What are Movement Disorders?
Movement disorders are neurological conditions that affect the speed, fluency, quality, and ease of movement. Abnormal fluency or speed of movement (called dyskinesia) may involve excessive or involuntary movement (hyperkinesia) or slowed or absent voluntary movement (hypokinesia).
Causes of movement disorders
Most movement disorders are associated with pathological changes in the brain especially in an area of the brain called the basal ganglia. This region is part of the grey matter that lies deep within the brain.
The defects may also lie in the base of the brain or cerebellum. This leads to difficulty in walking, locomotion or maintenance of posture and normal body balance.
Types of movement disorders
By Dr Ananya Mandal, MD
Movement disorders characteristically affect the speed, fluency, quality and ease of movements. These may be affliction of simple day to day tasks like writing, walking, etc.
Movement disorders may be severely debilitating and may affect the ability to perform day to day activities in many individuals. There are various types of movement disorders.
These include tremor, Parkinson’s disease and so forth. (1-5)
Tremor
The most common movement disorder is essential tremor. It affects one in 20 people under the age of 40 and one in five people over 65.
The disorder is characterized by shaking of the hand or fingers when it attempts to perform a task. The tremors are usually involuntary, rhythmic or pendulous movements of a part of the body.
Physiological tremor means faint tremor that may be triggered by nervousness etc.
Stress, exercise, weakness, or an overactive thyroid gland may lead to more persistent tremor.
Essential tremor usually affects the hands and feet, but voice tremors and head tremors are also seen. It may lead to severe disability.
Parkinson’s disease
Parkinson’s disease affects one in 500 individuals and in most cases is caused by genetic predisposition or exposure to certain drugs and toxins.
Parkinson’s disease is characterized by rigidity of muscles, tremors and shaking and a short “shuffling” gait.
Eventually the patient may fail to perform his or her daily activities and may have to depend on their caregivers. Parkinson’s disease is a severely debilitating disease.
Dyskinesia
This is a symptom of an underlying movement disorder. Dyskinesia literally means abnormal (dys) movements (kinesia).
This is characterized by spasms, tics and twitches or more complex slow writhing movements (athetosis), rapid, jerky movements (chorea) or spasm of a group of muscles (dystonia).
There may be hypokinesia or paucity of movement or akinesia lack of movements and brady kinesia or slowing of movements. These are all commonly seen in Parkinson’s disease.
These complex abnormalities of movement may appear slowly or may appear suddenly and unpredictably with a rapid return to normal.
Dyskinesia may be seen in Parkinson’s disease and other similar conditions. They may be seen on intake of certain drugs like Levodopa for Parkinson’s disease therapy or antipsychotic medications for psychiatric conditions.
Dystonia
Dystonia is characterized by sustained spasm or contraction of a group of muscles. This may lead to painful writhing movements or abnormally held postures.
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 by itself on rest.
Similar dystonia may affect the eyelids leading to blepharospasm. This leads to increased blinking and involuntary closing of the eyes.
Tired, stressed muscles are prone to dystonia. Anxiety and sharp emotions may also trigger dystonias.
Tics
These are small movements or twitches that are repeated in a group of muscles.
The movements include blinking, shrugging, grunting or grimacing.
Dysphonia
There are abnormal movements of the muscles involved in voice production and speech. The voice as a result becomes quivery, jerky or strained and hoarse.
Ataxia
This affects regular movement of walking, running etc. There is a problem with posture maintenance and control of coordination and balance.
Ataxia is usually a symptom of conditions such as multiple sclerosis or cerebral palsy rather than being a disease in itself. It is caused due to diseases of the cerebellum or base part of the back of the brain. Commonly alcohol consumption may lead to ataxia.
Restless legs syndrome
This is a common movement disorder affecting one in 10 individuals. There are intensely uncomfortable sensations in the legs and sometimes arms typically seen during bedtime or at rest.
It may be felt as tingling or creeping that is relieved by movement of the limbs. This leads to disturbed sleep and insomnia.
Huntington’s disease
This is a genetic condition that affects movements. There is chronic progressive chorea or rapid jerky purposeless movements of various groups of muscles. There is additional emotional, behavioral, and psychiatric abnormalities.
Other movement disorders
Other movement disorders include:-
- Myoclonus usually means rapid, uncontrolled, brief and irregular abnormalities of movement of a group of muscles.
- Affliction of multiple system leading to atrophies. This is called Shy Dragger syndrome
- Progressive supranuclear palsy (PSP) is a rare movement disorder that affects purposeful movements.
- Tourette’s syndrome – This is characterized by various tics and grunts.
- Wilson’s disease – This is caused by excess deposition of copper in the body leading to neurological and psychiatric symptoms along with liver disease
- Drug induced movement disorders – Abnormal movements, tremor; and dystonia and dyskinesias may be associated with intake of certain drugs. These could be due to antipsychotic medications or due to some anti-vomiting agents like metoclopramide etc.
How can functional rehabilitation help?
Depends on the pathophysiology of movement disorder. A well trained doctor in functional rehabilitation may be able to rehabilitate functional lesions at associated areas. Such as basal ganglia, ventral mesencephalon or frontal lobe.