Single Photon Emission Computed Tomography (SPECT) to Study Paroxysmal Hyperkinetic Movement Disorders
Single Photon Emission Computed Tomography (SPECT) to Study Paroxysmal Hyperkinetic Movement Disorders
This study will use single photon emission computed tomography (SPECT) 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. SPECT is a nuclear medicine test that produces
 three-dimensional images of the brain, showing blood flow and function in different brain
 regions. This test, which can detect the focus of epileptic seizures, will be used in this
 study to scan patients while they are experiencing a hyperkinetic movement attack, while they
 are not having and attack, and while they are simulating an attack.

 Patients 18 years of age and older who have paroxysmal movement attacks that can be easily
 induced by a specific trigger, such as a sudden movement or prolonged exercise, may be
 eligible for this study. Candidates will be screened with a medical history and review of
 their medical records, physical examination, videotape of attacks, and, for women, a
 pregnancy test.

 Participants will have three SPECT scans, separated from each other by at least 48 hours.
 Before each scan, the subject will perform an activity that ordinarily precipitates a
 movement attack, such as standing up from a chair, assuming a certain posture, or doing
 something strenuous. Each scan will try to record one of the following conditions:

 -  The subject performs the trigger activity, but does not have an attack;

 -  The subject performs the trigger activity and has an involuntary attack as a result;

 -  The subject performs the trigger activity and does not have an attack, but then mimics
 an attack voluntarily.

 After the condition is recorded, the subject will be given an injection of a radioactive
 agent called 99m Technetium and will then relax quietly for 40 to 60 minutes before the SPECT
 scan. For the scan, the subject lies on an examination table and the SPECT camera is moved
 near and around the head to image the brain. The scan takes about 40 minutes.

 Participants will also undergo one magnetic resonance imaging (MRI) scan. 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. The procedure takes about 30 minutes.
The purpose of this study is to determine the areas of the brain responsible for paroxysmal
 hyperkinetic movement disorders. Paroxysmal hyperkinetic movement disorders have been
 clinically recognized for a long time, although the exact neurophysiological mechanism
 leading to paroxysms of hyperkinetic movement attacks is not well understood. Paroxysmal
 hyperkinetic movement disorders are heterogenous, and the exact mechanism may differ in each
 subcategory. In paroxysmal dyskinesias, the idiopathic forms of paroxysmal hyperkinetic
 movement disorders, it is speculated that transient functional abnormality at the cellular
 level occurs in the basal ganglia without organic irreversible damage. Ion channel
 dysfunction is an attractive hypothesis to explain such transient dysfunction. Some patients
 with paroxysmal hyperkinetic movement disorders have a psychogenic etiology.

 A promising technique to evaluate physiological changes in the brain during an attack is
 ictal single photon emission computed tomography (SPECT) scanning. Ictal SPECT is a reliable
 method to detect a seizure focus during an epileptic seizure. We will utilize ictal SPECT
 scanning techniques during, and between attacks, and while they are simulating such attacks.
 The differential activation between the attacks of hyperkinetic movements and the voluntary
 movements may shed light on the regions of the brain and neurophysiological mechanisms
 responsible for generation of 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.