Normal Sleep:
Normal sleep is divided into non?rapid eye movement (NREM) and rapid eye movement (REM) sleep. The stages of sleep are stage I (light sleep), stage II, stages III and IV (deep or delta-wave sleep), and REM sleep; NREM sleep comprises stages I-IV. Sleep is an active process that cycle at an ultradian rhythm of about 90 minutes.
Waking usually transitions into NREM sleep. REM follows NREM sleep and occurs 4-5 times during a normal 8- to 9-hour sleep period. The first REM period of the night may be less than 10 minutes in duration, while the last may exceed 60 minutes.
For the purpose of analysis, overnight sleep has been divided into 3 equal time periods: sleep in the first third of the night, which comprises the highest percentage of NREM; sleep in the middle third of the night; and sleep in the last third of the night, the majority of which is REM. Awakening after a full night's sleep is usually from REM sleep
Sleep in adults
In adults, sleep of 8-8.4 hours is considered fully restorative. In some cultures, total sleep often is divided into an overnight sleep period of 6-7 hours and a mid-afternoon nap of 1-2 hours.
Stage I is considered a transition between wake and sleep. It occurs upon falling asleep and during brief arousal periods within sleep and usually accounts for 5-10% of total sleep time. Stage II occurs throughout the sleep period and represents 40-50% of total sleep time. Stages III and IV delta sleep occur mostly in the first third of the night. They are distinguished from each other only by the percentage of delta activity and represent up to 20% of total sleep time. REM represents 20-25% of total sleep time.
Sleep in infants
Infants have an overall greater total sleep time than any other age group; their sleep time can be divided into multiple periods. In newborns, the total sleep duration in a day can be 14-16 hours.
Over the first several months of life, sleep time decreases; by age 5-6 months, sleep consolidates into an overnight period with at least 1 nap during the day. REM sleep in infants represents a larger percentage of the total sleep at the expense of stages III and IV. Until age 3-4 months, newborns transition from wake into REM sleep. Thereafter, wake begins to transition directly into NREM.
Overall, electrocortical recorded voltage remains high during sleep, as it does during periods of wakefulness. Sleep spindles begin appearing in the second month of life with a density greater than that seen in adults. After the first year, the spindles begin decreasing in density and progress toward adult patterns. K-complexes begin by the sixth month of life.
Sleep in elderly persons
In elderly persons, the time spent in stages III and IV sleep decreases by 10?15% and the time in stage II increases by 5% compared to young adults, representing an overall decrease in total sleep duration. Latency to fall asleep and the number and duration of overnight arousal periods increase. Thus to have a fully restorative sleep, the total time in bed must increase. If the elderly person does not increase the total time in bed, complaints of insomnia and chronic sleepiness may occur. Sleep fragmentation results from the increase in overnight arousals and may be exacerbated by the increasing number of geriatric medical conditions, including sleep apnea, musculoskeletal disorders, and cardiopulmonary disease.
Monday, January 18, 2010
Sleep Disorders in Pregnancy and the Postpartum Period
Sleep Disorders in Pregnancy and the Postpartum Period
Pregnancy is associated with a host of physical and emotional changes. Physical changes include morning sickness, body aches including back pain, heartburn and of course foetal movement. Emotional changes include a huge range including anxiety, fear and depression. Emotions can swing wildly. According to a National Sleep Foundation poll as well as other research, 78% of women experience more disruption of sleep than they normally experience. These changes vary with the stage of pregnancy:
In the first trimester there are high levels of progesterone. This may be associated with increased sleepiness. Some of the physical changes may also disrupt night time sleep, leading to further increases in daytime sleepiness.
The second trimester usually has less severe disruption of sleep than earlier or later stages, but still not normal quality sleep.
The third trimester is associated with the most significant changes in sleep. The physical changes of pregnancy are their greatest and include general discomfort, increased nocturnal urination, heartburn, back pain and nasal congestion. Studies have suggested that virtually all women have some disruption of their sleep in the third trimester.
In addition to the disruption of sleep that is a consequence of the physical and hormonal changes, certain specific sleep problems may also occur in pregnancy.
