We were three middle-aged men crossing a park at night. To our left were flats, around us a gloomy expanse of grass. We muttered angrily.
Our path led us past some derelict, steel-shuttered public conveniences surrounded by bushes, where a group of teenage boys was lurking. They stepped out, barring our way.
I aimed a karate kick at the first hooded youth but he must have been armed, perhaps with a baseball bat, as I felt a blow on my cheek . . . and awoke in shock, on the floor beside the bed.
Gendered: REM sleep behaviour disorder (RBD) mostly afflicts men over the age of 50
It had been a vivid dream. There was no park, no thugs, no danger. The room was light, so it was after dawn (and I can’t do karate). But the pain was real as I realised that, dreaming, I’d kicked out and flung myself out of bed, cracking my cheekbone on the bedside table.
There was a livid bruise across my right cheek. An inch or two higher and it would have been my eye. My wife was sympathetic, though probably glad I’m not left-footed, or she would have been on the receiving end of the kick.
At work, when I recounted what had happened, colleagues were incredulous. ‘That’s the most ridiculous story I ever heard,’ said one. But it was true. It happened about a year ago. Then, last month, it happened again.
This time I was playing football against geriatrics dressed in nightclothes and slippers. I tried to flick the ball over one grandpa’s head, then felt a thunderous blow on my nose. And woke up. I’d done it again — kicked out in reality and hurled myself out of bed, hitting the bedside table. There was a cut on the side of my nose and blood was pouring from both nostrils. Wife, daughter and dog had all been rudely awoken.
Why was this happening to me?
It turns out I am one of countless Britons afflicted by parasomnias, unusual behaviour during sleep. This can include walking, talking, eating, as well as the more common kicking and arm-flailing.
Did you know? The incidence of RBD rises steeply after 60, and especially after the age of 80
My form is what is known as an REM sleep behaviour disorder.
Sleep is divided into five stages — in the first, we are almost daydreaming and easily awoken. Stage two is light sleep, and stages three and four are deep sleep, when we become hard to rouse and groggy if we do wake up.
The final stage is rapid eye movement (REM) sleep — when, for reasons not fully understood, our eyes dart around under closed lids. This is when we dream and when the body’s major muscles can’t move.
The complete cycle, from light sleep to REM, lasts around 90 minutes, then restarts from the beginning, so in a typical night, it is repeated four or five times. The time we spend in REM sleep varies, but is normally about 20 per cent of total sleep, says Dr Tim Quinnell, a consultant respiratory and sleep disorders physician at Papworth Hospital in Cambridge. This means we dream for about two hours each night.
Sleepwalking, sleep-talking and so-called ‘night terrors’ — feelings of fear that can make people lash out or scream — happen during non-REM sleep (mostly during the first third of the night).
These are sometimes known as ‘disorders of arousal’ and sufferers are thought to be half-asleep, half-awake at the time, but in the morning, they can’t recall having done or said anything unusual.
REM disorders, by contrast, involve muscles moving suddenly during vivid dreams when they ought to be immobilised (mostly in the last third of the night). Sufferers go straight from dreaming to wakefulness, and realise instantly what has happened.
Symptoms: Tell-tale signs include talking, eating, kicking and arm-flailing, plus sleep-walking
‘During the REM dreaming stage, people should be completely paralysed,’ says Dr Quinnell. ‘The eye and breathing muscles work but nothing else.’
A study at the University of Toronto in 2012 established that two brain chemicals, gamma-aminobutyric acid and glycine, normally work to keep muscles paralysed during REM sleep.
If these don’t function properly, the chemical ‘brake’ on the nervous system that should stop us acting out dreams can fail, and we start making noises or moving in keeping with our dreams. This, it seems, was what happened to me.
In fact, enacting parts of dreams turns out to be a condition in itself, REM sleep behaviour disorder, or RBD, which mostly afflicts men over the age of 50 (I am 56).
The incidence of RBD rises steeply after 60, and especially after 80. People have active, aggressive dreams that may recur.
I was having a dream that someone was attacking me and I threw a sack of potatoes at them,’ he said. ‘But what I was really doing was throwing a pillow at my wife.
‘Normally people in REM sleep have no muscle tone, so they can’t act out dreams,’ explains Dr Irshaad Ebrahim, a psychiatrist at The London Sleep Centre.
‘But with RBD there is a fault with the “switch” in your brain that turns off your muscles. It’s quite common, affecting 1.3 per cent of men.’
Exactly why this happens is a subject of research. The results of a large-scale study published in the journal Neurology in 2016 suggested that risk factors for RBD include having a history of head injury, high cholesterol, diabetes or pre-diabetes (a possible factor in my case, as my GP says I’m borderline pre-diabetic).
Diagnosing RBD involves referral to a sleep clinic for a polysomnogram, where the patient’s brainwaves, breathing and muscle movements are monitored so doctors can identify the stage of sleep where the problem is occurring.
Such referrals are becoming more common: last year it was reported that the number of sleep disorder tests carried out by the NHS had doubled in a decade.
‘The first-line treatment is a sedative drug such as a benzodiazepine, usually prescribed for insomnia and anxiety, and muscle relaxants,’ says Dr Quinnell.
‘People who have taken this medication say their dreams have “slowed down”.’
Another medication that can help is melatonin, a natural hormone which plays a role in regulating sleep, and has been shown to lower muscle tone.
RBD can be an early sign of Parkinson’s disease, which occurs as a result of a loss of nerve cells, reducing the brain’s levels of the chemical dopamine, which is crucial to movement.
‘If RBD becomes regular, up to 80 per cent go on to develop Parkinson’s,’ says Dr Quinnell.
Earlier this year, actor Alan Alda, 82, — ‘Hawkeye’ Pierce in the TV series M*A*S*H — revealed he had Parkinson’s. He saw his doctor after reading an article which said if you act out your dreams, there is a good chance it might be an early symptom of the disease.
‘I was having a dream that someone was attacking me and I threw a sack of potatoes at them,’ he said. ‘But what I was really doing was throwing a pillow at my wife.’
While RBD is linked with Parkinson’s later in life, Parkinson’s is also caused by environmental and genetic factors. As it doesn’t run in my family, I am erring on the optimistic side.
As I write, though, there is a bruise on my forehead and a graze on one elbow. Because it happened again a few nights ago, this time with another football match scenario. If it is repeated much more, I will ask to be referred to a sleep specialist.
But for now, I’ll just take my wife’s advice, to try to avoid beer before bed, and my daughter’s — move the bedside table.
And hope for the best.