Study of Standard Noninvasive Positive Pressure Ventilation (NIPPV) and Low Expiratory Pressure NIPPV in ALS Patients

The purpose of the study is to test whether noninvasive positive pressure ventilation (NIPPV) without expiratory positive airway pressure (EPAP) (inspiratory positive airway pressure (IPAP)-only) will result in an increase in patient usage of NIPPV compared with standard, Bi-level NIPPV. Secondarily, the investigators will assess measures of dyspnea, quality of life, patient satisfaction, and side effects.