title: Opposite effects of internal globus pallidus stimulation on pallidal neurones activity.
abstract: Besides clinical efficacy, the mechanisms of action of deep brain stimulation (DBS) are still debated. To shed light on this complex issue, we have taken the opportunity to record the response of globus pallidus internus (GPi) neurones to 100 Hz stimulations in a case of Lesch-Nyhan syndrome (LNS) where four pallidal electrodes were implanted. Three types of response were observed, 2/19 neurones were unaffected by DBS. About 7/19 neurones were inhibited during DBS stimulation and 10/19 neurones were excited during DBS stimulation. Both effects ceased when DBS was turned off. Inhibited neurones were situated lower that exited ones on the trajectory (1.25 and 4.65 mm above the center of GPi respectively). These observations suggest that locally DBS induces a reversible inhibition of neurone firing rate while at the same time distantly exciting the main afferents to and/or efferents from the GPi. Both actions would result in a strong GPi inhibition that does not preclude increased outflow from the GPi.
authors.affiliation: Neurosurgery, CHUV, 1011 Lausanne, Switzerland. etienne.pralong@hospvd.ch
authors.forename: Etienne
authors.initials: E
authors.lastname: Pralong
authors.forename: Claudio
authors.initials: C
authors.lastname: Pollo
authors.forename: Jean-Guy
authors.initials: JG
authors.lastname: Villemure
authors.forename: Damien
authors.initials: D
authors.lastname: Debatisse
mesh_terms: D001931:Brain Mapping; D002648:Child; D046690:Deep Brain Stimulation; D020821:Dystonic Disorders / Q000503:physiopathology / Q000628:therapy; D004567:Electrodes, Implanted; D004569:Electroencephalography; D005917:Globus Pallidus / Q000503:physiopathology*; D006801:Humans; D007926:Lesch-Nyhan Syndrome / Q000503:physiopathology* / Q000628:therapy; D008297:Male; D009123:Muscle Hypotonia / Q000503:physiopathology / Q000628:therapy; D009433:Neural Inhibition / Q000502:physiology; D009474:Neurons / Q000502:physiology; D012652:Self Mutilation / Q000503:physiopathology / Q000628:therapy; D012815:Signal Processing, Computer-Assisted; D013035:Spasm / Q000503:physiopathology / Q000628:therapy; D009435:Synaptic Transmission / Q000502:physiology; D013826:Theta Rhythm; D016896:Treatment Outcome