Double-whammy

Sleep glorious sleep! Walking, or sleeping, the talk. Over the last two years, I have tried to increase the duration and quality of my sleep. On reflection, it seems to be working for me. I feel so much better for it.

It is now clear that shift work, reduced sleep and poor quality sleep are risk factors for developing dementia. We need to maximise my chances of not developing dementia. Sleep is therefore important for one’s brain health. During sleep, your brain clears out cellular and intracellular debris and it consolidates memories. The study below, using MRI, shows that in ‘normal young adults’ those with reduced sleep have an MRI signature of poor brain health. 

Six years ago we did a survey on this blog and found that 71% of MSers, or respondents, had symptoms suggestive of sleep apnea. This is probably too high, but in other more systematic studies, approximately 50% of MSers have sleep apnoea. I suspect the reason for such a high prevalence of this comorbidity is due to MS affecting the brain stem and upper spinal cord. Sleep apnoea in MS is a problem and we should be screening all our patients for it.

In the same survey, 64% of respondents complained of insomnia, a persistent inability to fall asleep or stay asleep. Almost 50% of MSers volunteered symptoms suggestive of narcolepsy or daytime hypersomnolence and two-thirds had periodic limb movements or uncontrollable leg or arm jerks during sleep. The latter two are what I refer to as MS-related restless leg syndrome.

Not mentioned here is poor sleep due to nocturia; many MSers have to get up many times at night to pass urine. Other sleep problems more prevalent in MSers include poor sleep due to excessive alcohol consumption or overuse of daytime stimulants, the pernicious effect of anxiety and depression on sleep and pain. 

I have little doubt that poor sleep in MS contributes to worsening disability, fatigue and poor cognition. People who are sleep deprived don’t function well the next day. I suspect that the latter is worse in MSers who have reduced brain reserve and have to not only compensate for reduced reserve but sleep deprivation as well. A double-whammy! 

As poor quality sleep contributes to MS-related fatigue; unless you sort out your sleep you won’t get on top of your fatigue. 

Has your neurologist or HCP asked about your sleep? It may be worth downloading a sleep app for your smartphone as a screening tool to see how well you are sleeping at night. If it shows that you sleep duration and quality is poor your HCP may be able to refer you for a formal sleep study. In the interim, however, you need to improve your sleep hygiene and see if it makes a difference to how you are feeling. 

The following are some simple tips to improve your sleep hygiene:

Make sure you spend an appropriate amount of time asleep in bed; a minimum of 6 hours. Some people need more than this to feel refreshed. 

Limit daytime naps to 30 minutes. Please note that napping does not make up for inadequate nighttime sleep. 

Avoiding stimulants such as caffeine, modafinil and nicotine close to bedtime. 

Only drink alcohol in moderation. Alcohol is well-known to help you fall asleep faster, but too much disrupts sleep.

Exercise helps improve sleep quality. As little as 10 minutes of aerobic exercise per day can improve sleep quality. 

Don’t eat before going to bed. Heavy foods and fizzy drinks can trigger indigestion or heartburn/reflux that disrupts sleep.

Ensure you get adequate exposure to natural light; exposure to sunlight during the day, as well as darkness at night, helps to maintain a normal sleep-wake cycle. 

Establish a regular relaxing bedtime routine, which helps the body to recognise that it is bedtime. This could include taking a shower or bath or reading. However, avoid reading or watching emotionally upsetting content before attempting to sleep.

Making sure that your sleep environment is pleasant. Your mattress and pillows should be comfortable. The bedroom should be cool for optimal sleep (16-20°C). The bright light from lamps, smartphones and television screens can make it difficult to fall asleep, so turn those lights off or adjust them when possible. Use the blue filter mode on your smartphone and other devices that reduces the inhibition of melatonin from light. Consider using blackout curtains, eyeshades, earplugs, white noise machines and other devices that can make the bedroom more relaxing.

And if you have pain, nocturia, restless legs, sleep apnoea, etc. get these adequately managed via your HCP.

Please let us know what strategies work for you to improve your sleep.  An important role of this blog is to share best practice and alternative practices as well. We like it when our patients hack their own physiology to come up with solutions that work.

Don’t forget our treatment aim is to maximise your brain health and part of this philosophy is the holistic management of MS including sleep.

Yaffe et al. Sleep Duration and White Matter Quality in Middle-Aged Adults. Sleep. 2016 Sep 1;39(9):1743-7.

STUDY OBJECTIVES: Sleep duration has been associated with risk of dementia and stroke, but few studies have investigated the relationship between sleep duration and brain MRI measures, particularly in middle age.

METHODS: In a prospective cohort of 613 black and white adults (mean age = 45.4 years) enrolled in the Coronary Artery Risk Development in Young Adults (CARDIA) study, participants reported typical sleep duration, dichotomized into moderate sleep duration (> 6 to ≤ 8 h) and short sleep duration (≤ 6 h) at baseline (2005-2006). Five years later, we obtained brain MRI markers of white matter including fractional anisotropy, mean diffusivity, and white matter hyperintensities.

RESULTS: Compared to moderate sleepers, short sleepers had an elevated ratio of white matter hyperintensities to normal tissue in the parietal region (OR = 2.31, 95% CI: 1.47, 3.61) adjusted for age, race/sex, education, hypertension, stroke/TIA, depression, smoking status, and physical activity. White matter diffusivity was also higher, approximately a 0.2 standard deviation difference, in frontal, parietal, and temporal white matter regions, among those reporting shorter sleep duration in (P < 0.05 for all).

CONCLUSIONS: Short sleep duration was associated with worse markers of white matter integrity in midlife. These mid-life differences in white matter may underlie the link between poor sleep and risk of dementia and stroke.