Types of Movement Disorders
Dystonias are disorders that involve involuntary movements and muscle contractions that last for quite a while, resulting in twisting and repetitive movements or abnormal postures. An estimated 300,000 people in North America are affected by dystonia. Many cases of generalized dystonias appear to be inherited. Symptoms may first appear in childhood, late adolescence or early adulthood.
Types of DystoniasThere are many forms of dystonia. Movements may affect the entire body, a single muscle or a group of muscles. Dystonia is classified by the type of muscles affected such as neck, eyelids, voice and jaw.
Dystonias may also be classified by the part of the body affected:
- Generalized - entire body
- Hemibody - one side
- Focal - one body part
A body part affected by dystonia may also be affected by tremor. This is called dystonic tremor.
Experts with the Parkinson’s Disease and Movement Disorders Program are experienced in treating the many types of dystonias, such as those listed below.
Adult-onset dystoniaAdult-onset dystonia begins in adulthood. The Parkinson’s and Movement Disorders Program also treats many people whose dystonia began in childhood.
Dopa-responsive dystonia (DRD) / Segawa’s dystoniaDopa-responsive dystonia (DRD) / Segawa’s dystonia is a type of dystonia that usually begins in childhood or adolescence with progressive difficulty walking. Symptoms mimic those of cerebral palsy, and spasticity may occur in some cases.
MyoclonusMyoclonus is a sudden, involuntary and uncontrollable jerking of a muscle or group of muscles. Myclonus occurs in simple forms (e.g., a hiccup) in healthy persons and causes no problems. When more widespread, myoclonus may involve continual and severe muscle contractions. Myoclonic jerking may develop in people with multiple sclerosis, Parkinson’s disease, Alzheimer’s disease, epilepsy or other disorders.
Paroxysmal kinesigenic dyskinesia (PKD) and Paroxysmal Nonkinesigenic dyskinesia (PNKD)PKD attacks are short, lasting from seconds to 5 minutes, and affect muscles of the arms and legs. Muscles of the face, neck and/or legs and trunk may also be involved. PNKD involves attacks of dystonia or chorea that last from minutes to hours. Attacks may occur daily, or there may be weeks or months between attacks.
Focal dystoniasFocal dystonias are conditions localized to a part of the body. Examples include:
- Blepharospasm: an abnormal, involuntary blinking or spasm of the eyelids, associated with an abnormal function of the basal ganglia region of the brain. Vision problems may result.
- Cervical dystonia (spasmodic torticollis): dystonia that affects the neck and sometimes shoulders. Muscles in the neck that control the position of the head are affected, causing the head to twist and turn to one side and possibly pull forward or backward. Most people first experience symptoms in middle age. More information is available online from the National Spasmodic Torticollis Association.
- Oromandibular dystonia: continuous spasms of muscles of the face, jaw, pharynx, tongue and, in severe cases, the neck, larynx and respiratory system.
- Spasmodic dysphonia/laryngeal dystonia/vocal dystonia: a voice disorder caused by involuntary movements of muscles of the larynx (voice box). People may have trouble saying a word or two, or they may experience more serious problems communicating. Spasmodic dysphonia causes the voice to break or to have a tight or strained quality.
- Writer’s cramp and other task-specific dystonias: dystonia that occurs as a result of performing specific tasks, such as writing or playing the piano.
Diagnosing and Treating DystoniasNo single test confirms the diagnosis of dystonia. Instead, the diagnosis is made after obtaining a complete medical history (including family history) and performing a thorough neurological evaluation. The Medical College movement disorders neurologists are highly skilled at differentiating primary dystonias that are caused by genetic or other factors from secondary dystonias that are due to other conditions.
Deep brain stimulation (DBS) is now frequently used to treat patients with dystonia who do not respond adequately to medical therapy. Patients can often have dramatic improvements in their symptoms while reducing their medications.
Learn more about our comprehensive services for diagnosing and treating movement disorders.
Date: May 17, 2012
Online Editor(s): Richard Petre