title: Genital nerve stimulation increases bladder capacity after SCI: A meta-analysis.
abstract: Neurogenic detrusor overactivity (NDO) often results in decreased bladder capacity, urinary incontinence, and vesico-ureteral reflux. NDO can trigger autonomic dysreflexia and can impair quality of life. Electrical stimulation of the genital nerves (GNS) acutely inhibits reflex bladder contractions and can increase bladder capacity. Quantifying the effect of GNS on bladder capacity and determining what study factors and subject factors influence bladder capacity improvements will inform the design of clinical GNS interventions.
  
  
  
  We measured bladder capacity in 33 individuals with NDO, with and without GNS. These data were combined with data from seven previous GNS studies (n=64 subjects). A meta-analysis of the increase in bladder capacity and potential experimental factors was conducted (n=97 subjects total).
  
  
  
  Bladder capacity increased 131±101 ml with GNS across subjects in all studies. The number of individuals whose bladder capacity was greater than 300 ml increased from 24% to 62% with GNS. Stimulus amplitude was a significant factor predicting bladder capacity gain. The variance of the bladder capacity gain significantly increased with increasing infusion rate. Other factors did not contribute to bladder capacity gain.
  
  
  
  GNS acutely increases bladder capacity in individuals with NDO. The consistent increase in magnitude of bladder capacities across the eight studies, and the lack of dependence on individual-specific factors, provide confidence that GNS could be an effective tool for many individuals with NDO. Studies of the chronic effect of GNS on bladder control, with clinical measures such as urinary continence, are needed.
authors.affiliation: a Louis Stokes Cleveland Department of Veterans Affairs Medical Center , Cleveland , Ohio , USA.|b Department of Physical Medicine and Rehabilitation , MetroHealth Medical System , Cleveland , Ohio , USA.|c Cleveland VA Functional Electrical Stimulation Center , Cleveland , Ohio , USA.
authors.forename: Dennis J
authors.initials: DJ
authors.lastname: Bourbeau
authors.affiliation: d Department of Neurosurgery , Stanford University , Stanford , California , USA.|e Spinal Cord Injury Service , VA Palo Alto Health Care System , Palo Alto , California , USA.
authors.forename: Graham H
authors.initials: GH
authors.lastname: Creasey
authors.affiliation: c Cleveland VA Functional Electrical Stimulation Center , Cleveland , Ohio , USA.|f Department of Mathematics and Statistics , Case Western Reserve University , Cleveland , Ohio , USA.
authors.forename: Steven
authors.initials: S
authors.lastname: Sidik
authors.affiliation: a Louis Stokes Cleveland Department of Veterans Affairs Medical Center , Cleveland , Ohio , USA.|c Cleveland VA Functional Electrical Stimulation Center , Cleveland , Ohio , USA.|g Department of Physical Medicine & Rehabilitation , Case Western Reserve University , Cleveland , Ohio , USA.|h Ohio University Heritage College of Osteopathic Medicine , Athens , Ohio , USA.
authors.forename: Steven W
authors.initials: SW
authors.lastname: Brose
authors.affiliation: a Louis Stokes Cleveland Department of Veterans Affairs Medical Center , Cleveland , Ohio , USA.|c Cleveland VA Functional Electrical Stimulation Center , Cleveland , Ohio , USA.|i Departments of Biomedical Engineering and Urology , Case Western Reserve University , Cleveland , Ohio , USA.
authors.forename: Kenneth J
authors.initials: KJ
authors.lastname: Gustafson
mesh_terms: D004599:Electric Stimulation Therapy / Q000009:adverse effects / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D010525:Peripheral Nerves / Q000503:physiopathology; D013119:Spinal Cord Injuries / Q000150:complications*; D001743:Urinary Bladder / Q000294:innervation / Q000503:physiopathology; D001750:Urinary Bladder, Neurogenic / Q000209:etiology / Q000628:therapy*
keywords: Electrical stimulation; Genital nerve stimulation; Neurogenic bladder; Spinal cord injury