Studying Childhood-Onset Hemidystonia

Cerebral Palsy Clinical Trial

Official title: Characteristics and Mechanism of Childhood-Onset Hemidystonia

Status Completed

Clinical Trial Summary

Background:

• Childhood-onset dystonia is caused by a brain injury. It causes muscle contractions and twisting movements that the person with dystonia cannot control. The term hemidystonia is used when only one side of the body is affected. When dystonia starts during childhood, the brain and nerves may not develop normally. People with hemidystonia can become disabled because of the unwanted postures and twisting that dystonia causes. More research is needed to determine how dystonia affects brain development.

Objectives:

• To study brain function in people with hemidystonia.

Eligibility:

• Individuals between 18 and 40 years of age who developed hemidystonia before age 13. Only one wrist may be affected by hemidystonia, and participants must have at least some movement in that wrist.

• Healthy volunteers at least 18 years of age.

Design:

• This study requires five visits to the NIH Clinical Center: a screening visit and four study visits. Each visit will last up to 3 hours. Visits will be scheduled about once a week. The study procedures may be done in any order.

• Participants will be screened with a physical exam and medical history.

• Participants will have the following tests:

• Brain magnetic resonance imaging scan. During the scan, participants will be asked to move their hand at the wrist when they hear a tone.

• Motor tests of arm movement, balance, and walking. These tests may also examine nerve development and muscle tone.

• Two transcranial magnetic stimulation sessions to study the electrical activity of the muscles and brain. These sessions may also involve sensory tests. Participants will have hearing tests before the first session and after the second session.

• No treatment for hemidystonia will be provided as part of this study.

Clinical Trial Description

Objective

In childhood-onset hemidystonia, motor and sensory abnormalities pose a great challenge to voluntary movement. In an effort to inform future methods of treatment of this disorder, this study seeks to (1) characterize involuntary muscle activity, (2) explore neurophysiologic mechanisms of involuntary muscle activity, (3) characterize abnormalities of sensation, (4) assess performance on two sensorimotor tasks (voluntary postural control, and a reach-to-grasp arm movement), and (5) explore brain abnormalities using imaging in childhood-onset hemidystonia.

Study Population

The dystonia group will consist of 40 individuals (age 7-40 years) with childhood-onset hemidystonia. The control group will consist of 40 individuals within the same age range with no neurological disorders.

Design

This is a cross-sectional study, in which multiple assessments will be performed over a short period. Results in the dystonia group will be compared to results in the control group. Due to the laterality of brain injury in hemidystonia, outcomes from both arms and cortical hemispheres will be compared to each other. Outcomes within the dystonia group will be correlated with validated dystonia rating scales as well as with the age at the time of injury.

Outcome Measures

In Objective 1, we will analyze the timing of involuntary electromyographic (EMG) activity and kinematics triggered in the dystonic arm during various tasks. In Objective 2, we will investigate various types of intracortical inhibition (short intracortical inhibition, long intracortical inhibition, contralateral silent period, and ipsilateral silent period) and intracortical facilitation in motor cortical regions controlling the dystonic wrist flexor during voluntary contraction of the wrist extensor using transcranial magnetic stimulation (TMS). In addition, we will perform a coherence analysis between EMG activity in the wrist flexor and extensor muscles and between electroencephalographic (EEG) activity in the primary motor cortex and the contralateral wrist muscles. In Objective 3, we will test tactile sense (spatial and temporal), vibration sense, and stereognosis of the hand. In Objective 4, we will analyze seated limits of stability (voluntary postural control), and the timing and amplitude of EMG activity and kinematics in the arm during a reaching and grasping arm movement. In Objective 5, we will obtain brain scans with structural magnetic resonance imaging (MRI), diffusion tensor imaging (DTI), resting state functional connectivity MRI, and functional MRI during a simple task. ;

Related Conditions & MeSH terms

• Cerebral Palsy
• Dystonia

• NCT number: NCT01432899
• Study type: Observational
• Source: National Institutes of Health Clinical Center (CC)
• Status: Completed
• Start date: September 10, 2011
• Completion date: December 20, 2018