Inclusion Criteria:

• >18 years
• diagnosed with a unilateral diaphragm paralysis based on isolated phrenic nerve injury.

Unilateral diaphragm paralysis is defined as follows: complaints of dyspnea and / or orthopnea combined with a drop in VC of more than 15% when change from upright to supine position and a positive sniff test during fluoroscopy or ultrasonography. A positive sniff test means that the diaphragm stands still or even moves in cranial direction (paradoxical movement ) during the sniff inspiratory maneuver.

• Ability to provide written consent
• Time between diagnosis and treatment should be at least 1 year

Exclusion Criteria:

• Patients diagnosed with a bilateral diaphragm paralysis.
• A diaphragm paralysis in combination with a more systemic neurological or neuromuscular disorder like for example Amyotrophic Lateral Sclerosis ,
• Hypercapnia during daytime (PaCO2 > 6.0 kPa)
• Radiotherapy of the thorax
• Contra indication for diaphragm surgery.