Sleep problems are highly characteristic of people with SMS, more so than of other people with an intellectual disability (where sleep problems are also elevated).
There is now quite a lot of research into sleep difficulties in SMS and it is clear that sleep is a significant problem for nearly all people with the syndrome (75-100% depending of what measures of sleep are used), and that this sleep problem is likely to have a biological cause in most people. Sleep disturbance is evident both in people with SMS caused by a deletion and people with SMS caused by the mutation of RAI1. Despite our increasing knowledge, currently there remain many aspects of sleep in SMS which are not well understood.
Patterns of sleep over the lifespan
Infants are described by their caregivers as good sleepers, often having to be woken for feeds, yet even at this young age there is reduced overall sleep.
Significant sleep problems emerge in childhood which can impact on the child with SMS and those around them. Problems falling asleep are reported in some, but this is less problematic than frequent night-time waking (average of around half an hour) and early waking (e.g. before 5am), resulting in shortened sleep cycles. Out of sync waking can be particularly problematic in SMS as night-time behaviour can be very disturbing to other family members and can sometimes be dangerous for the child. Bed-wetting and snoring are also reported to be problematic. Daytime sleepiness is noted.
Older children, adolescents and adults
Activity appears to be elevated early in the night, suggesting difficultly initiating sleep at this age. As people get older, there appears to be reduced night-time sleep and increased but shorter naps. Despite this apparent reduction in sleep quality with age, caregivers report decreases in sleep problems with age; this is likely to be due to reduced disruptive night-time behaviours with age rather than improved sleep.
In addition to problems sleeping at night, daytime sleepiness is common – SMS naps have been described as ‘sleep attacks’, alluding to the sudden and irresistible nature of the urge for sleep. Daytime sleepiness may account for some disruptive behaviours shown by those with SMS. This suggestion is supported by a relationship between tantrums and increased melatonin (the hormone thought to be responsible for daytime sleepiness).
Impact on the family
Unsurprisingly, sleep-related difficulties, specifically behaviours shown in the morning, have been found to be related to increased stress in the family.
Possible causes of sleep disturbance
Sleep disorder in SMS has been primarily ascribed to an inverted release pattern of a hormone called melatonin, which disrupts circadian rhythm (the rhythm that tells our bodies when it is day and night in terms of sleeping patterns). This leads to elevated daytime levels of melatonin release and reduced night-time melatonin release, the opposite pattern to most people, resulting in daytime sleepiness and night-time waking. However, not all people with SMS who have sleep disturbance have this inverted melatonin release, suggesting that it is not the only cause of the sleep difficulties; therefore, it is also likely that environment and routine have a significant impact on sleep for people with SMS.
Environmental influences on sleep (night-time routines)
While there may be a biological factor affecting poor sleep in most people with SMS, is it still very important to ensure good sleep hygiene. This includes regular times for going to bed, routines (e.g. bath and a story) before bed and reducing stimulation (activity, TV, computer use) before bedtime.
There is extensive, high quality, information available for caregivers about sleep hygiene. It might be hard to repeatedly return a person with SMS to their bedroom if they seek out their caregiver, as is often suggested by guidelines, as this can go on for a very long time when the person is simply not as sleepy as other people would be in this situation. However, given suggestions that people with SMS find adult attention very rewarding, it is likely to be particularly important not to ‘reward’ waking with attention. This may be through returning the person to his/her room with no eye contact or conversation, but if this doesn’t work after sustained effort then it could be beneficial to distract a non-sleepy person with suitable activities.
If following guidelines designed for people with an intellectual disability and sleep disturbance, it is likely that caregivers will need to include some flexibility to accommodate specific features of SMS; for example, allowing daytime naps or using distractions at night to occupy those who are unable to go back to sleep.
If inverted melatonin release is the primary cause of sleep disorder in SMS, then treatment providing evening melatonin or suppressing its daytime release (e.g. beta-blockers) might be expected to be effective.
However, the evidence for the effectiveness of melatonin is mixed. Use of melatonin has certainly been reported as being effective in some people, including in combination with a second drug which blocks the effect of daytime melatonin release (a beta-blocker). Using this combination, there are reports of improvement in sleep behaviours (increased total sleep time, reduced early morning waking) and reduced hyperactivity and improved cognitive performance.
