Introduction to sleep disorders
Sleep disorders can impact our daily well-being and take many forms, such as:
- fatigue, with or without drowsiness, decreased energy, alertness, and productivity,
- memory and concentration problems,
- mood disorders, such as irritability, anxiety, and depression.
Lack of sleep affects overall quality of life. Constant fatigue can harm personal, social, and professional relationships.
Physiological sleep
A night's sleep consists of several sleep cycles, lasting an average of 90 to 110 minutes in adults. Thus, patients with physiological sleep have 4 to 6 sleep cycles per night. Each cycle consists of two stages of light sleep, followed by a stage of deep slow-wave sleep, and finally a stage of REM sleep (also known as rapid eye movement sleep). REM sleep is the most restorative phase of sleep, during which our brain is particularly active, with numerous dreams, and our muscles are completely relaxed.
Each individual requires different amounts and schedules of sleep, which are determined in particular by genetic factors.
Sleep disorders: possible causes and solutions
Insomnia
Insomnia is generally characterized by a subjective complaint from a person who experiences:
- difficulty falling asleep (sleep onset insomnia), or
- difficulty staying asleep (sleep maintenance insomnia), or
- early morning awakening
associated with a deterioration in quality of life with daytime fatigue, concentration and/or mood disorders, and decreased performance during the day.
It is estimated that 10 to 15% of the population currently suffers from significant insomnia, which can have a significant impact on health, including worsening chronic pain, increasing the risk of depression, and reducing quality of life. There are many factors that contribute to insomnia (genetic predisposition, anxious personality, family or work-related stress, environmental factors, chronic pain, poor sleep hygiene with irregular sleep-wake patterns).
Treatment is primarily medication-based, aiming to optimize sleep hygiene in the first instance, with the option of cognitive behavioral therapy over a few sessions.
Sleep apnea syndrome
Obstructive sleep apnea-hypopnea syndrome (OSAHS) is a sleep disorder characterized by repeated interruptions in breathing during sleep, most often due to obstruction of the upper airway.
Know more about sleep apnea syndrome
Restless Legs Syndrome
Restless legs syndrome (RLS) is a neurological disorder characterized by an unpleasant sensation in the legs, often described as discomfort with an irresistible urge to move the legs, particularly when resting, sitting, or lying down. These sensations are often accompanied by symptoms such as itching, tingling, hypersensitivity, and motor restlessness, and are relieved by moving the legs. Symptoms intensify in the evening and at night, disrupting sleep onset and/or sleep. RLS can have a significant impact on quality of life, particularly for people who suffer from it chronically, with fatigue, daytime sleepiness, and difficulty concentrating and remembering things.
It is important to know that restless legs syndrome can be exacerbated in certain situations, such as iron deficiency, taking certain medications (such as antidepressants), and pregnancy.
Treatment and management of RLS
Simple measures can help with symptoms: avoid coffee, tea, alcohol, and tobacco. Moderate and regular exercise, intellectual activity in the evening, massage and stretching exercises, compression stockings, or relaxation techniques can also reduce symptoms.
If these measures do not help, consult your doctor to check for possible iron, folic acid, or vitamin B12 deficiency, which could be causing the disorder. In cases of refractory symptoms that interfere with quality of life, specific treatment acting on dopamine receptors may be offered.
Restless leg syndrome and pregnancy
Periodic Limb Movement Disorder (PLMD)
PLMD, or periodic limb movement disorder, is a sleep disorder in which a person's arms or legs repeatedly twitch and contract during sleep.
Between 4% and 11% of adults suffer from PLMD. These movements are generally neither painful nor uncomfortable. Although they can involve the arms and hands, they most often involve flexing other parts of the body.
These movements can disrupt the sleep of those affected, causing micro-awakenings, but this is not always the case.
Circadian rhythm disorders
Circadian rhythm disorders refer to disturbances in the usual sleep-wake cycle.
Some people experience phase delay, falling asleep late and waking up late. This phenomenon is mainly observed (and is even physiological) in adolescents and is accentuated by exposure to screens in the evening. It may be associated with a genetic predisposition and is frequently linked to comorbidities such as depression.
More rarely, the opposite occurs, in which case the sleep-wake cycle is advanced by at least two hours. This disorder generally occurs in older individuals.
There are various specific therapies, including light therapy, chronotherapy, and taking melatonin before bedtime.
Narcolepsy and hypersomnia
A person with narcolepsy typically experiences episodes of excessive and uncontrollable daytime sleepiness. They may also experience a loss of muscle tone when emotional (cataplexy), sometimes hallucinations when falling asleep, and muscle paralysis upon waking. Paradoxically, their sleep is not of good quality. One of the difficulties in diagnosing this condition is that these patients, who are often overweight, do not always have all the typical symptoms and may also suffer from sleep apnea and hypopnea.
Patients with idiopathic hypersomnia also experience episodes of daytime sleepiness, typically sleeping for at least 10 to 11 hours per 24-hour period.
Parasomnia
Parasomnias are characterized by movements, behaviors, emotions, perceptions, and dreams that occur during falling asleep, slow-wave sleep, or REM sleep.
One example is sleepwalking. This is a sleep disorder that occurs during slow-wave sleep and manifests itself in automatic actions performed during sleep. It can affect people of any age, but it is most common in children. Sleepwalkers may get up and walk around without being aware of it.
Other examples of parasomnia include night terrors, confusional arousals, sleep-related eating disorders, and REM sleep behavior disorders.
Several factors can cause these phenomena, including heredity, age, stress, and alcohol consumption.
The key figure
One-third of the population suffers from moderate (26%) or pathological (7%) sleep disorders, but not everyone is affected to the same extent. Women suffer more frequently than men (37% vs. 29%), and sleep disorders increase with age.
Did you know?
Sleep disorders are both a risk factor for mental health and a symptom of mental illnesses such as depression. People with significant sleep disorders are much more likely to have symptoms of moderate to severe depression than those without sleep disorders (35% vs. 4%). Similarly, they are more likely to suffer from psychological distress (18% vs. 2%) or moderate to severe symptoms of generalized anxiety (25% vs. 3%).