paralysis(redirected from ocular paralysis)
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paralysis or palsy (pôlˈzē), complete loss or impairment of the ability to use voluntary muscles, usually as the result of a disorder of the nervous system. The nervous tissue that is injured may be in the brain, the spinal cord, or in the muscles themselves. Accordingly there may be general paralysis, involvement of only one side (hemiplegia), paralysis on both sides at one level (paraplegia or quadriplegia), or localized paralysis in a small group of nerves or muscles.
The cause of paralysis may be any injury that tears or compresses the nerves; it may be hemorrhage, tumor, infection, or substances toxic to nerve tissue. One of the most frequent causes of paralysis is stroke, in which hemorrhage, thrombosis, or obstruction of a cerebral vessel interferes with nerve function. Another disorder in which a resting tremor is one of the main symptoms, accompanied by slowness and poverty of movement, muscular rigidity, and postural instability is Parkinson's disease. Cerebral palsy is due to an injury to the brain motor tissue before or during birth. However, this disorder is nonprogressive. Partial or complete paralysis often accompanies multiple sclerosis.
absence of voluntary movement that is due to destruction or impairment of the motor centers of the spinal cord or brain or of tracts of the central or peripheral nervous system. A distinction is made between paralysis and paresis, the latter being a condition in which motor functions are weakened but present. Both conditions may be caused by disturbances of the blood circulation, inflammation, traumata, or tumors of the nervous system. An unusual kind of paralysis occurs in hysteria. Paralyses must be distinguished from motor disorders associated with inflammation of muscles and lesions of bones and joints, which restrict the range of movement mechanically. Paralysis may affect one muscle, one extremity (monoplegia), the arm and leg on one side (hemiplegia), both arms or both legs (paraplegia), or other combinations of muscles.
Peripheral paralysis is a flaccid paralysis that involves the motor cells of the spinal cord and its anterior roots, peripheral nerves, plexuses, or nuclei of the cranial nerves. Central paralysis is a spastic paralysis that involves the brain’s central motor neurons or their outgrowths in the spinal cord.
Peripheral paralysis is characterized by the complete absence of movement, decrease in muscle tone, loss of reflexes, and muscular atrophy. Sensory disorders occur when a peripheral nerve or plexus containing both motor and sensory fibers is affected.
Central paralysis is characterized not by the complete loss of motor functions but by their dissociation—the loss of some functions and intensification of others. While voluntary movement is absent, muscle tone and tendon and periosteal reflexes increase and pathological Babinski’s, Rossolimo’s, and other reflexes appear. Associated movements (synkinesis) are observed. These are involuntary movements that occur in paralyzed extremities during voluntary movements of healthy extremities. Sensory disturbances are also observed.
Extrapyrimidal paralysis arises when the subcortical structures of the brain are affected. Associated, reflex, and voluntary movements are absent (akinesia). Muscle tone is plastic, and the extremity can move only passively.
Electromyography and other special methods of examination are important for differential diagnosis.
The prognosis and treatment are determined by the disease that caused the paralysis. Among the special methods used to restore the functions of the extremity are massage and remedial gymnastics.
REFERENCESKrol’, M. B., and E. A. Fedorova. Osnovnye nevropatologicheskie sindromy. Moscow, 1966.
Kukuev, L. A. Struktura dvigatel’nogo analizatora. Leningrad, 1968.
V. B. GEL’FAND
What does it mean when you dream about paralysis?
Being unable to move may mean the dreamer feels helpless to control the situation at hand. Alternatively, perhaps the dreamer needs to “freeze” and do nothing about some issue for awhile.