Snoring

Snoring is the vibration of upper airway tissues during sleep. Snoring can disturb a bed partner's sleep and often brings the patient to medical attention. In many patients, snoring has been present for many years. Loud, habitual snoring may occur with or without obstructive sleep apnoea which is a chronic, disabling disease with far reaching medical consequences.

Obstructive Sleep Apnoea Syndrome

A common, chronic and disabling disorder with repetitive, partial or complete obstruction of upper airways during sleep. This is a leading cause of excessive daytime sleepiness and may contribute to the development of high blood pressure, heart attacks and strokes in these patients. Almost all patients have years of loud, habitual snoring. Other symptoms include repetitive temporary breathing pauses during sleep, waking with a headache, impotence, waking gasping or with a smothering sensation and restless sleep with bedcovers often in disarray upon arising. Most patients have un-restful sleep, mental fogginess and disorientation.

Periodic Leg Movement Disorder

A common condition with disagreeable leg sensations, usually at rest and prior to sleep onset, causing an irresistible urge to move the legs. Repetitive, stereotyped movements of the legs may occur during sleep. These movements may cause repeated arousals from sleep and sleep disruption at night. This results in excessive daytime sleepiness.

Other major sleep disorders with EDS

These include abuse of central nervous system stimulant drugs, major depression, idiopathic hypersomnolence (daytime sleepiness without a known cause) and rare disorders like the Kliene-Levin syndrome.

Full Overnight Polysomnography

Full overnight sleep study or polysomnography involves the recording of electrical activity of the brain, eyes and chin muscles. This allows sleep to be staged, quantitated and brief arousals from sleep to be recorded and identified. Recording the electrical activity of leg muscles helps in diagnosing periodic leg movement disorder. Standard respiratory measurements include recording overnight oxygen saturation by finger pulse oximetry, breathing movements of chest & abdomen, airflow from mouth & nose, and snoring. This is needed to diagnose obstructive sleep apnoea. Further channels to record additional data can be added.

Full overnight polysomnography or limited sleep study will always be required in all cases of snoring, suspected obstructive sleep apnoea or investigation of any sleep disorder.

Multiple Sleep Latency Test

Daytime sleepiness can be subjectively documented by the Stanford Sleepiness and Epworth Sleepiness scales. Multiple Sleep Latency Test (MSLT) is the most commonly used and experimentally validated objective test for quantifying daytime sleepiness. This is also used to document the presence of sleep onset dreaming sleep which is critical to establishing a diagnosis of narcolepsy.

The MSLT includes recording five 20 minute naps throughout the day at 2 hour intervals as per a strict protocol in a sleep inducing environment.

Other tests to objectively measure ability to stay awake are the Maintenance of Wakefulness Test and the OSLER Test.

Upper Airway Imaging

Done for patients with obstructive sleep apnoea requiring surgical correction. This includes plain X-rays, cephalometry and upper airway CT or MRI scans.

Sleep Masendoscopy

Videofluroscopy and nasendoscopy are the methods to directly visualize the dynamics of upper airways, sometimes during a sedative induced light sleep. These are used to delineate the exact site of collapse in the upper airways in patients with snoring and obstructive sleep apnoea requiring corrective palatal surgery or mandibular advancement splint.