Brain Function in Primary Lateral Sclerosis

Study Summary

This study will examine whether the motor cortex (the part of the brain that controls movement) works properly in patients with primary lateral sclerosis (PLS), a disorder in which voluntary movements are very slow. Healthy volunteers between 40 and 75 years of age and patients with ascending PLS (a subset of PLS) may be eligible for this study. Patients with ascending PLS have a slowing of finger-tapping movements that corresponds to a particular abnormality of certain neuronal (nerve cell) activity. Participants perform a finger-tapping reaction time exercise while brain wave activity (electroencephalography, or EEG) and muscle activity (electroymogram, or EMG) are measured. The subject is seated in front of a computer screen. A signal appears on the screen and the subject taps a key as quickly as possible in response to the signal. For the EEG, brain activity is recorded by placing electrodes (small metal discs) on the scalp with an electrode cap or glue-like substance. A conductive gel is used to fill the space between the electrodes and the scalp to make sure there is good contact between them. The brain waves are recorded while the subject taps his or her fingers very slowly. For the surface EMG, electrodes filled with a conductive gel are taped to the skin. Participants also undergo magnetic resonance imaging (MRI). This test uses a strong magnetic field and radio waves to obtain images of the brain. During the procedure, the subject lies still on a table that can slide in and out of the scanner - a narrow metal cylinder. Scanning time varies from 20 minutes to 3 hours, with most scans lasting between 45 and 90 minutes. Subjects can communicate with the MRI staff at all times during the scan and can ask to be moved out of the machine at any time.

Conditions Studied

Study Locations (1)