A new study by Rouse and colleagues at the MRC Cognition and Brain Sciences Unit, addressed two important clinical questions in frontotemporal dementia (FTD); (a) are there qualitative or clear distinctions between behavioural profiles in behavioural-variant FTD and semantic dementia, and (b) what are the precise roles of the prefrontal cortex and anterior temporal lobes in supporting social behaviour?

Questionnaires were completed by caregivers of FTD patients to assess levels of behavioural changes. FTD patients also completed a detailed neuropsychological battery and had structural MRI scanning, so the authors could explore the association of behavioural change in FTD with cognitive status and changes in grey matter volume.

They found a wide range of behavioural changes across FTD. Although quantitatively more severe on average in behavioural-variant FTD, and found no evidence for qualitative differences in behavioural profiles or “behavioural double dissociations”.  More severe apathy in both FTD subtypes was associated with (a) increased levels of impaired executive function and (b) anterior cingulate cortex atrophy. Together, the findings highlight the presence of a wide range of behavioural changes in both behavioural-variant FTD and semantic dementia, which vary by degree rather than quality.

The full paper can be read here: Matthew A Rouse, Masud Husain, Peter Garrard, Karalyn Patterson, James B Rowe, Matthew A Lambon Ralph, Behavioural changes in frontotemporal dementia and their cognitive and neuroanatomical correlates, Brain, 2025;, awaf061, https://doi.org/10.1093/brain/awaf061