Single Photon Emission Computed Tomography (SPECT) to Study Paroxysmal Hyperkinetic Movement Disorders

INCLUSION CRITERIA - Paroxysmal Dyskinesia Patients: Established diagnosis of paroxysmal hyperkinetic movement disorders. The diagnosis will be established by the preliminary screening in the NINDS Movement Disorders Outpatient Clinic, based on review of medical record, history, clinical evaluation, and video tapes of an attack. Age 18 or older. A reproducible trigger of paroxysmal hyperkinetic attacks, such as sudden movement, or prolonged exercise, which will produce attacks at least with 50% consistency. Patients only with paroxysmal attacks of hyperkinetic movements. Patients whose attacks can be precipitated easily. Patients whose typical attack last at least 15 seconds. Patients taking medication that may influence the central nervous system, such as phenytoin, phenobarbital, carbamazepine, clonazepam, and antidepressants (but not limited to these) for their paroxysmal dyskinesias (not seizures) will be asked to hold the medication prior to the study. A sufficient drug washout period will be established dependant upon the individual drug. Subjects may be admitted to the NIH if necessary. They will be asked to abstain from alcohol and caffeine 24 hours prior to the study as well. INCLUSION CRITERIA - Psychogenic paroxysmal hyperkenetic movement attack patients: Established diagnosis of psychogenic hyperkinetic movement disorders. The diagnosis will be established by the preliminary screening in the NINDS Movement Disorders Outpatient Clinic, based on review of medical record, history, clinical evaluation, and video tapes of an attack. Patients with clear onset, stereotyped, defined and evaluable hyperkinetic attacks. Patients only with paroxysmal attacks of hyperkinetic movements. Age 18 or older. A reproducible trigger of paroxysmal hyperkinetic attacks, such as sudden movement, startle or prolonged exercise, which will produce attacks at least with 50% consistency. Patients whose attacks can be precipitated easily. Patients whose typical attack last at least 15 seconds. Patients taking medication that may influence the central nervous system, such as phenytoin, phenobarbital, carbamazepine, clonazepam, and antidepressants (but not limited to these) will be asked to hold the medication prior to the study. A sufficient drug washout period will be established dependant upon the individual drug. Subjects may be admitted to the NIH if necessary. They will be asked to abstain from alcohol and caffeine 24 hours prior to the study as well. EXCLUSION CRITERIA: Age younger than 18 years old. Previous history of or MRI findings consistent with brain tumors, strokes, trauma or arterial venous malformations. Contraindication to MRI such as having devices not compatible with MRI (pacemaker, an implanted medical pump, brain stimulators etc.), metallic prostheses in their body (metal pins and rods, heart valves, cochlear implants etc.), and history of working with metals in the past, since such persons may potentially have small metal fragments in the eye without being aware of it. Any diagnosis of progressive neurological disorders other than paroxysmal hyperkinetic movement disorder. Any history of significant medical disorders requiring chronic treatment with other drugs that affect the CNS, which cannot be stopped. Ongoing radiation therapy for medical condition such as cancer. Women who are pregnant or nursing. Female subjects of child bearing potential will have specific interview and a pregnancy test prior to the study (before each imaging procedure if required) to ensure that they are not pregnant or nursing. Any subject who is not capable of giving an informed consent. This will be determined at the initial evaluation at NINDS clinic. Patients with Mini Mental Score less than 25 or significant psychiatric history will be further evaluated by detailed neuropsychiatric testing, or consultation with a psychiatrist.