title: Disruption of bimanual movement by unilateral subcortical electrostimulation.
abstract: OBJECTIVE
  Cortical areas involved in bimanual coordination have been regularly studied by functional neuroimaging and electroencephalography. However, the subcortical connectivity underlying this complex function has received less attention. Here, we used the technique of direct electrostimulation in awake patients who underwent surgery for brain glioma, with the goal to investigate the white matter pathways subserving bimanual coordination.
  
  
  METHODS
  Eight patients were operated under local anesthesia for a frontal low-grade glioma. Intraoperative subcortical electrostimulation mapping was used to search interference with bimanual coordination. The corresponding stimulation sites were reported on brain MRI.
  
  
  RESULTS
  All patients presented a complete arrest of the movement of both hands during unilateral subcortical stimulation of the white matter underneath the dorsal premotor cortex and the posterior part of the supplementary motor area, rostrally to the corticospinal tract, until the caudate nucleus and the anterior arm of the internal capsule. No movement deficits, especially no disturbances of bimanual coordination, were observed 3 months after surgery.
  
  
  CONCLUSIONS
  This is the first evidence of bilateral negative motor responses elicited by unilateral subcortical stimulation. Such findings support the existence of a bilateral cortico-subcortical network connecting the premotor cortices, basal ganglia, and spinal cord, involved in the control of bimanual coordination. A better understanding of this modulatory motor circuit may have important implications in fundamental neurosciences as well as in brain surgery.
authors.affiliation: Department of Neurosurgery, CHU Nancy, Nancy University Hospital, France.
authors.forename: Fabien
authors.initials: F
authors.lastname: Rech
authors.forename: Guillaume
authors.initials: G
authors.lastname: Herbet
authors.forename: Sylvie
authors.initials: S
authors.lastname: Moritz-Gasser
authors.forename: Hugues
authors.initials: H
authors.lastname: Duffau
mesh_terms: D000328:Adult; D001931:Brain Mapping; D046690:Deep Brain Stimulation / Q000009:adverse effects*; D007839:Functional Laterality / Q000502:physiology*; D006225:Hand / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D017567:Karnofsky Performance Status; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009069:Movement Disorders / Q000209:etiology*; D012640:Seizures / Q000628:therapy*
keywords: awake surgery; bimanual coordination; direct electrical stimulation; movement