Dystonia
Dystonia
Dystonia is a neurological disorder which affects approximately 30 to 50 in every 100,000 people worldwide.1 Characterized by sustained muscle contractions causing twisting and repetitive movements or abnormal postures, dystonia muscle spasms can be painful and interfere with day-to-day activities. The exact cause of Dystonia is not fully understood. It is believed that the portion of the brain called the basal ganglia, which controls movement, is not functioning properly or has been damaged in dystonia patients.
Symptoms
Dystonia is characterized by involuntary muscle contraction causing repetitive or twisting movements. Dystonia can affect a specific area of the body or be more widespread throughout several muscle groups. Dystonia is typically categorized based on cause, age of onset, and body distribution.
Dystonia Classification²
Classification by cause
| Primary Dystonia |
• Often hereditary due to mutation of gene DYT1 • Patient exhibits no other neurological disorder or brain abnormalities |
| Secondary Dystonia |
• Associated with lesion of central nervous system often caused by outside factor such as trauma, cerebral palsy, stroke or exposure to certain medications |
Classification by age of onset
| Early-onset Dystonia | • Symptoms begin in childhood, usually before the age of 20-30 |
| Late-Onset Dystonia | • Symptoms begin in adulthood, usually after the age of 30 |
Classification by body distribution
| Generalized Dystonia |
• Affects the entire body |
| Focal Dystonia |
• Affects one area of the body |
| Segmental Dystonia |
• Affects two or more contiguous body areas |
| Hemidystonia | • Affects one side of the body |
Diagnosis
The exact cause of Dystonia is not fully understood. However, regardless of the category or type of dystonia it is believed that the basal ganglia, the portion of the brain which controls movement, is not functioning properly or has been damaged. Diagnosis is usually done by a movement disorder neurologist. An accurate diagnosis requires thorough patient and family history, as well as physical and neurological exams. Additional laboratory, imaging, and genetic tests may be necessary to make a diagnosis.3
Treatment
There is currently no cure for dystonia but there are a variety of treatments available which may provide relief to symptoms. Selection of treatment varies from patient to patient and is often dependent on the type and severity of the dystonia. The typical treatment options include drug therapy, injections of botulinum toxin, and surgery. Deep Brain Stimulation (DBS) may be used to treat people with severe dystonia who fail treatment with pharmacologic agents and botulinum neurotoxin injections.
DBS Procedure
The DBS procedure includes a modest medical device which sends signals to the brain. The signals help control the motor functions that are affected by movement disorder symptoms such as tremor, slowness and rigidity.
The physician will place one or two insulated wires called leads in the brain. The leads are then connected to the stimulator (similar to a pacemaker), which is typically placed under the skin in the chest. The device produces mild electrical impulses that stimulate a specific region of the brain. This may help regulate signaling in the brain, resulting in improvement of dystonia symptoms. Although DBS is not a cure, it may help improve day-to-day experiences and quality of life.
