Eliciting information on differential sensation of heat in those with and without poststroke aphasia using a visual analogue scale

Background and Purpose - Aphasia can result in an inability to communicate the presence, location, or intensity of pain. Although visual analogue scales (VASs) exist, it is unknown whether they are useful in assessing pain in individuals with aphasia. The objective was to determine whether those with poststroke aphasia could respond differentially to thermal stimuli of varying intensities using a standardized VAS. Methods - Five groups of participants were assessed: those without stroke, those with stroke but without aphasia, and 3 groups with varying degrees of aphasia. A 10-cm vertical VAS was used to measure responses to varying thermal intensities delivered on the participant's forearm. Results - Across all 5 groups, a similar proportion demonstrated ability to discriminate between 2 temperatures (chi(2) = 1.899; P = 0.75). When presented with 4 temperatures, all groups performed more poorly, yet with similar success rates across groups (chi(2) = 0.1267; P = 0.88). The repeated-measures ANOVA revealed no effect of group but a significant effect of temperature (P < 0.0001). Conclusion - A VAS may be useful in clinical identification of differing intensities of stimuli in a substantial proportion of those with aphasia.