Читать книгу Spectrums of Amyotrophic Lateral Sclerosis - Группа авторов - Страница 14

The median survival of ALS is approximately three years from the onset, and about 70% of patients die within five years from onset. However, the duration of the disease differs widely in individual patients, ranging from a few months to over 10 years. Such remarkable variability is a major factor in favor of the hypothesis of ALS as a syndrome rather than a single disease. Median survival is worse in patients with bulbar onset ALS than with the spinal onset. Patients with disease onset before the age of 40 and patients with predominant UMN signs show a better prognosis. In most ALS patients, the cause of death is respiratory failure due to the degeneration of motor neurons controlling thoracic and diaphragmatic muscles. Of note, both the temporal and spatial patterns of the disease spread are important determinants of survival. Regarding the temporal pattern, the spreading rate of the degenerative process may vary among patients, with some patients showing a very rapid, aggressive course and others a slow progression. The spatial pattern is also important, since the sequence in which various body regions are involved is extremely variable and the survival changes if respiratory muscles are among the first or last to be affected.