Studies on the Galvanic Square Drawing Test

Abstract

Galvanic stimulation during the performance of the Square Drawing Test (SDT) yields noticeable deviation of the drawn lines of the writing test. Normal subjects and patients suffering from peripheral vestibular disorders or central vestibular disorders were examined using the Galvanic Square Drawing Test. Stimulation was given using bipolar-biauricular electrodes. Results of the Square Drawing Test, which is a modified vertical writing test of Fukuda and which has at least 5 parameters, were evaluated statistically regarding each parameter.
The following results were obtained.
1) The Galvanic Square Drawing Test was applied to normal subjects and patients and was found to be clinically useful.
2) Normal subjects and patients who suffered from peripheral vestibular disorders showed deviation of the drawn lines towards the side of the positive electrode during galvanic stimulation; and towards the side of the negative electrode after the stimulation was removed. Patients with central vestibular disorders showed no definite deviation of the drawing line on galvanic stimulation.
3) The Galvanic Square Drawing Test was useful for the differentiation of central vestibluar desorders from peripheral vestibular disorders.