Because of the increased weight and the swelling of tissues that occurs in pregnancy, many women have the onset of snoring for the first time in pregnancy. If the airway obstruction is significant enough and in particular if there is a predisposition due to genetic factors, obstructive sleep apnoea may also occur. This condition is not only characterized by loud snoring but by obstruction of airflow which in turn leads to significant interruptions of sleep and drops in oxygen level. The interrupted sleep can lead to marked daytime sleepiness. If daytime sleepiness does occur and is more severe than might be reasonably expected from hormonal changes alone, the diagnosis of sleep apnoea should be considered.
In the third trimester as many as 15% of woman may also experience a sensation of discomfort, often described as a "creepy crawly" sensation in the legs which leads to a need to move, kick or even get out of bed and walk. This condition also occurs commonly in non-pregnant men and women but there seems to be an increase due to pregnancy. The consequence can range from being slightly annoying to severely disruptive of sleep.
Pregnancy is associated with a host of physical and emotional changes. Physical changes include morning sickness, body aches including back pain, heartburn and of course foetal movement. Emotional changes include a huge range including anxiety, fear and depression. Emotions can swing wildly. According to a National Sleep Foundation poll as well as other research, 78% of women experience more disruption of sleep than they normally experience. These changes vary with the stage of pregnancy:
In the first trimester there are high levels of progesterone. This may be associated with increased sleepiness. Some of the physical changes may also disrupt night time sleep, leading to further increases in daytime sleepiness.
The second trimester usually has less severe disruption of sleep than earlier or later stages, but still not normal quality sleep.
The third trimester is associated with the most significant changes in sleep. The physical changes of pregnancy are their greatest and include general discomfort, increased nocturnal urination, heartburn, back pain and nasal congestion. Studies have suggested that virtually all women have some disruption of their sleep in the third trimester.
In addition to the disruption of sleep that is a consequence of the physical and hormonal changes, certain specific sleep problems may also occur in pregnancy.
Because of the increased weight and the swelling of tissues that occurs in pregnancy, many women have the onset of snoring for the first time in pregnancy. If the airway obstruction is significant enough and in particular if there is a predisposition due to genetic factors, obstructive sleep apnoea may also occur. This condition is not only characterized by loud snoring but by obstruction of airflow which in turn leads to significant interruptions of sleep and drops in oxygen level. The interrupted sleep can lead to marked daytime sleepiness. If daytime sleepiness does occur and is more severe than might be reasonably expected from hormonal changes alone, the diagnosis of sleep apnoea should be considered.
In the third trimester as many as 15% of woman may also experience a sensation of discomfort, often described as a "creepy crawly" sensation in the legs which leads to a need to move, kick or even get out of bed and walk. This condition also occurs commonly in non-pregnant men and women but there seems to be an increase due to pregnancy. The consequence can range from being slightly annoying to severely disruptive of sleep.
Menstrual Associated Sleep Disorder
Menstrual Associated Sleep Disorder
In recent years the problems with sleep that women may experience have been better appreciated. Women are among the most chronically sleep deprived members of society, with women from age 30-60 averaging just under 7 hours of sleep per night during the week. This is contributed to by a combination of factors, including the multiple roles many women have as wage earner, homemaker and mother. In addition of course, physiological differences due to changing hormone levels add unique issues for women with what we now recognize as an important effect on sleep quality.
Studies have shown that hormonal changes in the menstrual cycle can and do interfere with sleep for an average 2-3 days per monthly cycle. The interference with sleep appears due to a bloated feeling but clearly contributed to by other factors. The most marked disturbance occurs during the first few days of menstruation. An second time of disrupted sleep occurs as progesterone levels fall towards the end of the menstrual cycle. There may be difficulty falling asleep in this time period. The premenstrual period, the last few days before menstruation commences, is also associated with poorer sleep with insomnia common but sometimes hypersomnia or increased daytime sleepiness may also occur.
