Dyskinetic movements can be:
Dyskinetic movements often co-occur alongside spasticity.
Dyskinetic cerebral palsy results from injury to the part of the brain called the basal ganglia. Different forms of dyskinesia (dystonia, athetosis and chorea) result from injury to slightly different structures within the basal ganglia.
The basal ganglia is like the brain’s switchboard for interpreting messages between the movement centre and the spinal cord – it is responsible for regulating voluntary movements.
The basal ganglia through it’s connections with other areas of the brain also has other important non-motor related functions, such as regulating emotion, mood and behaviour.
Dystonia is characterised by involuntary muscle contractions that result in slow twisting or repetitive movements, or abnormal sustained postures, that are triggered by attempts to move.
Characteristics of dystonia include:
What part of the body is affected?
Dystonia can be present in only one part of the body, known as focal dystonia, or throughout the whole body, known as generalised dystonia.
Focal dystonia may only occur during a particular movement or task. For example, dystonia in the foot muscles may affect how a person stands on that foot.
Cervical dystonia is another example of a focal dystonia – this is dystonia in the neck muscles which causes the neck to twist, tilt or rotate.
Hemidystonia is where on arm and one leg on the same side of the body are affected by dystonia.
Generalised dystonia refers to dystonic movement that affects both legs and at least one arm, or the trunk in combination with at least one arm or leg. Generalised dystonia can affect mobility as well as cause speech and swallowing difficulties.
Sensory tricks
Some people with dystonia notice that specific sensations and movements, known as ‘sensory tricks’, temporarily suppress their unwanted movements.
Examples of sensory tricks include:
Some people use these sensory tricks to dampen an unwanted movement in order to prepare their body to make a desired movement.
Athetosis is characterised by slow, continuous, involuntary, writhing movements that are present at rest and made worse by attempts to move. People with athetosis experience fluctuations in muscle tone – with muscle tone alternating between being floppy (hypotonia) and extremely variable motion (hyperkinesias). One difficulty caused by this fluctuation in muscle tone is the inability to maintain a posture. This means that sitting and standing still can be difficult and a person may need to work and concentrate harder than usual to get their hand to a certain spot (like scratching their nose).
Characteristic of Athetosis include:
The term chorea is derived from the Greek word for ‘dance’. Chorea is characterised by involuntary movements that are brief, abrupt, irregular and unpredictable. People with mild chorea may appear fidgety or clumsy whilst people with more severe choreiform movements may display wild, violent movements that are large in amplitude (ballismus).
Movements can affect various body parts and interfere with movement, speech and swallowing. Chorea may worsen with attempts to move and anxiety or stress. Movements subside during sleep. Choreiform movements may occur with athetosis and when this occurs, they are known as choreoathetosis. They may also occur with dystonia.
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