Brain Anatomy in Dystonia

Objective

The term, dystonia, is used to describe a syndrome characterized by prolonged muscle
contractions causing sustained twisting movements and abnormal postures of the affected body
part(s). Although no structural brain abnormalities have been definitively demonstrated in
the visual inspection of MRI scans from patients with primary focal dystonia, there are
several lines of evidence for subtle structural brain abnormalities at both the subcortical
and cortical levels. We hypothesize that those abnormalities might be detected by using
appropriate acquisition and analysis methods.

Study population

This research will be conducted using patients with primary focal dystonia and normal
volunteers.

Design

By using high-resolution 3D structural magnetic resonance imaging (MRI) of the brain and
voxel-based morphometry (VBM), and diffusion tensor imaging (DTI) at 3 Tesla and high
resolution anatomical images at 7 Tesla, we will detect structural changes in patients with
primary focal dystonia in comparison with control subjects. VBM and DTI are methods
implemented in the statistical parametric mapping software (SPM2). Magnetic resonance
spectroscopy (MRS) will use special software to calculate gamma-aminobutyric acid (GABA)
levels in a region of interest.

Outcome measures

VBM and DTI analysis in SPM2 will enable us to make a voxel-wise comparison of local
concentration/volume of gray/white matter among these groups of subjects. This study can lead
to an improved knowledge of the pathophysiology of primary hand dystonia can help to
elucidate dystonia s pathogenesis/etiology and may lead to specific preventative or
therapeutic approaches. The MRS study will enable us to study GABA levels in the sensory
motor cortices, prefrontal cortex and basal ganglia in primary dystonia patients and normal
subjects.

- INCLUSION CRITERIA:

HEALTHY VOLUNTEERS: Healthy volunteers who consented to participate in the study and
matched for age, sex, handedness with the group of patients with primary focal hand
dystonia.

PATIENTS: Patient with primary focal dystonia from our dystonia patient database who
consented to participate in the study. This criterion will be established by the
preliminary screening in the Human Motor Control Outpatient Clinic.

EXCLUSION CRITERIA:

The following subjects will be excluded:

Healthy volunteers with cognitive complaints, abnormal neurological exam or history of past
neurological disease.

Dystonia patients with the presence of a second neurological disease or condition; abnormal
neurological findings on exam that are not related to primary focal dystonia.

Subjects with past or present neuropsychiatric illness, head trauma with loss of
consciousness, epilepsy, cerebro-vascular disease, migraine, past and present history of
alcohol abuse, medical conditions that may alter cerebral structure.

Subjects with abnormal MRI findings at visual inspection (prominent normal variants such as
mega cisterna or cavum septum pellucidum, signs of severe cortical or subcortical atrophy,
brain tumors, vascular diseases, trauma or AVMs).

Subjects with any metallic objects within them just prior to MR imaging (cardiac or neural
pacemaker, aneurysm clips [metal clips on the wall of a large artery], metallic prostheses
[including heart valves and cochlear implants] or shrapnel fragments. Welders and metal
workers are also at risk for injury and may not take part in the study because of possible
small metal fragments in the eye of which they may be unaware.

Subjects not capable of giving an informed consent.

Women who are pregnant

Children