Saccadic eye movements differentiate functional cognitive disorder from mild cognitive impairment

Area of Science:

• Neuroscience
• Ophthalmology
• Cognitive Science

Background:

• Functional Cognitive Disorder (FCD) presents subjective memory complaints without clear neurological or psychiatric cause.
• Objective diagnostic tools for FCD are lacking, posing challenges for clinicians in Memory Clinics.
• Eye movement analysis, particularly antisaccade tasks, has shown potential in differentiating neurological conditions.

Purpose of the Study:

• To investigate the utility of eye movement tasks in objectively differentiating Functional Cognitive Disorder (FCD) from Mild Cognitive Impairment (MCI) and healthy controls (HC).
• To determine if antisaccadic and prosaccadic eye movement parameters can serve as biomarkers for FCD.

Main Methods:

• Participants included patients with FCD, MCI, and healthy controls (HC).
• Eye movements were recorded during antisaccade and prosaccade tasks.
• Key parameters analyzed included reaction time (RT) mean and standard deviation (SD), and antisaccade error rate.

Main Results:

• Mild Cognitive Impairment (MCI) patients showed significant differences from healthy controls (HC) across multiple antisaccade parameters.
• MCI patients also differed significantly from Functional Cognitive Disorder (FCD) patients in antisaccade performance.
• Functional Cognitive Disorder (FCD) patients did not differ from HC in antisaccade tasks but showed differences in prosaccade RT-mean and RT-SD.

Conclusions:

• Eye movement tasks, specifically antisaccade and prosaccade metrics, show promise in aiding the objective diagnosis of Functional Cognitive Disorder (FCD).
• These findings suggest that eye tracking could become a valuable tool in Memory Clinics for distinguishing FCD from other cognitive conditions.
• Further research on sensitivity and specificity is warranted to establish eye movement tasks as a standard diagnostic feature.