Last week I wrote about my approach to assessing sleep problems in those with persistent pain. As an ex-insomniac I’ve spent a while learning about sleep so I can understand what’s going on, and why sleep can be such a problem. In this week’s post I want to dig a little deeper into what’s going on with poor sleep, as well as some of the unique features of sleep in people experiencing persistent pain.
Having reviewed the five main areas that are fundamental (and can/should be assessed by anyone working with people who experience persistent pain), the next area I want to look at with people is mood. There are two primary psychopathological contributors to poor sleep: the first we’ve dealt with last week (Question 4 – what’s going through your mind…) which is by far and away the most common initiator and maintainer of insomnia, and it doesn’t even need to be a diagnosable anxiety disorder! The second, you’ll probably have guessed, is depression.
Depression is common in people with both rotten sleep and ongoing pain (Boakye, Olechowski, Rashiq, Verrier, Kerr, Witmans et al, 2016), and there are some suggestions that pain and depression may be related and similar neurobiological processes may be involved for both (increased limbic activity being one of them). In depression, there is increased activity in the HPA Axis, reduced BDNF (brain-derived neurotrophic factor), and reduced 5HT with increased pro-inflammatory cytokines . In persistent pain, there may be activity in the HPA Axis, there is certainly reduced BDNF except in the spinal cord, and reduced 5HT, along with increased pro-inflammatory cytokines. And in sleep disturbances there is also increased activity in the HPA Axis, redced BDNF, reduced 5HT and guess what… increased pro-inflammatory cytokines. And all three interact with one another so that if you happen to be depressed, you’re more likely to experience pain that goes on, and your sleep will also reduce your mood and increase your pain. And the reverse. All very messy indeed!.
What this means is that assessing for low mood and the impact on sleep is important – if someone’s describing waking well before they usually do, in the wee small hours (anywhere from 3 – 5am if they usually wake at 7.00am) I’m ready to screen for low mood. To be honest I always assess for that anyway! Depression is also associated with low motivation and loss of “get up and go” so this is likely to interact with poor sleep, creating a very tired person.
There are three other very important aspects of sleep I like to assess for: sleep apnoea, where someone stops breathing for seconds to minutes at a time, often snorting awake, and this may be associated with snoring and daytime sleepiness. Often the person won’t be aware of their sleep apnoea, so it can be helpful for a bed-partner to let you know whether this is a feature of your patient’s sleep.
The next are a group of movement disorders of sleep, many of which are associated with the third area I assess, which are medications.
Movement disorders of sleep include restless leg syndrome – that feeling of absolutely having to move the legs, usually at night, and relieved by getting up to walk around, but in doing so, making it difficult to sleep. Another is periodic limb movement disorder of sleep, which can be every 5 – 30 seconds of leg twitching all night long, and in some cases, whole body twitching though this is less frequent and less rhythmic. This latter problem may not be noticed by the person – but their bed-mate will know about it! – and this problem may be associated with both sleep apnoea and restless leg, AND some doses of antidepressants. Another common contributor to these problems is low iron levels – worth checking both iron and medications!
Finally with medications, I like to understand not only what the person is taking, but also when they’re taking them. Several points are important here: some medications are usually sedating such as tricyclic antidepressants but in some people nortriptyline can paradoxically increase alertness! If that’s the case, timing the dose is really important and should be discussed with either the prescribing doctor, or a clinical pharmacist. Opioids depress respiration (ie slow breathing down) so can be problematic if the person has sleep apnoea AND is taking opioids, the drive to inhale may be less, causing more frequent and deeper periods without breathing normally. For restless legs and periodic limb movement disorder, some antidepressants (venlafaxine is one of them) in high doses can cause the twitching and once the dose is reduced, this fades away, at least a bit. There is a very small amount of research suggesting that NSAIDs can influence sleep quality in some people also.
The effects of poor sleep are many: anything from micro-sleeps during the day (problematic while driving or operating machinery!), to more irritability, sluggish responses, less concentration and more difficulty solving problems. Pain is associated with more frequent micro-wakenings during the night (Bjurstrom & Irwin, 2016) but findings with respect to whether deep sleep, REM sleep or light sleep were consistently more affected weren’t clear.
Having completed my assessment, more or less, I can also use a few pen and paper measures: Wolff’s Morning Questions (Wolff, 1974), Kryger’s Subjective Measurements (1991), Pittsburgh Sleep Quality Index (Bysse, Reynolds, Monk et al, 1989) and the Sleep Disturbance Questionnaire (Domino, Blair,& Bridges, 1984) are all useful. Speaking to the partner is an excellent idea because I don’t know about you but I never snore but my partner swears I do! Who do you believe?!
People experiencing insomnia are not very reliable when describing their own sleep habits – we’re terrible at noticing when we’re actually asleep or awake in those early stages of sleep, so we typically think we’ve slept less than we actually have. We also do a whole lot of things to avoid not sleeping – and these can actually prolong and extend our sleeplessness!
We’ll discuss what to do about the factors you may have identified in your sleep assessment in next week’s instalment, but you can rest assured it’s not crucial for you to do anything yourself about some things. For example, if someone has sleep apnoea, referring for a sleep study is important, but not something YOU need to do! But please make sure a referral is suggested to someone who can make it happen. Similarly with medications and sleep movement disorders, it’s not something you should tackle on your own – please discuss managing these with a specialist sleep consultant, psychiatrist, or the person’s own GP. Mood problems – treat as you would any time you find someone with a mood problem.
Next week – off to the Land of Nod: A roadmap?!
Boakye, P. A., Olechowski, C., Rashiq, S., Verrier, M. J., Kerr, B., Witmans, M., . . . Dick, B. D. (2016). A critical review of neurobiological factors involved in the interactions between chronic pain, depression, and sleep disruption. The Clinical Journal of Pain, 32(4), 327-336.
Buysse DJ, Reynolds CF 3rd, Monk TH, et al. The Pittsburgh Sleep Quality Index: a new instrument for psychiatric practice and research. Psychiatry Res 1989; 28(2):193–213.
Domino G, Blair G, Bridges A. Subjective assessment of sleep by Sleep Questionnaire. Percept Mot Skills 1984;59(1):163–70.
Kryger MH, Steljes D, Pouliot Z, et al. Subjective versus objective evaluation of hypnotic efficacy: experience with zolpidem. Sleep 1991;14(5):399–407.
Moul DE, Hall M, Pilkonis PA, et al. Self-report measures of insomnia in adults: rationales, choices, and needs. Sleep Medicine Reviews, 2004;8(3):177–98.
Wolff BB. Evaluation of hypnotics in outpatients with insomnia using a questionnaire and a self-rating technique. Clin Pharmacol Ther 1974;15(2):130–40.