The sensation of being unable to move at the moment of going to sleep or when waking up, usually lasting only a few seconds. It may be accompanied by hallucinations. Sleep paralysis most often occurs in people with narcolepsy. (See also cataplexy.)
Paralysis due to brain disease The most common form is unilateral palsy, or HEMIPLEGIA, generally arising from cerebral HAEMORRHAGE, THROMBOSIS or EMBOLISM affecting the opposite side of the BRAIN. If all four limbs and trunk are affected, the paralysis is called quadraplegia; if both legs and part of the trunk are affected, it is called paraplegia. Paralysis may also be divided into ?accid (?oppy limbs) or spastic (rigid).
In hemiplegia the cause may be an abscess, haemorrhage, thrombosis or TUMOUR in the brain. CEREBRAL PALSY or ENCEPHALITIS are other possible causes. Sometimes damage occurs in the parts of the nervous system responsible for the ?ne control of muscle movements: the cerebellum and basal ganglion are such areas, and lack of DOPAMINE in the latter causes PARKINSONISM.
Damage or injury Damage to or pressure on the SPINAL CORD may paralyse muscles supplied by nerves below the site of damage. A fractured spine or pressure from a tumour may have this e?ect. Disorders affecting the cord which can cause paralysis include osteoarthritis of the cervical vertebrae (see BONE, DISORDERS OF), MULTIPLE SCLEROSIS (MS), MYELITIS, POLIOMYELITIS and MENINGITIS. Vitamin B12 de?ciency (see APPENDIX 5: VITAMINS) may also cause deterioration in the spinal cord (see also SPINE AND SPINAL CORD, DISEASES AND INJURIES OF).
Neuropathies are a group of disorders, some inherited, that damage the peripheral nerves, thus affecting their ability to conduct electrical impulses. This, in turn, causes muscle weakness or paralysis. Among the causes of neuropathies are cancers, DIABETES MELLITUS, liver disease, and the toxic consequences of some drugs or metals – lead being one example.
Disorders of the muscles themselves – for example, muscular dystrophy (see MUSCLES, DISORDERS OF – Myopathy) – can disturb their normal working and so cause partial or complete paralysis of the part(s) affected.
Treatment The aim of treatment should be to remedy the underlying cause – for example, surgical removal of a displaced intervertebral
disc or treating diabetes mellitus. Sometimes the cause cannot be recti?ed but, whether treatable or not, physiotherapy is essential to prevent joints from seizing up and to try to maintain some tone in muscles that may be only partly affected. With temporary paralysis, such as can occur after a STROKE, physiotherapy can retrain the sufferers to use their muscles and joints to ensure mobility during and after recovery. Patients with permanent hemiplegia, paraplegia or quadraplegia need highly skilled nursing care, rehabilitative support and resources, and expert help to allow them, if possible, to live at home.... paralysis
Non-rapid-eye-movement (NREM) sleep This is subdivided into four stages, of which stage 1 is the lightest and stage 4 the deepest. The activity of the cerebral cortex (see BRAIN) is diminished and the body’s functions are mainly regulated by brain-stem activity. The metabolic rate is reduced; in keeping with this the temperature falls, respiration is reduced, cardiac output, heart rate, and blood pressure fall, and activity of the sympathetic nervous system is reduced. NREM sleep normally occurs at the onset of sleep except in neonates. During adult life, the duration – particularly of stages 3 and 4 – of NREM sleep becomes less, and very little of this deep sleep occurs after the age of 60 years.
NREM sleep has been thought to have several functions, such as energy conservation and growth. Growth hormone is produced in bursts during stages 3 and 4, and more cell division occurs during this type of sleep than during wakefulness. A controversial proposal has been that processing of information acquired during wakefulness occurs during NREM sleep.... sleep
Klumpke’s paralysis is caused by injury to the 1st thoracic nerve (one of the spinal nerves) in the brachial plexus, which is usually the result of dislocation of the shoulder.... klumpke’s paralysis
The weakness may last for minutes, hours, or even days, but there is no lasting effect.
The cause is thought to be temporary damage to the motor cortex (the area of the brain that controls movement).... todd’s paralysis
People with sleep apnoea may not be aware of any problem during the night, but they may be sleepy during the day, with poor memory and concentration. Severe sleep apnoea is potentially serious and may lead to hypertension, heart failure, myocardial infarction, or stroke.
