Insomnia, or sleeplessness,
is an inability to fall asleep or to stay asleep as long as desired. While
the term is sometimes used to describe a disorder
demonstrated by polysomnographic evidence of disturbed sleep,
insomnia is often practically defined as a positive response to either of two
questions: "Do you experience difficulty sleeping?" or "Do you
have difficulty falling or staying asleep?’’
Thus, insomnia is most often thought
of as both a sign and a symptom that can accompany several sleep, medical, and
psychiatric disorders characterized by a persistent difficulty falling asleep
and/or staying asleep or sleep of poor quality. Insomnia is typically followed
by functional impairment while awake. Insomnia can occur at any age, but it is
particularly common in the elderly. Insomnia can be short term (up to three
weeks) or long term (above 3-4 weeks), which can lead to memory problems, depression,
irritability and an increased risk of heart disease and automobile related
accidents.
Insomnia can be grouped into primary
and secondary, or comorbid, insomnia. Primary insomnia is a sleep
disorder not attributable to a medical, psychiatric, or
environmental cause. It is described as a complaint of prolonged sleep onset
latency, disturbance of sleep maintenance, or the experience of non-refreshing
sleep. A complete diagnosis will differentiate between:
- insomnia as secondary to another condition,
- primary insomnia co-morbid with one or more conditions,
or
- free-standing primary insomnia.
Classification
Types of insomnia
Insomnia can be classified as transient, acute, or chronic.
- Transient insomnia lasts for less than a week. It can be caused by another disorder, by changes in the sleep environment, by the timing of sleep, severe depression, or by stress. Its consequences – sleepiness and impaired psychomotor performance – are similar to those of sleep deprivation.
- Acute insomnia is the inability to consistently sleep well for a period of less than a month. Insomnia is present when there is difficulty initiating or maintaining sleep or when the sleep that is obtained is non-refreshing or of poor quality. These problems occur despite adequate opportunity and circumstances for sleep and they must result in problems with daytime function. Acute insomnia is also known as short term insomnia or stress related insomnia.
- Chronic insomnia lasts for longer than a month. It can be caused by another disorder, or it can be a primary disorder. People with high levels of stress hormones or shifts in the levels of cytokines are more likely to have chronic insomnia. Its effects can vary according to its causes. They might include muscular fatigue, hallucinations, and/or mental fatigue. Some people that live with this disorder see things as if they are happening in slow motion, wherein moving objects seem to blend together. Chronic insomnia can cause double vision.
Patterns of insomnia
Sleep-onset insomnia is difficulty falling asleep at the beginning of the
night, often a symptom of anxiety disorders.
Delayed sleep phase disorder can be
misdiagnosed as insomnia as it causes a delayed period of sleep, spilling over
into daylight hours.
Nocturnal awakenings are characterized by difficulty returning to sleep
after awakening in the middle of the night or waking too early in the morning: middle-of-the-night insomnia and terminal
insomnia. The former may be a symptom of pain disorders
or illness; the latter is often a characteristic of clinical depression.
Poor sleep quality
Poor sleep quality can occur as a result of, for example, restless legs,
sleep apnea
or major depression. Poor sleep quality is caused
by the individual not reaching stage 3 or delta sleep which has restorative
properties.
Major depression leads to alterations in the function of the hypothalamic-pituitary-adrenal axis,
causing excessive release of cortisol which can lead to poor sleep quality.
Nocturnal polyuria,
excessive nighttime urination, can be very disturbing to sleep.
Subjective insomnia
Some cases of insomnia are not really insomnia in the traditional sense.
People experiencing sleep state misperception often sleep for
normal durations, yet severely overestimate the time taken to fall asleep. They
may believe they slept for only four hours while they, in fact, slept a full eight
hours.
Symptoms and comorbidities
Symptoms of insomnia can be caused by or can be co-morbid with:
- Use of psychoactive drugs (such as stimulants), including certain medications, herbs, caffeine, nicotine, cannabis, cocaine, amphetamines, methylphenidate, aripiprazole, MDMA, modafinil, or excessive alcohol intake.
- Withdrawal from anti-depressant drugs such as opioids and benzodiazepines.
- Use of fluoroquinolone antibiotic drugs, see fluoroquinolone toxicity, associated with more severe and chronic types of insomnia
- Restless Legs Syndrome, which can cause sleep onset insomnia due to the discomforting sensations felt and the need to move the legs or other body parts to relieve these sensations.
- Periodic limb movement disorder (PLMD), which occurs during sleep and can cause arousals that the sleeper is unaware of.
- Pain An injury or condition that causes pain can preclude an individual from finding a comfortable position in which to fall asleep, and can in addition cause awakening.
- Hormone shifts such as those that precede menstruation and those during menopause
- Life events such as fear, stress, anxiety, emotional or mental tension, work problems, financial stress, birth of a child and bereavement.
- Mental disorders such as bipolar disorder, clinical depression, generalized anxiety disorder, post traumatic stress disorder, schizophrenia, obsessive compulsive disorder, dementia,or ADHD
- Disturbances of the circadian rhythm, such as shift work and jet lag, can cause an inability to sleep at some times of the day and excessive sleepiness at other times of the day. Chronic circadian rhythm disorders are characterized by similar symptoms.
- Certain neurological disorders, brain lesions, or a history of traumatic brain injury
- Medical conditions such as hyperthyroidism and rheumatoid arthritis
- Abuse of over-the counter or prescription sleep aids (sedative or depressant drugs) can produce rebound insomnia
- Poor sleep hygiene, e.g., noise or over consumption of caffeine
- Parasomnias, which include such disruptive sleep events as nightmares, sleepwalking, night terrors, violent behavior while sleeping, and REM behavior disorder, in which the physical body moves in response to events within dreams
- A rare genetic condition can cause a prion-based, permanent and eventually fatal form of insomnia called fatal familial insomnia.
- Physical exercise. Exercise-induced insomnia is common in athletes in the form of prolonged sleep onset latency.
Sleep studies using polysomnography have suggested that people who
have sleep disruption have elevated nighttime levels of circulating cortisol
and adrenocorticotropic hormone They also have an
elevated metabolic rate, which does not occur in people who do not have
insomnia but whose sleep is intentionally disrupted during a sleep study.
Studies of brain metabolism using positron emission tomography (PET) scans
indicate that people with insomnia have higher metabolic rates by night and by
day. The question remains whether these changes are the causes or consequences
of long-term insomnia.
A common misperception is that the amount of sleep required decreases as a
person ages. The ability to sleep for long periods, rather than the need for
sleep, appears to be lost as people get older. Some elderly insomniacs toss and
turn in bed and occasionally fall off the bed at night, diminishing the amount
of sleep they receive.
No comments:
Post a Comment