title: Galvanic vestibular stimulation improves arm position sense in spatial neglect: a sham-stimulation-controlled study.
abstract: BACKGROUND
  Disturbed arm position sense (APS) is a frequent and debilitating condition in patients with hemiparesis after stroke. Patients with neglect, in particular, show a significantly impaired contralesional APS. Currently, there is no treatment available for this disorder. Galvanic vestibular stimulation (GVS) may ameliorate neglect and extinction by activating the thalamocortical network.
  
  
  OBJECTIVE
  The present study aimed to investigate the immediate effects and aftereffects (AEs; 20 minutes) of subsensory, bipolar GVS (M = 0.6 mA current intensity) on APS in stroke patients with versus without spatial neglect and matched healthy controls.
  
  
  METHODS
  A novel optoelectronic arm position device was developed, enabling the precise measurement of the horizontal APS of both arms. In all, 10 healthy controls, 7 patients with left-sided hemiparesis and left-spatial neglect, and 15 patients with left hemiparesis but without neglect were tested. Horizontal APS was measured separately for both forearms under 4 experimental conditions (baseline without GVS, left-cathodal/right-anodal GVS, right-cathodal/left-anodal GVS, sham GVS). The immediate effects during GVS and the AEs 20 minutes after termination of GVS were examined.
  
  
  RESULTS
  Patients with neglect showed an impaired contralateral APS in contrast to patients without neglect and healthy controls. Left-cathodal/right-anodal GVS improved left APS significantly, which further improved into the normal range 20 minutes poststimulation. GVS had no effect in patients without neglect but right-cathodal/left-anodal GVS worsened left APS in healthy participants significantly.
  
  
  CONCLUSIONS
  GVS can significantly improve the impaired APS in neglect. Multisession GVS can be tested to induce enduring therapeutic effects.
authors: Saarland University, Saarbruecken, Germany. lena.schmidt@mx.uni-saarland.de
authors: Lena
authors: L
authors: Schmidt
authors: Ingo
authors: I
authors: Keller
authors: Kathrin S
authors: KS
authors: Utz
authors: Frank
authors: F
authors: Artinger
authors: Oliver
authors: O
authors: Stumpf
authors: Georg
authors: G
authors: Kerkhoff
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001132:Arm / Q000294:innervation*; D004185:Disability Evaluation; D004599:Electric Stimulation Therapy / Q000379:methods*; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010468:Perceptual Disorders / Q000534:rehabilitation*; D061088:Photoacoustic Techniques; D011434:Proprioception / Q000502:physiology*; D014722:Vestibule, Labyrinth / Q000502:physiology*
keywords: neglect; position sense; recovery; stroke rehabilitation; vestibular