Cerebral palsy is a group of permanent movement disorders appearing in early childhood and caused by abnormal development or damage to the parts of the brain that control movement, balance, and posture.
The symptoms often include poor coordination, stiff muscles, weak muscles, and tremors. There could also be problems with sensation, vision, hearing, swallowing, and speaking. Often babies with cerebral palsy have delayed milestones i.e. they do not roll over, sit, crawl, or walk as early as other children.
Cerebral palsy is the most common movement disorder in children and leading cause of childhood disability affecting function and development. It occurs in about 2.1 per 1,000 live births.
It is worth mentining that the incidence of the condition has not changed in more than 4 decades, despite advances in medical care.
The term cerebral palsy was coined more than a century ago and loosely means “brain paralysis.”
Cerebral palsy is generally considered to be due to nonprogressive brain insult. However, the clinical presentation of this condition changes as children and their developing nervous systems mature.
Pathophysiology of Cerebral Palsy
The brain lesions of cerebral palsy occur from the fetal or neonatal period to up to age 3 years. However, although insults to the brain after age 3 years, by definition, are not cerebral palsy.
However, the diagnosis of cerebral palsy may not be made until late in spite of an earlier insult as the symptoms may be revealed with growth.
Development of human brain starts with primary neurulation at 3-4 weeks of gestation and continue years after the birth.
Injury or abnormal development may occur at any time, resulting in the varied clinical presentations of cerebral palsy.
Risk Factors of Cerebral Palsy
The causes of cerebral palsy are numerous. They include insults in the prenatal, perinatal and postnatal. About 20—30% of the cases do not show any apparent risk factor.
Prenatal Factors
Maternal Factors
- Long menstrual cycle
- Previous pregnancy loss
- History of previous loss of newborn
- Maternal mental retardation
- Maternal thyroid disorder
- Maternal seizure disorder
- History of delivering a child with
- Low birth weight [< 2000 g ]
- Motor deficit
- Mental retardation
- Sensory deficit
Gestational Factors
- Polyhydramnios
- Treatment of the mother with thyroid hormone, estrogen or progesterone
- Maternal seizure disorder
- Maternal severe proteinuria or high blood pressure
- Maternal methyl mercury exposure
- Congenital malformations in the fetus
- Male sex of fetus
- Bleeding in third trimester
- Intrauterine growth retardation
Perinatal risk factors
- Prematurity
- Chorioamnionitis
- Non-vertex and face presentation of the fetus
- Birth asphyxia
Postnatal risk factors
- Infections (eg, meningitis, encephalitis)
- Intracranial hemorrhage (eg, due to prematurity, vascular malformations, or trauma)
- Periventricular leukomalacia (in premature infants)
- Hypoxia-ischemia (eg, from meconium aspiration)
- Persistent fetal circulation or persistent pulmonary hypertension of the newborn
- Kernicterus
Early childhood
- Toxins
- Severe jaundice
- Lead poisoning
- Physical brain injury
- Stroke
- Shaken baby syndrome
- Hypoxia to the brain (such as near drowning)
Types of Cerebral Palsy
Patterns of Motor involvement
Spasticity
- Increased resistance to passive movement esp in initial period
- Pyramidal tracts are affected
- Hyper-reflexia, clonus and extensor plantar response are seen
Involuntary movements
Involuntary motor activity accentuated by emotional stress occurs in lesions of the basal ganglia. Normally, these centers inhibit spontaneous rhythmic movements which are initiated by the cerebral cortex. It is known as extrapyramidal or dyskinetic cerebral palsy and comprises 10-15% of this disorder.
Involuntary movements are choreoatetoid or dystonic.
Choreic movements are gross, fast, arrhythmic and of sudden beginning, athetoid are continuous, uniform and slow.
Dystonia is characterized by intermittent twisting movements secondary to the simultaneous contraction of agonist and antagonist muscles involving extremities, neck and trunk.
Dystonic movements commonly determine bizarre postures, sustained for a variable period of time, followed by relaxation.
