Validity of quantitative tests measuring tremor.

A set of tests measuring tremor with an accelerometer has been developed to assist in objectively evaluating clinical trails. An experiment was designed to examine the consensual validity of the test measures for Resting, Sustention and Static Intention Tremor for 10 multiple sclerosis patients and 10 parkinsonian patients. Motion pictures of the patients performing the tremor tests were viewed by a senior neurologist who rated tremor using a nine-point ordinal scale. Comparisons made between the quantitative measures of tremor and the neurologist's ratings of tremor show that the tests are consensually valid. The methodology of this experiment may prove useful for examining in the future the consensual validity of new clinical instruments useful for evaluating trails.