investigations of snoring

Investigations of snoring

Epworth Sleepiness Scale
How likely are you to doze off or fall asleep in the following situations, in contrast to just feeling tired? This refers to your usual way of life in recent time. Even if you have not done of some these things recently, try to work out how they would have affected you. Use the following scale to choose the most appropriate number for each situation.
0= would never doze
1= slight chance of dozing
2= moderate chance of dozing
3= high chance of dozing

Situation chance of dozing
Sitting and reading _________________
Watching TV _________________
Sitting and inactive in a public place (theatre or meeting) _________________
As a passenger in a car for an hour without a break _________________
Lying down to rest in the afternoon when circumstances permit _______________
Sitting and talking to someone _________________
Sitting quietly after lunch( without alcohol) _________________
In a car, while stopped for a few minutes in the traffic _________________
TOTAL _________________


Normal 5 (plus minus 4)
Severe obstructive sleep apnoea 16 (plus minus 4)



Sleep nasendoscopy
Patients with a history of habitual, non-positional, heroic ( can be heard through a wall) snoring can be investigated by sleep nasendoscopy in which a sedated, snoring patient has a flexible nasendoscope inserted to identify the source of vibration.( after a full ear nose throat examination)


Simple studies
Video recordings
Detailed history from family members
Pulse oximetry

Polysomnography
Monitors oxygen saturation, airflow at the nose and mouth. Polysomnography is a comprehensive recording of the biophysiological changes that occur during sleep. The polysomnogram, or PSG, is usually performed at night, when most people sleep [[some labs can accommodate shift workers and do the test at other times). The PSG monitors many body functions including brain (EEG), eye movements (EOG), muscle activity or skeletal muscle activation (EMG), heart rhythm (ECG), and breathing function or respiratory effort during sleep.
For a polysomnogram, the EEG will generally consist of four "exploring" electrodes and two "reference" electrodes (unless a seizure disorder is suspected, in which case more electrodes will be applied to document the appearance of seizure activity). The exploring electrodes are usually attached to the scalp near the central and occipitial portions of the brain via a paste that will conduct electrical signals originating from the neurons of the cortex. These electrodes will provide a readout of the brain activity that can be "scored" into different stages of sleep (1, 2, 3, 4, REM, and Wakefulness).




EMG
EMG (Electromyogram)
Three leads are placed on the chin (one in the front and center and the other two underneath and on the jawbone) and two are placed on the inside of each calf muscle 2-4cm apart. These leads serve to demonstrate muscle movement during sleep. This is helpful in documenting a wake period, an arousal, or just a spastic movement.



Occurrence of 15 or more episodes of apnoea or hypopnoea during 1h of sleep indicates significant sleep apnoea.