Cerebral Palsy

cerebral palsyCerebral palsy is a nonprogressive central nervous system disorder that causes perceptual, postural, and movement disorders with an onset in infancy or early childhood. Although the CNS lesion is nonprogressive, the musculoskeletal pathology is progressive in most individuals. Most CNS insults are pre- or perinatal in origin. CNS injury may cause a variety of clinical problems.

Etiology

CP is an inclusive diagnosis with an extensive list of causes. Common causes include trauma, infection, and toxins. Common associations include prematurity, low Apgar score, difficult delivery, and neonatal illnesses.

Pathology

Most infants with CP show pathologic changes in the brain that correlate poorly with the clinical features. Focal and generalized involvement of the cortex, basal ganglia, and brain stem result from ischemic damage, atrophy, agenesis, gliosis, and degenerative changes. MR imaging shows abnormalities, which include periventricular leukomalacia in preterm infants and a variety of abnormalities in term infants. Extrapyramidal cerebral palsy shows lesions in the putamen and thalamus.

Pathophysiology

Cerebral palsy is an upper motor neuron syndrome. This causes spasticity, hyperreflexia, and cocontractions. In addition, weakness, loss of motor control, poor balance, and perceptual deficits occur.

The infant with cerebral palsy is born without deformity. A basic feature is a failure of longitudinal growth of muscle due to a lack of normal stretching by physiologic loading and stretching. The lack of relaxation and elongation leads to shortening. This process leads to torsional deformity of long bones and degenerative changes.

Tone

Disorders of tone and motion are major features of cerebral palsy.

  • Spasticity is increased tone with passive stretch. This response is greatest if the stretch is applied quickly. This is the common form of cerebral palsy.
  • Rigidity is an increased resistance to passive stretch that is independent of the speed of application. Rigidity may be a uniform (lead pipe) or intermittent (cog wheel) type. This is uncommon in cerebral palsy.
  • Athetosis is characterized by involuntary movement. The combination of athetosis and spasticity is referred to as tension athetosis.
  • Ataxia is a loss of coordination and balance.
  • Dystonia is an intermittent distorted posturing.
  • Ballismus is an uncontrolled involuntary motion.

Diagnosis

The diagnosis of cerebral palsy is suspected if a history of birth or developmental problems exist and the infant demonstrates a failure of achieving developmental milestones. It is usually not possible to be certain of the diagnosis until after 6 months of age. Does the mother believe the infant is normal? The mother’s intuition is often correct. She may sense that something is wrong in early infacy.

Examination is best performed on the parent’s lap while the history is being taken. Inquire about the pregancy and birth history. Observe the infant’s spontaneous movements, symmetry, and posture. Perform a neurological examination and note the response to positioning.

Standing Note stability. Compare the infant with normal milestones. Walking should be well established by 18 months. One leg standing is usually possible after age 4-5 years. Note the stability when the child is gently pushed forward, backward, from side to side. This stability is helpful in predicting the need for support when walking.

Gait observation is made in the hallway with adquate space. Note the heel-strike, foot-flat, toe-off sequence. Normally, the gait is symmetrical with stance occupying about 60% of the cycle. When running, the hemiplegic child will elevate the affected arm.

Upper limb Ask the child to remove and put back on his or her shoes. Not realizing this is part of the examination, the child will use the hands freely. This provides an opportunity to assess upper limb function and is especially useful in the child with hemiplegia.

Laboratory studies Laboratory studies may be useful in ruling out infectious agents. These are sometimes referred to as TORCH etiologies. The TO is for toxoplasmosis, the R for Rubella syndrome, C for Cytomegalic inclusion disease, and H for Herpes virus.

Progressive lesions Ruling out a progressive lesion as the cause of the problem is important objective of evaluation. The need for routine MRI evaluations of the nervous system is controversial. Order an MRI if the diagnosis of cerebral palsy is uncertain. Thoughtfully consider conditions that may be confused with cerebral palsy, such as spinal cord or brain tumors. These tumors are sometimes slow growing and can be confused with CP. Demyelinating, degenerative, or familial (spastic paraplegia) disorders must be ruled out. If any question exists, refer to a neurologist to confirm the diagnosis.

Distribution

Cerebral palsy is classified by distribution of involvement. Be aware that on careful examination the so-called uninvolved extremity often shows subtle abnormalities. Slight upper limb involvement is seen in diplegia and opposite limb abnormalities in hemiplegia. Side-to-side asymmetry is also common in spastic quadraplegia and diplegia.

  • Monoplegia is uncommon and affects a single limb.
  • Hemiplegia is common and affects the limbs on one side. The upper limbs are often more involved. Hemiparesis is the mild form.
  • Diplegia is common and affects the lower limbs more than the upper limbs. This pattern is sometimes called paraplegia.
  • Triplegia is uncommon and involves three limbs. This may be a combination of diplegia and hemiplegia.
  • Quadraplegia, or total body involvement, is common and most severe.

Gait Lab Evaluation

Most gait lab evaluations are performed on children with cerebral palsy. The value of gait analysis is controversial. Those who use analysis believe that these studies better define and document the problems, provide measured outcomes, and assist in decision making.

