Neurophysiological Studies in Patients With Paroxysmal Hyperkinetic Movement Disorders
This study will use three neurophysiological tests (see below) to determine what areas of the brain are responsible for paroxysmal hyperkinetic movement disorders. Patients with these disorders have sudden, brief attacks of movement, similar to epileptic seizures, but without loss of consciousness.
Normal volunteers and patients with two subtypes of paroxysmal hyperkinetic movement disorder, paroxysmal dyskinesia and psychogenic variant, that can be induced by a specific trigger, such as a sudden movement or prolonged exercise, will be included in this study. Candidates must be 12 years of age or older. Women of childbearing potential will be screened with a pregnancy test.
Participants will undergo one or more of the procedures detailed below. Patients' test results will be compared with those of normal volunteers. Before each test, participants will provide a medical history and undergo a brief physical examination. During each procedure, the subject will have surface electromyography (EMG) to measure the electrical activity of muscles. For EMG, electrodes (metal discs) filled with a conductive gel are taped to the skin over the muscle to be evaluated.
Functional Magnetic Resonance Imaging (fMRI)
MRI uses a strong magnetic field, radio waves, and computer technology to provide detailed images of the brain. For this test, the subject lies in a narrow cylinder (the scanner), while pictures of the brain are taken. Earplugs are worn to muffle loud noises caused by electrical switching of radio frequency circuits used in the scanning process. For functional MRI (fMRI), the subject is asked to mimic a movement that occurs during an attack, such as stiffening the hand to make a fist or flexing and rotating the arm inward, to detect changes in the brain regions involved in the movement. During the procedure, involuntary movements and voluntary movements will be monitored by surface EMG and by video camera. The test will last about 1-1/2 hours.
EEG measures the electrical activity of the brain (brain waves) with electrodes placed on the scalp. During the procedure, muscle activity will be recorded with EMG. The subject will first relax and then will be asked to mimic a movement attack. The test will last from 1-1/2 to 2 hours.
The subject will put on a headphone and hear loud noises in a random fashion. During the test, muscle activity will be recorded with EMG and with a video c...
|Official Title:||Neurophysiological Studies in Patients With Psychogenic Movement Disorders|
|Study Start Date:||March 2003|
|Estimated Study Completion Date:||February 2009|
Objective: The primary objective of this study is to determine the brain regions responsible during attacks for psychogenic paroxysmal hyperkinetic movement disorders using functional magnetic resonance imaging (fMRI). The secondary objective is to determine the neurophysiology during attacks for the same subjects compared to normal controls using electroencephalography (EEG) and Startle Reflex.
Study population: Psychogenic paroxysmal hyperkinetic movement disorder patients and a control group of healthy volunteers.
fMRI: Anatomical MRI and fMRI sequences are performed to obtain blood-oxygenation level-dependent (BOLD) imaging of brain activation during (1) triggered or provoked involuntary hyperkinetic movements and voluntary imitated movements in subjects with psychogenic paroxysmal hyperkinetic movement disorders and (2) voluntary imitated movements and rest states in healthy volunteers.
EEG: EEG will be recorded for jerk-locked back-averaging analysis.
Startle Reflex: Electromyography (EMG) will be recorded during exposure to auditory stimuli.
fMRI: BOLD will be obtained using baseline correction.
Startle Reflex: The latency, mean amplitude, and habituation of EMG amplitude will be measured.
|United States, Maryland|
|National Institutes of Health Clinical Center, 9000 Rockville Pike|
|Bethesda, Maryland, United States, 20892|