View clinical trials related to Dystonia.
Filter by:This study will look for abnormalities in a brain of persons affected with spasmodic dysphonia, a form of movement disorder that involves involuntary "spasms" of the muscles in the vocal folds causing breaks of speech and affecting voice quality. The causes of this disorder are not known. The study will compare results of magnetic resonance imaging (MRI) in people with spasmodic dysphonia and in healthy volunteers. People with adductor or abductor spasmodic dysphonia and healthy volunteers may be eligible for this study. Candidates are screened with a medical history, physical examination, and a test called nasolaryngoscopy. For this test, the inside of the subject's nose is sprayed with a decongestant, and a small, flexible tube called a nasolaryngoscope is passed through the nose to the back of the throat to allow examination of the larynx (voice box). During this procedure, the subject is asked to perform tasks such as talking, singing, whistling, and saying prolonged vowels. The nasolaryngoscope is connected to a camera to record the movements of the vocal folds during these tasks. Eligible participants then undergo MRI of the brain. MRI uses a strong magnetic field and radio waves instead of x-rays to obtain images of body organs and tissues. For this test, the subject lies on a table that slides into the MRI scanner, a narrow metal cylinder, wearing ear plugs to muffle loud knocking sound that occurs during the scan. During MRI anatomical images of the brain are obtained. Subject may be asked to participate in up to two scanning sessions. Each session takes about 1-1/2 hours. Participants may also be asked to volunteer for a brain donation program which is optional. Information gained from donated tissue may lead to better treatments and potential cures for spasmodic dysphonia.
This study will evaluate the effect of transcranial electrical polarization (TEP), also called direct current (DC) stimulation, on focal hand dystonia in people with writer's cramp. In dystonia, muscle spasms cause uncontrolled twisting and repetitive movement or abnormal postures. Focal dystonia involves just one part of the body, such as the hand, neck or face. When people with focal hand dystonia make small and repeated movements with their hands, there is extra activity in the part of the brain called the motor cortex. TEP is a method of brain stimulation that slows down the activity of the nerve cells in the motor cortex. This study may help researchers develop new ways to treat focal hand dystonia. People 18 years of age and older with focal hand dystonia may be eligible for this study. Participants have a neurological examination and are randomly assigned to one of two treatment groups: TEP or placebo stimulation. The TEP group receives stimulation to the parts of the brain used for hand movement, and the placebo group receives sham stimulation, which does not affect any area of the brain. There are three TEP/placebo sessions over a period of 7 to 10 days. The first session may last up to 2-1/2 hours; the other two sessions last 1-2 hours. For TEP, sponge electrodes are placed on the scalp and an electrical current is passed through the scalp and skull to the outer part of brain. Before and after each session, participants have a neurological examination, including an evaluation of the rate and severity of their movement problems. For this assessment, participants do a writing test while the electrical activity of their hand muscles is recorded using surface electromyography (EMG). For EMG, small metal disks (electrodes) filled with a conductive gel are taped to the skin over the muscles being tested. Patients are followed in the clinic the day after the end of TEP treatment for evaluation of their movement abilities and the effects of therapy, such as improvement of handwriting.
