title: Our first decade of experience in deep brain stimulation of the brainstem: elucidating the mechanism of action of stimulation of the ventrolateral pontine tegmentum.
abstract: The region of the pedunculopontine tegmental nucleus (PPTg) has been proposed as a novel target for deep brain stimulation (DBS) to treat levodopa resistant symptoms in motor disorders. Recently, the anatomical organization of the brainstem has been revised and four new distinct structures have been represented in the ventrolateral pontine tegmentum area in which the PPTg was previously identified. Given this anatomical reassessment, and considering the increasing of our experience, in this paper we revisit the value of DBS applied to that area. The reappraisal of clinical outcomes in the light of this revisitation may also help to understand the consequences of DBS applied to structures located in the ventrolateral pontine tegmentum, apart from the PPTg. The implantation of 39 leads in 32 patients suffering from Parkinson's disease (PD, 27 patients) and progressive supranuclear palsy (PSP, four patients) allowed us to reach two major conclusions. The first is that the results of the advancement of our technique in brainstem DBS matches the revision of brainstem anatomy. The second is that anatomical and functional aspects of our findings may help to explain how DBS acts when applied in the brainstem and to identify the differences when it is applied either in the brainstem or in the subthalamic nucleus. Finally, in this paper we discuss how the loss of neurons in brainstem nuclei occurring in both PD and PSP, the results of intraoperative recording of somatosensory evoked potentials, and the improvement of postural control during DBS point toward the potential role of ascending sensory pathways and/or other structures in mediating the effects of DBS applied in the ventrolateral pontine tegmentum region.
authors: Operative Unit for Stereotactic and Functional Neurosurgery, Regional Center for Functional Neurosurgery and DBS, CTO Hospital, ASL Roma 2, Via S. Nemesio 21, 00145, Rome, Italy. stereomaz@libero.it.
authors: Paolo
authors: P
authors: Mazzone
authors: Stereotactic and Functional Neurosurgery Service, Medical School, Federal University of Goias, Goiânia, Goias, Brazil.
authors: Osvaldo
authors: O
authors: Vilela Filho
authors: Department of Neurology, St. John the Baptist Hospital, Rome, Italy.
authors: Fabio
authors: F
authors: Viselli
authors: Operative Unit for Neurophysiopathology, ASL RMC, Rome, Italy.
authors: Angelo
authors: A
authors: Insola
authors: Department of Neuroradiology, University Hospital, Zurich, Switzerland.
authors: Stefano
authors: S
authors: Sposato
authors: Department of Biotechnological and Applied Biomedical Sciences (DISCAB), University of L'Aquila, L'Aquila, Italy.
authors: Flora
authors: F
authors: Vitale
authors: Department of Biotechnological and Applied Biomedical Sciences (DISCAB), University of L'Aquila, L'Aquila, Italy.
authors: Eugenio
authors: E
authors: Scarnati
mesh_terms: D001927:Brain Diseases / Q000266:history / Q000628:therapy*; D001933:Brain Stem / Q000000981:diagnostic imaging / Q000502:physiology*; D046690:Deep Brain Stimulation / Q000266:history* / Q000379:methods*; D049674:History, 21st Century; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D065821:Pontine Tegmentum / Q000502:physiology*
keywords: Atypical parkinsonisms; Deep brain stimulation; Parkinson’s disease; Pedunculopontine tegmental nucleus; Somatosensory evoked potentials; Ventrolateral pontine tegmentum