Eye movements in frontotemporal dementia: Abnormalities of fixation, saccades and anti-saccades

Alzheimers Dement (N Y). 2021 Dec 31;7(1):e12218. doi: 10.1002/trc2.12218. eCollection 2021.

Abstract

Introduction: Oculomotor function has not been systematically studied in frontotemporal dementia (FTD) and yet may offer a simple target to monitor disease activity.

Methods: We assessed fixation stability, smooth pursuit, pro-saccades, and anti-saccades using the Eyelink 1000-plus eye-tracker in 19 individuals with behavioral variant FTD (bvFTD) and 22 controls. Neuroanatomical correlates were assessed using a region of interest magnetic resonance imaging (MRI) analysis.

Results: Measures of fixation stability were impaired in the bvFTD group compared with controls. However, performance did not differ from controls in the pro-saccade tasks except in the vertical overlap condition. The bvFTD group performed worse in the anti-saccade task, which correlated strongly with executive function. Neural correlates included the orbitofrontal and ventromedial prefrontal cortices and striatum for fixation stability, and the dorsolateral prefrontal and parietal cortices and striatum for anti-saccades.

Discussion: Overall, oculomotor function is abnormal in bvFTD, with performance likely related to impairment of inhibitory control and executive dysfunction.

Keywords: anti‐saccades; behavioral variant frontotemporal dementia; eye‐tracking; fixations; oculomotor function; pursuit; saccades.