paralysis [pah-ral´ĭ-sis] (pl. paral´yses.)
Loss or impairment of motor function in a part due to a lesion of the neural or muscular mechanism; also, by analogy, impairment of sensory function (sensory paralysis
). Paralysis is a symptom of a wide variety of physical and emotional disorders rather than a disease in itself. Called also palsy
Types of Paralysis
. Paralysis results from damage to parts of the nervous system. The kind of paralysis resulting, and the degree, depend on whether the damage is to the central nervous system or the peripheral nervous system.
If the central nervous system is damaged, paralysis frequently affects the movement of a limb as a whole, not the individual muscles. The more common forms of central paralysis are hemiplegia
(in which one entire side of the body is affected, including the face, arm, and leg) and paraplegia
(in which both legs and sometimes the trunk are affected). In central paralysis
the tone of the muscles is increased, causing spasticity
If the peripheral nervous system is damaged, individual muscles or groups of muscles in a particular part of the body, rather than a whole limb, are more likely to be affected. The muscles are flaccid, and there is often impairment of sensation.
Causes of Central Paralysis
. stroke syndrome
is one of the most common causes of central paralysis. Although there is usually some permanent disability, much can be done to rehabilitate the patient. Paralysis produced by damage to the spinal cord can be the result of direct injuries, tumors, and infectious diseases. Paralysis in children may be a result of failure of the brain to develop properly in intrauterine life or of injuries to the brain, as in the case of cerebral palsy
. Congenital syphilis
may also leave a child partially paralyzed. Paralysis resulting from hysteria
has no organic basis and is a result of emotional disturbance or mental illness.
Causes of Peripheral Paralysis
. Until the recent development of immunizing vaccines, the most frequent cause of peripheral paralysis in children was poliomyelitis
, inflammation of a nerve, can also produce paralysis. Causes can be physical, as with cold or injury; chemical, as in lead poisoning; or disease states, such as diabetes mellitus or infection. Paralysis caused by neuritis frequently disappears when the disorder causing it is corrected.
paralysis of accommodation
paralysis of the ciliary muscles of the eye so as to prevent accommodation
ascending paralysis spinal paralysis that progresses upward.
birth paralysis that due to injury received at birth.
paralysis of an upper limb from damage to the brachial plexus
bulbar paralysis that due to changes in motor centers of the medulla oblongata; the chronic form is marked by progressive paralysis and atrophy of the lips, tongue, pharynx, and larynx, and is due to degeneration of the nerve nuclei of the floor of the fourth ventricle.
central paralysis any paralysis due to a lesion of the brain or spinal cord.
paralysis caused by an intracranial lesion; see also cerebral palsy
compression paralysis that caused by pressure on a nerve.
conjugate paralysis loss of ability to perform some parallel ocular movements.
crossed paralysis paralysis affecting one side of the face and the other side of the body.
crutch paralysis brachial paralysis caused by pressure from a crutch.
decubitus paralysis paralysis due to pressure on a nerve from lying for a long time in one position.
paralysis of the upper roots of the brachial plexus
due to destruction of the fifth and sixth cervical roots, without involvement of the small muscles of the hand. Called also Erb's palsy
weakening or paralysis of the facial nerve, as in bell's palsy
familial periodic paralysis a hereditary disease with recurring attacks of rapidly progressive flaccid paralysis, associated with a fall in (hypokalemic type), a rise in (hyperkalemic type), or normal (normokalemic type) serum potassium levels; all three types are inherited as autosomal dominant traits.
paralysis with loss of muscle tone of the paralyzed part and absence of tendon reflexes
infantile cerebral ataxic paralysis a congenital condition due to defective development of the frontal regions of the brain, affecting all extremities.
ischemic paralysis local paralysis due to stoppage of circulation.
Klumpke's paralysis (Klumpke-Dejerine paralysis) atrophic paralysis of the lower arm and hand, due to lesion of the eighth cervical and first dorsal thoracic nerves.
motor paralysis paralysis of the voluntary muscles.
1. any of various diseases characterized by episodic flaccid paralysis or muscular weakness.
Saturday night paralysis
paralysis of the extensor muscles of the wrist and fingers, so called because of its frequent occurrence in alcoholics. It is most often due to prolonged compression of the radial (musculospiral) nerve, and, depending upon the site of nerve injury, is sometimes accompanied by weakness and extension of the elbow. Called also musculospiral
or radial paralysis
sensory paralysis loss of sensation resulting from a morbid process.
paralysis occurring at awakening or sleep onset; it represents extension of the atonia of REM sleep
into the waking state and is often seen in those suffering from narcolepsy
or sleep apnea
. Called also waking paralysis
paralysis with rigidity of the muscles and heightened deep muscle reflexes and tendon reflexes
progressive ascending flaccid motor paralysis following the bite of certain ticks, usually Dermacentor andersoni;
first seen in children and domestic animals in the northern Pacific region of North America, and now seen in other parts of the world.
loss or impairment of motor function in a part due to a lesion of the neural or muscular mechanism; also, by analogy, impairment of sensory function (sensory paralysis). Called also palsy. Motor paralysis may be expressed as flaccid, in the case of lower motor neuron lesion, or spastic, in the case of an upper motor neuron lesion. See also paraplegia
and paralyses of individual cranial and peripheral nerves.
paralysis of accommodation
paralysis of the ciliary muscles of the eye so as to prevent accommodation.
manifested by flaccidity and lack of tone of the anal sphincter, and loss of house training restraint in companion animals.
pressure on sciatic nerves by a large fetus in late pregnancy in a cow can cause posterior paralysis that is cured by a cesarean section.
spinal paralysis that progresses forwards involving first the hindlimbs then the forelimbs, then the intercostal muscles, then the diaphragm, and finally the muscles of the neck.
that due to injury received by the neonate at birth.
manifested by fullness of the bladder and response to manual pressure. See also motor paralytic urinary bladder
see thiamin nutritional deficiency.
any paralysis due to a lesion of the brain or spinal cord.
paralysis caused by some intracranial lesion.
see thiamin nutritional deficiency.
that caused by pressure on a nerve.
paralysis of the newborn. Many cases are due to birth trauma especially when lay persons exert excessive traction. Other causes are enzootic ataxia, inherited congenital paraplegias in calves and pigs, spina bifida and spinal dysraphism and occipito-alanto-axial malformations in foals and puppies.
loss of ability to perform some parallel ocular movements.
paralysis affecting one side of the head and the other side of the body.
curled toe paralysis
a disease of poultry caused by a nutritional deficiency of riboflavin. See also curled toe paralysis
paralysis due to pressure on a nerve from lying for a long time in one position.
manifested by inability to swallow, and regurgitation.
weakening or paralysis of the facial nerve. See also facial
paralysis characterized by loss of voluntary movement, decreased tone of limb muscles, absence of tendon reflexes and neurogenic atrophy.
the absence of immune response to a specific antigen. See also tolerance
infectious bulbar paralysis ischemic paralysis
local paralysis due to stoppage of circulation.
lambing paralysis maternal
obstetric paralysis in the ewe.
combined motor and sensory paralysis.
paralysis of the voluntary muscles.
paralysis caused by damage to the local motor nerve supply. See also peripheral nerve paralysis (below).
peripheral nerve paralysis
the part deprived of its peripheral nerve supply shows flaccid paralysis, absence of spinal reflexes, muscle atrophy and a subnormal temperature.
paralysis of the hindlimbs, tail and perineum. See also paraplegia
loss of sensation resulting from a morbid process.
paralysis with rigidity of the muscles and heightened deep muscle reflexes.