A Cross-Sectional Study of Pain Sensitivity and Unpleasantness in People with Vascular Dementia.

OBJECTIVE Advanced age holds higher risk of both pain and dementia, with many studies finding dementia often heightens sensitivity to pain. VaD is the second most common type of dementia. Only a few observational or retrospective studies have examined pain responsiveness in VaD, suggesting it may increase pain unpleasantness (i.e., pain affect). This study compared thermal pain psychophysics between a cohort of vascular dementia (VaD) patients and healthy control (HC) subjects. DESIGN Single center, cross-sectional, between-subjects design. SUBJECTS Verbally communicative, probable VaD patients (N = 23) and age- and sex-matched HC (N = 23). METHODS A thermal psychophysics protocol assessed "mild pain" and "moderate pain" thresholds (oC temperature) and associated unpleasantness ratings (0-20 scale) in both VaD and HC groups. Psychophysics were compared between groups by way of a mixed-effects analysis, controlling for depressive symptoms. RESULTS There were no significant differences between groups for pain thresholds (main effect p = 0.086, Cohen's d: mild = 0.55, moderate = 0.27). However, unpleasantness ratings were higher in the VaD group compared to HC (main effect p = 0.003; mild pain p = 0.022, Cohen's d = 0.79; moderate pain p = 0.057, Cohen's d = 0.6). CONCLUSIONS These results are consistent with prior observational findings suggesting VaD may make patients more susceptible to pain, particularly its affective component.