Micro-awakenings and sleep apnea syndrome

Micro-wake-up definition

A wake-up call is a sudden, brief interruption of sleep. The sleeper wakes up for a few seconds to catch his breath and then goes back to sleep. The same thing happens again sometimes a few minutes later. The micro-awakening is triggered by the brain. It results in muscle contraction and the opening of the trachea allowing the passage of air again. When the frequency of micro-awakenings is important, we speak of micro-fragmentation of sleep. The more micro-awakenings there are, the less the sleep is restorative because these micro-cuts of sleep prevent the necessary deep sleep  for recovery. These multiple sleep interruptions lead to significant daytime fatigue, prompting the person to consult a doctor.

The causes of micro-awakenings

People who experience micro-awakenings are not aware of waking up constantly during the night. It is because they find themselves in a state of great fatigue in the morning that they decide to talk to the doctor about it. In the absence of a special event or illness that could be causing stress, anxiety or insomnia, the doctor may order a  polysomnography examination to find out the reason for fatigue. Electrodes applied to the head and in several places on the body make it possible to record the electrical activity of the brain and pick up various signals including eye movement and muscle tension.

This examination reveals the presence of certain sleep-related abnormalities such as breathing problems, increased leg movements or abnormal heart rhythm. It also makes it possible to specify at what moment of sleep the incidents appear and their impact on the different phases of sleep.

Polysomnography is essential to establish a link between micro-awakenings, daytime fatigue and a sleep disorder.
The syndrome of restless legs causes micro-cuts in sleep, but people who are affected know their disease because they also feel discomfort in the lower limbs during the day.
In case of sleep apnea, the person feels very tired in the morning even though they believe they have slept a sufficient number of hours. She does not remember the many micro-awakenings that were necessary to catch her breath.

The mechanism of micro-awakenings due to sleep apnea

Since sleep apnea is always accompanied by micro-awakenings necessary for the person to start breathing again, it is important to be familiar with this syndrome and to understand its mechanism. This is all the more true since severe sleep apnea eventually leads to serious health problems that increase the mortality risk.

What you need to know about sleep apnea syndrome

Sleep apnea is a trouble breathing occurring at night. It is characterized either by an apnea which means a cessation of breathing or by a hypopnea which consists of a decrease in the respiratory flow. This disorder is due to total or partial obstruction of the upper airways consisting of the nose, mouth, pharynx and larynx. This disease is also called sleep apnea-hypopnea syndrome (SAHOS) or obstructive sleep apnea syndrome (OSAS). An apnea can last up to 20 seconds, sometimes more and repeat itself up to 30 times or more per hour. Each apnea causes a micro-cut in sleep.
In France,1.5 million people are affected by this syndrome but the figure would be much higher if all the people concerned were diagnosed.

Symptoms that should suggest sleep apnea

As already said before, people suffering from micro-awakenings are not aware of them but many symptoms that accompany this disorder should attract attention:

1. heavy snoring and restless sleep
2. choking feeling and excessive sweating at night
3. frequent need to go to the bathroom at night
4. fatigue upon waking with headaches
5. sleepiness throughout the day and impaired memory
6. irritability
7. decreased sexual desire.

Causes of sleep apnea

The most common cases of sleep apnea are those due to upper airway obstruction. This obstruction in adults is often linked to obesity responsible for the formation of fatty tissue creating an obstacle to the passage of air. 60% of overweight adults are affected by obstructive sleep apnea.
Bulky tonsils, a too long soft palate or a malformation of the lower jaw can also be responsible for the obstruction of the pharynx.

Nocturnal apnea, which is always accompanied by sleep micro-cuts, can also be of neurological origin. This is called central sleep apnea syndrome. (BAGS). In this case, the apnea results from an abnormality of the central nervous system, where breathing is controlled.

People affected by sleep apnea

The risk of developing sleep apnea syndrome increases with age, but before the age of 60, men are more often affected than women. Beyond this age, as many men as women are affected.

Regardless of age, overweight and different metabolic disorders that accompany it increase the occurrence of sleep apnea and micro-cuts.

Children can also be victims of partial or total obstruction of the upper airways. Preterm children, asthmatics, those with allergic rhinitis or frequent ENT infections as well as babies with severe gastroesophageal reflux are regularly affected by sleep apnea syndrome. The micro-awakenings of babies and young children cause them to enter a hypertonic state, the opposite of what happens with adults. These children are said to be difficult when there is a specific cause for their condition. A medical care is essential.

The consequences of sleep apnea and micro-awakenings

The consequence that most affects the person suffering from sleep apnea is excessive daytime sleepiness. This fatigue, due to poor quality sleep, affects his life and also that of those around him.

What the person does not perceive are the consequences of the repeated lack of oxygen, called hypoxia. Ultimately, hypoxia leads to serious problems such as heart attack, stroke, high blood pressure, and sometimes a heart rhythm disorder.

The different treatments for sleep apnea

The treatment to adopt depends on the cause or causes of the disease. When these are anatomical, a surgical operation such as the removal of the tonsils can remedy the problem. While waiting for the operation, the situation can be improved with a small ventilation device or a mandibular advancement orthosis.

If the cause is not anatomical, the treatment consists of taking medication specific to the disease responsible for the apnea.