Hypothesis
Intradiaphragmatic phrenic stimulation, in ALS patients with functional phrenic nerves and who suffer from deterioration in diaphragmatic function, slows down the decline in diaphragmatic function and delays the need of respiratory assistance.

Principal Objective
To demonstrate that Intradiaphragmatic phrenic stimulation delays the need for NIV in ALS.

Secondary Objectives :
Demonstrate/prove that Intradiaphragmatic phrenic stimulation (IPS):

• Increases survival
• Improves the quality of life
• Improves sleep quality