Two Cases of Myasthenia Gravis Showing Fatigibility Presenting with Decreased Gain of Smooth Pursuit

Tracking Eye Movements for Diagnosis in Myasthenia Gravis: A Comprehensive Review

“…Oculography Techniques Four oculography techniques have been previously utilized in MG studies: electro-oculography (EOG) (46)(47)(48)(49)(51)(52)(53)(54)61), magnetic search coil (MSC) (65)(66)(67)(70)(71)(72), infrared oculography (IROG) (50,(56)(57)(58)(59)(60)(61)64), and video-oculography (VOG) (73,75,77). EOG uses electrodes placed near the eye at the inner and outer canthus to detect change in eye position, and although simple and inexpensive, it is prone to artifacts (83)(84)(85).…”

“…Video-oculography (VOG) is now a popular method, in research applications, due to its accuracy and convenience (89). Although yet to be used in larger studies of MG (75,77), VOG has better angular resolution, and greater vertical and horizontal range than either EOG or IR-OG (90). Indeed, VOG performance approaches that of MSC (91).…”

“…Assessment of vertical saccades has only been conducted in those with vertical restriction (65)(66)(67)72). A few studies have also studied OKN (46)(47)(48)(49)(50)(51)69,70), slow eye movements (74,76), smooth pursuit (77), and blink pattern and rate (73). Edrophonium was used in several studies to assess reversibility of neuromuscular blockade (56,58,62,(69)(70)(71)(72)(73)(74)(75)(76).…”

Oculomotor fatigability with decrements of saccade and smooth pursuit for diagnosis of myasthenia gravis

“…Although several previous studies have examined oculomotor fatigability in normal subjects and MG patients [ 24 – 26 ], their results have not been validated or translated into clinical practice for application of quantitative oculomotor fatigability for diagnosing MG [ 24 – 26 ]. With the development of techniques for recording and analyzing eye movements, oculomotor fatigability could be more easily evaluated and thoroughly described [ 24 – 28 ].…”

“…Although several previous studies have examined oculomotor fatigability in normal subjects and MG patients [ 24 – 26 ], their results have not been validated or translated into clinical practice for application of quantitative oculomotor fatigability for diagnosing MG [ 24 – 26 ]. With the development of techniques for recording and analyzing eye movements, oculomotor fatigability could be more easily evaluated and thoroughly described [ 24 – 28 ]. In the current prospective case–control study, we aimed to investigate the diagnostic yield of quantitation of oculomotor fatigability based on the decrement of oculomotor ranges after repetitive saccades and smooth pursuits using three-dimensional video-oculography (VOG) to distinguish MG patients from healthy controls (HCs).…”