Rigidity
This movement disturbance also a consequence of lesions of the basal ganglia relates to a generalized hypertonia secondary to a continuous contraction of flexor and extensor muscles.
Ataxia
It is characterized mainly by clumsy gait with broadening of the base secondary to the lack of balance. Ataxia is frequently associated with cerebellar hypoplasia and is rare in cerebral palsy.
Hypotonia
It means decreased resistance to passive movements and is a rare condition in cerebral palsy.
Mixed
This consists of combination of the movement alterative as described above.
Patterns Based on Topography
Monoplegia
- Only one limb is involved, rare
- Spasticity is the usual motor disorder.
Hemiplegia
It involves both upper and lower limb on the same sides. Significant number of patients have cortical sensory deficit, abnormal stereognosis and two point discrimination and position sense.
Paraplegia
Alterations observed are restricted to the lower limbs.
Diplegia
Upper and lower extremities are involved the legs more than the arms.
Triplegia
There is predominant of three limbs generally both legs and one arm.
Quadriplegia
It involves all four limbs, trunk, neck and head
The typical types of cerebral palsy are as follows:
- Spastic hemiplegia
- Spastic diplegia
- Spastic quadriplegia
- Dyskinetic cerebral palsy
- Mixed cerebral palsy
- Hypotonic cerebral palsy
- Monoplegia
Associated Abnormalities
Mental retardation
Epilepsy
15-30 % children may have epilepsy and is common in spastics than in the extrapyramidal forms.
Hearing impairment
Visual impairment
- Strabismus
- Nystagmus
- Myopia
- Hemianopia
- Cataract
- Chorioretinitis
- Retrolental fibroplasia
Perceptual and visual motor disorders
- Difficulty in perceiving spatial relationships.
Feeding disorders
- Poor weight gain
- Refusal of food
- Vomiting
- Gastro-oesophageal reflux
- impaired swallowing.
Dental problems
- Enamel hypoplasia occurs
- Impaired orofacial motor coordination
Drooling
- Due to dysfunction of oral muscle co-ordination.
Constipation
Bladder dysfunction
- Urodynamic abnormalities
- Upper motor type neurogenic bladder
Different Types Presentations of Cerebral Palsy
Spastic (pyramidal) cerebral palsy
- 75% of patients with cerebral palsy.
- Signs of upper motor neuron involvement
- Hyperreflexia
- Clonus
- Extensor Babinski response
- Persistent primitive reflexes
- Crossed adductor
- Child’s tendency to keep the elbow in a flexed position
- Hips flexed and adducted with the knees flexed and in valgus, and the ankles in equinus resulting in toe walking
Dyskinetic (extrapyramidal) cerebral palsy
- Extrapyramidal movement patterns – athetosis, chorea or choreoathetosis
- Abnormal regulation of tone and posture
- Deficits of coordination
- Abnormal movement patterns may increase with stress or purposeful activity. [Muscle tone is usually normal during sleep.]
- Normal intelligence n 78% of patients
- High incidence of sensorineural hearing loss
- Pseudobulbar involvement
- Dysarthria
- Swallowing difficulties
- Drooling
- Oromotor difficulties
- Abnormal speech patterns.
- Early hypotonia with movement disorder emerging at age 1-3 years
- Arms more affected than legs
- Gait difficulties
- Truncal instability
Spastic hemiplegic cerebral palsy
- One-sided upper motor neuron deficit
- Weak hip flexion and ankle dorsiflexion
- Overactive posterior tibialis muscle
- Supinated foot in stance
- Upper extremity posturing – shoulder adducted, elbow flexed, forearm pronated, wrist flexed, hand clenched in a fist with the thumb in the palm)
- Impaired sensation, impaired 2-point discrimination, and/or impaired position sense.
- Cognitive impairment in 28% of these patients.
- Circumduction gait of lower extremity on the affected side
- Specific learning disabilities
- Oromotor dysfunction
- Possible unilateral sensory deficits
- Visual impairment
- Seizures
Spastic diplegic cerebral palsy
- Period of hypotonia followed by extensor spasticity in the lower extremities
- Minimal functional deficits of the upper extremities.
