title: Deep brain stimulation for secondary dystonia: results in 8 patients.
abstract: BACKGROUND
  Dystonia is a medically intractable condition characterized by involuntary twisting movements and/or abnormal postures. Deep Brain Stimulation (DBS) has been used successfully in various forms of dystonia. In the present study, we report on eight patients with secondary dystonia, treated with DBS in our clinic.
  
  
  METHODS
  Eight patients (five males, three females) underwent DBS for secondary dystonia. The etiology of dystonia was cerebral palsy (n = 2), drug-induced (n = 1), post encephalitis (n = 2) and postanoxic dystonia (n = 3). The functional capacity was evaluated before and after surgery with the use of Burke-Fahn-Mardsen Dystonia Rating Scale (BFM scale), both movement and disability scale (MS and DS, respectively). The target for DBS was the globus pallidus internus (GPi) in 7 patients and in one patient, with postanoxic damaged pallidum, the ventralis oralis anterior (Voa) nucleus. Brain perfusion scintigraphy using Single Photon Emission Computed Tomography (SPECT) was performed in two separate studies for each patient, one in the "off-DBS" and the other in the "on-DBS" state.
  
  
  RESULTS
  Postoperative both MS and DS scores were found to be significantly lower compared to preoperative scores (p = 0.018 and p = 0.039, respectively). Mean improvement rate after DBS was 41.4% (0-94.3) and 29.5% (0-84.2) in MS and DS scores, respectively. The SPECT Scan, during the "on-DBS" state, showed a decrease in regional cerebral blood flow (rCBF), compared to the "off-DBS" state.
  
  
  CONCLUSIONS
  Our results seem promising in the field of secondary dystonia treatment. More studies with greater number of patients and longer follow-up periods are necessary in order to establish the role of DBS in the management of secondary dystonia. Finally, the significance of brain SPECT imaging in the investigation of dystonia and functional effects of DBS should be further evaluated.
authors.affiliation: Functional Neurosurgery Unit, Department of Neurosurgery, School of Medicine, University of Patras, 265 00, Rion, Greece.
authors.forename: P F
authors.initials: PF
authors.lastname: Katsakiori
authors.forename: Z
authors.initials: Z
authors.lastname: Kefalopoulou
authors.forename: E
authors.initials: E
authors.lastname: Markaki
authors.forename: A
authors.initials: A
authors.lastname: Paschali
authors.forename: J
authors.initials: J
authors.lastname: Ellul
authors.forename: G C
authors.initials: GC
authors.lastname: Kagadis
authors.forename: E
authors.initials: E
authors.lastname: Chroni
authors.forename: C
authors.initials: C
authors.lastname: Constantoyannis