His mother is understandably concerned, but Alex, like Jackie, is pretty relaxed about it all. It has been part of his life for as long as he can remember. At boarding school, his sleepwalking was the subject of initial alarm. ‘When I first started at school, we were in a dorm of sixteen,’ says Alex, ‘and when everyone first knew about it, I fell asleep with my earphones round my neck and I woke and I thought there was a rat sitting on my chest, so I screamed “Rat!”, and that woke everyone up in the dorm room. And obviously there wasn’t a rat, but people were terrified.’
Terror was soon replaced by amusement, though. Speaking of his roommate, Alex explains: ‘One time he woke up and apparently I was on my desk shouting that there was a tiny gazelle running round trying to eat my feet. At first he was really terrified, and then as it happened more and more he found the funny side of it.’
Over the years, the spectrum of Alex’s non-REM parasomnias has broadened. Some of his events are simply amusing. On one occasion, having been on a night out, he got to his friend’s house at about 2 a.m. before going to sleep. The next thing he knew, he was waking up in the neighbour’s front garden at 5 a.m., in just his underwear. He was being shouted at by a man through an open window; apparently he had tried to get into the neighbour’s house, waking up his wife and baby in the process. On another occasion, a different friend was woken by Alex at 3 a.m., crouched at the end of the bed, ordering a pizza. He was using his friend’s shoe as a telephone. His current flatmates also tell countless anecdotes about Alex’s exploits, which he listens to with a resigned grin. I suspect over the years he has got used to this. ‘There was one time we’d been at the pub one night, a group of us,’ says Gareth, a housemate of Alex. They had all retired to their respective bedrooms.
Then, an hour later, he just comes into my room, nonchalant, [and] gets into bed with me. And I was awake at the time, but was a bit tired and I was nudging him saying: ‘What’s going on?’, and he was having absolutely none of it, and then in the morning he wakes up and says: ‘Why am I in your bed?’, as if I’m supposed to have the answers. And the same thing happened another time. I woke up and there he was again. He was pretty sheepish and I said: ‘You’re naked under there, aren’t you?’, and he was like, ‘Yeah, yes I am.’ The next morning someone said: ‘You know, I actually went into your room for a chat and I saw someone else in there. So who’s the lucky girl?’, and I had to admit, ‘Well, actually, that was Alex.’
Another housemate reports further events.
I used to live in the room next to his, and [one night] I heard a great crashing and quite a lot of swear words. I ran in to make sure that everything was okay and he was lying on the floor – I don’t know why he still continues to sleep fully nude considering all these things that he does. He said that he thought that a train was coming at him, so he leapt up and bounced off his wall. He swore quite a bit because he thought the train was still coming at him. So he then leapt onto his desk which then crashed on top of him. So I ran into the room to make sure he was okay just to find him very, very confused. I now live in the room underneath him and I was woken up three times in the night because he believed that the circus was in town, but the manager of the circus needed to use our bathroom, so he kept going and opening the door and muttering nonsense to someone who wasn’t there and so I had to walk him back up to bed.
In contrast, some of Alex’s parasomnias have a darker side. The more comical episodes are often not remembered by Alex, and he is frequently only aware of them when his friends regale him with tales of his night-time antics in the pub. But it is those events associated with strong emotion, typically fear or anger, that Alex is more conscious of. ‘I remember much more the emotionally draining ones,’ he explains. ‘When I sleepwalk, I have no memory of those whatsoever, so that’s not when I feel panicked.’ The more terrifying events that disturb Alex’s sleep are often scenarios charged with the need to fight or run away – the so-called ‘fright-fight-flight’ response, mediated by adrenaline and the autonomic nervous system, linked to physical functions related to these responses to danger. Alex recalls that many episodes of his non-REM parasomnias are related to a snake in the bed, a nuclear bomb about to go off next door, or impending peril. ‘I fractured my finger once trying to save a girl from drowning. I leapt and tried to, like, catch her, but it was just the cupboard I lunged at and so I caught my finger quite badly. And I’ve tried to climb out of a window a few times, but then at the last second I’ve sort of stopped myself from doing it.’