This study will evaluate the effectiveness of deep brain stimulation (DBS) in treating primary generalized dystonia. Patients with dystonia have muscle spasms that cause uncontrolled twisting and repetitive movement or abnormal postures. Medical therapies are available, but not all patients get adequate relief from the abnormal movements or the pain associated with them. DBS is a surgical procedure that interrupts neuronal circuits in the Gpi and STN, areas of the basal ganglia of the brain that do not work correctly in patients with dystonia. The surgery results in decreased movement and therefore may lessen patients' symptoms and pain. Patients 7 years of age and older with generalized dystonia that does not respond to medical treatment may be eligible for this study. Candidates are screened with blood and urine tests, chest x-ray, and an electrocardiogram in patients 35 years of age or more. Participants undergo the following tests and procedures: - Magnetic resonance imaging. MRI uses a magnetic field and radio waves to produce images of the brain. The patient lies on a table that is moved into the scanner (a narrow cylinder), wearing earplugs to muffle loud knocking and thumping sounds that occur during the scanning process. The procedure usually lasts about 45 to 90 minutes, during which the patient is asked to lie still for up to 15 minutes at a time. - Transcranial magnetic stimulation. This procedure maps brain function. A wire coil is held on the scalp, and a brief electrical current is passed through the coil, creating a magnetic pulse that stimulates the brain. During the stimulation, the patient may be asked to tense certain muscles slightly or perform other simple actions. The stimulation may cause a twitch in muscles of the face, arm, or leg, and the patient may hear a click and feel a pulling sensation on the skin under the coil. During the stimulation, electrical activity of muscles is recorded with a computer, using electrodes attached to the skin with tape. - Neurologic evaluation. Before and after DBS, the patient's dystonia, including voice strength and difficulty swallowing, are measured with a standardized rating scale. - DBS treatment. Patients are randomly assigned to have electrodes implanted in either the Gpi or STN area of the basal ganglia. The electrodes are what stimulate the brain in DBS therapy. Before surgery, a frame is secured to the patient's head, and an MRI scan is done. DBS involves making two small incisions and two small holes in the skull, opening the lining around the brain, locating the Gpi or STN, securing the electrodes in place and connecting them to the pulse generator that is placed under the skin below the collar bone. Additionally, during the surgery, the patient is asked to move certain muscles. The muscle activity is recorded to gain a better understanding of the physiology of movement. After surgery, computed tomography (CT) and MRI scans are done to confirm placement of the electrodes. - Stimulation and evaluation. After surgery, patients' movements are evaluated during and after stimulation. The changes in movement and function are videotaped and scored according to a rating scale. The optimal stimulation settings are determined and the stimulators are adjusted accordingly. - Follow-up. Patients are evaluated, with videotaping, at 1, 2, 3, 6, 12, 18 and 24 months after surgery, and the stimulators are adjusted as needed.
Objectives The main objectives of this proposal are (1) to characterize motor learning abnormalities in patients with focal dystonia; (2) to show, using transcranial magnetic stimulation, that this abnormal motor learning went together with an impaired modulation by somatosensory inputs of short and long-interval paired-pulse inhibitions (sICI, lICI) and facilitations (sICF, ICF) of MEPs (ICIs and ICFs are thought to reflect activity of inhibitory and excitatory interneuron's in the primary motor cortex M1); (3) to show that abnormalities of long-term potentiation and long-term depression (LTP/LTD)-like mechanisms (tested using a paired associative stimulation (PAS) intervention), thought to play a crucial role in learning, are associated in dystonia with an abnormal modulation of ICIs and ICFs by somatosensory inputs. Study population 30 patients with a focal upper limb dystonia and 45 healthy volunteers will take part in the main study. 7 patients with a focal upper limb dystonia and 12 healthy volunteers will take part in the control study. Design In the main study: subjects will complete 5 different sessions: visit 1: clinical screening, 1 hour; visit PAS session, 3 hours; visit 3: a minimum of 7 days later, motor learning session, 3 hours; visit 4: follow-up 24 hours later, 1 hour and a half; visit 5, follow-up 48 hours later, 1 hour and a half. During the PAS session they will receive 15 minutes of repeated paired stimulations (transcranial magnetic stimulation -TMS- and peripheral stimulation) thought to produce LTP/LTD like phenomena in M1. During the motor learning sessions they will be asked to perform, as fast as possible, a metronome-paced (0.5 Hz) pinch of their index finger and thumb. They will have 3 blocks of motor practice during the motor learning session. Between each block of motor practice and before and after PAS, while they rest, subjects will receive paired-pulse transcranial magnetic stimulations (TMS) associated or not with peripheral nerve stimulation in order to assess interactions at M1 cortical level between somatosensory incoming volleys and intracortical inhibitory and excitatory interneuron's. In the control study: subjects will complete a unique session. They will receive a PAS intervention. Before and after the PAS intervention, spinal excitability will be tested by the means of H reflexes evoked in wrist flexor muscles. Outcome measures: The behavioral effect of the motor training or of the PAS intervention will be assessed by measuring the mean peak acceleration (MPA) of thumb movement during the blocks of motor practice and the mean maximal peak force (MPF) between the index finger and thumb before and after the blocks of motor practice. The activity of different sets of intracortical interneurons (short and long interval GABA related inhibitions: sICI, lICI, intracortical glutamate-related facilitation: ICF and short interval facilitation: sICF) can be tested using paired-pulse TMS paradigms. The effect of learning (or of PAS intervention) on the interaction between somatosensory afferent input and intracortical processes will be assessed by comparing the amount of sICI, lICI, ICF and sICF when associated or not with a peripheral nerve stimulation (median and ulnar nerve stimulation) in a trained muscle (flexor pollicis brevis: FPB) and a non-trained muscle (abductor digiti minimi: ADM) at different times during and after the motor learning or the PAS intervention. The effect of PAS on spinal cord excitability will be assessed by comparing the size of the H reflex before and after PAS.
