Cerebral palsy

Definition

“Cerebral palsy describes a group of permanent disorders of the development of movement and posture, causing activity limitation, that are attributed to non-progressive disturbances that occurred in the developing fetal or infant brain. The motor disorders of cerebral palsy are often accompanied by disturbances of sensation, perception, cognition, communication, and behaviour, by epilepsy, and by secondary musculoskeletal problems.”

Sources: International Workshop on Definition and Classification of Cerebral Palsy, Bethesda, Maryland, July 11–13. srpanj 2004; Executive Committee for the Definition of Cerebral Palsy: M.Bax, M.Goldstein, P.Rosenbaum, A.Leviton, N. Paneth).

Incidence

The incidence of cerebral palsy is 2-4‰.

Cause

The search for the causes and a possible primary prevention for cerebral palsy is still underway. What has changed in the last years is the realisation that despite earlier beliefs, the majority of cases of cerebral palsy are not caused by complications at birth, but rather by various prenatal factors and events.

In 2000, Stanley proposed that possible causal pathways of cerebral palsy are risk factors. These pathways are divided into prenatal, very premature birth (before 32 weeks gestation), extremely premature birth (before 28 weeks gestation), intrauterine growth retardation, signs of birth asphyxiation, multiple births and postnatally-acquired cerebral palsy.

There are many prenatal causal factors. The TORCH group infections (Toxoplasmosis, rubella, cytomegalovirus and herpes simplex), transmitted from the mother to the child during the first two trimesters can cause congenital brain defects and in the last trimester can cause brain damage. Alcohol consumption during pregnancy has long been recognised as a cause of brain damage, and it is known as fetal alcohol syndrome. Smoking during pregnancy is recognised as a factor leading to low birthweight and it has harmful effects as of the seventh week of gestation. There is also a rare disorder called familial cerebral palsy, which accounts for about 1.5% of the cases of cerebral palsy, and it is inherited autosomal recessively.

Very prematurely born children are 30 times more at risk for developing cerebral palsy than full term children.

Intrauterine infection is a possible cause of cerebral palsy in both preterm and full term children and beta-hemolytic streptococcus, E. coli and listeria monocytogenes are among the most common agents.

Intrauterine growth retardation is a condition in which a child’s birthweight is low in comparison with his age. The exact connection between this condition and cerebral palsy is not known.

Lack of oxygen during delivery is a possible, but not the most common, cause of cerebral palsy. There are a number of causes for this, as follows: extended and difficult delivery, umbilical cord prolapse, the presence of meconium in the amniotic fluid, birth trauma, breech presentation and so on.

Multiple births are also a risk factor for developing cerebral palsy, primarily because of the increased risk of preterm birth and low birthweight.

Possible postnatally acquired causes of cerebral palsy include blood clotting disorders, prenatal metabolic conditions, infection – as the most common cause of postnatal encephalopathy – and head injuries (as the next most common cause).

Clinical picture

Cerebral palsy is characterised by motor disorder. Besides the always present motor sympoms, cerebral palsy can have some other symptoms as well (epilepsy, slow development of speech and other speech problems, excessive drooling, mental retardation, eating disorders, behaviour disorders, sensibility issues, behaviour problems, learning disabilities etc). Not necessarily all children with cerebral palsy have all or some of the complications mentioned above, but they occur more often in children with cerebral palsy.
The term cerebral palsy is percieved by the parents as paralisis, the inability to move. Cerebral palsy almost never means complete immobility, but there are decreased movement abilites and their decreased quality.

The symptoms of cerebral palsy are not shown immediately, they develop over time. With small babies, the symptoms of cerebral palsy can go undetected for a long time, and it is stated that the parents of children with hemiparesis on average notice the problem when the child is 6-8 months old, which is relatively late for optimal rehabilitation. Also, the muscle tone of very small babies is usually not increased, which is the most recognizable sign of cerebral palsy, but on the contrary, the muscle tone of small babies is decreased at first.

The development of a child that will develop cerebral palsy is altered (slow, changed or with complete lack of several developmental milestones, such as turning from back to stomack and vice versa, the ability to sit etc.).

In all forms of cerebral palsy we find altered muscle tone (muscle tension) and it is most likely the high muscle tone of the extremities (hypertonus), low muscle tone (hypotonus), or sudden changes of muscle tone. Primitive reflexes are often also present.

Muscle tone and posture disorders often cause contractures at advanced point of development (limited movements of some joints) or deformations (skoliosis, hip luxation and subluxation, different foot deformaties like valgus or varus position).

The clinical picture of cerebral palsy can be very different in its severity or with its symptoms.

