What Is Cerebral Palsy?
What Is Cerebral Palsy?
Spastic Cerebral Palsy.
The word ‘spastic’ means ‘stiff’ and so children who have spastic cerebral palsy have a tendency to have stiff muscles. That stiffness may show itself only in one limb, two limbs. Three limbs or four. There are various names for the different combinations of limbs which are affected in all types. I will not highlight these at the end of this section.
Spastic cerebral palsy is usually caused by injury to the cortex, especially the motor cortex and to a bundle of nerve fibres called the corticospinal tract. Obviously, spasticity is very uncomfortable and has negative consequences for the child’s development, depending upon how many limbs are involved and it’s severity.
Athetoid Cerebral Palsy.
This type of cerebral palsy is caused by injury to a structure below the cortex called the ‘basal ganglia.’ The basal ganglia plays a role in motor function, cognitive processes, emotional processes and our ability to learn. It also acts as a ‘braking’ mechanism on the thalamus, a part of the brain which mediates our sensory experiences. So, without this inhibitory role, one can imagine a thalamus in effect operating without its ‘braking system’ which might produce many of the sensory distortions we see in some children who have cerebral palsy. It also acts as a ‘braking system’ for movement, which enables us for instance, to sit still. In order to sit still a ‘brake’ has to be placed on all other movements. Consequently injury at this level hampers the ‘braking system’ and we see children who cannot sit still and are in constant movement and children whose sensory perception is distorted. Injury to this part of the brain also exhibits itself in many children by retention of the primitive postural reflexes, as it is the role of the basal ganglia to suppress these in order to enable the child to move.
Children with basal ganglia injury are also more likely to have hypotonia, (floppy muscle tone) and persistently impaired balance and ambulation performance.