In recent years the problems with sleep that women may experience have been better appreciated. Women are among the most chronically sleep deprived members of society, with women from age 30-60 averaging just under 7 hours of sleep per night during the week. This is contributed to by a combination of factors, including the multiple roles many women have as wage earner, homemaker and mother. In addition of course, physiological differences due to changing hormone levels add unique issues for women with what we now recognize as an important effect on sleep quality.
Studies have shown that hormonal changes in the menstrual cycle can and do interfere with sleep for an average 2-3 days per monthly cycle. The interference with sleep appears due to a bloated feeling but clearly contributed to by other factors. The most marked disturbance occurs during the first few days of menstruation. An second time of disrupted sleep occurs as progesterone levels fall towards the end of the menstrual cycle. There may be difficulty falling asleep in this time period. The premenstrual period, the last few days before menstruation commences, is also associated with poorer sleep with insomnia common but sometimes hypersomnia or increased daytime sleepiness may also occur.
Stress and Occupational Related Sleep Disorders
Stress and Occupational Related Sleep Disorders
A common precursor and symptom of stress related illness is the disruption of the Sleep-Wake cycle. Psychological Stress for example due to deadlines, examinations or job crisis leads to activation of the sympathetic nervous system and an increased state of arousal. As a result of this heightened arousal, there is inevitably a degree of sleep disruption and insomnia that can lead to a vicious cycle of chronic insomnia. Timely and adequate treatment of the stressors and the associated sleep disturbances is highly effective in preventing the slide into a chronic state of sleep disruption. A combine approach using medication and Cognitive Therapy is proven to reduce the rate of chronic suffering in patients with stress induced sleep disruption.
A common precursor and symptom of stress related illness is the disruption of the Sleep-Wake cycle. Psychological Stress for example due to deadlines, examinations or job crisis leads to activation of the sympathetic nervous system and an increased state of arousal. As a result of this heightened arousal, there is inevitably a degree of sleep disruption and insomnia that can lead to a vicious cycle of chronic insomnia. Timely and adequate treatment of the stressors and the associated sleep disturbances is highly effective in preventing the slide into a chronic state of sleep disruption. A combine approach using medication and Cognitive Therapy is proven to reduce the rate of chronic suffering in patients with stress induced sleep disruption.
Medical and Psychiatric Sleep Disorders
Medical and Psychiatric Sleep Disorders
A significant body of knowledge is accumulating on the role of sleep and its disruption in the causes and prognosis of a variety of Medical and Psychiatric Disorders. It is now well established that poor sleep can contribute to dysfunction of the immune system and that in some psychiatric disorders where sleep disruption is prominent, adequate treatment of the sleep disorder may improve prognosis.
Anxiety Disorders
Individuals with chronic Anxiety are recognised by friends, family and colleagues as being 'nervous', 'tense', 'uptight' and 'always been a worrier'. Between 50% and 70% of people with Generalised anxiety Disorder report trouble sleeping and often report difficulty falling asleep because they cannot stop thinking about things at bedtime. There is ample scientific evidence from Polysomnography (PSG) testing to indicate that Anxiety Disorders result in problems of falling asleep and problems staying asleep. There is also evidence that adequate treatment of the sleep problems in these patients results in improvement of the anxiety symptoms and general functioning.
The American Psychiatric Association's Diagnostic and statistical Manual of Mental Disorders (DSM IV) lists the following core criteria for the diagnosis of Generalised Anxiety Disorder:
1. Excessive Anxiety and worry on most days for at least the past 6 months;
3 The person finds it difficult to control the worry;
3 The worry is associated with at least 3 of the following symptoms
Restlessness or feeling on edge;
Being easily fatigued;
Difficulty concentrating or mind going blank;
Irritability;
Muscle Tension;
Sleep Disturbances including difficulty falling asleep or staying asleep or restless unsatisfying sleep.
For more information on these problems please contact us.
Panic Disorder
The characteristic feature of panic disorder is the recurrent, unexpected occurrence of Panic Attacks that can occur in almost any environment or time of day. These are episodes when a person experiences a high degree of anxiety which is associated with symptoms such as heart palpitations, difficulty breathing, a sense of choking, chest pain, dizziness, feelings of unreality and gastrointestinal disturbances. Patients with Panic disorder frequently report being woken from sleep by a panic attack feeling a sensation of choking and rushing to the nearest window to get some air. These Sleep Panic Attacks occur in up to 70% of people with Panic Disorder.
