Pain perception and tolerance in patients with frontotemporal dementia

Pain management in elderly people with cognitive impairment poses special challenges, due to difficulties in pain assessment and specific neurodegenerative changes along pain pathways. Most studies have concentrated on Alzheimer's disease (AD) patients, in whom some contrasting findings have been found. For example, while psychophysical data suggest a selective blunting of the affective dimension of pain, pain-related fMRI signal increases have also been described. Few data have been reported in patients with frontotemporal dementia (FTD). By electrical stimulation, we have measured pain threshold and pain tolerance in clinically diagnosed FTD patients with SPECT cerebral hypoperfusion. We performed our analysis on two separate and overlapping subgroups selected on the basis of (1) neuropsychological scores below cut-off values (2) a strictly localized frontal and/or temporal hypoperfusion. We observed increased pain threshold in the first group and increased pain threshold and pain tolerance in the second group. Our results suggest differences in pain processing changes in distinct types of dementia, while at the same time caution that pain perception assessment may depend on the criteria adopted for diagnosis.