title: Anatomical and functional correlates of persistent pain in Parkinson's disease.
abstract: The pathophysiology of pain in Parkinson's disease (PD) is still poorly understood, although it is conceivable that supraspinal mechanisms may be responsible for pain generation and maintenance.
  
  
  
  We examined brain functional and anatomical changes associated with persistent pain in 40 PD patients, 20 with persistent pain and 20 without pain. We also examined 15 pain-free healthy participants of similar age, gender, and cognitive state as a control group. We assessed pain by the King's Parkinson's Pain Scale, the Visual Analogue Scale for pain, and the Leeds Assessment for Neuropathic Symptoms and Sign. All patients underwent structural, diffusion tensor imaging, and resting-state functional MRI. We compared clinical characteristics, whole-brain cortical thickness, subcortical volumes, diffusion tensor imaging scalar measures, and functional connectivity by network based statistics.
  
  
  
  The group with PD and persistent pain showed significant thinning in the bilateral temporal pole, left-medial orbitofrontal cortex, bilateral superior and left-inferior parietal areas, pars orbicularis, and right superior frontal, posterior cingulated, and precentral cortex. There were no significant subcortical volume and white matter differences between PD subgroups. Functional MRI showed a decrease of brain activity in the left frontal inferior orbital in PD patients with persistent pain, with greater activity bilaterally in the cerebellum and in the right inferior temporal areas. Only PD patients with persistent pain showed an accumbens-hippocampus disconnection without white matter and subcortical alterations.
  
  
  
  We showed that persistent pain in PD is associated with supraspinal structural and functional changes. We also highlighted the contribution of frontal, prefrontal, and insular areas in nociceptive modulation and accumbens-hippocampus disconnection. © 2016 International Parkinson and Movement Disorder Society.
authors.affiliation: Parkinson Unit, Institute for Research, Hospitalization and Health Care (IRCCS) San Camillo Rehabilitation Hospital, Venice, Italy.|Laboratory of Robotics and Kinematics, Neurorehabilitation Department, Institute for Research, Hospitalization and Health Care (IRCCS) San Camillo Hospital Foundation, Venice, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Polli
authors.affiliation: Parkinson Unit, Institute for Research, Hospitalization and Health Care (IRCCS) San Camillo Rehabilitation Hospital, Venice, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Weis
authors.affiliation: Parkinson Unit, Institute for Research, Hospitalization and Health Care (IRCCS) San Camillo Rehabilitation Hospital, Venice, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Biundo
authors.affiliation: Centre for Human and Aerospace Physiological Sciences, Pain Section, Neuroimaging, Institute of Psychiatry, Kings College London, London, United Kingdom.
authors.forename: Michael
authors.initials: M
authors.lastname: Thacker
authors.affiliation: Laboratory of Robotics and Kinematics, Neurorehabilitation Department, Institute for Research, Hospitalization and Health Care (IRCCS) San Camillo Hospital Foundation, Venice, Italy.|Department of Neuroscience, The University of Sheffield, Sheffield, United Kingdom.
authors.forename: Andrea
authors.initials: A
authors.lastname: Turolla
authors.affiliation: Parkinson Unit, Institute for Research, Hospitalization and Health Care (IRCCS) San Camillo Rehabilitation Hospital, Venice, Italy.
authors.forename: Kostantinos
authors.initials: K
authors.lastname: Koutsikos
authors.affiliation: Neuroscience Research and Development, Denmark Hill Campus, King's College Hospital, King's College London, London, United Kingdom.
authors.forename: K Ray
authors.initials: KR
authors.lastname: Chaudhuri
authors.affiliation: Parkinson Unit, Institute for Research, Hospitalization and Health Care (IRCCS) San Camillo Rehabilitation Hospital, Venice, Italy.
authors.forename: Angelo
authors.initials: A
authors.lastname: Antonini
mesh_terms: D000368:Aged; D002540:Cerebral Cortex / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D063132:Connectome; D056324:Diffusion Tensor Imaging; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009437:Neuralgia / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D010300:Parkinson Disease / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology
keywords: Parkinson's disease; chronic pain; fMRI; neuroimaging; neuropathic pain