Physicians are often consulted by patients who suffer some derangements of sleep. Most often the problem is one of sleeplessness, but sometimes it concerns excessive sleep or some other peculiar phenomenon occurring with sleep. A great deal of information about sleep and sleep abnormalities are now available as the result of development, and a new subspecialty in medicine, called sleep medicine is created. There are large number of centers for the diagnosis and treatment of sleep disorders.
Sleep is an elemental phenomenon of life .The neural control of sleep resides in the part of the brain called thalamus. Newborn baby sleeps from 16-20 hours a day. Total sleep time drops to 9 to 10 hours at age 10. Average asleep time in adult life is 6.5 hours. When deprived of sleep for periods of 60 to 200 hours, human beings experience increasing sleepiness, fatigue, irritability and difficulty in concentration. Performance of skilled motor activities also deteriorates. The work becomes slow. Self-care is neglected. Errors and accidents are more marked. Rarely it may also provoke psychotic episodes.
What are the various types of sleep disorders?
Insomnia is a sleep disorder, where the patient complaint that he is not able to sleep despite adequate opportunity for sleeping is available. Insomnia is used to describe any impairment in the various properties of sleep like duration and depth. There may be difficulty in falling asleep or one may wake up too early or any of the combinations may occur. Some form of sleep complaint is frequently present in 20-40% of the population at any given time. Most of them are elderly people and women.
It is a common practice to take sedative or hypnotic drugs for insomnia. But it should be taken only for a short period of time and under the supervision the physician. Commonly used drugs are flurazepam, triazolam and zolpidem. The cause for insomnia should be found and treated
Disorders of sleep due to neurological disease:
Many neurological diseases derange the total amount and the pattern of the sleep. Lesion in certain areas of the brain, particularly in upper pons, thalamic infarcts, medullary lesions will derange the sleep pattern. Major Head injury is an important cause of sleep disturbances. Patients with Parkinson disease, Alzheimer disease, Huntington chorea, Migraine, cluster headaches suffer from sleep disturbances.
Disorders of sleep associated with changes in circadian rhythm:
Sleep disturbances most commonly occur in shift workers, who periodically change their schedule form day to night and in transmeridional air travel (jet lag).
The disorders in this category occur only during sleep.
- Somnolescent (sleep) Starts: As the sleep comes, certain motor center in the brain becomes activated and the person may jerk his arms, legs or trunk and there may be frightening experience.
- Sensory Paroxysms: When the sensory center in the brain getting stimulated during the sleep, the patient may feel flashes of light, crashing sounds or dart through out the body.
- Sleep paralysis: Sometimes in the morning and less frequently while falling asleep, the person though awake and conscious, is unable to move their limbs. Breathing is normal and the person feels he is paralyzed. Slightest touch of the body will abolish the paralysis. If such attacks occur in narcolepsy, then drugs like tricyclic antidepressants are useful.
- Night terror and Night mares: Night terrors are main problem in childhood. The child wakens abruptly from sleep with intense fright or screaming. The pulse rate is high. There is no increasing psychological abnormality in these children with night terrors. If such problem persists in adulthood, then it will be associated with psychotic problems. Frightening dreams or nightmares are more frequent than night terrors. Watching terrifying movies or reading blood curling stories before bed time may predispose to night mares.
- Somnambulism (sleepwalking): It occurs more often in children of 4-6 years of age. The parents must guard the child against injury by locking the doors and making him sleep in the floor. Reassurance of parents is necessary explaining them that somnambulism is not a psychiatric disease.
- Nocturnal epilepsy: This is the convulsive disorder occurring during sleep, especially in children.
Trypnasomiasis is a common cause for sleeping sickness in Africa. Lesions in the mdibrain, subthalamus, and hypothalamus of the brain also cause excessive sleep.
Sleep apnea and excessive day time sleepiness:
Causes for excessive day time sleepiness include:
- Medication like sedatives, antihistaminics, antidepressants, alcohol abuse
- Acute medical illness
- Post surgical and post anesthetic causes
- Multiple sclerosis and dementia
- Following viral encephalitis
The usual age of onset for narcolepsy is 15-35 years. There are frequent attacks of day time sleepiness, which are irresistible. There are several attacks during the day, usually after meals, while sitting in the class or boring or sedentary situations. The attack rarely last longer than 15 minutes. Cataplexy is the sudden loss of muscle power when laughing or while in anger or excitement in narcolepsy patients. The head of the patient fall forward, jaw drops down, knees tend to buckle. The patient is fully conscious during the attack. Nacrolepsy is controlled to some extent by stimulant drugs like modafinil and dextroamphetamine. Cataplexy is controlled to some extent by tricyclic antidepressants like imipramine. There is no total cure for these conditions.
Sleep Palsies and Acroparesthesias:
Acroparesthesias are frequent in adult women. The patient will wake up from the sleep complaining of numbness and tingling sensation of fingers and hands.
It is the nocturnal grinding of teeth.
It is bed wetting during night time. During day time there is no problem. Boys are more commonly affected than girls. 1-10% of the children aged 4-14 years have this problem. Imipramine at bedtime is a useful drug in reducing the frequency of nighttime bedwetting.