Profiles of impairments in social and non-social cognition: vascular dementia compared to Alzheimer's disease and behavioral variant frontotemporal dementia

Objective
Impairments in emotion recognition, which are associated with negative patient and caregiver outcomes, were previously demonstrated in patients with behavioral variant frontotemporal dementia (bv-FTD) and Alzheimer’s Disease (AD). To date, it is unclear whether patients with vascular dementia (VaD) display deficient emotion recognition as well. Therefore, we investigated profiles of impairments in emotion recognition and non-social cognitive functions (memory, processing speed, executive functions), comparing VaD patients to bv-FTD and AD patients, as well as to a healthy control group (HC).

Participants and Methods
Sixty-eight memory clinic patients with early-stage VaD (n=22), bv-FTD (n=21) and AD (n=25) and 30 HCs who performed Ekman 60 Faces Test (EFT; emotion recognition), Auditory Verbal Learning Test (AVLT; memory - encoding and retrieval) and Trailmaking Test (TMT A, TMT B/A; attention/processing speed, executive functions), were retrospectively included and analyzed for differences between and within groups, using age, education and sex adjusted median standardized norm scores.

Results
All patient groups performed significantly poorer than HCs on EFT (all p<.001). EFT performance in VaD patients was in between bv-FTD and AD (only bv-FTD < AD, p<.05). On the non-social cognition tests, all patient groups were impaired on AVLT encoding and TMT B/A compared to HCs (both p<.05). Neurocognitive profiles, including social and non-social cognition, also differed between and within patient groups, with most severely affected domains: processing speed in VaD, emotion recognition in bv-FTD and memory retrieval in AD.
4. Conclusions

Conclusions
We found clear impairments in emotion recognition in patients with VaD, as well as clearly defined neurocognitive profiles in early-stage VaD, bv-FTD and AD. The addition of an emotion recognition test allows to create more distinctive neurocognitive profiles covering a broader set of domains, which will facilitate a more timely and accurate diagnosis in clinical practice.