The term of cerebral palsy describes a condition and unites a group of clinical syndromes that characterize violation of normal kinetic (motor) and intellectual (mental) development of a child. The reason for development of cerebral palsy is a nonreversible damage of brain. Manifestation of the disease depends on the location of the damage, area of spread and degree of gravity. Gravity can vary from light to very heavy motor dysfunctions, when the entire body is involved.
Notwithstanding the fact that together with the child’s growth detection of cerebral palsy and expression of clinical symptoms often undergoes changes, it does not mean that the disease aggravates.
Epidemiology and Demography
Cerebral palsy is a result of damage of a developing brain which can occur in the period of fetus’ being in the womb, during the labour or during the first two years of life.
Areal of spread and frequency are not defined. According to the data of World Health Organization and various sources, its average frequency equals to 2.5-4 cases per every 1,000 newborns.
Besides motor dysfunction (movement), cerebral palsy is almost always accompanied by other dysfunctions, including cognitive (consciousness), visual, auditory, speech, attention and behavioural. Cerebral palsy is also often accompanied by epilepsy. Approximately 65% of the entire population of cerebral palsy patients have various degrees of dysfunction or deficiency of metal development and difficulty of learning.
Cerebral palsy among timely born newborns usually has prenatal origin. Intranatal occurrences can play a less significant role, and they are mainly preconditioned by previously existing anomalies – prenatal hypoxic-ischemic occurrences, hemorrhage of embryo and mother, placental infarction, shock, embryonic infections (especially meningitis or ventriculitis).
Cerebral palsy is associated with intranatal asphyxia in approximately 10-20% of cases. Around 10-18% of cerebral palsy cases, mainly spastic, are formed after neonatal period. Causes include trauma, cerebrovascular damages, heavy cases of anoxia and hypoxia, infections of central nervous system.
Risk of cerebral palsy development increases with the decrease of gestational age (prematurity). This risk increases 20 times among newborns with weight up to 1,500 gr. Notwithstanding this, among premature newborns prenatal factors can also play a big role. Main dysfunctions which later cause cerebral palsy among premature children are periventicular leucomalacia, intracranial hemorrhage, post-hemorrhage hydrocephalus, bronchopulmonary dysplasia.
Cerebral palsy is the result of damage of the so-called motor cortex of the brain before birth, during labour or during first 2 years after birth. Notwithstanding the fact that the damage as such remains invariable, its clinical manifestation (expression) changes together with the child’s growth and development. Growing up, the majority of children with cerebral palsy improve their motor (kinetic) skills, but the quality and speed of improvement is always low as compared to healthy children.
The reason for kinetic function disorder can lie in various neurological deficiencies. Pathology of the central nervous system associated with the cerebral palsy includes: hemorrhage, mechanic damages, deep hypoxemia of structures, cortex hypoxemia, transitional or irreversible ischemia.
Finally, clinical manifestation of neurological damages depends on damage type and quality, localization of irreversible damage, ability of the central nervous system to adapt and reorganize after damage.
Diplegia is associated with periventricular leucomalacia; dyskinesis – with damage of hyperbilirubinemia and basal ganglions; hemiplegia usually develops in timely born children and in majority of cases is associated with damage of one hemisphere. Quadriplegia is associated with diffuse damage of brain.
Diagnostics of cerebral palsy requires patient examination and physical test. Physical test includes evaluation of pose, expansion of active and passive movements, strength of sensitivity, muscle tone (spasticity), type and quality of movement damage, deformation of extremities.
In certain cases considerable diagnostics value is given to the so-called neuro-imaging research (cranial US, MRI, CAT). These researches are especially important for early diagnostics to provide further early intervention, for evaluation of damage quality of central nervous system, prognosis, as well as for cases difficult from the diagnostic point of view, when clinical manifestation, history and evaluation tools do not give the possibility for exact diagnostics and syndrome identification.
In certain cases it is also necessary to conduct genetic research on congenital metabolism defects and other genetic disorders, with the aim of differential diagnostics.
Differential diagnostics must be conducted for the following diseases and conditions:
• neurodegenerative diseases;
• congenital metabolism defects;
• developing of traumatic diseases of spinal marrow;
• neuromuscular diseases;
• progressing hydrocephaly;
• subdural hematoma.
Quality of severity depends on localization of irreversible damage, expansion area, clinical type of cerebral palsy, associated disorders, ability of the central nervous system to adapt and reorganize post-damage.
Cerebral palsy syndromes are classified according to types and distribution of motor (kinetic) damages. The majority of modern classifications identify the following syndromes: spastic, dyskinetic, ataxic and atonic.
