tokens: The objective of this study was to explore the functional anatomy of the globus pallidus internus ( GPi ) by studying the effects of unilateral pallidotomy on parkinsonian ' off ' signs and levodopa - induced dyskinesias ( LID ). We found significant positive correlations between the preoperative levodopa responsiveness of motor signs and the levodopa responsiveness of scores in timed tests ( Core Assessment Program for Intracerebral Transplantations ) in the contralateral limbs and the improvement in these scores after surgery , whereas there was no correlation with the improvement in LID .