title: The deep brain stimulation of the pedunculopontine tegmental nucleus: towards a new stereotactic neurosurgery.
abstract: The application of deep brain stimulation (DBS) to the pedunculopontine tegmental nucleus (PPTg) has required profound modifications of classic neurosurgical techniques and of the criteria for evaluation of clinical results. This review analyzes a novel method of targeting the PPTg, based on angio-computerized tomography (angio-CT) scans and the tridimensional reconstruction of nuclei and cerebral vessels, and considers the advantages of applying these methods in comparison to the more traditional approach based on reference points obtained through the evaluation of the bicommessural line. Validation of the results obtained following unilateral PPTg DBS through neurophysiological recordings and objective measurements of functional parameters suggests that the PPTg may be considered as an initial target for the treatment of motor symptoms in selected patients affected by idiopathic Parkinson's disease (PD), which, if required, could be followed by DBS of other target areas. Moreover, on the basis of the observations derived from stimulating the PPTg, the potential utility attributed up to date to intraoperative neurophysiological recordings for identifying neurosurgical targets should be revisited, and the need for changes in the intraoperative management of patients has arisen from the body of evidence accumulated over recent years. The results obtained by different groups following PPTg DBS in parkinsonian patients are not uniform, most likely due to a cautious acceptance of this methodology, the experience progressively acquired, the criteria for patient selection and to subtle differences in target location. Although the role of PPTg in PD and/or in other pathologies remains to be clarified, pursuing the traditional approach on classical basal ganglia targets may limit the perspective of DBS based on multiple implantations.
authors.affiliation: Functional and Stereotactic Neurosurgery, CTO Hospital ASL Roma C, Via San Nemesio 21, 00145, Rome, Italy. stereomaz@libero.it
authors.forename: Paolo
authors.initials: P
authors.lastname: Mazzone
authors.forename: Stefano
authors.initials: S
authors.lastname: Sposato
authors.forename: Angelo
authors.initials: A
authors.lastname: Insola
authors.forename: Eugenio
authors.initials: E
authors.lastname: Scarnati
mesh_terms: D000368:Aged; D000818:Animals; D001931:Brain Mapping; D046690:Deep Brain Stimulation / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000379:methods*; D045042:Pedunculopontine Tegmental Nucleus / Q000502:physiology*; D012018:Reflex / Q000502:physiology; D013238:Stereotaxic Techniques