The impact of white matter damage on cognition in PSP syndrome: a DT MRI study (P1.181)

Objective: To explore the impact of white matter (WM) tract damage on cognitive performances in a relatively large sample of patients with probable progressive supranuclear palsy syndrome (PSPs) using diffusion tensor (DT) MRI. Background: Beside of motor symptoms, PSPs is characterized by behavioral abnormalities and cognitive impairment. This might be related to the disconnection between cortico-cortical and cortico-subcortical structures due to damage of the main WM tracts. Methods: We enrolled 32 patients with probable PSPs in a moderate stage of the disease (mean H&Y score: 3.3) and 22 matched healthy controls. Patients underwent an extensive neuropsychological evaluation. DT MRI and tract-based spatial statistics were used to assess the regional patterns of WM microstructural damage in patients relative to controls. Then, a regression analysis was conducted to correlate DT MRI metrics of the main WM tracts with cognitive variables. Results: PSPs patients showed prominent attentive-executive deficits that were related to the damage of specific WM tracts as revealed by DT MRI. The following significant correlations were observed: attentive matrices scores with WM damage of the fornix, left cingulum, superior longitudinal fasciculus (SLF), right superior fronto-occipital fasciculus and bilateral cortico-spinal tract (CST); Raven matrices scores with fornix; token test scores with DT MRI measures of the fornix, bilateral inferior and middle cerebellar peduncle, cingulum, CST, inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, left SLF and splenium of corpus callosum; fluencies scores with damage to bilateral superior cerebellar peduncles, left SLF and CST. Conclusions: In PSPs, WM damage has a central role in the development of executive and language dysfunction. Study supported by: CurePSP Foundation (#MD505-12_001).