- Delayed development of gross motor skills.
- Cognitive in appx 30%
- Scissoring gait pattern
- Learning disabilities and seizures less common
Spastic quadriplegic cerebral palsy
- All limbs affected
- Full-body hypertonia
- Truncal hypotonia with extremity hypertonia
- Oromotor dysfunction
- Risk of cognitive difficulties
- Multiple medical complications
- Seizures
- Legs affected equally or more than arms, categorized as double hemiplegic if arms more involved than legs
Classification based on the degree of severity
- Mild—fine movement alterations only;
- Moderate—variable difficult in relation to speech and gross movement, but daily activity performance is functional;
- Severe—inability to walk, use the hands and communicate through speech.
Clinical Presentation
The basic presentation of the child with cerebral palsy is failure of developmental signs. It could be failure to suppress primitive reflexes [like Moro] or failure to meet expected developmental milestones.
Abnormal muscle tone is the most frequently observed symptom. Cerebral palsy frequently manifests as early hypotonia for the first 6 months to 1 year of life, followed by spasticity.
Following are the other common problems note in patients with cerebral palsy –
- Mental retardation
- Visual and hearing impairments
- Speech and language disorders
- Oromotor dysfunction
When suspected, it is important to scan for risk factors including
- Maternal exposure to illicit drugs, toxins, infections
- Maternal diabetes;
- Acute maternal illness
- Trauma
- Radiation exposure
- Events in antenatal care
- Early frequent spontaneous abortions
- Parental consanguinity
- Family history of neurologic disease
- Perinatal events
- Neonatal complications
History should assess gross motor, fine motor, language, and social milestones from birth until the time of evaluation.
Important Motor Milestones
|
|
| Head control | 2 months |
| Rolling | 4 months |
| Sitting at age | 6 months |
| Walking. | 1 year |
On examination following findings may be noted
- Joint contractures secondary to spastic muscles
- Hip – Excessive flexion, adduction, and femoral anteversion
- Scissoring of the legs
- Knee flexion and extension with valgus or varus stress
- Foot equinus with varus or valgus of the hindfoot
- Hypotonic to spastic tone
- Growth delay
- Persistent primitive reflexes.
- Increased reflexes
- Abnormal gait
The diagnosis of cerebral palsy is essentially clinical and difficult to establish in infants under 12 months until the deformities become evident as the CNS matures.
Differential Diagnoses
- Duchenne muscular dystrophy
- Herediatory sensory—motor neuropaties
- Brain tumors
- Intraspinal tumors
- Spinal cord injury following birth
- Inherited Metabolic Disorders
- Metabolic Myopathies
- Metabolic Neuropathy
- Traumatic Peripheral Nerve Lesions
- Tumors of the Conus and Cauda Equina
- Vascular Malformations of the Spinal Cord
Lab Studies
There are no definitive laboratory studies for diagnosing cerebral palsy but following studies can be used to rule out other causes.
- Thyroid function studies – To rule out abnormal thyroid
- Lactate and pyruvate levels: Mitochondrial cytopathy
- Ammonia levels: Liver dysfunction or urea cycle defect
- Organic and amino acids: Inherited metabolic disorders
- Chromosomal analysis: Genetic syndrome
- Cerebrospinal protein – Asphyxia in the neonatal period [raised protein levels]
Imaging studies
To evaluate brain damage and identify persons at risk for cerebral palsy include the following:
- Cranial ultrasonography
- Performed in the early neonatal period
- Tells about structural abnormalities
- Evidence of hemorrhage or hypoxic-ischemic injury
- Computed tomography identify
- Congenital malformations
- Intracranial hemorrhage
- Periventricular leukomalacia
- Early craniosynostosis.
- MRI
- Clearly defines cortical and white matter
- Tells whether appropriate myelination is present for a given age
- Electroencephalography – in seizure disorders
- Electromyography and nerve conduction studies are helpful when a muscle or nerve disorder is suspected
Management of Cerebral Palsy
Management of patients with cerebral palsy must be individualized based on clinical presentation.
