title: Effect of bilateral subthalamic electrical stimulation in Parkinson's disease.
abstract: BACKGROUND
  Bilateral high frequency subthalamic stimulation has been reported to be effective in the treatment of Parkinson's disease and levodopa-induced dyskinesias. To analyze the results of this surgical procedure we critically reviewed 17 parkinsonian patients with advanced disease complicated by motor fluctuations and dyskinesias.
  
  
  METHODS
  Between January 1998 and June 1999 these 17 consecutive patients (age 48-68 years; illness duration 8-27 years) underwent bilateral stereotactically guided implantation of electrodes into the subthalamic nucleus in the Department of Neurosurgery of the Istituto Nazionale Neurologico "C. Besta." Parameters used for continuous high-frequency stimulation were: frequency 160 Hz, pulse width 90 microsec, mean amplitude 2.05 +/- 0.45 V. Parts II and III of the UPDRS were used to assess motor performance before and after operation by the neurologic team. The follow-up ranged between 6 and 18 months.
  
  
  RESULTS
  At latest examination, mean UPDRS II and III scores had improved by 30% (on stimulation, off therapy) with mean 50% reduction in daily off time. Peak dyskinesias and early morning dystonias also improved in relation to therapy reduction. Side effects were persistent postoperative supranuclear oculomotor palsy and postural instability in one case, worsened off-medication hypophonia in three, and temporary nocturnal confusion episodes in three. Postoperative MRI revealed a clinically silent intracerebral haematoma in one case. One electrode required repositioning.
  
  
  CONCLUSIONS
  Continuous high frequency STN stimulation is an effective treatment for advanced PD. A functionally useful and safe electrode placement can be performed without microrecording.
authors.affiliation: Department of Neurosurgery, Istituto Nazionale Neurologico "C. Besta,", Milan, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Broggi
authors.forename: A
authors.initials: A
authors.lastname: Franzini
authors.forename: P
authors.initials: P
authors.lastname: Ferroli
authors.forename: D
authors.initials: D
authors.lastname: Servello
authors.forename: L
authors.initials: L
authors.lastname: D'Incerti
authors.forename: S
authors.initials: S
authors.lastname: Genitrini
authors.forename: P
authors.initials: P
authors.lastname: Soliveri
authors.forename: F
authors.initials: F
authors.lastname: Girotti
authors.forename: T
authors.initials: T
authors.lastname: Caraceni
mesh_terms: D000368:Aged; D004599:Electric Stimulation Therapy / Q000009:adverse effects / Q000295:instrumentation; D004566:Electrodes; D006801:Humans; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000009:adverse effects; D010300:Parkinson Disease / Q000503:physiopathology / Q000601:surgery / Q000628:therapy*; D012720:Severity of Illness Index; D013238:Stereotaxic Techniques / Q000009:adverse effects; D020531:Subthalamic Nucleus / Q000503:physiopathology*