Cerebral palsy
Incidence
The overall prevalence of significant cerebral palsy ranges from 1.5 to 2.5 per 1000 live births. Broad category of disease with most cases having a low recurrence risk.
Clinical Characteristics
Cerebral palsy embraces a range of conditions that involve abnormal movement or posture; the cause is a brain injury that occurs before birth or during early childhood. Cerebral palsy does not progress-that is, it does not become worse as the child ages. Cerebral palsy may be further defined by its distribution-all four limbs (quadriplegia) or one side of the body (hemiplegia, diplegia) involved; it can also be defined by manifestations such as spasticity, hypotonia, choreoathetosis, or ataxia. Spasticity refers to rigid muscles with toe-walking and increased reflexes, hypotonia to muscle weakness, choreoathetosis to spontaneous, sudden movements and posturing, ataxia to unsteady walking, balance and trembling. Overlap among the forms of cerebral palsy is common.The overall prevalence of significant cerebral palsy ranges from 1.5 to 2.5 per 1000 live births. Many different causes can produce the symptoms that are collectively grouped under the term "cerebral palsy." These include respiratory insufficiency in the newborn period (6-14% of cases), congenital disorders involving abnormal development of the brain (50-60% of cases), brain infections such as meningitis (8-10% of cases), and prematurity or low birth weight (25-30% of cases). Recent studies have made clear that most children with cerebral palsy (90-95%) have some type of genetic or congenital disorder rather than injury during labor or delivery. The initial diagnosis of cerebral palsy must exclude other disorders such as spinal cord tumors, spina bifida (usually obvious from inspection), tethered cord (an anomaly of the lower spinal cord), and neurologic disorders such as myopathies (muscle diseases) or spinal muscular atrophies (progressive diseases involving death of spinal nerve cells). The diagnosis of cerebral palsy requires observation of the child over time because its symptoms often emerge and change. Spasticity is nearly always preceded by hypotonia that, while delaying motor milestones, may be less obvious to parents and clinicians. On the other hand, early alterations in movement and tone may lessen or disappear. Clues include the persistence of simple reflexes like the grasp reflex, asymmetry of movements or reflexes, variations in muscle tone, and delays in the sequence of motor milestones. The average child with cerebral palsy is not diagnosed until about 12 months of age, and some experts have suggested that a definitive diagnosis be deferred until 2 years of age. Outcomes of cerebral palsy vary from profound disability in most areas of brain and motor function to minimal dysfunction. By definition, individuals with cerebral palsy have a permanent impairment in muscle function that does not become worse with age. The nature of this impairment (spastic or choreo-athetoid, diplegia or quadriplegia) may emerge gradually in the early months and years. All children pass through an initial phase of low muscle tone (hypotonia), so spasticity at birth implies that the brain abnormality and hypotonia occurred in the womb. Cerebral palsy may "worsen" or appear to progress when there is a failure to address nutritional issues, seizures, or underlying medical illnesses. Epilepsy occurs in about 1/3 of people with cerebral palsy, with a prevalence of 50% in those with hemiplegia. At least 30% have mental retardation that occurs most commonly in those with spastic quadriplegia. On the other hand, cognition may be underestimated in individuals with choreoathetosis due to impairment of the oral muscles needed for speech. Even those without mental retardation are at increased risk for learning disability, vision, or hearing loss. The oral muscular problems, together with altered swallowing, can cause feeding problems, reflux (spitting up), aspiration (swallowing fluid into the lungs with choking), and drooling. In severe cases, nasogastric or gastrostomy tube feeding may be necessary. Inadequate food intake, accentuated by higher energy demands from spastic muscles, may impair growth and cause failure to thrive. Delays in the acquisition of bowel and bladder control are common. Urologic evaluation for urinary bladder dysfunction may be necessary, and chronic constipation due to altered intestinal mobility may require referral to gastroenterology.
Precipitants
none
Provocation Tests
none
Diagnostic Procedures
It is a clinical diagnosis.