People with Panic Disorder experience these panic attacks on a frequent basis and as result may become afraid of going to places or situations that they associate with previous panic attacks. At its worst, these people may become totally housebound and unable to work or live according their previous norms. Panic Disorder is three times more common in Women as opposed to men and the average age at which it begins is 22 years.
Sleep complaints by patients with panic disorder include Insomnia, restless, broken sleep, and the more disabling Sleep Panic Attacks or Nocturnal Panic.
The combination of Medical Treatment with Cognitive therapy is highly effective in returning the patient to a normal life.
For more information on these problems please contact us.
Depression
Depression or depressive disorders refer to a constellation of symptoms in which mood related symptoms are the predominant feature.
The core features of Depression are summarised below:
1. Depressed Mood most of the day, nearly everyday, for at least two weeks;
2. Decreased interest or pleasure in almost all daily activities;
3. Insomnia or excessive sleepiness;
4. Significant loss of weight and appetite;
5. Psychomotor Agitation or Retardation;
6. Fatigue and Loss of energy;
7. Feelings of worthlessness or excessive or inappropriate guilt;
8. Decreased ability to concentrate;
9. Preoccupation with Morbid thoughts such as death and dying
More than 80% of patients with depression complain of Insomnia with remainder complaining of excessive sleepiness.
Many patients with Depression report an improvement in their Depressive symptoms after their sleep pattern has returned to normal.
The Sleep Problems in patients with Depression is the most studied of all the psychiatric disorders.
The Sleep Disturbances in Depression are summarised below
1 Problems with the Continuity of Sleep - patients with depression characteristically have a prolonged sleep onset and increased wakefulness during sleep. Early morning waking is also considered a characteristic symptom;
2
Slow-Wave Sleep Deficits - Patients with depression have a decreased amount of Slow-Wave sleep (or deep sleep) especially during the first half of the night;
3 Rapid Eye Movement (REM) sleep abnormalities - The time from falling asleep to the onset of REM sleep is reduced in patients with depression - this decrease in REM onset latency is one of the most robust findings in depression. Other abnormalities of REM sleep include a longer duration of the first REM period, an increased number of rapid eye movements (REM Density) and an overall increase in the percentage of REM sleep
For more information on these problems please contact us.
Dementia
The term Dementia refers to a group of illnesses that have as their essential feature loss of memory associated with degeneration of the brain. The most frequent type of Dementia is Alzheimer's Disease. Other causes of Dementia are Parkinson's Disease, Huntington's Disease, Fatal Familial Insomnia and vascular or Multi-Infarct Dementia.
The following Sleep Disorders occur frequently in patients with Dementia:
1. Sleep Apnoea
2. Sundowning - a state similar to delirium that occurs in the early evening
3. Sleep Disruption at night
4. REM Sleep Dyscontrol
5. Forced Awakenings from Sleep
6. Disturbances of the Circadian/Biological Clock
A significant body of knowledge is accumulating on the role of sleep and its disruption in the causes and prognosis of a variety of Medical and Psychiatric Disorders. It is now well established that poor sleep can contribute to dysfunction of the immune system and that in some psychiatric disorders where sleep disruption is prominent, adequate treatment of the sleep disorder may improve prognosis.
Anxiety Disorders
Individuals with chronic Anxiety are recognised by friends, family and colleagues as being 'nervous', 'tense', 'uptight' and 'always been a worrier'. Between 50% and 70% of people with Generalised anxiety Disorder report trouble sleeping and often report difficulty falling asleep because they cannot stop thinking about things at bedtime. There is ample scientific evidence from Polysomnography (PSG) testing to indicate that Anxiety Disorders result in problems of falling asleep and problems staying asleep. There is also evidence that adequate treatment of the sleep problems in these patients results in improvement of the anxiety symptoms and general functioning.
