While snoring is often the sound most associated with sleep problems, it’s far from the only one. Many people around the world suffer from a range of sleep disorders that go undiagnosed, significantly impacting their health and quality of life. A sleep study, or polysomnography, is a useful diagnostic tool that can uncover these hidden issues.

This article will delve into the world of sleep studies, explaining what they are, why they’re important, and what they can reveal about your overall health.

What is a Sleep Study?

A sleep study test procedure is a comprehensive method that records various physiological activities while you sleep. Typically conducted in a sleep clinic or at home, it involves attaching sensors of a sleep study machine (polysomnography or PSG machine) to your body to monitor:

• Brain waves (EEG): To track your sleep stages and identify disruptions.
• Eye movements (EOG): To detect rapid eye movement (REM) sleep.
• Muscle activity (EMG): To monitor muscle tone and movements, particularly in the legs and chin.
• Heart rate (ECG): To assess your heart’s rhythm and identify any abnormalities.
• Breathing patterns: To measure airflow through your nose and mouth, and chest and abdominal movements.
• Blood oxygen levels: To monitor any drops in oxygen saturation.

In addition, a Positive Airway Pressure (CPAP/BPAP) machine may also be used to deliver pressurised air to keep the airways open during sleep. Video and audio recordings may also be used to document your sleep behaviours, such as movements, body position, and any sounds you make.

What to Expect During a Sleep Study?

If your doctor recommends a sleep study, you may be wondering what to expect. Here’s a general overview:

• Preparation: You’ll usually be asked to avoid caffeine and alcohol on the day of the study and to maintain your regular sleep schedule as much as possible.
• Arrival and Setup: You’ll arrive at the sleep clinic in the evening and be shown to a private room. A trained technician will attach sensors to your head, face, chest, limbs, and fingers using a mild adhesive.
• During the Study: You’ll be monitored throughout the night while you sleep. You’re free to move and change positions as needed. The technician will be nearby to assist you if you need anything.
• Morning: The sensors will be removed in the morning, and you’ll be able to go home.
• Results: The data from the sleep study will be analysed by a sleep specialist, who will then discuss the results with you and recommend any necessary treatment.

What Can a Sleep Study Test Diagnose?

Let us understand the possible disorders and diagnoses based on sleep study test results –

• Obstructive Sleep Apnoea (OSA): This is one of the most common sleep disorders, characterised by repeated episodes of upper airway obstruction during sleep. OSA can lead to loud snoring, excessive daytime sleepiness, disrupted sleep, and an increased risk of cardiovascular disease, stroke, and type 2 diabetes.
• Central Sleep Apnoea: Unlike OSA, central sleep apnoea occurs when the brain fails to send the correct signals to the muscles that control breathing. This results in pauses in breathing during sleep and can be associated with underlying medical conditions.
• Periodic Limb Movement Disorder (PLMD): PLMD involves repetitive leg movements during sleep, often causing arousal and disrupted sleep. It can be associated with restless legs syndrome (RLS) and other medical conditions.
• Narcolepsy: This neurological disorder is characterised by excessive daytime sleepiness, sudden sleep attacks, cataplexy (sudden muscle weakness), sleep paralysis, and hallucinations. A sleep study, often combined with a multiple sleep latency test (MSLT), is crucial for diagnosing narcolepsy.
• REM Sleep Behaviour Disorder (RBD): RBD involves acting out dreams during REM sleep, which can lead to injuries to the sleeper or their bed partner. It is often associated with neurological conditions like Parkinson’s disease.
• Insomnia: While insomnia is often diagnosed based on a person’s self-reported symptoms, a sleep study can help to identify any underlying physiological factors that may be contributing to sleep difficulties.
• Parasomnias: These are a group of sleep disorders that involve abnormal movements, behaviours, or experiences during sleep. Examples include sleepwalking, sleep talking, sleep terrors, and “confusional arousals”.

The Wider Health Implications of Untreated Sleep Disorders

Untreated sleep disorders can have far-reaching consequences for both physical and mental health such as:

• Cardiovascular Health: Sleep apnea, in particular, has been strongly linked to an increased risk of hypertension, coronary heart disease, heart failure, arrhythmias, and stroke. The repeated drops in oxygen levels and sleep disruptions associated with sleep apnoea put significant strain on the cardiovascular system.
• Metabolic Disorders: Poor sleep has been shown to disrupt glucose metabolism, leading to insulin resistance and an increased risk of type 2 diabetes. It can also affect hormone levels that regulate appetite, contributing to weight gain and obesity.
• Mental Health: Sleep deprivation and sleep disorders can significantly impact mood, emotional regulation, and cognitive function. They can increase the risk of depression, anxiety, irritability, and difficulty concentrating.
• Cognitive Function: Lack of sleep can impair memory, attention, and decision-making abilities. This can affect performance at work or school, increase the risk of accidents, and negatively impact overall quality of life.
• Increased Accident Risk: Daytime sleepiness caused by sleep disorders can increase the risk of accidents, particularly car accidents and workplace accidents.
• Reduced Quality of Life: Sleep disorders can have a significant impact on daily functioning, energy levels, and overall well-being. They can affect relationships, social activities, and the ability to enjoy life.

Treatment Options for Sleep Disorders

The treatment for a sleep disorder will depend on the specific condition diagnosed. Some common treatment options include:

• Lifestyle changes: These may include weight loss, quitting smoking, avoiding alcohol before bed, and improving sleep hygiene.
• Continuous Positive Airway Pressure (CPAP): This is the gold standard treatment for obstructive sleep apnoea. It involves wearing a mask that delivers a constant flow of air to keep the airway open during sleep.
• Oral appliances: These are custom-fitted mouthguards that can help to reposition the jaw and tongue to keep the airway open.
• Medications: Medications may be used to treat certain sleep disorders, such as narcolepsy or restless legs syndrome.
• Surgery: In some cases, surgery may be necessary to correct anatomical problems that are contributing to sleep apnea.
• Cognitive Behavioural Therapy for Insomnia (CBT-I): This is a structured programme that helps people with insomnia to identify and change the thoughts and behaviours that are interfering with their sleep.

Sources:

• https://clinmedjournals.org/articles/jsdm/journal-of-sleep-disorders-and-management
• https://www.mayoclinic.org/tests-procedures/polysomnography/about
• https://www.ncbi.nlm.nih.gov/books/NBK563147/