18 Jan Dystonia
Dystonia is a complex neurological movement disorder characterized by involuntary muscle contractions and pain. It is the third most common movement disorder in the United States have dystonia, following essential tremor and Parkinson’s disease. It can occur at any age and has no ethnic predilection.
Dystonia is a disorder involving from the basal ganglia, a deep part of the brain which helps control movement coordination. When dysfunctioning, the brain control of the speed and fluidity of movement is lost, leading to unwanted movements, such as uncontrollable twisting, repetitive movements or abnormal postures and positions. It can affect any part of the body, including the arms, legs, trunk, face and even vocal cords.
Dystonia has a wide clinical presentation given the wide range of body parts and functions it can impact. It can severely disable the patients by impacting daily functions. While it is not life-threatening, it can be socially embarrassing and physically disabling, leading to emotional distress or even depression. The mental health component of this disorder needs to be properly addressed.
Generally speaking, the younger a patient is at onset, the greater the chance that symptoms will spread. Focal dystonia is limited to one area of the body and can affect the neck (cervical dystonia or spasmodic torticollis), eyes (blepharospasm), face (oromandibular dystonia), vocal cords (laryngeal dystonia) or arms/legs (limb dystonia), trunk (truncal dystonia), etc. Focal dystonia is more common in patients in their 40s and 50s (adult-onset dystonia). Women are three times more likely to get affected as compared to men. Segmental dystonia is when two or more parts of the body that are adjacent or close to one another are involved. Up to 30 percent of people with focal dystonia have associated segmental dystonia as well. It commonly affects the eyelids, jaw, mouth and lower face. Multifocal dystonia involves two or more body parts distant from one another. Hemidystonia is one example of it and affects half of the body.
Dystonias may be primary (idiopathic) or secondary. The primary dystonias may have a genetic origin. Secondary dystonias typically result from environmental (carbon monoxide, cyanide, manganese or methanol exposure), pathological (tumors, cerebral palsy, Parkinson’s disease, stroke, multiple sclerosis, hypoparathyroidism or vascular malformations, brain/spinal cord injuries, inflammatory, infectious or postinfectious brain conditions) or pharmacological factors.
Management of dystonia includes botulinum toxin (Botox) injections, medication, and surgery. Botulinum toxin type B has been approved by U.S. Food and Drug Administration for treatment of cervical dystonia. It has mild to moderate side effects such as dry mouth, dysphagia, and indigestion. Surgery is considered when other treatments have failed. The surgical approaches used for the treatment of dystonia include thalamotomy, pallidotomy, etc. Deep brain stimulation (DBS) has also been tried recently with some success. However, these procedures are associated with considerable morbidity as well. So surgery should be judiciously approached in these patients and the risks and benefits should be carefully assessed.