Efficacy and safety of posteroventral pallidotomy for the treatment of advanced Parkinson's disease

OBJECTIVES: To analyze the results, efficacy and safety of unilateral micro electrode guided pallidotomy for the treatment of advanced Parkinson's dise ase, three months and one year after surgery. PATIENTS AND METHODS: 23 patients with advanced Parkinson's disease (mean a ge 58,9 years and mean disease duration 14,4 years) were submitted to palli dotomy. Neurological evaluation, three months (n = 23) and one year (n = 16 ) after surgery, was performed during the morning in overnight <<off>> cond ition and after receiving 100-150% of their usual I-dopa dose. Parkinsonian symptoms were evaluated in each follow up visit through motor scales, acti vities of daily living scales, a dyskinesia rating scale and motor timed te sts. RESULTS: Contralateral dyskinesias improved 92% three months after surgery and 89% at one year. Parkinsonian motor scores were reduced by 36.5% after three months and by 26.7% one year after surgery. In the one year follow up visit, contralateral tremor improved 48%, rigidity 36.2% and bradykinesia 37.4%. All these changes were statistically significant (p < 0.01). Adverse effects were minor or transient. Antiparkinsonian medication dosage did no t significantly change during the study period. CONCLUSION: Microelectrode guided unilateral pallidotomy is an effective an d safe procedure to improve contralateral motor symptoms in Parkinson's dis ease, being specially useful for the treatment of I-dopa induced dyskinesia s.