Others have found that, while sleep aides (of which melatonin was the most frequently used) are the most common pharmacological treatment used in SMS and the earliest started treatment, their use does not affect caregiver ratings of disruptive behavioural outcomes.
Importantly, melatonin is not reported to be universally effective for improving sleep, for example, it can enable people to go to sleep earlier (yet settling is not reported to be the primary sleep problem in SMS) but then they may wake earlier, thus their total sleep is the same. In some people, melatonin is described as having no effect at all.
There are different types of melatonin which can be used (including time release melatonin), and other medications have also been used with varying effectiveness. It is important that the prescription and use of medication to treat sleep difficulties is monitored closely by a clinician experienced in this area and with experience of working with people with an intellectual disability.
What might help?
Help the person know when it is ok to get up – Clocks which can be set to show when it is ok to get up in the morning with a sunshine (and moon and stars at night-time when they should stay in bed), such as ‘Gro clocks’, may help to explain this aspect of time. This will not change the person’s sleep but can reduce disruption caused by night-time and early waking.
Create a dark environment – Use black-out blinds to create total darkness in the person’s bedroom.
Allow daytime naps but consider their timing – Preventing a tired person with SMS from napping in the day at all is unlikely to improve their night-time sleep. Allowing naps may also improve daytime behaviour. Naps during the middle of the day (12-3) are better, as later naps might reduce ability to sleep during the evening/night-time.
Investigate medical issues – There are health issues in SMS which may affect sleep quality. Gastro-oesophageal reflux (where stomach acid escapes into the oesophagus causing discomfort) can affect sleep, as lying down can make it easier for the acid to escape (see the ‘Health’ section). If signs of reflux are being shown, a GP or paediatrician may be able to carry out further investigations. In older people with SMS, sleep disordered breathing (e.g. loud snoring, sleep apnoea) may be an issue due to risk factors, including weight gain, hypotonia and ear, nose and throat abnormalities, and this can affect sleep. If a person is snoring or gasping/snorting when asleep, it may be appropriate to seek medical advice.
Seek professional input – If sleep problems become an issue, you may want to approach your health visitor, GP or paediatrician for advice, or ask to be referred to a Sleep Clinic or the local Child Clinical Psychology Service or Child Mental Health Clinic. Careful use of medication, which is monitored regularly by a clinician with experience of working with people with an intellectual disability, may help some people with SMS to sleep better. However, not everyone will be helped by medication. Furthermore, the effects of medication vary between different people and can change over time in the same person.
Ensuring the person’s safety – Minimising the disruption caused by night-time and early morning waking and ensuring the safety of the person with SMS may help to reduce the problems caused by sleep disturbance. Some ideas that other caregivers have found to be helpful include:
- Create a room where the person cannot cause harm to themselves (e.g. removing large/heavy objects or using padding on hard surfaces).
- Use safety gates or secure room systems to prevent the person from injuring themselves while walking through the house.
- Provide safe activities to engage the person during periods of wakefulness. While sleep is best promoted in a dark environment, it may be a pragmatic approach for people who simply cannot go back to sleep after following all sleep hygiene guidance to allow them to read books or use their computer/tablet. In reference to the latter, electronic devices should be set to ‘low light’ or a filter setting to reduce the blue light emitted, which is most damaging to sleep.
- Attach a small alarm bell on doors to alert caregivers that their door has been opened.
- Peep holes or ‘stable’ door designs can allow caregivers to check on the person without having to enter the room.
- Use of an enclosed bed can provide security and comfort, for example safety sleepers (pictured right). These can be costly and funding can be hard to obtain, however.
A Guide to SMS Booklet
Our booklet – Smith-Magenis Syndrome: Guidelines for Parents and Teachers – provides a lot of practical and helpful advice about coping with all aspects of SMS. It covers sleep, social relationships, behaviours, feeding difficulties, toilet training, dressing, school concerns, behaviour in adulthood, siblings and sources of further help.
Get a copy of SMS Booklet