what is primary lateral sclerosis
Primary Lateral Sclerosis: Primary lateral sclerosis is a rare neuromuscular disease characterized by progressive muscle weakness in the voluntary muscles. (Source: excerpt from NINDS Primary Lateral Sclerosis Information Page: NINDS) ... more about Primary Lateral Sclerosis. Primary Lateral Sclerosis: A neurological disorder involving the upper motor nerves and causing progressive muscle weakness in the extremities and facial area.