Distinctive Convergence Eye Movements in an Acquired Neurosensory Dysfunction

Area of Science:

• Neuroscience
• Ophthalmology
• Diplomatic Health

Background:

• In 2016, diplomats in Havana reported unusual sensory experiences and neurological symptoms.
• These symptoms presented uniquely, prompting investigation into their cause and effects.

Purpose of the Study:

• To quantitatively analyze video-oculography data from individuals affected by the Havana Syndrome.
• To objectively differentiate Havana Syndrome's neurosensory effects from mild traumatic brain injury (mTBI).

Main Methods:

• Retrospective analysis of pupillary light reflex and eye movements using video-oculography.
• Comparison of data from 19 Havana Syndrome cases, 17 mTBI cases, and 62 controls.
• Application of non-linear least squares regression and linear discriminant analysis for classification.

Main Results:

• Distinct patterns of eye and pupil behavior were observed in Havana Syndrome cases compared to mTBI and control groups.
• Linear discriminant analysis achieved >91% accuracy in differentiating the groups.
• No confusion was found between Havana Syndrome and mTBI acute neurosensory findings.

Conclusions:

• Eye and pupil movement patterns offer an objective method to distinguish Havana Syndrome from mTBI.
• This objective screening can aid in guiding affected individuals toward appropriate medical care.
• Further research into Havana Syndrome's etiology and long-term effects is warranted.