Non-invasive ventilation (NIV) has already shown to improve survival and quality of life in patients with amyotrophic lateral sclerosis (ALS). Quality of sleep seems already to be impaired in patients with preserved diaphragmatic dysfunction. Until now, only few research has been performed on the quality of sleep in patients with ALS when using NIV, and these data are mainly based on patient reported outcomes.Further on, only very little research has been done on patient-ventilator interaction.

Our study would like to perform research on quality of sleep before and after NIV use by using full polysomnography with incorporation of transcutaneous carbon dioxide measurement and built-in ventilator software.

Inclusion Criteria:

• Patients with ALS (according to El Escorial criteria) who are planned to start to use NIV, objectivated by a decreased inspiratory muscle force with a restrictive pulmonary function and

  1. symptoms of nocturnal alveolar hypoventilation or
  2. increased daytime arterial carbon dioxide partial pressure (PCO2)(> 45 mmHg) or
  3. a ≥ 10 mmHg increase in transcutaneous PCO2 during sleep in comparison to a normal awake supine value

Exclusion Criteria:

• Patients < 18 years
• Patients not willing to start NIV

Amyotrophic lateral sclerosis patients, which are followed at the Neuromuscular Reference Centre UZ Leuven, in need for NIV treatment