Frontotemporal dementia patients exhibit deficits in predictive saccades

Area of Science:

• Neuroscience
• Ophthalmology
• Neurology

Background:

• Predictive saccades and timing are crucial for motor control and everyday activities.
• The frontal lobe is implicated in predictive eye movements, making it vulnerable in frontotemporal dementia (FTD).

Purpose of the Study:

• To investigate oculomotor performance in frontotemporal dementia (FTD) patients during a predictive saccade task.
• To compare FTD patient performance with young and older adults to identify specific deficits.

Main Methods:

• Participants performed an oculomotor task designed to elicit predictive saccades at varying temporal rates.
• Performance metrics were analyzed to assess saccade accuracy and timing in FTD patients, controls, and a C9ORF72 mutation carrier.

Main Results:

• FTD patients exhibited significant deficits in producing predictive saccades, particularly when inter-saccadic intervals were short (~500 ms).
• An asymptomatic C9ORF72 mutation carrier displayed oculomotor patterns similar to FTD patients and later developed FTD symptoms.

Conclusions:

• The frontal lobe plays a critical role in timing predictive movements over short timescales.
• Impaired predictive saccade function in FTD may represent an early clinical sign, suggesting potential as a diagnostic aid.