CEREBRAL PALSY

paralysis (loss of volitional control over a motor function) resulting from a brain disorder suffered either before or at birth or during infancy. The meaning of the term cerebral palsy is broad, usually including all motor disturbances attributable to a cerebral disorder of early life. Specifically, however, two types of infantile cerebral palsy are meant: spastic and athetosic. In the spastic type, there is a severe paralysis of the voluntary movements, with spastic contracture of the extremities either on one side of the body (hemiplegia) or on both sides (diplegia). In the latter, spastic contracture and paralysis are usually more prominent in the lower extremities than in the arms and hand (Little's diplegia), or only the legs may be affected (paraplegia). In the athetosic type, the voluntary movements may not be paralyzed, and spastic contractures may be slight or absent. Instead, there are slow, changing, mobile spasms in the face, neck, and extremities, either on one side (hemiathetosis) or, more frequently, on both sides (double athetosis), with resulting involuntary movements in the whole body or its parts, facial grimacing, and inarticulate speech (dysarthria), all of which increase under stress or excitement. In the spastic type, the cerebral damage affects especially the nerve cells and connections of the cerebral cortex (outer gray matter), either of one cerebral hemisphere (contralateral to paralysis), as in infantile hemiplegia, or of both hemispheres, as in diplegia. In the athetosic type, damage to the brain particularly affects the basal ganglia underlying the cerebral cortex. Cerebral palsy does not necessarily imply mental retardation; many children affected with cerebral palsy grow to be mentally competent adults. Any cerebral disorder in early life may, however, result in impairment, sometimes severe, of the subsequent intellectual and emotional development. Epileptic attacks in the form of convulsive seizures, especially in the parts affected by the paralysis, occur in many children with cerebral palsy. In the spastic type of cerebral palsy, mental retardation and epileptic attacks are particularly frequent. In the athetosic type, the incidence of severe mental retardation is much lower, and occurrence of convulsive seizures is exceptional. Children affected with athetosis may be perceptive and intelligent; because of the involuntary movements and dysarthria, however, they are often unable to communicate by intelligible words or signs and, thus, may appear mentally retarded. The causes of cerebral palsy are multiple and variable but basically involve a malfunctioning of the complex neuronal circuits of the basal ganglia and the cerebral cortex. Heredity plays only a small role. It may manifest itself in neoplastic malformations of nerve cells, interstitial tissues, and blood vessels of the brain with tendency to produce tumours, or it may express itself in an abnormal chemistry of the brain. Fetal diseases and embryonic malformations of the brain are more common causes of cerebral palsy than is heredity. Incompatibility of parental blood types, leading to severe jaundice of the newborn, may cause brain damage and cerebral palsy. Asphyxia at birth was once thought to be the most common immediate cause of a great majority of cerebral palsies; research conducted in the 1980s indicated that abnormalities of delivery often are markers of earlier brain damage and that the causes of cerebral palsy are much less certain than was previously believed. Postnatal diseasesparticularly infections of infancy and childhood, severe head injuries, and poisoningare other, less common, causes of cerebral palsy. Treatment with the so-called muscle-relaxant drugs is, at best, palliative, temporary in effect and limited in value. The basic program of treatment aims at the psychological management, education, and training of the child to develop whatever sensory, motor, and intellectual assets are still available to him, in order to compensate for the physical liabilities.