Video-Oculographic Saccadic Fatigability Distinguishes Myasthenia Gravis From Unilateral Ocular Motor Cranial Nerve Palsy in Diplopia: A Prospective Diagnostic Study.
Eye-movement testing accurately distinguishes myasthenia gravis from cranial nerve palsy in vertical double vision.
Video-Oculographic Saccadic Fatigability Distinguishes Myasthenia Gravis From Unilateral Ocular Motor Cranial Nerve Palsy in Diplopia: A Prospective Diagnostic Study.
To determine whether repetition-based saccadic fatigability measured with three-dimensional video-oculography (video-oculography) distinguishes myasthenia gravis (myasthenia gravis) from unilateral ocular motor cranial nerve palsy (cranial nerve palsy) in patients with diplopia.
In this prospective cross-sectional diagnostic study conducted from August 2022 to July 2024, consecutive patients with myasthenia gravis or unilateral third, fourth, or sixth cranial nerve palsy, and healthy controls underwent repetitive horizontal and vertical saccade testing (±°15 targets; 75 cycles at 0.25 Hz).
eye-movement testing correctly told apart myasthenia gravis from nerve palsy most of the time
The cohort comprised 231 participants: 93 with myasthenia gravis, 54 with cranial nerve palsy and 84 healthy controls.
Myasthenia gravis showed greater repetition-related range decrement and longer time to target acquisition than healthy controls and axis-matched cranial nerve palsy.
In the horizontal comparison (myasthenia gravis vs. sixth cranial nerve palsy), AUCs were 0.800 for percentage range change and 0.787 for percentage time-to-target change.
Cranial nerve palsy showed early baseline slowing, whereas myasthenia gravis showed progressive hypometria with relatively preserved peak velocity.
Repetition-based video-oculography captures a dynamic fatigability signature in myasthenia gravis that differs from the more static deficit of unilateral ocular motor cranial nerve palsy.
Quantitative saccadic fatigability may provide a useful objective adjunct to the neuro-ophthalmic evaluation of diplopia.