Vivid, violent dreams and REM sleep behaviour disorder

I remember well a patient in his late 70s, let’s call him Bill, who came to see me a few years ago reporting increasingly vivid dreams. This had come on over the previous few months. His wife said he had started ‘acting out’ these dreams in his sleep. He would wake her with his kicking and shouting, and with flailing limbs he would sometimes fall out of bed. It was awful for both Bill and his wife, but I was at a loss as to what to do about it. I wanted to avoid a potentially addictive benzo or z drug, so I tried some low dose amitriptyline. This just made it worse…A few months later cognitive and motor problems started to emerge in Bill, and the diagnosis of Parkinson’s Disease then became apparent. 

One of the most interesting papers I’ve read this year was on REM Sleep Behaviour Disorder, BJGP 2023. REM (rapid eye movement) sleep behaviour disorder, or RBD, is clearly what Bill had and now many other past consultations with patients reporting similar symptoms spring to mind. RBD is a fascinating condition, but awareness amongst clinicians is low and I certainly wish I’d been aware of it when Bill saw me!

So, what is going on here? Anyone who has read Matt Walker’s brilliant book Why We Sleep, or who tracks their own sleep with their smart watch or fitness device, will be very aware of the significance of the REM phases of sleep. During this REM sleep phase we have our most active and intense dreams, we process memories and emotions and also consolidate information and learning. 

Although our eyes move rapidly during this sleep phase we are otherwise paralysed – we have muscle atonia. All other skeletal muscle tone is lost so we cannot act out (thank goodness!) our crazy, and at times frankly scary, dreams. This is managed via the brainstem, but if this pathway is damaged atonia is lost and people can then physically act out their dreams. This is what happens with RBD. It is a relatively common condition, but it is because of the potential link between RBD and neurodegenerative disease which is why, the paper argues, we need to be more aware of the condition and to pick it up earlier in primary care.

This link with neurodegenerative disease is strong. It affects 50% of people with Parkinson’s Disease, 80% of those with dementia with Lewy Bodies and almost everyone with multi-system atrophy and it can be the first presenting symptom in all these syndromes. It can occur as an isolated phenomenon in otherwise healthy people, but 80% to 90% of these people will go on to develop a neurodegenerative disease in the next 10 years. That is one scary statistic.

The paper states that we GPs have a ‘crucial role in identifying the symptoms of RBD’.  But, when we see patients reporting sleep symptoms, RBD may be difficult to distinguish from night terrors (talking or shouting during sleep) and periodic limb movement disorder (vigorous limb movements during sleep) so specialist confirmation of the diagnosis by neurology or a sleep clinic is needed. However, with referral waits to these services incredibly long the most useful discriminating question to ask patients is ‘Have you been told or suspect yourself, that you seem to act out your dreams when asleep?’. This simple question has been validated with a 94% sensitivity and 87% specificity compared to the gold diagnostic standard of video polysomnography, so a positive response strongly suggests the diagnosis and should prompt a referral. 

So, having read this paper what will I do differently next time I see a patient like Bill? Firstly, I would definitely not prescribe amitriptyline. Antidepressants, including SSRI, SNRI and TCA can make RBD worse and if they are being taken you should consider dose reduction and withdrawal. Secondly, behavioural advice, including alcohol avoidance and sleep protection using pillow barriers, is also important. Thirdly, I would actively look for early signs of neurodegenerative disease such as Parkinson’s symptoms or cognitive impairment. Fourthly, I would refer for specialist confirmation. Finally, if medication is needed whilst waiting for the specialist I would consider a trial of melatonin and if this is ineffective consider low dose clonazepam (with the usual caution regarding drowsiness, confusion and falls risk) as both have some evidence to support them, although this evidence is not strong J Neurol 2022. 

Thanks to the BJGP and the authors of this great paper for this highly clinically relevant advice. I just wish I’d known this when I first saw Bill…