALS (A:n = 8 vs. B:n = 4). The frequency of assisted ventilation support had been significantly increased for 22 of 44 group A patients (50%) including 5 patients supported by non-invasive positive pressure ventilation, compared to 12 of 48 group B patients (25%, P < 0.01). Two patients in group B and 6 patients in group A who were still alive at time of the investigation were excluded. Mean interval between symptom onset and diagnosis was 14.7 months (A:14.0 months; B:15.4 months). No differences were observed between groups A, B and C regarding sex ratio, mean total ALS-FRS score at diagnosis. Mean survival times were as follows obtained from Kaplan-Meier survival curves; group A:30.8 months, group B:31.0 months until the time of PEP, group C:67.2 months until the time of SEP. Symptoms started in the upper limbs (U) in 37 patients, in the lower limbs (L) in 34, in the bulbar region (B) in 19, as combined type in 9 and in respiratory muscles in 1. Mean survival time until PEP was 33.9 months for U, 34.8 months for L, 28.6 months for B and 18.2 months for C (P < 0.001). Combined-type patients with ALS revealed shorter the time until diagnosis (*P < 0.01) and faster the time until PEP than the other ALS types (P < 0.001 Log-rank test). A significant correlation was found between 1/delta FS and the time until PEP (y = 9.64x + 12.6, r2 = 0.545, p < 0.001, y = PEP, x = 1/delta FS).
Conclusions: Combined type ALS displayed significantly shorter time to PEP than other types. ALS outcome was significantly related to the progression rate of symptoms from total score for ALS-FRS at time of diagnosis.