Parasomnia

What is a parasomnia? 

Parasomnia is a sleep disorder where you experience abnormal movement or behaviour during sleep. Despite being asleep, it can seem to others as though you are awake and carrying out these movements consciously. While simple movements usually occur as you transition from being asleep to awake, complex movements can occur during various stages of sleep.  

Parasomnias are usually triggered by disruptions in your sleep cycle, with common causes including alcohol consumption, certain medications, fever, sleep deprivation, stress, and changes to your sleep schedule. Parasomnias can be associated with other medical conditions, including those affecting your mental health, such as anxiety, depression, and PTSD.  

Our world-leading sleep specialists at Royal Brompton and Harefield hospitals can diagnose and manage all types of parasomnias. We provide personalised care, ensuring you receive the most effective treatment for a good night’s sleep.

Types of parasomnias

Parasomnias are categorised by the stage of sleep in which they occur – either non-rapid eye movement (non-REM) or rapid eye movement (REM) sleep.

Non-REM parasomnias 

Non-REM parasomnias usually happen during the first few hours of sleep, when you are in the deeper stages of sleep. During these episodes, you will not be fully awake and may not be responsive if someone tries to bring you out of your sleep. You will also often have no memory of the episode afterward.

Non-REM parasomnias include:

• sleepwalking – you may get out of bed and move about, typically with your eyes open. You might also mumble, talk or even perform everyday activities while asleep
• night terrors – you may wake up suddenly feeling extremely scared, potentially screaming or crying, as well as breathing rapidly
• confusional arousals – you may sit up in bed and appear frightened or disoriented, before falling back asleep without remembering the event
• sleep-related eating disorder – you may eat or drink while asleep, including substances that are inedible or harmful  
• sexsomnia – you perform sexual behaviours during sleep without being aware of it

REM parasomnias

REM sleep is a stage of sleep where you experience vivid dreams and increased brain activity. Your muscles will also usually be in a state of temporary paralysis to prevent you from moving.  

The main REM-related parasomnia is REM sleep behaviour disorder (RBD). In this condition, you won’t have the normal muscle paralysis during REM sleep, causing you to physically act out your dreams. This may involve talking, punching, kicking, shouting or attempting to jump out of bed.

Other parasomnias

Some additional parasomnias that can occur during transitions between sleep and wakefulness include:   

• exploding head syndrome – you experience a sensation of a loud noise or explosion in your head while falling asleep or waking up
• sleep enuresis – you involuntarily wee during sleep (commonly referred to as bedwetting) 
• sleep-related hallucinations – you hear, feel or see things that aren’t there when falling asleep or waking up. These are vivid and often frightening hallucinations 
• catathrenia – you repeatedly groan or grunt when breathing out during sleeping, without being aware that you are doing this

If you are concerned about parasomnia and would like to speak to one of our sleep specialists, get in touch with our team to arrange an appointment.  

Symptoms of parasomnias

Symptoms of parasomnias can vary depending on your parasomnia type. However, the most common symptoms include:

• difficulty sleeping throughout the night 
• waking up confused, anxious or fearful 
• being tired during the day 
• moving, talking or performing activities during your sleep that your bed partner tells you about in the morning  
• being tired or sleepy during the day

You may not know what your parasomnia symptoms are if you sleep alone, as they only occur while you sleep. However, if you notice changes in how tired you feel during the day, you may have problems with your sleep.  

If you are experiencing symptoms of a parasomnia and would like a diagnosis, contact our team to arrange an appointment with one of our sleep specialists.

What causes parasomnias?

The causes of parasomnias can vary from person to person, but they are often triggered by something that disrupts your normal sleeping pattern.   

Common sleep disruptions include:  

• certain medications 
• intrinsic sleep pathology, which includes restless legs syndrome, narcolepsy and obstructive sleep apnoea  
• irregular sleep schedules, such as those caused by shift work or jet lag  
• sleep deprivation

Other potential triggers of parasomnias include:  

• fever 
• stress 
• drinking alcohol or other stimulants like caffeine 
• pregnancy 
• genetic factors 
• inflammatory diseases 
• mental health conditions, including anxiety, depression and post-traumatic stress disorder (PTSD) 
• neurological disorders, such as Parkinson’s disease or multiple sclerosis 

Sometimes, the underlying cause of a parasomnia is unknown.

Who is at risk of parasomnias? 

Anybody can develop a parasomnia, but some people may have a higher risk than others.  

Some of the main risk factors for parasomnias include:  

• a childhood history of parasomnias  
• a family history of parasomnias 
• having other sleep disorders such as obstructive sleep apnoea 
• existing medical conditions and medications  
• lifestyle factors contributing to when you can sleep (such as shift work)

Parasomnias tend to be more common in children. However, they’re also possible in adults.

Complications of parasomnias

The most common complication of parasomnias is disrupted sleep, which can leave you feeling tired and negatively affect your daily life. 

Other complications can include harming yourself or others accidentally during episodes, as these behaviours are involuntary.  

Diagnosing parasomnias

Our sleep specialists are experts in diagnosing parasomnias and use a range of comprehensive tests. During your initial consultation, we will ask questions about your medical history, family history and lifestyle.  

We will also recommend keeping a sleep diary and asking your bed partner to observe you during sleep to make note of any unusual behaviours.

Diagnostic tests may include a:

• sleep study (polysomnogram) – this involves monitoring your sleep through measurements of your brain waves, heart rate, eye movements and breathing. We will also record your movements and behaviour on video. Together, this information helps us confirm if you have a parasomnia and which type you have
• neurological CT or MRI scans – these scans help us detect abnormalities within your brain to determine potential neurological causes of parasomnia. However, these scans are not required for all patients

Our experts provide fast, accurate diagnoses for parasomnias and other sleep disorders to guide your personalised treatment plan. Contact our team to arrange an appointment.

Treating parasomnias

Treatment of parasomnias can often require a multidisciplinary approach and may involve a combination of treatments to determine what works best for you. Our sleep medicine team provide the expertise to help manage your condition and get the rest you need.

Safety precautions during sleep 

It is important to take safety precautions with parasomnias, as you could accidentally harm yourself or someone else. To reduce the risk while you are sleeping, you can consider:   

• locking your doors  
• removing dangerous or sharp objects from your bedroom or reach 
• securing light furniture around you, like bedside lamps 
• padding the corners of your bed 
• using plastic cups or bottles for drinking water at night 
• installing alarms on windows and doors if sleepwalking leads you outside  
• sleep alone if you display aggressive or unwanted behaviours during sleep 

Promoting good sleep hygiene 

Good sleep hygiene is key to managing parasomnias. You can consider: 

• turning off the lights, television and any other electronic devices, like your phone, before bed 
• keeping the temperature of your room cool 
• avoiding caffeine and alcohol, especially close to bedtime  
• avoiding strenuously exercise near bedtime 
• maintaining a regular sleep and waking schedule

Additional treatments

For some people, lifestyle changes may not be enough to treat parasomnias. In this case, we may recommend other treatments, including:   

• medications – these are prescribed when behavioural approaches are not effective 
• psychological therapies – cognitive behavioural therapy (CBT) can help address stress, anxiety and depression, which may worsen parasomnia symptoms 

Our team will ensure your treatment plan encompasses your specific needs, allowing you to get the good night’s sleep you need. If you would like to speak to one of our sleep specialists about treatment for parasomnias, contact our team to arrange an appointment.