Movement disorders refer to a group of neurological conditions characterized by abnormal voluntary movements, involuntary movements, slow movement and reduced movement. These conditions of the brain, spinal cord and nerves affect a person’s ability to produce and control movement. There are more than 600 known movement disorders—including conditions caused by injuries, genetics, seizure disorders, cancers (e.g., brain tumors) and infection—affecting about six million people in the United States.
Movement disorders often include numerous symptoms, including dyskinesia (problems with voluntary movement), hyperkinesia (excessive voluntary movement), hypokinesia (slow voluntary movement), ataxia (lack of coordination) and dystonia (prolonged muscle contraction), and are categorized as neuro-genetic disorders (e.g., Huntington’s disease), developmental disorders (e.g., cerebral palsy), metabolic disorders (e.g., Gaucher’s disease), cerebrovascular diseases (e.g., stroke), trauma (e.g., head injury), convulsive disorders (e.g., epilepsy), infectious diseases (e.g., AIDS) and brain tumors.
There are many types of movement disorders, including:
- Ataxias: Degenerative disorders affecting the brain, brain stem or spinal cord that erode muscular coordination, causing weakness and atrophy. These disorders are usually inherited and have no treatment.
- Dystonia: Individuals with this condition often experience involuntary muscle contractions that force parts of the body into abnormal postures or movement, which can be painful.
- Essential tremor: Individuals with this condition experience uncontrollable shaking, usually in the hands, though sometimes in the head, neck, face, jaw, and even the tongue and voice.
- Huntington’s disease: This is a progressive, degenerative disease caused by the deterioration of certain brain cells. The condition is hereditary and fatal, and there is no treatment.
- Muscular system atrophy: Shy-Drager syndrome is the distinctive disorder for this term, and is characterized by abnormalities in the autonomic nervous system that cause blood pressure to drop when standing or sitting up, causing in dizziness or momentary loss of consciousness.
- Myoclonus: Patients with this condition experience twitching or intermittent spasms in a muscle or group of muscles.
- Parkinson’s disease: This condition is characterized by a progressive degeneration of the nerve cells in a part of the brain that controls movement, causing patients to suffer from tremor or shaking, slowed movement, shuffling gait, and stiff or rigid limbs.
- Progressive supranuclear palsy: This is a rare brain disorder that causes serious, permanent gain and balance-control problems.
- Restless legs syndrome: This is a neurological disorder characterized by unpleasant sensations in the legs and an urge to move them.
- Rhett syndrome: This progressive neurological disorders leads to decreased muscle tone, autistic-like behavior, wringing and waving hand movements, diminished ability to express feelings, avoidance of eye contact, a lag in brain and head growth, gait abnormalities and seizures.
- Spasticity: This is a condition characterized by increased muscle contractions that cause stiff and awkward movement due to stroke, cerebral palsy, multiple sclerosis, Lou Gehrig’s disease, and spinal cord or brain injury.
- Tardive dyskinesia: This condition, caused by the long-term use of neuroleptic drugs, is characterized by repetitive, involuntary movements such as lip smacking, blinking, grimacing, or rapid arm or leg movements.
- Tourette’s syndrome: Patients with this inherited disorder have repeated involuntary movements and uncontrolled vocal tics.
- Wernicke-Korsakoff syndrome: This severe memory disorder is often associated with chronic alcoholism, though the direct cause is a vitamin B1 deficiency.
- Wilson’s disease: This inherited disorder cause excessive copper accumulation in the body, leading to neurological or psychological symptoms including tremor, rigidity, personality changes and inappropriate behavior.