So what is Cerebral Palsy, anyway?
Short Answer: It's a condition caused by damage to the brain
in utero or during birth, or by an organic inability of the brain to develop
and/or grow properly. It is not a
pediatric stroke, though the symptoms are similar.
Are there different types of Cerebral Palsy?
Short Answer: Yes. CP is generally accepted as having 4
major types: Spastic, Ataxic, Dyskenetic,
and Mixed. Below is a brief
description of each type.
Spastic Cerebral
Palsy is the most common type of CP. Approximately 80% of people with Cerebral
Palsy have a spastic type. Types of spastic CP are categorized by which parts
of the body are most affected, and 3 general types have been defined: Spastic quadriplegia (all four limbs
affected); Spastic diplegia (two
limbs on opposite sides of the body affected, most commonly the legs); and Spastic hemiplegia (affecting one side
of the body.) Occasionally you'll see a 4th type of spastic CP
mentioned in medical literature -- Spastic
tertraplegia, denoting marked
involvement of both legs and one arm or hand -- but it doesn't seem to
be widely accepted as part of the categorization process, and is generally
lumped in with diplegia. (Remember,
we're categorizing by what is most
affected; Cerebral Palsy of any type is a whole body condition.)
Spastic CP is
characterized by a noticeable and chronic increase in muscle tone. People with
types of Spastic CP often exhibit stiff, labored movements, limb rigidity, and
joint problems. They also have trouble with balance and both fine and gross
motor skills -- symptoms that are present across the CP spectrum, no matter the
type. Problems with sight, hearing, and/or speech are common among all types as
well.
The next type of Cerebral Palsy is called Ataxic CP (or Ataxia.) The most marked
symptoms of Ataxia are those found in any other type of Cerebral Palsy:
problems with walking, balancing, and coordination. Those with Ataxic CP may
exhibit an unsteady gait and have an especially difficult time with quick
movements or with tasks that require a great deal of fine motor control, such
as writing.
Next comes Dyskenetic
CP. At one time called "Athetoid" this category has been renamed
and expanded to include any type of Cerebral Palsy of which the primary symptom
is uncontrollable muscle movement. (Athetoid
now falls under this umbrella, as do Choreoathetoid and Dystonia.) Those
with a type of Dyskenetic CP exhibit uncontrollable movements of the arms,
hands, legs, facial muscles, and tongue. They may have a difficult time
swallowing, drinking from a straw, and talking. Muscle movements produced by
Dyskenetic CP may be fast and jerky or slow and writhing, and muscle tone can
vary from too tight to too loose from day to day, or even within the same day.
Mixed CP occurs
when a person exhibits symptoms of more than one type of Cerebral Palsy. The
most common type of Mixed CP is Spastic-Dyskinetic. I myself was re-categorized
as having a Mixed type of CP when I developed dyskinesia in high school:
trouble controlling my arms (they like to bend on their own), and an
occasional, sustained, repetitive tic of the neck and face, and I am now
classified as Spastic-Diplegic-Dyskinetic. (Mixed.)
Note: Cerebral
Palsy is notoriously difficult to classify. Due to the nature of brain
abnormalities, symptoms such as dyskinesia, intention tremor, and dysphagia
(trouble swallowing) can appear suddenly throughout a person's lifetime.
Categorization is mainly for purposes of statistical analysis and broad
treatment goals.
What parts of the brain does Cerebral Palsy affect?
Short Answer: All types of CP primarily involve the cerebellum, the area of the brain responsible for balance, coordination, and voluntary movement. Also affected is the cerebrum, which is the main "body" of the brain that houses the areas responsible for all other brain functions. (See diagram below.) Depending on the type of CP, different parts of the cerebrum may or may not be affected. (Some people have trouble with the part of the brain responsible for speech, others with the part of the brain responsible for sight, etc. CP is multi-symptomatic, meaning an individual can have trouble with many of these things simultaneously.)
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| Diagram of the human brain showing the cerebellum (against the brain stem) and the cerebrum, labelled with some of the things for which different areas are responsible. |
This post is one in a series dealing with the technical aspects of Cerebral Palsy. Tune in next week for more information on the side effects of Cerebral Palsy, and its treatment.
