Objective: To explore the nature history of amyotrophic lateral sclerosis (ALS) including type at onset, involvement of region, patterns of spread, survival time and prognosis.
Methods: A total of 86 patients with sporadic ALS underwent follow-ups at 6-month intervals. Symptom appearances were determined by the revised version ALS functional rating scale. The data were analyzed with Kaplan-Meier curves, t test and variance.
Results: Their median survival time was 33 months. Median survival time with combined type onset (combined-type ALS<1) defined as involvement of two regions within 1 month of initial presentation was 12 months; Median survival time with combined type onset (combined-type ALS 2-3) defined as involvement of two regions within 2-3 months from single-site onset was 19 months. The median survival time with combined type onset was shorter than with single-site onset. The interval from onset to involvement of a second region was correlated significantly with survival. ALS frequently involved anatomically close to regions in a longitudinal manner and rarely skipped more distantly in disease progression. Early manifestations of bulbar symptoms within 1 year and appearance of respiratory symptoms in patients with normally preserved motor neuron function were associated with a worse survival. Nine patients surviving >5 years had a lower limb onset with a relatively younger age of onset.
Conclusion: The patients with combined type onset, shorter time of interval from onset to involvement of a second region, early involvement of bulbar and respiratory functions are associated with poor prognosis. Lower limb and younger age onset may achieve a better survival.