Management of cerebral palsy focuses on goal of maximizing the person’s independence and community participation.
A multidiscilplinary approach is required.
Management of abnormal movements
Botulinum toxin
Botulinum toxin (Botox) type A may reduce spasticity for 3-6 months.
Phenol intramuscular neurolysis
Phenol can be used to treat spasticity in some large muscles.
Drugs
- Antiparkinsonian like levodopa
- Anticonvulsant drugs
- Antidopaminergic, and antidepressant agents:
- Antispasticity agents like
Surgery
Surgical treatments used in patients with cerebral palsy include the following:
- Intrathecal baclofen pump insertion – To treat spasticity and/or dystonia
- Selective dorsal rhizotomy – To treat velocity-dependent spasticity
- Stereotactic basal ganglia surgery may improve rigidity, choreoathetosis, and tremor
- Orthopedic surgery for scoliosis, joint contractures or dislocation
Rehabiltation Therapy
- Physical activity and reduction of sedentary behaviour
- Physiotherapy
- Speech therapy
- Conductive education
- Biofeedback
- Massage therapy
- Occupational therapy
- Orthotics
Complications of Cerebral Palsy
Cerebral palsy complications may affect multiple systems
Gastrointestinal
- Failure to thrive
- Feeding and swallowing
- Obesity
- Gastroesophageal reflux and associated aspiration pneumonia
- Constipation
Dental problems
- Dental caries
- Malocclusion
- Gingival hyperplasia.
Respiratory
- Increased risk of aspiration pneumonia because of oromotor dysfunction
- Chronic lung disease/bronchopulmonary dysplasia
- Bronchiolitis/asthma
Neurologic complications
- Epilepsy
- Hearing loss
Vision Problems
- Visual-field abnormalities due to cortical injury
- Strabismus
- Retinopathy of prematurity.
Neuro-cognitive
- Epilepsy [15-60%] – more common in patients with spastic quadriplegia or mental retardation.
- Mental retardation (30-50%), most commonly associated with spastic quadriplegia
- Attention-deficit/hyperactivity disorder
- Learning disabilities
- Increased prevalence of depression
- Sensory integration difficulties
- Increased prevalence of or autism
Prognosis of Cerebral Palsy
With appropriate management, patients may be able to fully integrate socially and academically.
The morbidity and mortality of cerebral palsy relate to the severity of this condition and concomitant medical complications, such as respiratory and gastrointestinal difficulties. In patients with quadriplegia, the likelihood of epilepsy, extrapyramidal abnormalities, and severe cognitive impairment is greater than in those with diplegia or hemiplegia.
Cognitive impairment occurs more frequently in persons with cerebral than in the general population. Many patients with this can ambulate independently or with assistive equipment.
Patients with severe forms of cerebral palsy may have a significantly reduced life span but patients with milder forms of this disorder have a life expectancy close to the general population.
References
- Moster D, Wilcox AJ, Vollset SE, Markestad T, Lie RT. Cerebral palsy among term and postterm births. JAMA. 2010 Sep 1. 304(9):976-82.
- Dabney KW, Lipton GE, Miller F. Cerebral palsy. Curr Opin Pediatr. 1997 Feb. 9(1):81-8.
- Jacobsson B, Hagberg G. Antenatal risk factors for cerebral palsy. Best Pract Res Clin Obstet Gynaecol. 2004 Jun. 18(3):425-36
- Odding E, Roebroeck ME, Stam HJ. The epidemiology of cerebral palsy: incidence, impairments and risk factors. Disabil Rehabil. 2006 Feb 28. 28(4):183-91.
- Girard S, Kadhim H, Roy M, Lavoie K, Brochu ME, Larouche A, et al. Role of perinatal inflammation in cerebral palsy. Pediatr Neurol. 2009 Mar. 40(3):168-74.
- Jones MW, Morgan E, Shelton JE, Thorogood C. Cerebral palsy: introduction and diagnosis (part I). J Pediatr Health Care. 2007 May-Jun. 21(3):146-52.
