Central Sleep Apnea

Sleep apnea

Central sleep apnea refers to a breathing disorder that occurs when an individual sleeps and that most commonly affects people with serious heart problems. A person affected has recurring breathing pauses while asleep. Those with idiopathic or undetermined causes has general good outlook. ^{[1] [2] [3]}

Epidemiology

The condition is rare and is estimated to affect only 1% of the general population. Reported cases usually involve people in the middle to late ages. Certain reports claim male predilection. ^[1]

Causes

Central sleep apnea is quite complex thus the exact mechanism still has to be determined. Some factors are implicated in its pathophysiology. Among these are impairment of the function of some body organs including the heart and brain thus patients with neurodegenerative diseases like Parkinson’s disease which primarily affects the brain are more prone to have central sleep apnea. Moreover, it has also been asserted that changes in hormone and protein levels as well as gas concentration may lead to the development of the condition. Other risk factors are obesity, stroke, cervical spine surgery patients and sleeping in a supine position or in high altitude. ^{[2] [3] [4]}

Signs and Symptoms

Primary among the symptoms is interrupted breathing during sleep. Nighttime awakening is therefore common. Affected individual may report snoring as witnessed by a bedtime partner, too much sleeping in daytime, waking unrefreshed, fatigue and shortness of breath. The person may also notice voice changes or loss of sensation depending on the part involved. ^{[1] [2]} 

Diagnosis

History and physical exam make a physician suspect central sleep apnea. To confirm it, a diagnostic sleep study or polysomnogram (PSG) carried out overnight is done. ^[2] If relevant, other laboratory exams are requested like blood glucose or serum creatinine level. Routine imaging studies are often not part of assessment however in cases where in patients had stroke or brain tumor, imaging studies like MRI may help. ^[1] ECG and lung function tests are also sometimes done. ^[3]

Treatment

The decision to treat is a case to case basis. Patients with congestive heart failure may benefit with continuous positive airway pressure. ^[1] In some cases, oxygen or bilevel positive airway pressure (BiPAP) are indicated. ^[3]

References:

1.      http://emedicine.medscape.com/article/304967-overview

2.      http://www.snoreaustralia.com.au/central-sleep-apnoea.php

3.      http://www.nlm.nih.gov/medlineplus/ency/article/003997.htm

4.      http://www.mayoclinic.com/health/central-sleep-apnea/DS00995

Public Discussion