Movement-Related Brain Networks Involved in Hand Dystonia

Conditions:Neurology, Orthopedic
Therapuetic Areas:Neurology, Orthopedics / Podiatry
Age Range:18 - Any
Start Date:August 25, 2005
End Date:April 27, 2018

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The Role of Cortical Coherence in Focal Hand Dystonia

This study will use various methods to measure the activity of the motor cortex (the part of
the brain that controls movements) in order to learn more about focal hand dystonia. Patients
with dystonia have muscle spasms that cause uncontrolled twisting and repetitive movement or
abnormal postures. In focal dystonia, just one part of the body, such as the hand, neck or
face, is involved.

Patients with focal hand dystonia and healthy normal volunteers between 18 and 65 years of
age may be eligible for this study. Each candidate is screened with a medical history,
physical examination and questionnaire. Participants undergo the following procedures:

Finger Movement Tasks

Subjects perform two finger movement tasks. In the first part of the study, they move their
index finger repetitively from side to side at 10-second intervals for a total of 200
movements in four blocks of 50 at a time. In the second part of the study, subjects touch
their thumb to the other four fingers in sequence from 1, 2, 3 and 4, while a metronome beats
2 times per second to help time the movements. This sequence is repeated for a total of 200
movements in four blocks of 50 at a time.


This test records brain waves. Electrodes (metal discs) are placed on the scalp with an
electrode cap, a paste or a glue-like substance. The spaces between the electrodes and the
scalp are filled with a gel that conducts electrical activity. Brain waves are recorded while
the subject performs a finger movement task, as described above.


MEG records magnetic field changes produced by brain activity. During the test, the subjects
are seated in the MEG recording room and a cone containing magnetic field detectors is
lowered onto their head. The recording may be made while the subject performs a finger task.


Electromyography (EMG) measures the electrical activity of muscles. This study uses surface
EMG, in which small metal disks filled with a conductive gel are taped to the skin on the

Magnetic resonance imaging

MRI uses a magnetic field and radio waves to produce images of body tissues and organs. The
patient lies on a table that can slide in and out of the scanner (a narrow metal cylinder),
wearing earplugs to muffle loud knocking and thumping sounds that occur during the scanning.
Most scans last between 45 and 90 minutes. Subjects may be asked to lie still for up to 30
minutes at a time, and can communicate with the MRI staff at all times during the procedure.


This questionnaire is designed to detect any sources of discomfort the subject may have
experienced during the study.


Dystonia is a disabling movement disorder that manifests with sustained co-contraction of
agonist and antagonist muscles, giving rise to abnormal twisted postures and overflow of
muscle activity. Abnormal neurophysiologic parameters of the somatosensory and motor cortex
have been demonstrated, although it is unclear how these changes lead to the predominant
motor manifestations. In normal voluntary movement, communication between sensory and motor
cortices is important and these interactions may be dysfunctional in dystonia. Coherence is a
powerful method used to assess brain communication and has been instrumental in demonstrating
the interregional interactions involved in normal movement. Inappropriate connectivity in
terms of the duration of communication or the extent of spread over sensorimotor areas may
give rise to the involuntary overflow of movements that characterize dystonia. We propose to
examine changes in coherence associated with disorganized movements to yield insight as to
the brain networks involved in the development and expression of the disease.

Study population

Patients with focal hand dystonia and normal volunteers will take part in the study.


In this study, EEG/MEG coherence analysis will be used to investigate corticocortical and
corticomuscular interactions during voluntary hand movements in focal hand dystonia patients
and normal subjects. Power spectral changes in the beta and alpha frequency range over the
hand sensorimotor cortex will be studied using a 28-channel EEG montage while subjects
perform various tasks involving the hand. The interregional coherence between sensory and
motor, premotor and motor, and interhemispheric cortices will be assessed for changes between
study populations.

Outcome Measures

Comparison of interregional coherence changes will be performed between dystonia patients and
normal volunteers as well as between affected and unaffected sides. Furthermore, coherence
changes will be compared between rest and during task performance.


- Normal subjects: Healthy volunteers ages 18 and older who consent to participate in
the study

- Patients ages 18 and older diagnosed with focal hand dystonia unilateral focal hand
dystonia who consent to participate in the study


- Normal subjects: abnormal neurologic exam or history of previous neurological disease
that might affect the functioning of the hands

- Dystonia patients: presence of a second neurologic disease or condition that might
affect the functioning of the hands; abnormal neurologic findings on exam not related
to the focal hand dystonia that might affect the functioning of the hands; the use of
Botulinum toxin within 3 months prior to study participation

- For MRI studies, patients with metallic implants will be excluded to avoid potential
risks from this procedure

- For MRI studies, women who are pregnant are excluded from this part of the protocol.
All women of childbearing potential will have a pregnancy test performed prior to MRI
studies, which must be negative, before proceeding.
We found this trial at
9000 Rockville Pike
Bethesda, Maryland 20892
Bethesda, MD
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