Cessation of breathing, especially during sleep, is the primary symptom of central sleep apnea. People with apnea of unknown cause may have frequent awakenings and complain of insomnia.

If a neurological condition is causing the apnea, it may also produce other symptoms such as difficulty swallowing, change in voice, variable weakness, or numbness throughout the body, depending on the underlying disease and what parts of the nervous system it has affected.

• Respiratory function studies
• All-night polygraphic sleep monitoring
• MRI
• Tests to diagnose underlying medical condition