Stroke And Insomnia: Exploring The Chronic Connection

Sleep disorders are a common occurrence in stroke survivors, with up to 50% of patients experiencing insomnia during the first few months after a stroke. Sleep-disordered breathing, insomnia, hypersomnia, parasomnias, and sleep-related movement disorders are all sleep issues that can be caused by a stroke.

Insomnia is the most common sleep disorder in stroke patients, with 20-56% of patients experiencing it. It can be caused by stroke location, environmental factors, or medication side effects. It can also be a result of brain injury, with certain areas of the brain, when damaged, leading to a loss of sleep.

Sleep-disordered breathing, or abnormal breathing patterns that interrupt sleep, is another common sleep issue in stroke survivors, with two-thirds experiencing it. Obstructive sleep apnea, the most common type of sleep-disordered breathing, causes breathing to stop for 10 or more seconds multiple times a night. This can increase blood pressure and blood clotting and put more strain on the heart.

Other sleep issues that can occur after a stroke include hypersomnia, or excessive sleepiness; sleep-wake cycle disorders, where the sleep schedule is no longer determined by day and night; and parasomnias, which include sleepwalking and sleep terrors.

Sleep disorders can negatively impact stroke recovery, leading to issues such as fatigue, dizziness, injuries, anxiety, depression, and impaired cognitive abilities. They can also increase the risk of another stroke, so it is important to treat them. Treatment options include medication, bright light therapy, melatonin, and continuous positive airway pressure (CPAP) machines.

Sleep-disordered breathing

The relationship between insomnia and SDB is complex and unclear, but patients with both conditions have poorer sleep quality and are more likely to have psychiatric disorders. The management of comorbid SDB and insomnia involves screening patients with insomnia or psychiatric disorders for SDB. While interviews may be effective in diagnosing SDB in patients with insomnia, polysomnography can diagnose veiled SDB.

To address comorbid SDB and insomnia, therapies should target both disorders. Patients should first be encouraged to improve their sleep hygiene and make lifestyle changes to improve sleep. Treatments for SDB include continuous positive airway pressure and oral appliances, while upper airway surgery may improve sleep outcomes in some patients. The use of pharmacological drugs such as hypnotics for the treatment of insomnia in patients with SDB remains controversial.

Obstructive sleep apnoea (OSA) is the most prevalent form of SDB. It is caused by an obstructed upper airway, which induces paroxysmal hypoxia and leads to OSA during sleep. The most common blocked locations are the palate and tongue. In addition, abnormal airway pressure changes occur after airway obstruction, along with altered intrathoracic pressure, blood pressure fluctuations, and sympathetic activation. These events can induce stroke, and OSA is a known risk factor for cerebrovascular diseases.

Central sleep apnoea (CSA) has lower morbidity than OSA but is prevalent in specific populations with cardiac and cerebrovascular diseases. CSA is characterised by a syndrome of periodic airflow decline or interruption dysregulated by central ventilation. Weak respiration lowers blood oxygen levels and may induce stroke or heart failure. CSA is, therefore, an independent stroke risk factor and improves with stroke recovery.

The treatment of choice for OSA is continuous positive airway pressure (CPAP). There are different reports on the outcomes of CPAP treatment, with most studies suggesting beneficial effects, particularly on sleepiness, depression, functional recovery, and recurrent events. However, some reports suggest that CPAP treatment could not improve stroke outcomes or sleepiness and, in some cases, even worsened health conditions.

Insomnia

Treatments for insomnia in stroke patients include cognitive-behavioural therapy, sedative antidepressants, and acupuncture.

