Chapter 18
A Good Night’s Sleep — Part 1
I have had a number of interesting patients over the years who have experienced sleep disorders. For example, Peter (not his real name), who had slept perfectly well up to age 73 when he started to get night-time cravings. He would suddenly sit up in bed, go downstairs, fill a plate with food from the fridge, eat it all and return to bed. He had no memory of the event the next morning. This went on for over a year and happened almost weekly. He and his wife thought nothing of these night-time cravings. However, one night, the night ‘cravings’ changed radically. His wife was woken by the sight of Peter trying to eat the pages from his bedside book. When she tried to stop him, he lashed out at her. The following morning, despite no memory of the event, her black eye served as testimony to the story. Peter came to me because of a blood pressure problem and, during the consultation, his wife mentioned the sleep behaviours. We performed a sleep study, which included EEG during sleep, and from the results of this coupled with his story, we diagnosed REM sleep disorder. Remember that we are temporarily paralysed during REM sleep? This disorder is caused by a malfunction in the part of the brain that normally suppresses muscle activity while people are dreaming, so that they are not paralysed and can act out their dreams. Peter’s brain left him free to move during REM phase sleep, allowing him to go into the kitchen while fully asleep. REM sleep disorder is more common with age and present in 10 per cent of people over 70. It can be treated by drugs which refashion abnormal brain waves. Once treated there were no more night cravings for Peter. A very well-known disorder is ‘sleepwalking’, when a person appears awake, their eyes open, but they are actually asleep. Again, this is quite common: one in ten of us will experience sleepwalking at some stage in our lifetime, with some people sleepwalking regularly throughout their life. Fortunately, it is not associated with any significant underlying health problems, although the act itself risks accidents. Bedwetting is another sleep disorder and is common in children but can occasionally persist into adult life, and in some cases gets worse with age. Others gain control after childhood but relapse later in life. As we age, the number of times we pass urine at night increases. For men, this is a particularly common issue – the prostate gland often enlarges with age and presses against the bladder, irritating it and resulting in a more frequent need to pass urine. It can be managed ‘conservatively’ by ceasing intake of fluids after 4pm. There are also effective medications to control the bladder irritation. ‘Night terrors’ occur in 10 per cent of children and are most often seen between the ages of 3 and 7.
Chapter 5: A Good Night’s Sleep
Most of us grow out of them but they persist in 2 per cent. I well remember a very sad and spectacular case attributed to night terrors some years ago in the UK. A retired miner, a ‘decent and devoted’ husband, strangled his wife of over 40 years during a night terror. He had suffered with persistent night terrors since childhood. He was in the throes of a nightmare about a ‘boy racer’ who had broken into their camper van where they were sleeping and he dreamed that he was fighting him off. While still asleep, during the ‘fight’, he strangled his wife. He awoke and rang 999, weeping that he had killed his wife. The miner was acquitted because of his known long history of night terrors and his clear devastation at what had happened. The Crown Prosecution Service accepted he had not been in control of his actions and that he was not a danger to anyone else.
This was of course an exceptionally rare and tragic case. In the majority of cases of night terrors, people are jolted from slumber, terrified, confused and unable to communicate. They may thrash about or get out of bed during episodes. Night terrors occur during deep sleep, don’t require specific treatments and generally are not indicative of any worrying underlying problem.
Chapter 5: A Good Night’s Sleep
‘Sleep paralysis’ is a frequent adult sleep disorder where we experience a sensation of being unable to move the body or limbs when either falling asleep or waking up. Almost two thirds of us experience sleep paralysis at some time. Unless it is frequent and troublesome it does not require treatment and will not harm. Some of my patients who experience this believe they have had a mini stroke or are at risk of a stroke – this is very understandable given the symptoms but is not so.
I have personally experienced sleep hallucinations and they are not pleasant. In one of my posts as a young junior doctor, I was on a ‘one in two’ rota, which meant working every day 8am to 6pm including 24-hour call on alternate days. The hospital was particularly busy and I was in a perpetual state of fatigue. When sleeping, I would wake up convinced that I heard my pager going off and ring the switchboard to find that no one had bleeped me – this was an auditory hallucination and I had heard a non-existent emergency bleep. Once I moved to a more humane rota and got more sleep, the hallucinations disappeared. I am not alone in my experience of sleep hallucinations: one in four of us experience hallucinations associated with stress or fatigue and they occur at all ages.
Chapter 5: A Good Night’s Sleep
Sometimes, if hallucinations are not caused by stress or fatigue but are repetitive and frightening, with a person believing that they see, hear, touch or sense something that isn’t there, then a form of epilepsy known as narcolepsy, may be the cause. This should be investigated because it can be treated.
Although it is common for people in many Western societies to sleep in a single consolidated block of about eight hours during the night, this is by no means the only sleep pattern. In fact, following this schedule and foregoing an afternoon nap would seem highly abnormal to many people around the world. In cultures with roots in hot regions, afternoon napping is commonplace and built into daily routines.
Afternoon naptime typically coincides with a brief lag in the body’s internal alerting signal. This signal, which increases throughout the day to offset the body’s drive to sleep, wanes slightly in mid-afternoon, giving sleep an advantage and edge over the wakefulness drive. Napping typically happens during the warmest period of the day and generally follows a large midday meal, which explains why afternoon sleepiness is so often associated with warm afternoon sun and heavy lunches. This is the worst time of day to have to deliver a lecture, particularly to an older audience, for whom napping after the midday meal is even more likely.
Chapter 5: A Good Night’s Sleep
For some people, 10-minute ‘power naps’ are effective. Others find 20 minutes sufficient. Ninety-minute naps, provided that the NREM-REM cycle is complete, are also good to re-vitalise or re-boot. However, it depends on one’s individual sleep behaviour and, with time, we learn what period of napping best suits us. If a person has insomnia, then afternoon napping may confuse the body clock and make the insomnia worse. If you nap, try to do so before 3pm. As people get older, they have more fragmented sleep and this is not uncommonly associated with napping by day. For some, this is necessary to preserve function and regenerate energy. For others, daytime napping exacerbates nocturnal sleep problems. It’s best to work out one’s own napping preference and stick with that, albeit in the knowledge that needs and patterns may change with age.
Chapter 5: A Good Night’s Sleep
We can use sleep to enhance learning. Periods of sleep following learning consistently enhance our ability to retain the content of the material. And of course, the converse is true, which is not surprising considering the role of sleep in memory consolidation: insufficient sleep reduces cognitive ability, including concentration, memory and learning. When it comes to sleep and anxiety disorders, William Shakespeare’s Macbeth had it right when he referred to sleep as the ‘balm of hurt minds’. Research from the University of California, Berkeley has shown that while a full night of slumber stabilises emotions, a sleepless night triggers anxiety levels to rise by as much as 30 per cent. Some 40 million American adults have anxiety disorders and this figure continues to rise. The type of sleep most apt to calm and reset an anxious brain is deep NREM sleep. Sufficient deep sleep decreases anxiety overnight by reorganising connections in the brain, restoring activity in areas that regulate emotions and lowering heart rate and blood pressure. Thus, sleep is a natural, non-pharmaceutical remedy for anxiety. The amount and quality of sleep from one night to the next predicts how anxious we feel the next day. Even subtle nightly changes in sleep affect anxiety levels. So what can stop us from getting enough NREM deep sleep?