Cortical Function in Primary Lateral Sclerosis and Amyotrophic Lateral Sclerosis

This study will test whether primary lateral sclerosis (PLS) and amyotrophic lateral sclerosis (ALS) affect parts of the brain responsible for thinking, planning, memory and emotion.

Healthy volunteers 18 years of age and older and patients with PLS and ALS may be eligible for this study.

Participants undergo the following procedures:

• Rating motor function: Subjects are asked to contract certain muscles in the face, arms and legs, to tap their finger on a keyboard rapidly, to walk 20 feet, and to read a paragraph out loud.
• Electroencephalography (EEG): The electrical activity of the brain (brain waves) is recorded while subjects tap their finger very slowly. For this test, electrodes are placed on the scalp using a cap or an adhesive substance. A conductive gel is used to fill the space between the electrodes and the scalp to ensure good contact.
• Surface electromyography (EMG): The electrical activity of the muscles is measured. Electrodes filled with a conductive gel are taped to the skin over the muscle tested.
• Neuropsychological testing: Testing may include questionnaires, pen-and-paper or computerized tests, and motor tasks.
• Magnetic resonance imaging (MRI): MRI uses a strong magnetic field and radio waves to produce images of the brain. The subject lies on a table that slides into the scanner. Scanning time varies from 20 minutes to 3 hours, with most scans lasting 45-90 minutes.