His ex-girlfriend Katie confirms this. She says that many of his events relate to natural disasters, and she has frequently been woken by him trying to drag her out of bed. Katie says:
I wake up and Alex is panicked and he has gotten up . . .
He is running round the room trying to get out. And then obviously he’s aware that I’m there and he tries to pick me up and sort of drag me out of bed as well. And at that point I’m already sort of awake, calling: “Alex, Alex!” It takes me quite a long time to get through to him and then eventually he wakes up and that’s it.
His housemate Gareth reports another occasion when Alex injured himself. ‘Two of his friends were sleeping on mattresses on the floor and he believed that the rotary blades of a helicopter were breaking off while they were spinning and flying at him, so he was dodging and diving to move from them,’ Gareth tells me. ‘And as the final one came at him, he completely swan-dived onto what he thought was grass but was actually our two friends on their mattress. They were woken up at 4 a.m. by a quite large Alex landing on them saying, “Oh, God, did you see that helicopter?’ ”
* * *
Many of Alex’s events are similar to Jackie’s. His sleepwalking, like Jackie’s sleep-motorbiking, involves complex activities and interaction with his environment – picking up a shoe to call for a takeaway pizza, getting into bed with his flatmates, and on one occasion finding tumblers, filling them with water and placing them next to the bed of each of his sleeping housemates in the middle of the night – an act of unconscious kindness. These events, as with Jackie, happen without any awareness, with no memory, and perhaps importantly are fairly neutral in terms of emotional content. These types of non-REM parasomnias represent a classical view of this condition, that people with this type of problem generally have no recollection at all of these events. But it is clear that Alex is certainly aware of some of his events. It is also clear that Alex is having dreams of a sort, despite me telling you that these phenomena emanate from non-REM sleep as opposed to REM or dreaming sleep. In fact, in recent years, we have begun to understand that previous notions of REM sleep being the stage of sleep exclusively in which we dream is not correct. It seems that dreaming in non-REM sleep is not unusual at all, although the content of the dreams is different.
Individuals woken from REM sleep often describe dreams with a narrative structure, a story evolving like the plot of a book or a film. In contrast, the dreaming of non-REM sleep often contains only simple visual imagery, like animals, people or inanimate objects. When mixed in with strong emotional stimulation, these images are often scary or even terrifying – spikes crashing down from the ceiling, insects on the walls, or snakes in the bed. And it appears that this surge of adrenaline mediated by the autonomic nervous system means it is more likely for people in this sort of episode to wake up, sometimes partially but sometimes fully, and to remember their experiences, like Alex’s more fear-inducing events.
And the origin of this ‘fright-fight-flight’ response? It seems that one of the areas identified in neuroscientific studies of sleepwalkers as being particularly active, the cingulate cortex, part of the limbic system, is the neurological seat of this experience. Triggering this area, either directly using electrical stimulation or when epileptic seizures arise in this region spontaneously, results in the adrenaline surge that apparently feeds into Alex’s more distressing sleep terrors.
* * *
So it seems that sleepwalking, and conditions wit
hin the spectrum of non-REM parasomnias, represent a battle between wake and sleep in various parts of the brain. At one end of the spectrum, there is simple sleep-talking, sleepwalking or sleep-sex (see Chapter 10), when there is no awareness, no emotion, but the ability to speak in fully formed sentences or to move. Very few parts of the brain are awake, perhaps only those that allow people to see, to move or to talk. The areas of the brain responsible for rational thought and memory certainly seem to be in deep slumber. At the other end of the spectrum are sleep terrors such as Alex’s, where the emotional stimulus is so intense that it drives the person to be almost fully awake, whereby the majority of the brain is fully functioning, with the exception of a bit of rational thinking perhaps. In children, these sleep terrors are generally not remembered, which may well simply be a function of how deeply young children sleep and the level of stimulation required to fully wake a child in deep, non-REM sleep.