Children with less severe forms of cerebral palsy can have limitations that are smaller that the usual undertanding of cerebral palsy. The line between „a very clumsy child“ and a less severe form of cerebral palsy is sometimes vague.

Severe cases can have different problems with walking (limping, walking difficulties, walking with walking aids, for example walker or in wheel chair), with sitting (the inability to sit up, unstable sitting ets.), with fine motor skills and with all motor functions in general.

In the most severe cases these children (and later of course as adults) are completely depending on care of others 24 hours a day.

The time of diagnosing cerebral palsy varies from establishment to establishemnt, from country to country. In Policlynic we do not connect the diagnosis of cerebral palsy with chronological age of the child, insted we diagnose it when we think that the abnormal movement patterns have become permanent.

Prognosis

Giving a prognosis on future possibilities or limitations for people with cerebral palsy before 1997. was mostly descriptive, i.e. the severity of the clinical picture was usually characterised as slight, less severe, and severe form.
To give the prognosis of the illness itself, including the most frequently asked question, will the child be able to walk, was ungrateful.

Since 1997. we use classification of the clinical picture severity that has been proven to be very reliable and that gives relatively dependable prognosis for future possibilities and limitations for a child with cerebral palsy, and it is the most used classification in the world today. It is the Gross Motor Function Classification System (GMFCS), which consists of 5 level, according to the severity of the clinical picture.

GMFCS (The Gross Motor Function Measure ) describes motor abilities of children with cerebral palsy. It is based on their independent mobility, with special stress on sitting and walking. The difference between each level is based on functional possibilities, and the need for different aids (walker,crutches, wheelchair), and the quality of movements is not particularly important for this classification.

Level I includes children with the least severe form of cerebral palsy and with minimum limitations, and Level V children with the most severe forms of cerebral palsy, usually completely depending on help and care of others. During the classification to a certain level, it is important to see what the child can do now and what are his/her motor limitations, having in mind average, and the best functioning. Children are classified to a certain level according to severity of the clinical picture and their age (until 2 years of age, between 2 and 4 years of age, between 4 and 6 years of age).

The stability has a special significance in GMFCS. The sources state that the child classified to a certain GMFCS level will most likely stay there no matter what therapy or intervention it undergoes (which is not the attitude at Polyclinic, although we do not wish to undermine the significance and stability of GMFCS-; see Rehabilitation approach according to Stojčević Polovina)

Literature:
1) Palisano R, Rosenbaum P, Walter S, Russell D, Wood E., Galuppi B.: Development and validation of a gross motor function classification system for children with cerebral palsy. Dev Med Child Neurol 1997; 39: 214-23.
2) Rosenbaum P, Palisano R., Bartlett DJ, Galuppi BE, Russell D.,: Delopment of the Gross Motor Function Classification System for cerebral palsy, Dev Med Child Neurol 2008, 50: 249-253

The natural course of cerebral palsy

It is often expected, as we see in the every day situations, that the a child with cerebral palsy will in time get better. Equally often we hear opinions such as „the child will be able to correct his/her movements, sitting etc. When he/she gets older and understands more.” („He/she will know to step on the heel, and not on his/her toes, when he/she gets older“).

To avoid unrealistic expectations it is necessary to know the natural course of cerebral palsy over many years. The course od this illness can be simply explained by classification that measures the severity of the clinical picture in children with CP (GMFCS).

Each level of GMFCS can be linked to a specific percentage of motor abilities (usually as percetnage we take the result of GMFM testing – see GMFM). For example, a child with cerebral palsy, estimated as GMFCS level V, it is expected that during its development this child will reach about 15% of the motor values, if tested with GMFM. When the child reaches its motor values limit (for a child with CP GMFCS level V it will be in when 2 years old) it is not likely that it will advance any more, and it is even more unlikely that it will go to level IV (less severe form). It is most likely that it will stay the same, and getting slightly worse in time no matter what kind of therapy or intervention it undegoes. Palisan and associates study from 2006. shows that 73% of children with cerebral palsys remainned in the same GMFCS condition, and the ones that had changed the level were usually worse (higher level of GMFCS-a). This scenario represents the natural course of cerebral palsy.

This is the opinion and attitues of most of the scientists and doctors dealing with cerebral palsy. The attitued at Polyclinic is different, we think that intensive rehabilitation can influence the natural course of cerebral palsy (see Rehabilitation approach by Stojčević Polovina).

Classification

There is more than one classification of cerebral palsy

The Swedish classification of cerebral palsy was adopted (in Croatia) at a conference in Brijuni in 1990 because of its simplicity. According to this classification, CP is divided into the following types and sub-type.

Cerebral palsy can also be divided into the following groups according to the body parts that are affected: