Somatosensory Evoked Potentials and pain assessment in Alzheimer's disease

PurposeThe purpose of the study is to quantify, by means of pain-related Somatosensory Evoked Potentials, the pain experience in subjects with Alzheimer's disease and to compare their psychophysiological response with that of persons without dementia.SubjectsTwenty-seven subjects of both sexes, aged over 65 years and residing at the nursing home of Padua, participated: 10 subjects with probable mild to moderate Alzheimer's disease and 17 without dementia.MethodsWe measured the threshold values of thermal, mechanical and electrical pain and then we recorded the Somatosensory Evoked Potentials elicited by painful and non-painful electrical stimuli. Three components evoked by pain were analyzed: P100 and N150, which reflect discriminative/sensory processing, and P260, which reflects cognitive and emotional processing.ResultsThere were no significant differences between the two groups with regard to three pain thresholds, as well as to P100 and N150 amplitudes. Although present in the Alzheimer's disease group, P260 was significantly lower even respect to that in subjects without dementia.DiscussionAlzheimer's disease patients retain a stimuli perception and detection capacity comparable to that in similarly aged subjects without dementia while, although present, the cognitive and emotional response to pain seems to be reduced.ConclusionThe difficulties in the cognitive and affective elaboration of pain and the patients’ inability to communicate, prevent people/persons with AD to be adequately treated at a pharmacological level. Therefore, the priority is to identify all the nonverbal behaviour through which people with dementia communicate to the outside their pain, so you can act quickly.