title: Pedunculopontine Nucleus Region Deep Brain Stimulation in Parkinson Disease: Surgical Techniques, Side Effects, and Postoperative Imaging.
abstract: The pedunculopontine nucleus (PPN) region has received considerable attention in clinical studies as a target for deep brain stimulation (DBS) in Parkinson disease. These studies have yielded variable results with an overall impression of improvement in falls and freezing in many but not all patients treated. We evaluated the available data on the surgical anatomy and terminology of the PPN region in a companion paper. Here we focus on issues concerning surgical technique, imaging, and early side effects of surgery. The aim of this paper was to gain more insight into the reasoning for choosing specific techniques and to discuss shortcomings of available studies. Our data demonstrate the wide range in almost all fields which were investigated. There are a number of important challenges to be resolved, such as identification of the optimal target, the choice of the surgical approach to optimize electrode placement, the impact on the outcome of specific surgical techniques, the reliability of intraoperative confirmation of the target, and methodological differences in postoperative validation of the electrode position. There is considerable variability both within and across groups, the overall experience with PPN DBS is still limited, and there is a lack of controlled trials. Despite these challenges, the procedure seems to provide benefit to selected patients and appears to be relatively safe. One important limitation in comparing studies from different centers and analyzing outcomes is the great variability in targeting and surgical techniques, as shown in our paper. The challenges we identified will be of relevance when designing future studies to better address several controversial issues. We hope that the data we accumulated may facilitate the development of surgical protocols for PPN DBS.
authors.affiliation: Division of Neurosurgery, Toronto Western Hospital, University of Toronto, Toronto, Ont., Canada.
authors.forename: Clement
authors.initials: C
authors.lastname: Hamani
authors.forename: Andres M
authors.initials: AM
authors.lastname: Lozano
authors.forename: Paolo A M
authors.initials: PA
authors.lastname: Mazzone
authors.forename: Elena
authors.initials: E
authors.lastname: Moro
authors.forename: William
authors.initials: W
authors.lastname: Hutchison
authors.forename: Peter A
authors.initials: PA
authors.lastname: Silburn
authors.forename: Ludvic
authors.initials: L
authors.lastname: Zrinzo
authors.forename: Mesbah
authors.initials: M
authors.lastname: Alam
authors.forename: Laurent
authors.initials: L
authors.lastname: Goetz
authors.forename: Erlick
authors.initials: E
authors.lastname: Pereira
authors.forename: Anand
authors.initials: A
authors.lastname: Rughani
authors.forename: Wesley
authors.initials: W
authors.lastname: Thevathasan
authors.forename: Tipu
authors.initials: T
authors.lastname: Aziz
authors.forename: Bastiaan R
authors.initials: BR
authors.lastname: Bloem
authors.forename: Peter
authors.initials: P
authors.lastname: Brown
authors.forename: Stephan
authors.initials: S
authors.lastname: Chabardes
authors.forename: Terry
authors.initials: T
authors.lastname: Coyne
authors.forename: Kelly
authors.initials: K
authors.lastname: Foote
authors.forename: Edgar
authors.initials: E
authors.lastname: Garcia-Rill
authors.forename: Etienne C
authors.initials: EC
authors.lastname: Hirsch
authors.forename: Michael S
authors.initials: MS
authors.lastname: Okun
authors.forename: Joachim K
authors.initials: JK
authors.lastname: Krauss
mesh_terms: D046690:Deep Brain Stimulation / Q000009:adverse effects / Q000379:methods*; D006801:Humans; D010300:Parkinson Disease / Q000000981:diagnostic imaging* / Q000601:surgery*; D045042:Pedunculopontine Tegmental Nucleus / Q000000981:diagnostic imaging* / Q000601:surgery*; D011182:Postoperative Care / Q000379:methods; D011183:Postoperative Complications / Q000000981:diagnostic imaging* / Q000209:etiology