title: Discrepancy between stimulus response and tolerance of pain in Alzheimer disease.
abstract: BACKGROUND
  Affective-motivational and sensory-discriminative aspects of pain were investigated in patients with mild to moderate Alzheimer disease (AD) and healthy elderly controls using the cold pressor test tolerance and repetitive stimuli of warmth and heat stimuli, evaluating the stimulus-response function.
  
  
  METHODS
  A case-control design was applied examining 33 patients with mild to moderate AD dementia and 32 healthy controls with the cold pressor test (4°C). Warmth detection threshold (WDT) and heat pain threshold (HPT) were assessed using 5 stimulations. A stimulus-response function was estimated using 4 incrementally increasing suprathreshold heat stimuli.
  
  
  RESULTS
  Cold pressor tolerance was lower in patients with AD dementia than in controls (p = 0.027). There were no significant differences between groups regarding WDT and HPT. Significant successive increases in HPT assessments indicated habituation (p < 0.0001), which was similar in the 2 groups (p = 0.85). A mixed model for repeated measures demonstrated that pain rating of suprathreshold stimuli depended on HPT (p = 0.0004) and stimulus intensity (p < 0.0001). Patients with AD dementia had significantly lower increases in pain ratings than controls during suprathreshold stimulation (p = 0.0072).
  
  
  CONCLUSIONS
  Our results indicate that AD dementia is not associated with a propensity toward development of sensitization or a lack of habituation, suggesting preservation of sensory-discriminative aspects of pain perception. The results further suggest that the attenuated cold pressor pain tolerance may relate to impairment of coping abilities. Paradoxically, we found an attenuated stimulus-response function, compared to controls, suggesting that AD dementia interferes with pain ratings over time, most likely due to memory impairment.
authors: From the Danish Dementia Research Centre, Department of Neurology (C.J.-D., B.B.A., G.W.), the Multidisciplinary Pain Centre, Neuroscience Center (M.U.W.), and the Department of Clinical Neurophysiology (M.B.), Rigshospitalet, University of Copenhagen; the Danish Pain Research Centre, Department of Neurology (T.S.J.), Aarhus University Hospital; and the Regional Dementia Research Centre, Department of Neurology (P.H.), Roskilde Hospital, University of Copenhagen, Roskilde, Denmark. christina.jensen-dahm@regionh.dk.
authors: Christina
authors: C
authors: Jensen-Dahm
authors: From the Danish Dementia Research Centre, Department of Neurology (C.J.-D., B.B.A., G.W.), the Multidisciplinary Pain Centre, Neuroscience Center (M.U.W.), and the Department of Clinical Neurophysiology (M.B.), Rigshospitalet, University of Copenhagen; the Danish Pain Research Centre, Department of Neurology (T.S.J.), Aarhus University Hospital; and the Regional Dementia Research Centre, Department of Neurology (P.H.), Roskilde Hospital, University of Copenhagen, Roskilde, Denmark.
authors: Mads U
authors: MU
authors: Werner
authors: From the Danish Dementia Research Centre, Department of Neurology (C.J.-D., B.B.A., G.W.), the Multidisciplinary Pain Centre, Neuroscience Center (M.U.W.), and the Department of Clinical Neurophysiology (M.B.), Rigshospitalet, University of Copenhagen; the Danish Pain Research Centre, Department of Neurology (T.S.J.), Aarhus University Hospital; and the Regional Dementia Research Centre, Department of Neurology (P.H.), Roskilde Hospital, University of Copenhagen, Roskilde, Denmark.
authors: Troels Staehelin
authors: TS
authors: Jensen
authors: From the Danish Dementia Research Centre, Department of Neurology (C.J.-D., B.B.A., G.W.), the Multidisciplinary Pain Centre, Neuroscience Center (M.U.W.), and the Department of Clinical Neurophysiology (M.B.), Rigshospitalet, University of Copenhagen; the Danish Pain Research Centre, Department of Neurology (T.S.J.), Aarhus University Hospital; and the Regional Dementia Research Centre, Department of Neurology (P.H.), Roskilde Hospital, University of Copenhagen, Roskilde, Denmark.
authors: Martin
authors: M
authors: Ballegaard
authors: From the Danish Dementia Research Centre, Department of Neurology (C.J.-D., B.B.A., G.W.), the Multidisciplinary Pain Centre, Neuroscience Center (M.U.W.), and the Department of Clinical Neurophysiology (M.B.), Rigshospitalet, University of Copenhagen; the Danish Pain Research Centre, Department of Neurology (T.S.J.), Aarhus University Hospital; and the Regional Dementia Research Centre, Department of Neurology (P.H.), Roskilde Hospital, University of Copenhagen, Roskilde, Denmark.
authors: Birgitte Bo
authors: BB
authors: Andersen
authors: From the Danish Dementia Research Centre, Department of Neurology (C.J.-D., B.B.A., G.W.), the Multidisciplinary Pain Centre, Neuroscience Center (M.U.W.), and the Department of Clinical Neurophysiology (M.B.), Rigshospitalet, University of Copenhagen; the Danish Pain Research Centre, Department of Neurology (T.S.J.), Aarhus University Hospital; and the Regional Dementia Research Centre, Department of Neurology (P.H.), Roskilde Hospital, University of Copenhagen, Roskilde, Denmark.
authors: Peter
authors: P
authors: Høgh
authors: From the Danish Dementia Research Centre, Department of Neurology (C.J.-D., B.B.A., G.W.), the Multidisciplinary Pain Centre, Neuroscience Center (M.U.W.), and the Department of Clinical Neurophysiology (M.B.), Rigshospitalet, University of Copenhagen; the Danish Pain Research Centre, Department of Neurology (T.S.J.), Aarhus University Hospital; and the Regional Dementia Research Centre, Department of Neurology (P.H.), Roskilde Hospital, University of Copenhagen, Roskilde, Denmark.
authors: Gunhild
authors: G
authors: Waldemar
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000503:physiopathology*; D016022:Case-Control Studies; D005260:Female; D006185:Habituation, Psychophysiologic / Q000502:physiology*; D006801:Humans; D008297:Male; D010147:Pain Measurement; D058748:Pain Perception / Q000502:physiology*; D017288:Pain Threshold / Q000502:physiology*