The American Psychiatric Association's Diagnostic and statistical Manual of Mental Disorders (DSM IV) lists the following core criteria for the diagnosis of Generalised Anxiety Disorder:
1. Excessive Anxiety and worry on most days for at least the past 6 months;
3 The person finds it difficult to control the worry;
3 The worry is associated with at least 3 of the following symptoms
Restlessness or feeling on edge;
Being easily fatigued;
Difficulty concentrating or mind going blank;
Irritability;
Muscle Tension;
Sleep Disturbances including difficulty falling asleep or staying asleep or restless unsatisfying sleep.
For more information on these problems please contact us.
Panic Disorder
The characteristic feature of panic disorder is the recurrent, unexpected occurrence of Panic Attacks that can occur in almost any environment or time of day. These are episodes when a person experiences a high degree of anxiety which is associated with symptoms such as heart palpitations, difficulty breathing, a sense of choking, chest pain, dizziness, feelings of unreality and gastrointestinal disturbances. Patients with Panic disorder frequently report being woken from sleep by a panic attack feeling a sensation of choking and rushing to the nearest window to get some air. These Sleep Panic Attacks occur in up to 70% of people with Panic Disorder.
People with Panic Disorder experience these panic attacks on a frequent basis and as result may become afraid of going to places or situations that they associate with previous panic attacks. At its worst, these people may become totally housebound and unable to work or live according their previous norms. Panic Disorder is three times more common in Women as opposed to men and the average age at which it begins is 22 years.
Sleep complaints by patients with panic disorder include Insomnia, restless, broken sleep, and the more disabling Sleep Panic Attacks or Nocturnal Panic.
The combination of Medical Treatment with Cognitive therapy is highly effective in returning the patient to a normal life.
For more information on these problems please contact us.
Depression
Depression or depressive disorders refer to a constellation of symptoms in which mood related symptoms are the predominant feature.
The core features of Depression are summarised below:
1. Depressed Mood most of the day, nearly everyday, for at least two weeks;
2. Decreased interest or pleasure in almost all daily activities;
3. Insomnia or excessive sleepiness;
4. Significant loss of weight and appetite;
5. Psychomotor Agitation or Retardation;
6. Fatigue and Loss of energy;
7. Feelings of worthlessness or excessive or inappropriate guilt;
8. Decreased ability to concentrate;
9. Preoccupation with Morbid thoughts such as death and dying
More than 80% of patients with depression complain of Insomnia with remainder complaining of excessive sleepiness.
Many patients with Depression report an improvement in their Depressive symptoms after their sleep pattern has returned to normal.
The Sleep Problems in patients with Depression is the most studied of all the psychiatric disorders.
The Sleep Disturbances in Depression are summarised below
1 Problems with the Continuity of Sleep - patients with depression characteristically have a prolonged sleep onset and increased wakefulness during sleep. Early morning waking is also considered a characteristic symptom;
2
Slow-Wave Sleep Deficits - Patients with depression have a decreased amount of Slow-Wave sleep (or deep sleep) especially during the first half of the night;
3 Rapid Eye Movement (REM) sleep abnormalities - The time from falling asleep to the onset of REM sleep is reduced in patients with depression - this decrease in REM onset latency is one of the most robust findings in depression. Other abnormalities of REM sleep include a longer duration of the first REM period, an increased number of rapid eye movements (REM Density) and an overall increase in the percentage of REM sleep
For more information on these problems please contact us.
Dementia
The term Dementia refers to a group of illnesses that have as their essential feature loss of memory associated with degeneration of the brain. The most frequent type of Dementia is Alzheimer's Disease. Other causes of Dementia are Parkinson's Disease, Huntington's Disease, Fatal Familial Insomnia and vascular or Multi-Infarct Dementia.
The following Sleep Disorders occur frequently in patients with Dementia:
1. Sleep Apnoea
2. Sundowning - a state similar to delirium that occurs in the early evening
3. Sleep Disruption at night
4. REM Sleep Dyscontrol
5. Forced Awakenings from Sleep
6. Disturbances of the Circadian/Biological Clock
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