Documentation is the greatest strength and may be compared with radiographic evaluations providing objective data that can be a permanent record for the paitent. Most measures are made for pre- and postinterventions and help eliminate observer bias. These studies provide force generation, muscle length, EMG patterns, and energy consumption measures.

The studies depend upon the facilities of the specific laboratory. Commonly performed studies in cerebral palsy include a careful physical examination and motion and energy expenditure evaluations.

Cerebral Palsy Treatment

Management is challenging, as the disease is complex, extensive, permanent, and varied. Manage with the perspective that the long-term success places priorities on communication, socialization, independence, and finally, mobility. Optimal management requires considered application of the best of many choices of interventions for the particular child. Avoid ineffective treatments, as they are harmful to the child and draining on the family’s energy and resources.

Therapy

Established therapy techniques are valuable in assessment, providing family support, facilitating bonding, improving self-care skills, providing infant stimulation, promoting use of adaptive equipment, and facilitating family interaction with the child.

Specific modalities are controversial and include:

  • Alternative medicine measures that include acupuncture, vitamins, yoga, herbs, meditation, special diets, massage, and magnetic fields, among others.
  • Adeli suit is based on elastic band restraints to promote active exercises, as utilized by the Russian Cosmonaut Space program.
  • Conductive education has evolved from the Peto Institute of Budapest, Hungary.
  • MOVE program (mobility opportunities via education) is based on promoting functional gaols.
  • CranioSacral Therapy (CST) proposes to enhance the natural healing process through improvement in the operation of the nervous system.
  • Hippotherapy is based on improving function through horseback riding, using the dynamic movement of the horse to organize the nervous system.
  • Hyperbaric oxygen therapy seeks to promote healing of injured neural cells.
  • Inhibitory casting derives benefit from immobilization in a functional position.
  • Neurodevelopmental therapy (NDT) seeks to promote normal reactions and inhibit pathological responses.
  • TES, or threshold electrical stimulation, has the goal of therapeutic stimulation to exercise good muscles and provide feedback-timing cues to help facilitate recovery. The procedure takes place at night during sleep.

Adaptive Equipment

Adaptive equipment includes standing devices and aids for self-care. These devices are often very practical and effective in improving function.

Mobility aids include wheelchairs, carts, and motorized devices, which allow the child greater independent mobility.

Cast correction is effective as a temporary means of overcoming recently acquired fixed contractures.

Night splinting is sometimes useful in managing the child following surgery to prevent early recurrence and provide comfort.

Orthotics

Braces and splints have specific indications. The ankle-foot orthosis is the only brace shown to be useful. Several types of AFOs are available.

Solid AFO These AFOs are nonarticulated and provide maximum stability. These orthotics are the most durable and least expensive.

Hinged AFO These AFOs allow ankle motion and may incorporate plantarflexion (PF) or dorsiflexion (DF) stops to limit unwanted motion.

Ground reaction force AFO The GRFO helps stabilize the knee by altering the shape or length of the footplate.

The posterior leaf spring (PLS) orthosis allows limited dorsiflexion in stance.

Spasticity Management

Management of spasticity is a central part of treatment and has become more effective with new techiques. Different treatments may have a focal or general effect.

Phenol is used for intraneural injection in the obturator nerve for adductor spasticity. Injection of the musculocutaneous nerve is used for temporary reduction of spasticity of the elbow flexors.

Botulinum toxin, a neurotoxin derived from clostridium botulinum, is injected in skeletal muscle to produce a dose-dependent reversible effect of paresis. The agents are commercially available as Botox, Dysport, and BTX-A. This method of chemodenervation is useful in providing better muscle balance across joints to improve range of motion. The injections are reconstituted shortly before use, and injected in controlled dosage through a small needle under local analgesia into the muscle, using anatomic landmarks or sites as determined by electromyography, ultrasonography, or both.

The agent is commonly used in cerebral palsy for toe-walking, scissoring, and a couching gait in the lower limb, or for reduction of flexion deformities of the forearm. The effect provides about 3–6 months of reduction in muscle tone. The high cost of the agent and short duration of the effect limit its value.

Intrathecal baclofen is administered by an implanted battery-driven pump to control severe generalized spasticity. This treatment is powerful and useful in severe generalized spasticity in the extremities, and improves upper-extremity function. Complications from the intrathecal catheter occur in 20% of patients, and infection occurs in about 5%. Progressive scoliosis has been reported. Replacing the baclofen is required at about 3-month intervals. When batteries are exhausted, the unit must be replaced surgically.

Rhizotomy Selective dorsal rhizotomy is performed through a L1–S1 laminoplasty with a selective section of 20% of the dorsal rootlets. The procedure reduces spasticity and creates weakness of the lower limbs. The laminoplasty reduces the risk of spinal deformity. Physical therapy is necessary to overcome the weakness. The procedure improves range of motion and functional improvement is reported. The procedure is best performed on ambulatory children with spastic diplegia with dynamic deformity. Reports of spinal deformity, hip subluxation, and planovalgus foot deformities have been reported. Orthopedic procedures are still required in about 70% of patients and should be postponed for 1–2 years after rhizotomy.

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