And what about Jackie’s sleep-motorbiking? Where does that fit in? Clearly, during these activities, she must have the ability to see, and probably to hear. She can get dressed, pop her helmet on, grab the keys, change gears, avoid a crash, and navigate home, then get undressed and back into bed. In fact, the only areas of her brain clearly not functioning properly are those involved in memory, hence her lack of awareness, and in rational thinking, since who would rationally get up in the middle of the night, go for an aimless motorbike ride and then go back to sleep? So is this kind of behaviour really sleep, with a bit of wake, or is Jackie essentially awake, with a small area of her brain asleep?
* * *
Having handed her motorbike keys to her landlady, and eventually selling her motorbike, Jackie thought she had dealt with her sleep issues quite successfully. She had subsequently always lived on her own, and until recently has always been single, and had not had any further problems with her sleepwalking.
For the past few years, she has been living in an apartment in a block directly on the seafront in Seaford, a small peaceful town on the coast of Sussex. The pace of life suits her, and she enjoys volunteering, keeping the coastal paths clear of shrubs and in good condition. ‘Seaford is a wonderful place to live,’ she tells me. ‘The sea cliffs are right up there, and over in that direction are the Downs,’ she points out to me as we stand on the pebble beach in front of her apartment. With the waves gently lapping the shingle and the seagulls crying overhead, this quiet little town strikes me as an unlikely location for such bizarre happenings at night. She has good relations with her neighbours, and her block of flats is a friendly place. Few of her neighbours know of her sleepwalking past, except for one friend, with whom she went on a cruise. Jackie would wander the ship at night, and eventually took to asking the cabin crew to take her key card away at night and slip it back under the door at 6 a.m.
* * *
One morning, a few years ago, she came out of her apartment and bumped into a couple living in the same block. To her surprise, they asked her what she had been doing at 1.30 or 2 a.m. ‘I said, “I was asleep.” They said, “No, no, you were driving out [of the car park] as we were coming home. We were coming back late from a show quite a way away and you were driving out.’ ” Initially, a puzzled Jackie denied going anywhere, but soon it dawned on her what might have happened.
‘Okay, where did I go?’ she asked.
‘Oh, well, you turned left out of the road and you went down towards the promenade.’
‘Well, okay. Did you see me return at all?’ she pressed.
‘No, we went straight in and went to bed. We just wondered where you were going.’
‘I have no idea,’ Jackie replied.
To her alarm, Jackie realised that as she had previously been sleep-motorbiking, she was now sleep-driving. Piecing her actions together, she realised that she must have gotten up, got dressed, unlocked the front door, driven the car for some distance, before reverse parallel parking into the same spot and getting back into bed. ‘I have no idea where I went or how long I was away, but I came back and parked in exactly the same place,’ Jackie explains. ‘Nothing was out of order when I got up in the morning.’ Anxious about the possibility of harming herself or others by driving through the streets of Seaford in her sleep, Jackie made an appointment with her doctor. Having told the story of her sleep-driving episode, the only thing her general practitioner could suggest was locking her up. ‘They said, “Oh dear, we’ll have to find you a secure unit,’ ” Jackie remembers. ‘And I said, “Oh no, I’m not a criminal,” and I’m afraid I got up and walked out.’ Desperate for a solution, Jackie thought laterally. She had recently started a new relationship with a man named Ed, also in his seventies. One morning, Ed had woken to find the front door ajar, having locked the door before retiring to bed. It was apparent that Jackie’s nocturnal wanderings were not waking Ed up in the night. In fact, when I talk to Ed about Jackie’s sleep issues, he chuckles in a slightly bemused fashion. Apart from one or two events, when evidence of Jackie’s sleepwalking is obvious in the mornings, Ed is largely oblivious at night, as, ironically, he sleeps so deeply.