Sleep-wake cycle disorders

• Jet lag disorder: This disorder occurs when a person travels to a different time zone, disrupting their sleep-wake cycle.
• Shift work sleep disorder: This disorder affects people who work night shifts or have variable work schedules, making it difficult to adjust their sleep-wake cycle.
• Delayed sleep-wake phase disorder: People with this disorder go to sleep and wake up much later than normal, often conflicting with work or school obligations.
• Advanced sleep-wake phase disorder: People with this disorder go to sleep and wake up much earlier than normal, which can lead to excessive sleepiness in the evening.
• Irregular sleep-wake rhythm disorder: People with this disorder experience a chaotic sleep schedule with short bouts of sleep spread throughout the day and night. It is commonly seen in people with neurodevelopmental disorders or brain injuries.
• Non-24-hour sleep-wake rhythm disorder: This disorder occurs when a person's circadian rhythm extends beyond the regular 24-hour cycle, resulting in bedtimes and wake times that gradually shift later each day. It is commonly seen in blind individuals but can also affect sighted people.
• Circadian rhythm sleep-wake disorders can lead to insomnia, excessive sleepiness, difficulty concentrating, memory problems, and accidents or injuries due to daytime sleepiness. Treatment options include adjusting lighting and sleep schedules, melatonin supplements, and strategic light avoidance or napping.

Stroke-induced sleep disorders

Sleep disorders are common after a stroke, and they can have a detrimental effect on recovery. Sleep-disordered breathing (SDB) is the most prevalent type of sleep disorder in stroke survivors, affecting two-thirds of patients. SDB is characterised by abnormal breathing patterns that interrupt sleep, leading to excessive sleepiness during the day and difficulty concentrating. Obstructive sleep apnea (OSA) is the most common form of SDB, causing the sleeper to stop breathing for 10 or more seconds, multiple times a night. OSA can be life-threatening, as it increases the risk of blood clotting and puts more strain on the heart.

Insomnia is also common in stroke survivors, with around 20-56% of patients affected. This involves difficulty falling or staying asleep, and it can cause fatigue, irritability, and memory problems.

Circadian disturbances, or sleep-wake cycle disorders, are another common issue for stroke survivors, affecting 20-40% of patients. This is when the sleep schedule is no longer determined by day and night, leading to difficulty falling asleep at night and waking up in the morning.

Other symptoms of stroke-induced sleep disorders include:

• Loud snoring
• Shortness of breath
• Increased sweating
• Gasping for breath
• Headaches
• Fatigue
• Memory problems
• Depression

Treatment

There are several ways to treat sleep disorders following a stroke:

• Avoiding sleep medicines
• Using a specially designed dental appliance to open airways during sleep
• Avoiding sleeping on the back
• Using a continuous positive airway pressure (CPAP) machine to open airways
• Bright light therapy
• Taking melatonin
• Keeping the bedroom dark, quiet, and at a comfortable temperature
• Increasing physical activity during the day
• Exposing yourself to light during the day
• Following a regular sleep schedule
• Having a bedtime routine
• Avoiding food, drink, and TV in bed
• Limiting caffeine and alcohol

Sleep apnea

OSA is an independent risk factor for stroke, meaning that people with OSA have an increased risk of experiencing a stroke even in the absence of other risk factors. The risk of having a stroke increases with the severity of OSA, which is determined by the number of breathing disruptions a person experiences each night. Mild OSA is defined as 5 to 14 episodes of abnormal breathing per hour, moderate OSA is 15 to 30 episodes per hour, and severe OSA is more than 30 episodes per hour.

OSA is associated with other conditions that can increase the risk of stroke, including heart disease, hypertension, diabetes, and abnormal heart rhythms. These and other health consequences of OSA can further increase the risk of stroke. People with OSA are also twice as likely to have a hole in their heart called a patent foramen ovale, which increases the risk of a stroke.

OSA is the most common type of sleep apnea to develop after a stroke, occurring in as many as 70% of people who have had a stroke, compared to up to 30% of the general population. Detecting and treating OSA is an important aspect of medical care after a stroke, as treatment for OSA can improve a person's recovery and reduce the risk of additional strokes. Central sleep apnea (CSA) is another type of sleep apnea that happens when the brain is unable to send the proper signals to the muscles responsible for breathing. CSA occurs in between 6% to 24% of people after a stroke and may be most common within the first five days.

Cheyne-Stokes breathing is a breathing pattern that involves cycles of increased and reduced airflow and is considered a type of CSA when reductions in airflow also involve pauses in breathing during sleep. After a stroke, as many as 20% of people develop Cheyne-Stokes breathing, which often resolves over time but may still require treatment.

Treating sleep apnea can reduce the risk of having a stroke and improve a person's recovery, reduce the length of time they spend in the hospital, and enhance their overall sense of well-being.

Frequently asked questions