title: Neuropathic pain symptoms on the modified painDETECT correlate with signs of central sensitization in knee osteoarthritis.
abstract: OBJECTIVE
  Clinical tools are needed to identify and target a neuropathic-like phenotype, which may be associated with central sensitization (CS), in osteoarthritis (OA). The modified painDETECT questionnaire (mPD-Q) has face and content validity for identifying neuropathic-like symptoms in knee OA. To further validate the mPD-Q, this study assessed the unknown relationship between mPD-Q scores and signs of CS on quantitative sensory testing (QST) in knee OA.
  
  
  METHODS
  36 Individuals were recruited with chronic, symptomatic, knee OA without other pain/neurological conditions. Reference QST data were obtained from 18 controls/32 eligible knees, enabling identification of sensory abnormalities/CS among case knees. A standardized questionnaire assessed psychological factors (depressive symptoms and pain catastrophizing), and for individual knees, mPD-Q and pain intensity scores. A standardized/comprehensive QST protocol was conducted for each knee. QST signs of CS were defined as: mechanical hyperalgesia and/or enhanced temporal summation and/or allodynia. The relationship between the presence of CS (yes/no) and a pre-selected mPD-Q score (≤12 or >12), by knees, was assessed using generalized estimating equations.
  
  
  RESULTS
  Among 57 eligible case knees, 45.6% had ≥1 sign of CS. Controlling for age, knees with higher mPD-Q scores (>12.0) had higher odds of having QST signs of CS (adjusted odds ratio (OR) = 5.6; 95% confidence interval (CI), 1.3-22.9). This relationship was unaffected by controlling for depression and pain intensity, but was attenuated by pain catastrophizing.
  
  
  CONCLUSIONS
  Among painful OA knees, higher mPD-Q scores were associated with greater odds of having signs of CS. Thus, the mPD-Q may aid the identification of CS in people with chronic knee OA.
authors: Division of Rheumatology, Department of Medicine, Women's College Hospital, Toronto, ON, Canada. j.hochman@utoronto.ca
authors: J R
authors: JR
authors: Hochman
authors: A M
authors: AM
authors: Davis
authors: J
authors: J
authors: Elkayam
authors: L
authors: L
authors: Gagliese
authors: G A
authors: GA
authors: Hawker
mesh_terms: D000368:Aged; D058443:Catastrophization / Q000175:diagnosis / Q000209:etiology / Q000523:psychology; D059350:Chronic Pain / Q000175:diagnosis / Q000209:etiology / Q000523:psychology; D003866:Depressive Disorder / Q000175:diagnosis; D005260:Female; D006801:Humans; D006930:Hyperalgesia / Q000175:diagnosis / Q000209:etiology / Q000523:psychology; D008297:Male; D008875:Middle Aged; D009437:Neuralgia / Q000175:diagnosis* / Q000209:etiology* / Q000523:psychology; D020370:Osteoarthritis, Knee / Q000150:complications* / Q000523:psychology; D010147:Pain Measurement / Q000592:standards*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D011795:Surveys and Questionnaires / Q000592:standards*
keywords: Central sensitization; Modified painDETECT; Osteoarthritis; Pain; Quantitative sensory testing