Lene Vase

Expectations and positive emotional feelings accompany reductions in ongoing and evoked neuropathic pain following placebo interventions

Publikation: Bidrag til tidsskrift/Konferencebidrag i tidsskrift /Bidrag til avisTidsskriftartikelForskningpeer review

  • Gitte L Petersen, Danmark
  • Nanna B Finnerup
  • Kasper Grosen, Danmark
  • Hans K Pilegaard
  • Irene Tracey, Centre for Functional Magnetic Resonance Imaging of the Brain (FMRIB), Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, UK.
  • ,
  • Fabrizio Benedetti, Department of Neuroscience, Clinical and Applied Physiology Program, University of Turin Medical School, Turin, Italy.
  • ,
  • Donald D Price, Division of Neuroscience, Department of Oral and Maxillofacial Surgery, University of Florida, Gainesville, FL, USA.
  • ,
  • Troels S Jensen
  • Lene Vase

Research on placebo analgesia and nocebo hyperalgesia has primarily included healthy subjects or acute pain patients, and it is unknown whether these effects can be obtained in ongoing pain in patients with chronic pain caused by an identifiable nerve injury. Eighteen patients with post-thoracotomy neuropathic pain were exposed to placebo and nocebo manipulations, in which they received open and hidden administrations of pain-relieving (lidocaine) or pain-inducing (capsaicin) treatment controlled for the natural history of pain. Immediately after the open administration, patients rated their expected pain levels on a mechanical visual analogue scale (M-VAS). They also reported their emotional feelings via a quantitative/qualitative experiential method. Subsequently, patients rated their ongoing pain levels on the M-VAS and underwent quantitative sensory testing (QST) of evoked pain (brush, pinprick, area of hyperalgesia, wind-up-like pain). There was a significant placebo effect on both ongoing (P = 0.009-0.019) and evoked neuropathic pain (P = 0.0005-0.053). Expected pain levels accounted for significant amounts of the variance in ongoing (53.4%) and evoked pain (up to 34.5%) following the open lidocaine administration. Furthermore, patients reported high levels of positive and low levels of negative emotional feelings in the placebo condition compared with the nocebo condition (P ⩽ 0.001). Pain increases during nocebo were non-significant (P = 0.394-1.000). This is the first study to demonstrate placebo effects in ongoing neuropathic pain. It provides further evidence for placebo-induced reduction in hyperalgesia and suggests that patients' expectations co-exist with emotional feelings about treatments.

Sider (fra-til)2687-2698
StatusUdgivet - 2014

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