Sleep and Pain

Key points:

1. Good sleep is a foundation for good health and happy mind.

2. Sleep and Pain sensation share the similar neural circuitry and neurotransmitters involved in regulation.

3. There is evidence suggest that the relationship between sleep and pain is bidirectional.

4. Educate good sleep hygiene, create a restful environment, winding down and de-stressing technique for a better sleep.

March 19 2021 is the 14th annual World Sleep Day with slogan: ‘Regular Sleep, Healthy Future’. Sleep is a vital physiological function for us to restore the energy expenditure throughout the day and to refresh our busy mind. Here I have listed some insights why sleep is important, how does it chronic pain inter-related with sleep disturbance and some tips on sleeping better.  

Why is Sleep important?

Good sleep is a foundation for good health and happy mind. Most adults require 7-9 hours of sleep a night, but after age 60, nighttime sleep tends to be shorter, lighter and interrupted. As mentioned above, sleep allows your body and mind to recharge, leaving you refreshed and alert when you wake up. However, sleep deprivation leaves people vulnerable to attention lapses, reduced cognition, delayed reactions, and mood shifts. It is also associated with several health conditions, such as obesity, diabetes, high blood pressure, heart disease, stroke and poor mental health.

Neuroscience about Sleep

1. Suprachiasmatic nucleus within Hypothalamus: the structure receiving information about light exposure directly from the eyes and control behavioural rhythm.

2. Brain Stem: releasing a neurotransmitter called GABA, which reduces activity of arousal centres and playing a vital role in REM sleep to relax muscles tension.

3. Thalamus and Cerebral cortex: help us to tune out the external world and filling it up with dreams.

4. Pineal gland: the production powerhouse of melatonin that helps regulating the circadian rhythm (sleep-wake cycle)

5. Basal forebrain and Midbrain: contain cells that secrete adenosine, which are supporting the urge to sleep (aka sleep drive). Drinking caffeine are essentially blocking the actions of the adenosine.

6. Amygdala: the area where emotional cells are involved during REM sleep

How do Sleep Disturbance and Chronic Pain inter-relate? 

There are few researches to evaluate the impact of sleep disturbance on Pain. It is more evident when sleep is manipulated (by means of deprivation or through medications) are linked to the the pain intensity in the following day. The perceived ratings of sleep disturbance are also linked to next day pain. 

There is consistent evidence to suggest pain negatively impacts sleep both proximally and long term. It is likely the relationship are bidirectionally meaning pain is causing sleep disturbance, while poor sleep also causing more pain. 

Hypnotics are frequently used for sleep induction and maintenance. However, the benefits are believed to be short-lived. In addition, the benefits may be outweighed by associated problems such as cognitive impairment, possible dependence, and interference on stage 3 and stage 4 sleep. 

More often, Low dose tricyclic antidepressants with properties of sedating antihistaminic and anticholinergic side effects are commonly used in patients with pain, mostly with its superior effect of antineuropathic analgesic properties. However, it is frequently associated with adverse effects, such as dry mouth and  cognitive dysfunction, if dose is escalated. 

Cognitive behavioural therapy have demonstrated substantial efficacy in insomnia and pain management. The two most potent forms of CBT include sleep hygiene education, stimulus control and sleep restriction therapies. It is very common that people with chronic pain and insomnia will be referred to psychologist for mind training. 

How to Sleep Better

1. Sleep hygiene.

   1. Set a consistent sleep schedule. This means going to bed and waking up at the same time everyday.

   2. Unplug an hour before bed. Minimal screen time is essential for good sleep.

   3. Get regular (early) exercise. Effects of exercise may take a few weeks before creating a substantial impact.

   4. Avoid day naps. Short power nap of 20 mins can lift your mood and leave your more refreshed, in the short term. A late-afternoon snooze is likely to decrease your homeostatic sleep drive.

2. Create a restful environment. Your bedroom should be free of stress and distraction.

   1. The ideal room is cool and dark. The optimal temperature for most people are 16-20 degree Celsius.

   2. Peace and quiet. Sometimes, people use “white noise” or ambient sounds to mask disruptive noises like traffic or construction.

   3. Bedding and sleep position. If you are side sleeper, your pillow should support your head, neck, ear and shoulder. If you sleep on your back, consider a thinner pillow to reduce stress on your neck. Choose a pillow that is hypoallergenic to lessen the chance of nighttime congestion.

   4. Declutter your bedroom.

3. Wind down at the end of the day. Decompress and unwind your busy day.

   1. Dim the lights. Think about lamps, dimmer switch, cradles or indirect lights.

   2. Limit caffeine and alcohol. Caffeine – coffee, tea and soft drinks. Avoid foods that might upset your stomach – spicy and greasy

   3. Exposure to natural lights in the morning. Tuning your circadian rhythm.

   4. Less evening work. Each work message keeps your mind active.

4. De-stress. Reduce active mind caught up in the emotional stir-ups.

   1. Stretching before bed. Try some yoga or stretching to relieve tension and relax.

   2. Gratitude list for the day. Giving thanks can make you happier and getting the right conditions for better sleep.

   3. Warm bath. Relax the muscle tension and mind, lowering both heart rate and blood pressure.

   4. Mindfulness exercise. Meditation in the evening help to de-stress and fall asleep, by easing with thoughts and reducing stress.

Dr Chow Chow wishes everyone has a restful night and sleep well 🙂 

#WorldSleepDay

Reference:

1. Brain Basics: Understanding Sleep. National Institute of Neurological Disorders and Stroke. https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/understanding-Sleep. Accessed on 16 March 2021.

2. Why Do We Need Sleep? Sleep Foundation. https://www.sleepfoundation.org/how-sleep-works/why-do-we-need-sleep. Accessed on 16 Match 2021

3. Menefee LA, Cohen MJ, Anderson WR, Doghramji K, Frank ED, Lee H. Sleep disturbance and nonmalignant chronic pain: a comprehensive review of the literature. Pain Med. 2000;1(2):156-172.

4. Giving thanks can make you happier. Harvard Health Publishing. Harvard Medical School. https://www.health.harvard.edu/healthbeat/giving-thanks-can-make-you-happier. Accessed on 16 March 2021.

5. How to sleep better. Headspace. https://www.headspace.com/sleep/how-to-sleep-better. Accessed on 16 March 2021