Cerebral palsy overview

# Overview
Cerebral palsy is defined as a group of permanent disorders of the development of movement and posture, causing activity limitation, that are attributed to nonprogressive disturbances that occurred in the developing fetal or infant brain. Cerebral palsy can be classified based on the number of limbs involved, physiologically and functionally. The motor disorders of cerebral palsy often are accompanied by disturbances of sensation, perception, cognition, communication, and behavior, by epilepsy, and by secondary musculoskeletal problems. Intraventricular hemorrhage and periventricular leukomalacia are the two main pathologies that play a vital role in the development of cerebral palsy. Birth asphyxia is believed to be the principal etiology for cerebral palsy. However, recent studies demonstrated that 70% to 80% of cases of cerebral palsy are due to antenatal factors, while only 10% to 28% of cases are due to birth asphyxia in term and near-term infants. The incidence of cerebral palsy is approximately 150-250 per 100,000 live births worldwide. Decline in the trends of cerebral palsy is due to advances in perinatal care. The prevalence of different motor patterns of cerebral palsy has remained remarkably static over the last 20 years. Common risk factors in the development of cerebral palsy include prematurity, fetal birth asphyxia, multiple births, and maternal illness. The most common symptoms of cerebral palsy include abnormal - early hypotonia followed by spasticity, gross motor developmental delay, definite hand preference before age 1 year, failure to crawl, failure to thrive or growth failure. The d]iagnosis of cerebral palsy is clinical and there is no specific test to confirm the diagnosis of cerebral palsy. MRI is the diagnostic neuroimaging study of choice and findings include hypoxic-ischemic lesions, cortical malformations, and lesions of the basal ganglia. Pharmacologic medical therapies for cerebral palsy include botulinum toxin, intrathecal baclofen, and oral antispastics.

# Historical Perspective
The first detailed medical descriptions for cerebral palsy dates back to the era of Hippocrates in his work Corpus Hippocraticum. Although there is lack of detailed medical descriptions from before the 19th century, mentions to cerebral palsy can be found in representational art, literary sources and paleopathology. In 1827, Jean Baptiste Cazauvieilh was the first to report cerebral atrophy in individuals with congenital paralysis and tried to distinguish between lesions in the developing brain with those related to trauma. In 1853, Little named spastic diplegia as Little's disease. In 1861, after twenty years of experience and nearly 200 cases, Little put forth a theory that asphyxia at birth could cause permanent central nervous system damage in cerebral palsy patients. Between 1891 and 1897, Sigmund Freud was the first to describe a classification system for cerebral palsy in his several volumes entitled Cerebral Palsy. In 1953, Virginia Apgar generated a scoring system, "APGAR" that forced obstetricians to examine the condition of newborns at birth and assess the need for treatment.

# Classification
Cerebral palsy can be classified based on number of limbs involved, physiologically and functionally. Based on number of limbs involved cerebral palsy can be classified into monoplegia, hemiplegia, diplegia, paraplegia and quadriplegia. Physiologically, cerebral palsy can be divided into a spastic type (pyramidal), and an extrapyramidal type. The extrapyramidal types of cerebral palsy include athetoid, choreiform, ataxic, rigid, and hypotonic. The Manual Ability Classification System (MACS) and the Gross Motor Function Classification System (GMFCS) are two most commonly employed systems for functional classification of cerebral palsy. The Manual Ability Classification System (MACS) classifies children with cerebral palsy into five levels. The levels are based on the childrens self-initiated ability to handle objects and their need for assistance or adaptation to perform manual activities in everyday life. The Gross Motor Function Classification System (GMFCS) also classifies children with cerebral palsy into five levels. The levels are based on self-initiated movement abilities, in particular sitting and walking.

# Pathophysiology
Cerebral palsy is defined as a group of permanent disorders of the development of movement and posture, causing activity limitation, that are attributed to nonprogressive disturbances that occurred in the developing fetal or infant brain. The motor disorders of cerebral palsy often are accompanied by disturbances of sensation, perception, cognition, communication, and behavior, by epilepsy, and by secondary musculoskeletal problems. Intraventricular hemorrhage (IVH) and periventricular leukomalacia (PVL) are the two main pathologies that play a vital role in the development of cerebral palsy. The insult to the brain is believed to occur between the time of conception and age 2 years, at which time a significant amount of motor development has occurred. Intraventricular hemorrhage is defined as a condition in which bleeding from the subependymal matrix occurs into the ventricles of the brain. Preterm infants are at increased risk of intraventricular hemorrhage because of underdeveloped blood vessels. Ischemia and infection are two important factors that play a vital role in the pathogenesis of periventricular leukomalacia. Since preterm and even term neonates have low cerebral blood flow, the periventricular white matter is susceptible to ischemic damage resulting in motor damage.

# Causes
Birth asphyxia is believed to be the principal etiology for cerebral palsy. However, recent studies demonstrated that 70% to 80% of cases of cerebral palsy are due to antenatal factors, while only 10% to 28% of cases are due to birth asphyxia in term and near-term infants. Causes of cerebral palsy are often multifactorial.

# Differentiating Cerebral palsy from Other Diseases
Cerebral palsy must be differentiated from other diseases that cause spasticity, hypotonia, ataxia and dystonia such as inherited metabolic disorders, intellectual disability, metabolic myopathies, metabolic neuropathy, traumatic peripheral nerve lesions, tumors of the conus and cauda equina and vascular malformations of the spinal cord.

