Considering the extreme complexities involved in co-ordinating the interactions of several different parts of the brain to trigger the nervous system, which sends signals to the muscles, it’s hardly surprising that things can go wrong and result in disorders. Among these is abnormal involuntary movement, or dyskinesia.
Although they vary in their clinical appearance, as well as in their underlying causes and treatments, the one thing they all have in common is that they can cause extreme embarrassment, frustration, pain or fear to those afflicted by them.
The causes of dyskinesia are little understood although some are induced by exposure to certain chemicals, brain injuries and genetic predispositions. The effects, especially in serious cases, are obvious: tremors, tics, twitches, shaking, spasms, abnormal postures, poor eye/hand co-ordination, and speech and balance problems.
The most common type of dyskinesia is essential tremor, which causes uncontrolled shaking, usually in the arms and the hands. This affects one in 20 people under the age of 40 and one in five people over the age of 65. This hereditary condition usually responds well to medication and alcohol.
The second most common condition is the neurodegenerative disorder Parkinson’s disease, which has received much publicity since global icons Michael J Fox and Muhammad Ali were diagnosed with the condition. Parkinson’s affects motor skills, speech and other functions, and is characterised by muscle rigidity, tremors, a slowing of physical movement and, in extreme cases, the loss of physical movement.
There is no cure or treatment that can slow down the progression of Parkinson’s, although aggressive therapy early in the course of the disease has been shown to improve quality of life. Also new-generation medication shows promise in treating the condition.
The third most common form is dystonia. This neurological disorder is characterised by involuntary muscle contractions, which force parts of the body into abnormal, painful spasms and postures.
Dystonia causes abnormal involuntary movements because of disorders in the part of the brain known as the basal ganglia and has many different characteristics.
Blephorospasm affects the muscles of the eye and head-causing rapid blinking. In extreme cases it can force the eyelids to close involuntarily. Oromandibula dystonia affects the muscles of the jaw and the tongue, causing severe facial distortions.
Spasmodic dystonia affects the muscles of the vocal chords in the larynx, reducing the voice to a whisper. Cervical dystonia affects the neck muscles and causes the head to rotate to one side or to be pulled down towards the chest.
Focal dystonia is localised to one group of muscles and is also common, such as writer’s cramp. All dystonia conditions are generally believed to be aggravated by stress, anxiety and tiredness.
Restless leg syndrome causes uncomfortable sensations in the legs and occurs at night while a person is lying down. Relief usually comes when the individuals stretch their legs.
Other forms of involuntary movement can be a sign of the onset of a serious condition, such as Huntington’s disease. This hereditary degenerative brain disorder, which over time reduces a sufferer’s ability to walk, talk and think, also has no cure.
Tourette’s syndrome, associated with motor and vocal tics, is an inherited neuropsychi-atric disorder that starts in childhood. The severity of the tics tends to decrease as children reach adolescence and Tourette’s is rare in adults.
Abnormal involuntary movements will be the topic of Bonitas House Call on July 16 on SABC2 at 9am
This article originally appeared in the Mail & Guardian newspaper as a sponsored feature