She hit upon the idea of rigging up the front door to her apartment with a bell. ‘A friend of mine very helpfully bought me a bell that I have on the chain lock. I hang it on there so that hopefully my partner, if I happen to go out of a night, will hear the bell jingling and will be able to stop me from going anywhere I shouldn’t be.’ In principle, this should have worked, but frustratingly Ed was such a heavy sleeper that he did not stir. A louder bell or buzzer was not an option for Jackie: ‘The noise I’d need would be loud enough for the rest of the neighbours to hear and, you know, you can’t upset them,’ she confesses. After trial and error, Jackie and Ed have finally hit upon a solution for her sleep-driving. Jackie has invested in a safe, in which she locks away her front door key and house key. Her fear of opening the safe in the night has resulted in one other important adaptation: the safe has a time-lock. Once locked for the night, it will not open again until 6 a.m. – the ultimate safeguard for her. ‘A neighbour down the hallway has spare keys for the car and for the door, because if anything happened in the night whereby we had to get out . . .’
It is difficult to know if Jackie is still getting up in the night but unable to get out of the apartment or if she is simply not getting up. Perhaps she is somehow subconsciously aware that she does not have the keys available to her. Ed’s deep sleep means that he is not really a reliable witness to this.
Interestingly, Jackie says that she thinks the reason she stopped wandering around the cruise ship a few years earlier was because she somehow knew that if she went out of the cabin she would not be able to get back in; I had assumed in error that it was because she was locked in her cabin. Additionally, she tells me of a time when she left her flat in Seaford in the middle of the night and found the main door to the block wedged open in the morning. She assumes she did this in her sleep so that she could get back in. This certainly sounds like some degree of awareness, and perhaps supports the view that her brain is largely awake. If that is the case, you might expect her to wake feeling tired, as many sleepwalkers do, but instead she feels refreshed, none the wiser for these events.
* * *
So, these bizarre behaviours arising from very deep sleep have an underlying neurobiological explanation. The human brain has the ability, at least in some people, to be awake and asleep at the same time, with different areas of the brain in different states simultaneously. In fact, this situation probably arises much more commonly than we think. In very recent years, it has become apparent that this mixed state extends into the middle of the day. ‘Local sleep’, sleep activity only affecting small areas of the brain rather than the entirety of the brain, seems to occur in full wakefulness.
When kept awake for prolonged periods, rats demonstrate neurones in the cerebral cortex that fall silent for brief periods, in the same way as they do in deep sleep. These ‘off-periods’ are associated with increased errors during certain tasks. Similarly, when
sleep-deprived, the human brain exhibits changes in activity suggesting very focal areas of sleep continuously occurring in the cortex, meaning that when we are tired, we really are ‘half-asleep’, or perhaps ‘one-tenth asleep’. These changes, like in rats, are linked to performance errors when undertaking certain tasks, and would certainly explain why we feel less capable when sleep-deprived.
* * *
But why do some adults sleepwalk and others not? The short answer is that we just do not know. What we are aware of is that adults who sleepwalk often have other people in their family who also do it. A study of sleepwalking in twins has shown that if your twin sleepwalks, you are much more likely to sleepwalk if you are an identical rather than a non-identical twin. This of course implies that something in our genes predisposes us to sleepwalking and other non-REM parasomnias. In a single four-generation family containing twenty-two sleepwalkers, researchers found a large region of chromosome 22 to be linked to this condition. The region contains twenty-eight genes, and so far, efforts have not been able to identify a specific genetic cause. Other studies have shown an association between sleepwalking and other non-REM parasomnias, and an area of the genome encoding the HLA system, a grouping of genes implicated in immune function. Why this should be related to sleepwalking, though, remains a mystery.
But genetic predisposition is not the only explanation.
A common feature of people with non-REM parasomnias is the worsening by certain environmental or lifestyle factors. Many of my patients report that sleep deprivation, alcohol, daytime stress or anxiety can increase the likelihood of events. So, we know that these events are as a result of incomplete waking from deep sleep. In theory, therefore, there are two possibilities as to why these events might arise.
The Nocturnal Brain Page 5