Neuropathological comorbidities in Frontotemporal Lobar Degeneration: Implications for Diagnosis

Our findings demonstrate that age-related co-pathologies are common in FTLD but at low burden, with AD neuropathologic changes and AGD being the most prevalent. The relative higher frequency of intermediate to advanced ADNC levels in PSP and CBD suggests that co-existing AD pathology may contribute to the clinical presentation and progression of these disorders. HS, particularly in FTLD-TDP43 type A, FTLD-FET, and Pick's, highlights distinct vulnerabilities within the FTLD spectrum. Conversely, neocortical and limbic LBD co-pathology was rare, reinforcing its limited role in FTLD. These findings emphasize the importance of comprehensive neuropathological assessments to refine diagnosis, improve prognostication, and guide future therapeutic strategies.