This study will use a technique called blink reflex to study and compare how the brain controls muscle movement in patients with craniofacial dystonia, their first-degree relatives, and healthy, normal volunteers. People with dystonia have sustained muscle contractions that cause twisting and repetitive movements or abnormal postures. In focal dystonia, this happens in one area of the body, such as the hand, neck, or face. Three groups of people may be eligible for this study: 1) patients 18 years of age and older with craniofacial dystonia; 2) first-degree relatives of patients with craniofacial dystonia; and 3) normal volunteers matched in age to the patients. Candidates are screened with physical and neurological examinations. Participants undergo a blink reflex study. Patients with dystonia who are receiving botulinum toxin injections must stop the medication 3 months before participating in the study and must stop any other dystonia medications, such as benzodiazepines and anticholinergics, for 12 hours before the study. For the blink reflex procedure, subjects are seated in a comfortable chair with their hands placed on a pillow on their lap. Metal electrodes are taped to the forehead for delivering small electrical shocks that feel like very brief pinpricks. Subjects receive 25 to 50 electrical stimuli, some as single shocks and some in pairs. The electrical activity of muscles that respond to the stimuli is recorded with a computer. The study takes from about 1 to 2 hours.
This study will examine the action of sensory tricks on an occurrence known as surround inhibition when there is a disorder of muscle tone affecting a single body part in isolation. Surround inhibition refers to a situation that suppresses unwanted movements, known as dystonia, in surrounding muscles during voluntary actions. There are tricks-various actions-that people use to temporarily stop those unwanted movements. Such tricks can include touching the affected body part, placing an object in the mouth, pulling the hair, and others. Often these tricks are beneficial early in the illness but become less effective as it progresses. This study is guided by a hypothesis that sensory tricks will restore surround inhibition and by another hypothesis that it is the application of the tricks, not simply sensory input, that is effective in doing that restoring. Emphasis is on cervical dystonia, involuntary actions affecting the neck, in which the tricks commonly involve the cheeks and chin. The technique used in the study is transcranial magnetic stimulation (TMS). Patients ages 18 and older who have cervical dystonia with at least one effective trick and patients with no effective trick may be eligible for this study. There will also be a control group of healthy participants. Participants will be asked to show the sensory trick and may be asked to be videotaped. During the TMS procedure, they will be seated in a comfortable chair, with hands placed on a pillow on the lap. Small electrodes-soft strips that stick to the skin-will be placed on the skin to record the electrical activity of some muscles in the neck that are activated by the stimulation from TMS. In TMS, there will be a wire coil held over the scalp. A brief electrical current will be passed through the coil, creating a magnetic pulse that stimulates the brain. Patients will hear a click and may feel a pulling sensation on the skin under the coil. There may be muscle twitches of the face, arm, or leg. In addition, patients may be asked to tense certain muscles slightly or perform other simple actions so that the coil can be positioned appropriately. Patients will sometimes be asked to bite down and tap their teeth slightly for about 1-1/2 minutes at a time. They will be asked to show the sensory trick. The stimulation is usually not painful, although sometimes strong contractions of the scalp muscles can cause discomfort or a headache. Patients can ask to have the procedure discontinued at any time. The testing session takes about 2 hours, done on an outpatient basis.
