Percutaneous gastrostomy, mechanical ventilation and survival in amyotrophic lateral sclerosis : an observational study in an incident cohort.

OBJECTIVE:To analyze disease-modifying effects of percutaneous endoscopic gastrostomy (PEG) insertion for supporting nutrition, noninvasive ventilation (NIV), and tracheostomy-assisted ('invasive') ventilation (TIV) in amyotrophic lateral sclerosis (ALS). METHODS:We retrospectively analyzed survival in a large population-based incident cohort that was prospectively followed up in our center. Analysis considered several known ALS-related prognostic variables. RESULTS:In this population, PEG and NIV in multivariable analysis significantly correlated to survival as computed by disease onset to death/tracheostomy. NIV was associated with better survival while PEG was associated with reduced survival. Other independent prognostic factors were age at ALS onset, diagnostic delay, and flail arm/leg and pure upper motor neuron (PUMN) phenotypes. The length of survival after TIV was significantly associated with age at ALS onset (inverse correlation) whereas other variables did not. The length of survival after TIV correlated to age at ALS onset in such a way that each additional year of age at ALS onset decreased survival by about 0.7 months. Patients who underwent both TIV and NIV did not experience a better survival than those who underwent TIV alone. CONCLUSION:The lack of effect of enteral nutrition on ALS survival probably reflected the timing of PEG insertion in patients with more severe disease. By contrast, patients who used mechanical ventilation had an increased overall survival compared with non-ventilated ones. The study also provided new information showing that the combined use of NIV and TIV did not may prolong ALS survival as compared to TIV alone.