6533b81ffe1ef96bd1277ca8

RESEARCH PRODUCT

Is pain sensitivity altered in people with Alzheimer's disease? A systematic review and meta-analysis of experimental pain research

Brendon StubbsBrendon StubbsDavy VancampfortNicola VeroneseClaudio LuchiniMarco SolmiGiuseppe SergiTrevor Thompson

subject

Dementia painAgingmedicine.medical_specialtyPain toleranceBFPainDiseaseBiochemistryExperimental pain03 medical and health sciences0302 clinical medicineEndocrinologyAlzheimer DiseaseHeart RateInternal medicineThreshold of painGeneticsmedicineNoxious stimulusHumans030212 general & internal medicinePsychiatryMolecular BiologyAlzheimer's disease; Dementia pain; Experimental pain; Meta-analysis; Systematic review; Aging; Biochemistry; Cell Biology; Endocrinology; Genetics; Molecular BiologyPain MeasurementFacial expressionMini–Mental State Examinationmedicine.diagnostic_testbusiness.industryCell BiologyAlzheimer's diseaseConfidence intervalMeta-analysisMeta-analysisSystematic reviewAlzheimer's disease; Dementia pain; Experimental pain; Meta-analysis; Systematic reviewAlzheimer's disease Dementia pain Experimental pain Meta-analysis Systematic reviewbusiness030217 neurology & neurosurgery

description

Background Clinical studies suggest people with Alzheimer's disease (AD) have altered pain sensitivity. Experimental pain research is equivocal. Objective Conduct a meta-analysis to investigate if people with AD have altered pain sensitivity compared to healthy controls (HCs). Methods Three authors searched electronic databases from inception till November 2015 for experimental pain studies in AD vs. HCs. Outcome measures were pain threshold, tolerance, pain ratings, heart rate response to noxious stimuli and the Facial Action Coding System (FACS). Random effect meta-analysis calculating Hedges' g ± 95% confidence intervals (CI) was conducted. Results Thirteen studies were identified, including 256 people with AD (74.6 (± 5.6) years, 59% females with a mean mini mental state examination (MMSE) score of 19.2) and 260 HCs. Meta-analysis demonstrated no significant difference in pain threshold (g = 0.025, 95% CI − 0.315-0.363, p = 0.88, n AD = 135, n HCs = 157), pain tolerance (g = − 0.363, 95% CI − 2.035-1.309, p = 0.67, n AD = 41, n HCs = 53) or pain intensity ratings (g = 0.03, p = 0.89, n AD = 138, n HCs = 135). Heart rate response to pain was less pronounced in AD but not significant (g = − 0.746, p = 0.11). People with AD (n = 90) had significantly higher FACS scores versus HCs (n = 109) (g = 0.442, p = 0.03) indicating increased pain. Meta-regression demonstrated that an increasing percentage of AD female participants moderated pain threshold (p = 0.02) whilst MMSE scores did not (p = 0.19). Conclusion People with AD have a greater sensitivity to pain when validated observer ratings of facial expressions are used. Verbal response to painful stimuli, even under experimental conditions, may mean pain is not identified in people with AD. Clinically useful observer rated pain tools may be the most appropriate way to assess pain in AD. © 2016 Elsevier Inc.

yearjournalcountryeditionlanguage
2016-09-01Experimental Gerontology
https://doi.org/10.1016/j.exger.2016.05.016