Clinical Research Directory

Deep Brain Stimulation Surgery for Focal Hand 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.

Effects of Neuromodulation in Laryngeal Dystonia

Laryngeal dystonia (LD) causes excessive vocal fold abduction (opening) or adduction (closing) leading to decreased voice quality, job prospects, self-worth and quality of life. Individuals with LD often experience episodic breathy voice, decreased ability to sustain vocal fold vibration, frequent pitch breaks and in some cases, vocal tremor. While neuroimaging investigations have uncovered both cortical organization and regional connectivity differences in structures in parietal, primary somatosensory and premotor cortices of those with LD, there remains a lack of understanding regarding how the brains of those with LD function to produce phonation and how these might differ from those without LD. Intervention options for people with LD are limited to general voice therapy techniques and Botulinum Toxin (Botox) injections to the posterior cricoarytenoid (PCA) and/or TA (thyroarytenoid) often bilaterally, to alleviate muscle spasms in the vocal folds. However, the effects of injections are short-lived, uncomfortable, and variable. To address this gap, the aim of this study is to investigate the effectiveness of repetitive transcranial magnetic stimulation (rTMS), a non-invasive neuromodulation technique, in assessing cortical excitability and inhibition of laryngeal musculature. Previous work conducted by the investigator has demonstrated decreased intracortical inhibition in those with adductor laryngeal dystonia (AdLD) compared to healthy controls. The investigators anticipate similar findings in individuals with with other forms of LD, where decreased cortical inhibition will likely be noted in the laryngeal motor cortex. Further, following low frequency (inhibitory) rTMS to the laryngeal motor brain area, it is anticipated that there will be a decrease in overactivation of the TA muscle. To test this hypothesis, a proof-of-concept, randomized study to down-regulate cortical motor signal to laryngeal muscles will be compared to those receiving an equal dose of sham rTMS. Previous research conducted by the investigator found that a single session of the proposed therapy produced positive phonatory changes in individuals with AdLD and justifies exploration in LD.