Disinhibition in Frontotemporal Dementia and Alzheimer's Disease: A Neuropsychological and Behavioural Investigation.

OBJECTIVE: Cognitive tests of inhibitory control show variable results for the differential diagnosis between behavioural variant of Frontotemporal Dementia (bvFTD) and Alzheimer's disease (AD). We compared the diagnostic accuracies of tests of inhibitory control and of a behavioural questionnaire, to distinguish bvFTD from AD. METHODS: Three groups of participants were enrolled: 27 bvFTD patients, 25 AD patients, and 24 healthy controls. Groups were matched for gender, education, and socio-economic level. Participants underwent a comprehensive neuropsychological assessment of inhibitory control, including Hayling Test, Stroop, the Five Digits Test (FDT) and the Delay Discounting Task (DDT). Caregivers completed the Barratt Impulsiveness Scale 11th version (BIS-11). RESULTS: bvFTD and AD groups showed no difference in the tasks of inhibitory control, while the caregiver questionnaire revealed that bvFTD patients were significantly more impulsive (BIS-11: bvFTD 76.1+9.5, AD 62.9+13, p < .001). CONCLUSIONS: Neuropsychological tests of inhibitory control failed to distinguish bvFTD from AD. On the contrary, impulsivity caregiver-completed questionnaire provided good distinction between bvFTD and AD. These results highlight the current limits of cognitive measures of inhibitory control for the differential diagnosis between bvFTD and AD, whereas questionnaire information appears more reliable and in line with clinical diagnostics.

Hearts and Minds: Emotion Recognition and Mentalizing in Parkinson's Disease and Progressive Supranuclear Palsy.

OBJECTIVE: There are scarce data comparing Parkinson's disease (PD) and Progressive Supranuclear Palsy (PSP) in social cognition (SC). We aimed to compare patients with PSP and PD in SC. METHODS: We included three groups: PD (n = 18), PSP (n = 20) and controls (n = 23). Participants underwent neuropsychological exams, including the mini-version of the Social and Emotional Assessment, which is composed of the facial emotion recognition test (FERT) and the modified faux-pas (mFP) test, which assesses Theory of Mind (ToM). RESULTS: Patients with PD scored lower than controls in the FERT, but not in the mFP test. Patients with PSP performed worse than controls in both the mFP and FERT. PD and PSP groups did not differ in the FERT, but PSP performed worse than PD in the mFP test. The mFP test distinguished PSP from PD with 89% accuracy. CONCLUSION: The assessment of ToM may contribute to the differentiation between PD and PSP.