Obstructive Sleep Apnoea (OSA)

A study of 1,475 people found that those with moderate to severe obstructive sleep apnoea were 3 - 4 times more likely to have a stroke than a comparable group without. This study was presented to the American Thoracic Society International Conference in May 2005 (more info).

Other studies have shown that those with this disease have a more difficult time in recovering from stroke and are more likely to die from stroke. So whether it's stroke prevention, or stroke recovery, this is a health problem that you need to manage.

What It Is

OSA is a disease where the upper airway is obstructed during sleep. This is obstruction is caused by the muscles controlling the tongue and soft palate relaxing, which in turn causes the airway to narrow. The result is snoring and breathing difficulties. When the muscles are too relaxed, the airway becomes completely blocked and the person's breathing is affected.

Depending on how severe it is, a person's breathing can stop for between 10 seconds and two minutes. The brain alerts the body that its oxygen supply has been affected and the body wakes up and breathes. Most of the time the person doesn't realise that they've woken up, breathed and gone back to sleep again. This sleep interruption can occur hundreds of times during the night, resulting in extremely fragmented sleep and the person not getting the refreshment that they need.

The diagrams below (from the Sleep Disorders Resource Centre), show a normal airway and an abnormal airway. You can see that when you are asleep, the airway is affected by the prone position, and problems aggravate this.

The diagram below shows the normal situation, with the person in the upright position.

The diagram below shows a person who suffers from sleep apnoea in a prone position. Just being prone collapses the airway. There are multiple places where an obstruction can occur. The soft palate can collapse the airway and the jaw can push the tongue back into the airway.

Indicators of Sleep Apnoea

The following are indicators of sleep apnoea:

• Gasping, choking or stopping breathing whilst sleeping
• Snoring at a level that disturbs other people (in the bed with you or in the household)
• Feeling tired and/or unrefreshed during the day
• Carrying too much weight
• High blood pressure.

If you have two or more of these indicators, then there is a good chance that you have sleep apnoea.

Further, those who have OSA, are more susceptible to being irritable (through lack of sleep) and depression. Depression is another side effect of stroke, so the two are linked again. In addition, OSA is also assocated with impotence in men and with menstrual problems in women.

Diagnosis

The way to diagnose sleep apnoea is to conduct a sleep study to monitor the number of times the person's sleep is disrupted during the night. This is something that is generally done via an overnight stay in a facility. (It is possible to do a "take home" version of this but the results can be compromised by the individual's ability to "wire themselves up" correctly and because fewer measurements can be taken.)

Electronics and wires are attached to the person's face, scalp, chest and legs. Whilst it sounds annoying, the electrodes are all attached externally and most people are able to fall asleep. The electrodes monitor sleeping, the sleep interruptions, blood pressure, heart rate, leg twitching etc. This all enables the physician to determine just how any times the individual wakes up and the severity of the problem.

Treatment Options

A range of options then exist for controlling sleep apnoea. The categories of treatment are:

• Continuous Positive Airway Pressure (CPAP) machines which deliver air through the nose to keep the upper airway open. The modern masks that have been developed are tolerated well by most people and, as a result, most patients no longer experience sleep apnoea whilst they use the device. These are most appropriate to people with moderate to severe cases.
• Oral Devices are most useful for those with mild cases of OSA. These reposition the lower jaw to hold the airway open.
• Surgery is a final option for some sufferers.

These should be considered as a form of stroke prevention, particularly for those who have already suffered a stroke.