# Epidemiology and Demographics
The incidence of cerebral palsy is approximately 150-250 per 100,000 live births worldwide. Decline in the trends of cerebral palsy is due to advances in perinatal care. The prevalence of different motor patterns of cerebral palsy has remained remarkably static over the last 20 years. Most patients are identified by 2 years of age due to delayed motor milestones. Cerebral palsy usually affects individuals of the black non-Hispanic children race. White non-Hispanic children are less likely to develop cerebral palsy. Males are more commonly affected by cerebral palsy than females. The male to female ratio is approximately 1.5 to 1.

# Risk Factors
Common risk factors in the development of cerebral palsy include prematurity, fetal birth asphyxia, multiple gestation, maternal illness, fetal brain malformation, maternal teratogen exposure, low socioeconomic status, nonvertex presentation, postmaturity, and head injury.

# Screening
There is insufficient evidence to recommend routine screening for cerebral palsy. Serial follow-up exams of all newborns from neonatal intensive care are warranted until it is evident that there is no failure in developmental milestones or development of spasticity.

# Natural History, Complications, and Prognosis
Although the neurologic deficit is permanent and non-progressive, if cerebral palsy is left untreated it can have a dynamic effect on growth and development of the patient resulting in gait abnormalities. Cerebral palsy affects multiple systems. Common complications include contractures, hip dislocation, scoliosis, failure to thrive, dental caries (enamel dysgenesis, malocclusion, and gingival hyperplasia), increased risk of aspiration pneumonia, bronchiolitis/asthma, epilepsy, and mental retardation.

# Diagnosis

## Diagnostic Criteria
The diagnosis of cerebral palsy is clinical and there is no specific test to confirm the diagnosis of cerebral palsy. Diagnostic evaluation may include magnetic resonance imaging (MRI) of the brain, electroencephalography (EEG), lumbar puncture, metabolic and genetic testing and, screening for thrombophilia.

## History and Symptoms
A positive history of failure to meet the expected developmental milestones, failure to suppress the primitive reflexes, intellectual disability or mental retardation, visual or hearing problems, speech or language problems, and oromotor dysfunction is suggestive of cerebral palsy. The most common symptoms of cerebral palsy include abnormal muscle tone- early hypotonia followed by spasticity, gross motor developmental delay, definite hand preference before age 1 year, failure to crawl, failure to thrive or growth failure. Less common symptoms of cerebral palsy may include hypotonia with decreased resistance to movement.

## Physical Examination
Patients with cerebral palsy usually have abnormal neck or truncal tone, asymmetric posture, abnormal strength, gait and coordination. Physical examination of patients with cerebral palsy is usually remarkable for neuromuscular findings such as tremors or involuntary movements, athetosis, chorea, muscle rigidity, sensory loss, diplegia/hemiplegia/quadriplegia, intellectual disability, dystonia, normal/increased/decreased tone, persistent or asymmetric fisting, abnormal oromotor patterns, tongue retraction and thrust, tonic bite, oral hypersensitivity, grimacing, poor head control and spastic cerebral palsy presents with features of upper motor neuron lesion.

## Laboratory Findings
There are no diagnostic laboratory findings associated with cerebral palsy. The American Academy of Neurology (AAN) recommends lab studies if there is no specific structural abnormality present-, the presence of atypical features in history or physical examination and cerebral palsy associated with brain malformation. Following labs may help to rule out other diseases and may include thyroid function tests, lactate and pyruvate levels, organic and amino acids, ammonia levels and chromosomal analysis

## Electrocardiogram
There are no diagnostic ECG findings associated with cerebral palsy. Findings on an ECG suggestive of cerebral palsy may include increased heart rate, shorter PR interval and shorter QRS duration.

## X-ray
There are no diagnostic x-ray findings associated with cerebral palsy. An x-ray may be helpful in the diagnosis of complications of cerebral palsy which include recurrent aspirations and scoliosis.

## Ultrasound
Cranial ultrasonographic findings may include intraventricular hemorrhage, hypoxic-ischemic injury to the periventricular white matter and periventricular leukomalacia.

## CT scan
CT scan findings suggestive of cerebral palsy may include congenital malformations, intracranial hemorrhage and periventricular leukomalacia.

## MRI
MRI is the diagnostic neuroimaging study of choice especially for older children and is preferred over CT scan. The diagnostic yield of MRI depends upon the type of CP (mixed > quadriplegic > hemiplegic > diplegic > ataxic > dyskinetic) and the timing of birth. MRI findings in patients with CP may include hypoxic-ischemic lesions (eg, periventricular leukomalacia-PVL), cortical malformations and lesions of the basal ganglia.

## Other Imaging Findings
There are no other imaging findings associated with cerebral palsy.

## Other Diagnostic Studies
Other diagnostic studies for cerebral palsy may include electroencephalography, EMG and nerve conduction studies, placental examination, and screening for associated conditions such as intellectual disability, visual impairment, hearing impairment, speech and language impairment.

# Treatment

## Medical Therapy
Pharmacologic medical therapies for cerebral palsy include botulinum toxin, intrathecal baclofen, and oral antispastics. The management of cerebral palsy should be individualized according to the patient's need and status of disease. The disease itself is not progressive but the presentations might change with the maturation of the brain and the development of the skeletal system. Medical therapy aims at improvement of the motor function through relieving the spasticity of the limbs and preventing the occurrence of convulsions.

## Surgery
Surgery is not the first-line treatment option for patients with cerebral palsy. Surgery is usually reserved for patients with severe disease causing functional abnormalities. Surgical interventions include selective dorsal rhizotomy and tendon lengthening or transfer.
n lengthening or transfer.

## Primary Prevention
Effective measures for the primary prevention of cerebral palsy include avoiding preterm birth, avoiding complicated delivery and avoiding head trauma in the neonate.

## Secondary Prevention
There are no established measures for the secondary prevention of cerebral palsy.