title: Outcome of unilateral pallidotomy in advanced Parkinson's disease: cohort study of 32 patients.
abstract: OBJECTIVE
  In a randomised trial to study the efficacy of unilateral pallidotomy in patients with advanced Parkinson's disease, patients having pallidotomy within 1 month after randomisation were compared with patients having pallidotomy 6 months after the primary outcome assessment. Of the 37 patients enrolled 32 had a unilateral pallidotomy. The follow up study of these patients is presented to report (1) clinical outcome; (2) adverse effects; (3) cognitive and behavioural effects; (4) relation between lesion location and outcome; and (5) preoperative patient characteristics predictive for good outcome.
  
  
  METHODS
  Outcome measures were the motor section of the unified Parkinson's disease rating scale (UPDRS), levodopa induced dyskinesias, disability, quality of life, and a comprehensive neuropsychological assessment. Multivariate logistic regression was used to identify preoperative patient characteristics independently associated with good outcome.
  
  
  RESULTS
  Off phase assessment showed a reduction in parkinsonism from 49 to 36.5 points on the UPDRS 6 months after surgery. Improvements were also demonstrated for activities of daily living and quality of life. In the on phase dyskinesias were reduced. All effects lasted up to 12 months after surgery. Three patients had major permanent adverse effects. Besides worsening of verbal fluency after left sided surgery, systematic cognitive deterioration was not detected. Patients taking less than 1000 levodopa equivalent units (LEU)/day were more likely to improve.
  
  
  CONCLUSIONS
  The positive effects of unilateral pallidotomy are stable up to 1 year after surgery. Patients taking less than 1000 LEU per day were most likely to improve.
authors.affiliation: Department of Neurology (H2-222), Academic Medical Centre, PO Box 22700, University of Amsterdam, 1100 DE Amsterdam, The Netherlands.
authors.forename: R M
authors.initials: RM
authors.lastname: de Bie
authors.forename: P R
authors.initials: PR
authors.lastname: Schuurman
authors.forename: D A
authors.initials: DA
authors.lastname: Bosch
authors.forename: R J
authors.initials: RJ
authors.lastname: de Haan
authors.forename: B
authors.initials: B
authors.lastname: Schmand
authors.forename: J D
authors.initials: JD
authors.lastname: Speelman
mesh_terms: D000203:Activities of Daily Living; D000978:Antiparkinson Agents / Q000627:therapeutic use; D003071:Cognition; D003131:Combined Modality Therapy; D006233:Persons with Disabilities / Q000145:classification; D005260:Female; D005500:Follow-Up Studies; D005917:Globus Pallidus / Q000601:surgery*; D006801:Humans; D007980:Levodopa / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009048:Motor Skills; D009460:Neurologic Examination; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000145:classification / Q000503:physiopathology / Q000523:psychology / Q000601:surgery*; D011237:Predictive Value of Tests; D011788:Quality of Life; D012307:Risk Factors; D012720:Severity of Illness Index; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000978:Antiparkinson Agents; D007980:Levodopa