title: Low frequency stimulation of the nucleus tegmenti pedunculopontini increases cortical metabolism in parkinsonian patients.
abstract: OBJECTIVE
  To evaluate the effects of 25-Hz deep brain stimulation of the nucleus tegmenti pedunculopontini (PPTg) on brain metabolic activity.
  
  
  METHODS
  Six patients with Parkinson's disease (PD) who had bilateral stereotactic implantation of PPTg at least 12 months prior to evaluation were included in our study. All underwent, in separate sessions, 18-FDG-PET in core assessment programme for intra-cerebral transplantation as well as motor evaluation [Unified Parkinson's disease rating scale (UPDRS)--Section III] and a battery of cognitive testing.
  
  
  RESULTS
  PPTg-ON (low bipolar contacts, 25 Hz) promoted a significant increase of glucose utilization in bilateral prefrontal areas including dorsolateral prefrontal cortex (DLPFC, BA9), orbito-frontal cortex (BA47), anterior cingulate (BA 25-32), superior frontal gyrus (BA 10) and supramarginal gyrus (BA40); a significant increase of uptake and consumption of FDG also occurred in the left ventral striatum, left subgyral (BA 46), right insula (BA 13) and right superior temporal gyrus (BA 22). PPTg-ON was associated with a significant decrease of glucose utilization in the left cerebellar anterior lobe (culmen) and right cerebellar posterior lobe (declive). In the same patients, PPTg-ON improved delayed recall (P < 0.05) and executive functions whilst the UPDRS revealed a modest (-21%) and variable treatment effect.
  
  
  CONCLUSIONS
  Low frequency stimulation of PPTg, a sub-region of the pedunculopontine nucleus complex, causes a minor motor benefit but a peculiar profile of cognitive improvement associated with a significant increase in FDG consumption in both prefrontal areas and mono-lateral ventral striatum. These data are consistent with multiple limbic and/or associative domains modulated by PPTg stimulation in our patients with PD.
authors.affiliation: Clinica Neurologica, Dipartimento di Neuroscienze, Università di Pisa, Pisa, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Ceravolo
authors.forename: L
authors.initials: L
authors.lastname: Brusa
authors.forename: S
authors.initials: S
authors.lastname: Galati
authors.forename: D
authors.initials: D
authors.lastname: Volterrani
authors.forename: A
authors.initials: A
authors.lastname: Peppe
authors.forename: G
authors.initials: G
authors.lastname: Siciliano
authors.forename: M
authors.initials: M
authors.lastname: Pierantozzi
authors.forename: V
authors.initials: V
authors.lastname: Moschella
authors.forename: U
authors.initials: U
authors.lastname: Bonuccelli
authors.forename: P
authors.initials: P
authors.lastname: Stanzione
authors.forename: A
authors.initials: A
authors.lastname: Stefani
mesh_terms: D002531:Cerebellum / Q000000981:diagnostic imaging / Q000378:metabolism; D003072:Cognition Disorders / Q000209:etiology / Q000378:metabolism / Q000628:therapy; D046690:Deep Brain Stimulation / Q000379:methods*; D004734:Energy Metabolism / Q000502:physiology; D005260:Female; D005947:Glucose / Q000378:metabolism; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000628:therapy*; D045042:Pedunculopontine Tegmental Nucleus / Q000378:metabolism / Q000502:physiology*; D049268:Positron-Emission Tomography / Q000379:methods; D013238:Stereotaxic Techniques; D016896:Treatment Outcome
chemical_list: D005947:Glucose