Using Pupillometry to Evaluate Balance in Patients Implanted with a Cochleo-Vestibular Implant

Area of Science:

• Neuroscience
• Ophthalmology
• Rehabilitation Medicine

Background:

• Bilateral vestibulopathy significantly increases cognitive effort for maintaining balance.
• Pupillometry is a validated method for quantifying cognitive effort.
• Vestibular implants may reduce the cognitive load associated with balance.

Purpose of the Study:

• To test if pupillometry can quantify increased cognitive effort in bilateral vestibulopathy.
• To assess if vestibular implants reduce cognitive workload during balance tasks.

Main Methods:

• Pupillometry was used to record cognitive effort in subjects with bilateral vestibulopathy.
• Balance tasks (posturography, sensory integration tests) were performed with and without vestibular implant activation.
• Mean relative pupil diameter (MRPD) was calculated to index cognitive workload.

Main Results:

• A 10.7% to 24.2% reduction in MRPD was observed when the vestibular implant was active.
• The reduction in cognitive effort was most pronounced during moderately difficult balance tasks.
• Vestibular implant activation showed a lesser effect on easy or very difficult tasks.

Conclusions:

• Pupillometry is a promising tool for quantifying postural cognitive effort in bilateral vestibulopathy.
• Vestibular implants demonstrably reduce cognitive workload associated with maintaining balance.
• Further research is needed to address technical challenges in pupillometry application.