This study will collect information on (tricks) patients with focal dystonia use to relieve their symptoms. Dystonia is a movement disorder caused by sustained muscle contractions often causing twisting and abnormal posturing. Dystonia may be generalized, affecting at least one leg and the trunk of the body, segmental, affecting adjacent body parts, or focal, affecting a single body part, such as the hand or eyelid. It may be task-specific, such as writer's, musician's or sportsman's cramps. Some patients with focal dystonia use (tricks), such as touching the face or hand, to stop or alleviate the abnormal movement. This study will survey the types of tricks people with focal dystonia use in order to learn more about the disorder. Patients 18 years of age and older with focal dystonia may be eligible for this study. Candidates will be screened for eligibility with a medical history, clinical evaluation, and review of their medical records. In one 30- to 45-minute clinic visit, participants will be interviewed about their dystonia symptoms and the tricks they use to relieve the symptoms. They may be asked to show the investigators how the tricks work
This study will use transcranial magnetic stimulation (TMS) and electrical stimulation of nerves to examine how the brain controls muscle movement in focal hand dystonia (writer's cramp). Normally, when a person moves a finger, the brain's motor cortex prevents the other fingers from moving involuntarily. Patients with focal hand dystonia have difficulty with individualized finger movements, possibly due to increased excitability of the motor cortex. Musicians, writers, typists, athletes and others whose work involves frequent repetitive movements may develop focal dystonia of the hand. Healthy normal volunteers and patients with focal dystonia 18 years of age and older may be eligible for this study. For the TMS procedure, subjects are seated in a comfortable chair with their hands placed on a pillow on their lap. An insulated wire coil is placed on the scalp. A brief electrical current is passed through the coil, creating a magnetic pulse that stimulates the brain. This may cause muscle, hand or arm twitching if the coil is near the part of the brain that controls movement, or it may induce twitches or transient tingling in the forearm, head or face muscles. Subjects will be asked to move a finger. Just before this movement, a brief electrical stimulation will be applied to the end of either the second or fifth finger. Metal electrodes will be taped to the skin over the muscle for computer recording of the electrical activity of the hand and arm muscles activated by the stimulation. The testing will last 2-3 hours.
This study will use transcranial magnetic stimulation, or TMS (described below), to examine how the brain controls muscle movement to prevent unwanted movements in surrounding muscles. For example, when a person moves a finger, a part of the brain called the cortex prevents unwanted movements in other fingers by a process called cortical inhibition. In people with the muscle disorder dystonia, cortical inhibition does not work properly and patients suffer from uncontrolled and sometimes painful movements. A better understanding of how this process works in normal people may shed light on what goes wrong in dystonia and how the condition can be treated. Healthy normal volunteers 19 years of age and older may be eligible for this study. Candidates will be screened with a medical history and physical and neurological examinations. People with a current medical or surgical condition or neurological or psychiatric illness may not participate, nor may individuals who are taking medication that may influence nervous system function. Participants will undergo TMS to record the electrical activity of muscles in the hand and arm that are activated by magnetic stimulation. For the procedure, subjects are seated in a chair with their hands placed on a pillow in their laps. A wire coil in placed on their scalps. A brief electrical current is passed through the coil, creating a magnetic pulse that stimulates the brain. Subjects will be asked to move their second finger in response to a loud beep or visual cue. In some trials, a brief, mild electrical shock will also be applied to the end of either the second or fifth finger. The shock is not painful. TMS may cause muscle, hand or arm twitching if the coil is near the part of the brain that controls movement, or it may induce twitches or temporary tingling in the forearm, head, or face muscles. The twitching may cause mild discomfort, but the procedure is rarely considered painful.
This study will use transcranial magnetic stimulation (TMS) to examine how the brain controls muscle movement in dystonia. Dystonia is a movement disorder in which involuntary muscle contractions cause uncontrolled twisting and repetitive movement or abnormal postures. Dystonia may be focal, involving just one region of the body, such as the hand, neck or face. Focal dystonia usually begins in adulthood. Generalized dystonia, on the other hand, generally begins in childhood or adolescence. Symptoms begin in one area and then become more widespread. Healthy normal volunteers and patients with focal [or generalized] dystonia [between 21 and 65 years of age] may be eligible for this study. Participants will have transcranial magnetic stimulation. For this test, subjects are seated in a comfortable chair, with their hands placed on a pillow on their lap. An insulated wire coil is placed on the scalp. A brief electrical current is passed through the coil, creating a magnetic pulse that stimulates the brain. (This may cause muscle, hand or arm twitching if the coil is near the part of the brain that controls movement, or it may induce twitches or transient tingling in the forearm, head or face muscles.) During the stimulation, subjects will be asked to either keep their hand relaxed or move a certain part of the hand in response to a loud beep or visual cue. Metal electrodes will be taped to the skin over the muscle for computer recording of the electrical activity of the hand and arm muscles activated by the stimulation. There are three parts to the study, each lasting 2-3 hours and each performed on a separate day.