title: Tremor control after pallidotomy in patients with Parkinson's disease: correlation with microrecording findings.
abstract: The goals of this study were to analyze the effect of pallidotomy on parkinsonian tremor and to ascertain whether an association exists between microrecording findings and tremor outcome. Forty-four patients with Parkinson's disease who had drug-induced dyskinesia, bradykinesia, rigidity, and tremor underwent posteroventral pallidotomy. Using a 1-mu-tip tungsten electrode, microrecordings were obtained through one to three tracts, starting 10 mm above the pallidal base. Tremor severity was measured on a patient-rated, 100-mm Visual Analog Scale (VAS), both preoperatively and 3 to 9 months (mean 6 months) postoperatively. Preoperatively, tremor was rated as 50 mm or greater in 24 patients (55%) and as less than 25 mm in 13 patients (30%). Postoperatively, tremor was rated as 50 mm or greater in five patients (11%) and less than 25 mm in 29 patients (66%). The difference was significant (p = 0.0001). Four patients (9%) had no postoperative tremor. Tremor improved by at least 50% in eight (80%) of 10 patients in whom tremor-synchronous cells were recorded (Group A) and in 12 (35%) of 34 patients in whom tremor-synchronous cells were not recorded (Group B). This difference was significant (p = 0.03). Tremor improved by at least 50 mm in all (100%) of the seven Group A patients with severe (> or = 50 mm) preoperative tremor and in nine (53%) of 17 Group B patients with severe preoperative tremor. This difference was also significant (p = 0.05). The authors prefer two conclusions: 1) after pallidotomy, tremor improves by at least 50% in two-thirds of patients with Parkinson's disease who have severe (> or = 50 mm on the VAS) preoperative tremor; and 2) better tremor control is obtained when tremor-synchronous cells are included in the lesion.
authors.affiliation: Division of Neurosurgery, Oregon Health Sciences University, Portland, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Taha
authors.forename: J
authors.initials: J
authors.lastname: Favre
authors.forename: T K
authors.initials: TK
authors.lastname: Baumann
authors.forename: K J
authors.initials: KJ
authors.lastname: Burchiel
mesh_terms: D000328:Adult; D000368:Aged; D004594:Electrophysiology; D005260:Female; D005917:Globus Pallidus / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D009474:Neurons / Q000502:physiology; D010300:Parkinson Disease / Q000503:physiopathology* / Q000601:surgery*; D016896:Treatment Outcome; D014202:Tremor / Q000503:physiopathology* / Q000601:surgery*