Obstructive sleep apnoea is the most common type and may affect anyone, but more often middle-aged men, especially those who are overweight. The most common cause is over-relaxation of the muscles of the soft palate in the pharynx, which obstructs the passage of air. Obstruction may also be caused by enlarged tonsils or adenoids. The obstruction causes snoring. If complete blockage occurs, breathing stops. This triggers the brain to restart breathing, and the person may gasp and wake briefly.
In central sleep apnoea, breathing stops because the chest and diaphragm muscles temporarily cease to work, probably due to a disturbance in the brain’s control of breathing. Causes include paralysis of the diaphragm and disorders of the brainstem. Snoring is not a main feature.People who are overweight may find losing weight helps.
Alcohol and sleeping drugs aggravate sleep apnoea.
In one treatment, air from a compressor is forced into the airway via a mask worn over the nose.
Night-time artificial ventilation may be needed.
Tonsillectomy, adenoidectomy, or surgery to shorten or stiffen the soft palate may be performed.... sleep apnoea
Physiological changes, such as a fall in temperature and blood pressure, take place just before sleep and continue during the early stages of NREM sleep. There is an intrinsic rhythm of sleep which in most subjects has a periodicity of around 25 hours. This can be modi?ed by external factors to bring it into line with the 24-hour day. Two peaks of a tendency to sleep have been identi?ed, and these usually occur between around 14.00–18.00 hours, and 02.00–06.00 hours. There are, however, di?erences according to age, in that, for instance, infants sleep for most of the 24 hours; during adolescence there is also an increase in the duration of sleep. Sleep requirements fall later in life, but there are wide genetic di?erences in the amount of sleep that people require and also the time at which they fall asleep most readily.
The internal clock can be disturbed by a variety of external factors which include irregular sleeping habits due, for instance, to shift work or jet lag. Sleep is also more likely to occur after physical exertion, reading and social activity. The duration and intensity of exposure to light can also modify sleep profoundly. Light promotes wakefulness and is the main factor that adjusts the 25-hour internal rhythm to the 24hour daily cycle. Neural connections from the retina of the EYE act on an area in the brain called the supra-chiasmatic nucleus which stimulates the pineal gland which produces MELATONIN. This is thought to trigger the range of neurological and metabolic processes that characterise sleep.... rapid-eye-movement (rem) sleep
Vigorous respiratory movements are made to overcome the obstruction during each apnoea. These are associated with snoring and snorting noises. The apnoea ends with a mini-arousal from sleep. As a result, sleep becomes fragmented and sleep deprivation, manifested as sleepiness during the day, is common. This may result in accidents – for instance, at work or while driving – and sleep apnoea is also linked with an increased risk of STROKE, heart attacks and HYPERTENSION.
The diagnosis of sleep apnoea has recently been facilitated by linking specially designed software with ELECTROCARDIOGRAPHY performed during sleep, with minimal disturbance of the subject.
Initial treatment is directed at correcting the cause (e.g. obesity), but if the apnoeas persist or are severe a nasal mask and pump which introduces air under slight pressure into the upper airway (continuous positive airway pressure, CPAP) is almost invariably e?ective.... sleep apnoeas
Parasomnias These include medical disorders such as ASTHMA, ANGINA PECTORIS or EPILEPSY which are made worse by sleep, and a range of behavioural alterations which are usually related to a speci?c sleep stage or to a change from one state of sleep to another. Sleepwalking, night terrors, and nightmares are examples.
Insomnia Insomnia is de?ned as a di?culty in initiating or maintaining sleep. It affects around 15 per cent of the population at any one time, and is often due to a poor pre-sleep routine (e.g. taking excessive stimulants such as ca?eine); unsatisfactory sleep due to poor environments such as an uncomfortable bed or a cold or noisy bedroom; anxiety and/or depression; or occasionally to a physical problem – for example, pain – or a medical disorder associated with sleep such as obstructive SLEEP APNOEAS or periodic limb movements.
Excessive daytime sleepiness This is usually due to sleep deprivation caused either by inadequate duration of sleep, or by poor quality of sleep. The individual’s lifestyle is often a cause and modi?cation of this may relieve the problem. Other common causes of excessive daytime sleepiness are depression, obstructive sleep apnoeas, periodic limb movements, excessive alcohol or other drug intake, and, less commonly, NARCOLEPSY.... sleep, disorders of
Irritability and a shortened attention span may occur after a short night’s sleep.
Longer periods without sleep leave a person increasingly unable to concentrate or perform normal tasks.
Three or more sleepless nights may lead to hallucinations and, in some cases, to paranoia.... sleep deprivation
Health Encyclopedia