Introduction 

A concussion is the most common form of traumatic brain injury, often referred to as mild traumatic brain injury (mTBI).¹ Whilst most people recover fully, some symptoms can persist leading to post-concussion syndrome (PCS). Sleep abnormalities are often seen in those with PCS, but there are ways to help address these disturbances from improving sleep hygiene to therapy. 

We all know that a good night’s sleep can reap many benefits on our health and well-being, from boosting our immune systems to helping us feel happy, alert, refreshed and functional. How can a concussion impact our sleep? And what can be done to restore this vital slumber?

What is a concussion?

A concussion is medically described as a mild traumatic brain injury, characterised by a brief loss of mental function following impact to the head or excessive movement of the brain (for example, from whiplash). As noted by the UK’s National Health Service (NHS), it is “the most common but least serious type of brain injury”.

Symptoms include:

• Loss of consciousness
• Memory loss 
• Disturbances in vision, such as blurry vision
• Confusion, blankness of expression, or delays in communication 
• Dizziness
• Irritability 

Typically, a concussion does not cause complications or long-term health problems. However, repeated, severe concussions (as in some sports like boxing) can increase the risk of mental impairment and dementia.²

At the physiological level, a concussion refers to a cascade of complex disruptive events in the brain. These include:³

• Increases in inflammatory markers (substances released after injury)
• Changes in neurotransmitter activity
• Changes in neuronal function 
• Changes in glucose metabolism 
• Altered blood flow

These events can change the brain’s “neuronal architecture” and lead to altered physiological and behavioural states. This includes sleep disturbance, in roughly 30-85% of patients, with a majority resolving within 3 months after the initial injury.³

What sleep problems are experienced following a concussion?

Concussions tend to resolve within 7-10 days from the point of injury, but roughly 10-25% of people do not recover completely and develop PCS.¹ PCS can come with sleep disturbances and abnormalities, such as obstructive sleep apnoea, insomnia or hypersomnia. 

The presence of sleep disturbance after a concussion is concerning, as it is a risk factor for prolonging the recovery time.⁴ This is not surprising when we consider the critical role of sleep in helping our bodies to repair and restore.⁵ Concussions that are not related to sport were found to be more associated with sleep disturbance, compared with concussions that were sport-related.⁴ 

Insomnia 

Insomnia refers to the difficulty initiating or maintaining sleep, for a minimum of three nights per week for three months. This can lead to distress, impaired function, poor physical and mental health, and reduced quality of life.^5,6 Insomnia is significantly more prevalent in those who have sustained an mTBI compared to the general population.^5,6

Hypersomnia

Hypersomnia refers to excessive sleepiness and can occur following a concussion. Sleepiness is common after a traumatic brain injury, with the extent of sleepiness linked to the severity of the injury. Most concussion patients suffering from hypersomnia will recover, but for some, sleepiness can persist for about a year after the initial injury.⁷

Sleep apnoea

Patients with sleep apnoea suffer from interruptions to their breathing during sleep, and this can be caused by either a physical blockage (obstructive) or by problems with the nervous system or brain centres regulating breathing patterns (central). This ongoing disruption to sleep can have many adverse impacts on health, such as cognitive impairment, reduced neural repair and increased likelihood of accident or injury.¹ 

It has been challenging to calculate the exact prevalence of sleep apnoea in PCS patients, but one significant risk factor has been identified: increased age.¹ Another risk factor is high Body Mass Index (BMI) but the results have not been statistically significant to date.¹

Other, less common sleep disturbances that can occur following a concussion include: 

• Narcolepsy 
• Periodic limb movement disorder (PLMD) 
• Circadian rhythm sleep disorders 

What can be done to help?

Further research is needed to understand and define exactly which interventions could help prevent or reduce sleep disturbances following a concussion. Some indicative research suggests the following approaches may be beneficial, to identifying, monitoring and treating sleep disturbance:

Monitoring for sleep apnoea

Evidence suggests that those with PCS are at a high risk of developing sleep apnea. Patients who have had a concussion should be routinely assessed for sleep apnoea and other breathing disorders. Despite the higher risk of sleep disorders in older populations, young people should also be routinely assessed following concussion as mTBI is common in the younger population.¹

Continuous sleep monitoring throughout the recovery process should be tailored to the individual, as symptoms will vary. Appropriate measures include manual sleep behaviour monitoring or using technologies for recording sleep patterns.⁸

Sleep hygiene

Limiting risk factors for poor sleep and improving sleep hygiene. Some preliminary findings from a systematic review of the literature found that some interventions related to sleep hygiene, alone or together with other treatments, could reduce sleep disturbances in patients suffering from a traumatic brain injury.⁹

Therapy

Undertaking therapy may be beneficial. There is an established relationship between traumatic brain injury and post-traumatic stress disorder (PTSD), particularly among veterans.¹⁰ Sleep disturbance is a shared symptom, as are some of the treatment options for conditions. In particular, cognitive behavioural therapy (CBT) is a core intervention used for sleep disturbances from a TBI:

• When co-occurring with PTSD, trauma-focused CBT is recommended due to the complex interchange between trauma and sleep disturbance. However, more research is needed in this area¹⁰
• CBT can also be applied for specific sleep disturbances, as outlined in the table below, as can other more specific interventions

Light therapy

The use of light therapy can help improve sleep. A randomised, double-blind, placebo-controlled trial looked at how blue-wavelength light could help shift sleep patterns in adults recovering from mTBC.¹¹ They found that 30 minutes of exposure to blue light in the morning reduced daytime sleepiness and improved cognitive performance in participants recovering from a concussion. 

Compared to an amber light control, blue light created favourable structural changes in the brain regions involved in sleep, and could be used to facilitate brain repair following injury.¹¹

Melatonin

Taking melatonin has been tested and shown to be effective. This hormone supplement is a synthetic version of the melatonin produced in the brain at night to regulate our sleep-wake cycles and circadian rhythms. In the UK, it is available by prescription only and is only used in the short term.

One study found that melatonin improved sleep disturbances in 67% of concussion patients who had suffered from a sleep disturbance.⁴  If you are considering melatonin, always consult your healthcare professional first.

The table below summarises the key sleep disturbances expressed from a concussion and the first-line treatments for each:⁶

Summary

A concussion is a mild traumatic brain injury caused from impact to the head or violent and excessive movement of the brain. Most concussions resolve over time, but sometimes, symptoms last for a longer period of time. Sleep disturbances can occur post-concussion, from insomnia to hypersomnia and sleep apnoea. 

To manage and improve sleep problems after a concussion, a range of interventions and therapies are available. Cognitive behavioural therapy is the mainstay treatment, particularly for insomnia, but other techniques such as the use of blue light therapy, taking melatonin and improving sleep hygiene can be beneficial. Healthcare providers should continually monitor the sleep patterns of patients with concussions to be able to provide the right support as early as possible.