title: Sensory cognitive abnormalities of pain in autism spectrum disorder: a case-control study.
abstract: BACKGROUND
  The Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) recently included sensory processing abnormalities in the diagnostic criteria for individuals with autism spectrum disorder (ASD). However, there is no standard method for evaluating sensory abnormalities in individuals with ASD.
  
  
  METHODS
  Fifteen individuals with ASD and 15 age- and sex-matched controls were enrolled in this study. We compared objective pain sensitivity by measuring the pain detection threshold and pain tolerance to three different stimuli (electricity, heat, and cold). Then, we compared both subjective pain sensitivity, assessed by the visual analog scale (VAS), and quality of pain, assessed by the short-form McGill Pain Questionnaire (SF-MPQ), to determine the maximum tolerable pain intensities of each stimulation.
  
  
  RESULTS
  The pain detection threshold and pain tolerance of individuals with ASD were not impaired, indicating that there were no differences in the somatic perception of pain between groups. However, individuals with ASD were hyposensitive to subjective pain intensity compared to controls (VAS; electrical: p = 0.044, cold: p = 0.011, heat: p = 0.042) and hyposensitive to affective aspects of pain sensitivity (SF-MPQ; electrical: p = 0.0071, cold: p = 0.042).
  
  
  CONCLUSIONS
  Our results suggest that the cognitive pathways for pain processing are impaired in ASD and, furthermore, that our methodology can be used to assess pain sensitivity in individuals with ASD. Further investigations into sensory abnormalities in individuals with ASD are needed to clarify the pathophysiologic processes that may alter sensory processing in this disorder.
authors.affiliation: Department of Psychiatry, Osaka University Graduate School of Medicine, D3, 2-2, Yamadaoka, Suita, Osaka, 565-0871 Japan.
authors.forename: Yuka
authors.initials: Y
authors.lastname: Yasuda
authors.affiliation: Department of Psychiatry, Osaka University Graduate School of Medicine, D3, 2-2, Yamadaoka, Suita, Osaka, 565-0871 Japan ; Molecular Research Center for Children's Mental Development, United Graduate School of Child Development, Osaka University, D3, 2-2, Yamadaoka, Suita, Osaka, 565-0871 Japan.
authors.forename: Ryota
authors.initials: R
authors.lastname: Hashimoto
authors.affiliation: Department of Anesthesiology and Intensive Care Medicine, 2-2, Yamadaoka, Suita, Osaka, 565-0871 Japan ; Immunology Frontier Research Center, BioSystems Building, Osaka University, 1-3, Yamadaoka, Suita, Osaka, 565-0871 Japan.
authors.forename: Aya
authors.initials: A
authors.lastname: Nakae
authors.affiliation: Department of Anesthesiology and Intensive Care Medicine, 2-2, Yamadaoka, Suita, Osaka, 565-0871 Japan.
authors.forename: Hongling
authors.initials: H
authors.lastname: Kang
authors.affiliation: Department of Psychiatry, Osaka University Graduate School of Medicine, D3, 2-2, Yamadaoka, Suita, Osaka, 565-0871 Japan.
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Ohi
authors.affiliation: Department of Psychiatry, Osaka University Graduate School of Medicine, D3, 2-2, Yamadaoka, Suita, Osaka, 565-0871 Japan.
authors.forename: Hidenaga
authors.initials: H
authors.lastname: Yamamori
authors.affiliation: Department of Psychiatry, Osaka University Graduate School of Medicine, D3, 2-2, Yamadaoka, Suita, Osaka, 565-0871 Japan.
authors.forename: Michiko
authors.initials: M
authors.lastname: Fujimoto
authors.affiliation: Department of Anesthesiology and Intensive Care Medicine, 2-2, Yamadaoka, Suita, Osaka, 565-0871 Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Hagihira
authors.affiliation: Department of Psychiatry, Osaka University Graduate School of Medicine, D3, 2-2, Yamadaoka, Suita, Osaka, 565-0871 Japan.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Takeda
keywords: Autism spectrum disorder (ASD); Pain processing; Quality of pain; Sensory abnormality; Short-form McGill Pain Questionnaire (SF-MPQ); Visual Analog Scale (VAS)