Clinical manifestation – spastic syndromes
Spastic syndromes can be symmetrical, asymmetrical, including both legs dominantly as in case of diplegia, all four extremities as in case of quadriplegia, three extremities, or only one extremity. Identification of these variations is important from the point of view of etiology, associated clinical signs and prognosis.
Patients with spastic cerebral palsy show upper motor neuron damage syndrome which includes: spastic hypertension (muscle spasticity), hyperreflexia, clonospasm, difficult voluntary movements, damage of fine motor function, difficulty in isolated performance of separate movements and weakness.
With time, patterns of spasticity cause shortening of tendon matter, muscle and vessel contracture, bone deformation, vessel fallout or dislocation. Dynamic deformations and motion disorders are especially manifested during relocation or performance of other activity.
Pathological walking and static anomalies include: tiptoeing (foot equinus); damaged walking (thigh flexion, knee flexion, pes calcaneus (heel foot)); impulsive walking (thigh flexion, knee flexion, foot equinus); crosswise walking (thigh adduction). Spinal deformations associated with cerebral palsy are scoliosis, cyphosis and lordosis.
Dyskinetic syndromes are characterized by involuntary movements, athetosis, chorea or dystonia. Infants with such type of cerebral palsy usually show muscle hypotension, preservation of primitive reflexes, hypersalivation, involuntary grimace, delayed psychomotor development. As different from spastic syndromes, these syndromes are not characterized with contractures. Typical signs become visible later, together with the child’s growth. Abnormal movements become especially manifested and are often provoked by emotion, change of pose or voluntary, purposeful motion.
During dyskinetic syndromes various forms of involuntary motions are usually manifested. However generally two types of these syndromes are mentioned: mainly athetoid, with choreiform, athetoic or combined motions, normal or diminished muscle tone (especially in early age); and mainly distonic, with dominating distonic component, tension, preserved newborn primitive (non-reduced) reflexes.
Children with mainly distonic type of dyskinetic syndrome are usually characterized with grave motor and intellectual incapability. Pyramidal signs and anarthria are often. There are transitional forms of two types described above.
Ataxic syndromes are manifested in timely born children with earlier prenatal etiology. This is a clinically and etiologically heterogeneous group. Some cases are the result of genetic heritage. A considerably small number of patients show appendix congenital hypoplasia defined by the term “pure ataxia”.
The majority of patients with ataxic cerebral palsy manifest hypotension, delayed motor and speech development. With time, condition of the majority of patients improves. Generally, but not always, damage of motor function and associated incapability are especially grave. Speech development depends on intellectual skills. In the majority of cases speech is slow, impulsive and “explosive”.
It is a heterogeneous group, usually of timely born infants, who manifest considerable muscle hypotension for a long time. These children often manifest cerebral dysgenesis, microcephaly, mental retardation. Neurological examination does not reveal signs characteristic for other syndromes of cerebral palsy. Tone is changeable and sometimes impression of increase is noticeable too. But the character of this hypertension is different from hypertension manifested during spastic syndromes. This type of hypertension is more characterized as “paratomy” – growing resistance manifests in joints during passive movement, its intensity proportionate to the power with which passive movement is performed. Sometimes this resistance is erratically taken for voluntary movement. Atonic form has been described for a long time but is less frequently mentioned in modern classification.
Attention must certainly be paid to the fact that clinical presentation during cerebral palsy is not always “clean”. During spastic syndromes involuntary movements are often noticed, while during dyskinetic and ataxic syndromes pyramidal signs are noticed. Furthermore, all syndromes of cerebral palsy are characterized by abnormal motor actions and poses of certain quality, so that voluntary movement which is normally complex, coordinated and diverse becomes uncoordinated, stereotypical and limited. In case of grave damage, an attempt to start a voluntary movement can cause performance of pyramidal reflexes, simultaneous contraction of agonist and antagonist muscles and massive, generalized movements. At the same time, performance of separate, isolated movements becomes impossible. It is considered that final and manifested formation of the syndrome generally takes place at the age of 5.
It is highly important to diagnose syndromes of cerebral palsy, while each of them has a specific treatment programme and prognosis.
Early prognosis is difficult except for the cases when we deal with grave damages. Prognosis is mainly connected with the clinical type of cerebral palsy, motor development speed, evolution of newborn reflexes, intellect deficiency, sensor disorders, quality of emotional and social adaptation.
Children who start walking before the age of 2 more often have normal or borderline intellect. Generally, the graver the motor deficiency, the graver is the intellectual damage. In large amount of cases prognosis, independent of walking, is bad for children who do not hold head until the age of 20 months, do not crawl until the age of 5 years. Children who sit independently before the age of 2 years and begin crawling before the age of 30 months, in general can walk independently later.
Prognosis improves in case of early intervention. Early intervention preconditions partial prevention of contractures and deformations, helping optimization of pose and functions.