TYPES OF MOVEMENT DISORDERS

The most common movement disorder is Essential Tremor. It affects one in 20 people under the age of 40 years and one in five people over 65 years. It can affect any person of any age.

The disorder is characterized by involuntary shaking movements of the hand or fingers, or less commonly, other parts of the body, on attempting to hold them up or to perform a task. The tremors are usually rhythmic or pendulous in nature.

Essential Tremor usually affects the hands, head and/or voice and can migrate down to legs and feet, but can affect any part of the body in between. Depression and anxiety are a very real side effect. This condition may be severely disabling in the long term.

This is a faint tremor that is sometimes triggered by nervousness or other stimuli. The tremor may be exacerbated or become more constant in the presence of stress, exercise, weakness, or an overactive thyroid gland.

Restless Leg Syndrome (RLS) is a neurological disorder characterised by unpleasant sensations in the legs and the compelling need to move the legs, usually experienced when trying to sleep.

This is a fairly common movement disorder affecting one in 10 individuals. The strange sensation, usually in the calves, has been described as a type of cramp, soreness or a creeping, crawling feeling and may lead to disturbed sleep and insomnia.

Parkinson’s Disease, the best-known movement disorder, is a severely debilitating progressive neurological condition. The cause of Parkinson’s Disease remains unknown, but it is thought to have genetic and environmental components and in most cases is likely to be caused by genetic predisposition or exposure to certain drugs and toxins. It affects one in 500 individuals.

Although less common than other movement disorders, Parkinson’s Disease can severely impair quality of life, because it hampers regular movement. Eventually, the patient may be unable to cope with activities of daily living (ADL) and may have to depend on a caregiver.

Parkinson’s disease is characterized by rigidity of muscles, facial immobility, tremors and a shortened “shuffling” gait.

Dystonia affects 0.4% of the population and is another type of movement disorder where there is excessive spasm of a group of muscles, making them painful and difficult to move.

Leading to abnormal postures or writhing, twisting movements of part of the body, or abnormally held postures, dystonia is characterized by sustained spasm, or contraction, of a group of muscles, of other muscles that are not necessary for the movement, and of antagonistic muscles.

Writer’s cramp is an example of focal dystonia that affects the fingers of the writing hand. It is often sudden in onset and disappears spontaneously on rest.

Similarly, dystonia may affect the eyelids leading to blepharospasm. This manifests as increased blinking and involuntary closing of the eyes.

Tired, stressed muscles are prone to dystonia. Anxiety and sharp emotions may also trigger dystonias.

Dyskinesia literally means abnormal (dys) movements (kinesia). It is characterized by spasms, tics and twitches; by more complex slow writhing movements (athetosis); rapid, jerky movements (chorea); or spasm of a group of muscles (dystonia).

Sometimes the main symptom may be reduced movement (hypokinesia), lack of movements (akinesia), or slowing of movements (bradykinesia). These are all commonly seen in Parkinson’s Disease and other similar conditions.

These complex abnormalities of movement may appear slowly or may have an acute onset, with an unpredictable course, and a rapid return to normal.

Dyskinesia may be induced by certain drugs used to treat Parkinson’s Disease, or by some antipsychotic medications used in the therapy of specific psychiatric conditions.

These are small repetitive movements or twitches of a group of muscles. The movements that may result include blinking, shrugging, grunting or grimacing.

There are abnormal movements of the muscles involved in voice production and speech. The voice becomes quivery, jerky or strained and hoarse as a result. This condition is common to Parkinson’s Disease.

This disorder affects balance and the control of muscles involved in walking, running and other locomotor activities. It involves defects in posture maintenance as well as in the control of coordination and may manifest as lurching or staggering movements.

Ataxia is usually a symptom of conditions such as Multiple Sclerosis or Cerebral Palsy, rather than being a disease, in its own right. It is caused by diseases of the cerebellum or of the base of the brain. Alcohol consumption is a common cause of ataxia.

A neurodegenerative condition that causes problems with balance, vision, speech, movement and swallowing. Progressive Supranuclear Palsy (PSP) is very rare, with fewer than 1,000 cases per year in Australia.

Treatments can help manage the condition, however, there is no known cure. Not only is it more prevalent in persons over 60 years of age, it has a higher incidence in males.

Often mistaken for Parkinson’s Disease or Alzheimer’s, correct diagnosis may require lab tests or imaging. The condition can last several years or be lifelong.

This is a genetic condition that affects muscle movements because of the atrophy of voluntary motor neurons in some parts of the brain. The patient develops chronic progressive chorea or rapid jerky purposeless movements of various groups of muscles. In addition, the patient shows emotional, behavioural, and psychiatric abnormalities.

Various other movement disorders include:

• Myoclonus: rapid, uncontrolled, brief and irregular movements of a group of muscles
• Multiple System Atrophy, or Shy-Drager syndrome, is caused by degeneration of neurons in certain parts of the brain and spinal cord, resulting in a Parkinsonian picture with autonomic instability leading to orthostatic hypotension.
• Tourette’s Syndrome: characterized by various tics and grunts
• Wilson’s Disease: caused by excessive deposition of copper in the body, leading to neurological and psychiatric symptoms along with liver disease
• Drug-induced movement disorders: Abnormal movements, tremor, dystonia and dyskinesias may be associated with certain drugs. These could include antipsychotic medications or other medications which affect the central nervous system.