How Does Cerebral Palsy Affect the Brain?

Many of the symptoms of cerebral palsy are the same, no matter the cause or the specific type of CP. These symptoms include abnormal muscle tone, including muscles that are too loose and result in difficulty keeping the body and limbs upright, or that are too tight and result in a lack of flexibility. There is a lack of control in motor development and coordination, often affecting reflexes as well. Those afflicted with cerebral palsy often have difficulty standing or sitting straight, or keeping their legs straight when walking. Other symptoms include uncontrollable facial expressions, difficulties with balance and unsteadiness.

Ataxia is when a person has difficulty performing voluntary movements, from picking up an object to walking across a room. It occurs when there is physical damage to the brain that interrupts signals traveling from it to various parts of the body. Causes of this damage can include a stroke, a tumor, severe head trauma, a reaction to medication or exposure to toxic materials that damage the brain, such as lead or mercury. Vestibulo-cerebellar dysfunction results in difficulty controlling eye movements, and defective signals between the eye and the brain. As a result, this type of condition makes it difficult for individuals to keep their balance and control their posture. Cerebro-cerebellar dysfunction is an error in the connections in the cerebellum, resulting in difficulty making precise, voluntary movements. Cerebro-cerebellar dysfunction manifests as slurred speech, irregular writing and involuntary tremors.

The athetoid/dyskinetic form of CP is associated with a defect in the system of the brain that produces dopamine, and results in difficulty keeping still. Some of the symptoms can be nearly indistinguishable from those of Tourette's, including rapid eye movements, facial tics, grimacing (and other uncontrollable facial expressions), and the compulsive making of noises, such as tongue clicks. Individuals with athetoid/dyskinetic cerebral palsy often have difficulty holding themselves in an upright position, sitting or standing, and have a mixed muscle tone that--along with the small, involuntary movements--makes holding and manipulating objects difficult.

The most common of all types of cerebral palsy, this makes up between 70 and 80 percent of all diagnosed cases. In spastic cerebral palsy, there has been damage to the motor cortex in the brain that affects the nervous system and control over muscle groups. There is a defect in the system that transfers gamma amino butyric acid, an amino acid that regulates excitability in nerves. Spastic cerebral palsy is area-sensitive, and often affects a certain part of the brain, which translates into difficulties in certain parts of the body. In spastic hemiplegia, one side of the brain is affected; in turn, one side of the body shows outward symptoms. Spastic diplegia affects the lower half of the body more than the upper half, creating difficulties in walking. Spastic quadriplegia affects all extremities.

Because of the outward signs of the disability, it is frequently assumed that those afflicted by it are less intelligent. This has been proven false, however. The parts of the brain that are affected by cerebral palsy are those that control movement, not intelligence. People afflicted with cerebral palsy often have sharp intellects masked by outward disabilities that are rooted only in their movement. While there is a percentage (little more than 30 percent) of sufferers who can also be diagnosed with a mental handicap or a physical one like blindness or severe seizures, many of those diagnosed with cerebral palsy have IQs on a par with those of non-sufferers.

Cerebral palsy does not get worse with time, and there have been some developments that can lessen the symptoms. Medications may help repair some of the chemical imbalances in the brain, and to relax stiff, uncontrollable muscles. Often, medications are injected directly into the afflicted area, whether into the muscle tissue itself or into the spine. Physical therapists have had some success in counteracting the signals sent to the brain by retraining muscles and joints. Speech therapists can also help in some of the cases in which slurred speech is one of the symptoms. In some cases where there is a miscommunication between the brain and the nerves, there has been success with surgical procedures that sever the connections between the two.