New Uses for an Old Diagnostic Test.

Through the use of a simple computer program, a classic test for rating severity of Parkinson's disease--drawing a simple spiral--now may detect the disorder at the early clinical level, as well as provide valuable information on the efficacy of drug therapy. The test--which is quick, accurate, and noninvasive--can be utilized to distinguish Parkinson's disease from similar disorders, such as essential tremor and dystonia.

Developed by Seth L. Pullman, director of the Clinical Motor Physiology Laboratory and co-director of the Surgery Center for Movement Disorders, and his colleagues at Columbia-Presbyterian Medical Center's Neurological Institute, New York, the computer program measures several parameters and color-codes the pressure applied at different points of a hand-drawn spiral. Patients with Parkinson's disease consistently exert substantially less pressure on one half of the spiral than on the other. The new test has a decided advantage over the...