3 Clinical Trials for Various Conditions
Task-specific focal dystonias are characterized by selective activation of dystonic movements during performance of highly learned motor tasks, such as writing or playing a musical instrument. To date, there is only limited knowledge about the distinct neural abnormalities that lead to the development of task-specificity in focal dystonias, which affect similar muscle groups but result in different clinical manifestations, such as writer's cramp vs. pianist's dystonia or spasmodic dysphonia vs. singer's dystonia. Our goal is to dissect the pathophysiological mechanisms underlying the phenomenon of task specificity in isolated focal dystonias using multi-level brain network analysis in conjunction with neuropathological examination of postmortem brain tissue from patients with dystonia. Rather than viewing these disorders as interesting curiosities, understanding the biology of task-specific activation of motor programs is central to understanding dystonia.
Researchers want to test a procedure called deep brain simulation (DBS) to treat focal hand dystonia (FHD). A device called a neurostimulator is placed in the chest. It is attached to wires placed in brain areas that affect movement. Stimulating these areas can help block nerve signals that cause abnormal movements. Objectives: To test DBS as treatment for FHD. To learn about brain and nerve cell function in people with dystonia. Eligibility: People ages 18 and older with severe FHD who have tried botulinum toxin treatment at least twice Design: Participation lasts 5 years. Participants will be screened with: Medical history Physical exam Videotape of their dystonia Blood, urine, and heart tests Brain MRI scan Chest X-ray Neuropsychological tests: answering questions, doing simple actions, and taking memory and thinking tests. Hand movement tests Participants will have surgery: A frame fixes their head to the operating table. A small hole is made in the skull. Wires are inserted to record brain activity and stimulate the brain while they do simple tasks. The wires are removed and the DBS electrode is inserted into the hole. The neurostimulator is placed under the skin of the chest, with wires running to the electrode in the brain. They will have CT and MRI scans during surgery. Participants will recover in the hospital for about 1 week. The neurostimulator will be turned on 1 4 weeks after discharge. Participants will have regular visits until the study ends. Visits include: Checking symptoms and side effects MRI Movement, thinking, and memory tests If the neurostimulator s battery runs out, participants will have surgery to replace it.
The investigational drug being studied in this protocol is Incobotulinumtoxin A (Xeomin®). Botulinum toxin (BoNT) prevents the release of the acetylcholine from peripheral nerves, inhibiting muscle contractions. BoNT is effective in relaxing overactive muscles. In musician's dystonia, the ability to reduce abnormally overactive muscles in the hand can be critical for the musical professional to continue his or her career. With the use of EMG/electrical stimulation and/or ultrasound guidance, the injector can precisely localize the individual muscles that are affected in this condition with great accuracy. Prior studies have shown that BoNT injections produce beneficial effects in forearm muscles, and less effect in shoulder or proximal arm muscles. Possible risks in treating patients with BoNT include excessive weakness of the injected muscles. The drug may also affect non-targeted muscles. However these risks will be minimized during the screening period by carefully targeting the affected muscles and by administering low doses of BoNT. Small booster doses may be given at follow up visit (2, 4, 14 and 16-weeks after the primary injection date) if the initial injection was insufficient to produce sufficient efficacy in relief of the focal dystonia and did not produce excess weakness of the targeted muscle.