title: Investigation of central nervous system dysfunction in chronic pelvic pain using magnetic resonance spectroscopy and noninvasive brain stimulation.
abstract: BACKGROUND
  Recent studies demonstrate that chronic pelvic pain is associated with altered afferent sensory input resulting in maladaptive changes in the neural circuitry of pain. To better understand the central changes associated with chronic pelvic pain, we investigated the contributions of critical pain-related neural circuits using single-voxel proton magnetic resonance spectroscopy (MRS) and transcranial direct current stimulation (tDCS).
  
  
  METHODS
  We measured concentrations of neural metabolites in 4 regions of interest (thalamus, anterior cingulate cortex, primary motor, and occipital cortex [control]) at baseline and after 10 days of active or sham tDCS in patients with chronic pelvic pain. We then compared our results to those observed in healthy controls, matched by age and gender.
  
  
  RESULTS
  We observed a significant increase in pain thresholds after active tDCS compared with sham conditions. There was a correlation between metabolite concentrations at baseline and quantitative sensory assessments. Chronic pelvic pain patients had significantly lower levels of NAA/Cr in the primary motor cortex compared with healthy patients.
  
  
  CONCLUSIONS
  tDCS increases pain thresholds in patients with chronic pelvic pain. Biochemical changes in pain-related neural circuits are associated with pain levels as measured by objective pain testing. These findings support the further investigation of targeted cortical neuromodulatory interventions for chronic pelvic pain.
authors.affiliation: Laboratory of Neuromodulation, Spaulding Rehabilitation Hospital, Harvard Medical School, Boston, MA, U.S.A.|Division of Neurology, Santa Casa de São Paulo Medical School, SP, Brazil.|Institute of Physical Medicine and Rehabilitation, Clinics Hospital of the University of Sao Paulo Medical School, Brazil.
authors.forename: Marcel
authors.initials: M
authors.lastname: Simis
authors.affiliation: Laboratory of Neuromodulation, Spaulding Rehabilitation Hospital, Harvard Medical School, Boston, MA, U.S.A.
authors.forename: Jay S
authors.initials: JS
authors.lastname: Reidler
authors.affiliation: Laboratory of Neuromodulation, Spaulding Rehabilitation Hospital, Harvard Medical School, Boston, MA, U.S.A.
authors.forename: Debora
authors.initials: D
authors.lastname: Duarte Macea
authors.affiliation: Laboratory of Neuromodulation, Spaulding Rehabilitation Hospital, Harvard Medical School, Boston, MA, U.S.A.
authors.forename: Ingrid
authors.initials: I
authors.lastname: Moreno Duarte
authors.affiliation: Department of Radiology, Beth Israel-Deaconess Medical Center, Harvard Medical School, Boston, MA, U.S.A.
authors.forename: Xiaoen
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Radiology, Beth Israel-Deaconess Medical Center, Harvard Medical School, Boston, MA, U.S.A.
authors.forename: Robert
authors.initials: R
authors.lastname: Lenkinski
authors.affiliation: Department of Gynecology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, U.S.A.
authors.forename: John C
authors.initials: JC
authors.lastname: Petrozza
authors.affiliation: Laboratory of Neuromodulation, Spaulding Rehabilitation Hospital, Harvard Medical School, Boston, MA, U.S.A.|Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, U.S.A.
authors.forename: Felipe
authors.initials: F
authors.lastname: Fregni
mesh_terms: D000328:Adult; D059350:Chronic Pain / Q000175:diagnosis* / Q000378:metabolism / Q000628:therapy; D004599:Electric Stimulation Therapy / Q000379:methods; D005260:Female; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000378:metabolism; D059408:Pain Management / Q000379:methods; D010147:Pain Measurement / Q000379:methods*; D017699:Pelvic Pain / Q000175:diagnosis* / Q000378:metabolism / Q000628:therapy; D065908:Transcranial Direct Current Stimulation / Q000379:methods*
keywords: brain stimulation; chronic pelvic pain; magnetic resonance spectroscopy; tDCS; transcranial direct current stimulation