Acquired Elliptical Pendular Nystagmus Suppressed by Blinks and Saccades

𝗢𝗿𝗶𝗴𝗶𝗻𝗮𝗹 𝗗𝗲𝘀𝗰𝗿𝗶𝗽𝘁𝗶𝗼𝗻: This is a 70-year-old man who experienced the gradual onset of oscillopsia over weeks about 3 months prior to this video recording. Examination demonstrated elliptical pendular nystagmus which was atypical for infantile nystagmus or oculopalatal tremor (no palatal tremor on exam). The remainder of the ocular motor and neurologic exam was normal. Contrast-enhanced MRI months prior was normal. Consistent with acquired pendular nystagmus, the movements briefly suppressed following blinks, and suppressed to a more significant degree following saccades. One theory for acquired pendular nystagmus is that it is due to an unstable neural integrator. In this case, blinking and saccades may serve to reset this unstable system, albeit transiently. In this particular case, work-up is ongoing although the differential diagnosis includes: most common - multiple sclerosis and oculopalatal tremor; less common - peroxisomal assembly disorders, toluene abuse, Whipple's disease, acute brainstem stroke, spinocerebellar degeneration, hereditary spastic paraplegia (SPG7 mutation), celiac disease, disorders of vitamin E and coenzyme q10 metabolism, and immune mediated among others. 𝗡𝗲𝘂𝗿𝗼-𝗼𝗽𝗵𝘁𝗵𝗮𝗹𝗺𝗼𝗹𝗼𝗴𝘆 𝗮𝗻𝗱 𝗡𝗲𝘂𝗿𝗼-𝗼𝘁𝗼𝗹𝗼𝗴𝘆 𝗧𝗲𝘅𝘁𝗯𝗼𝗼𝗸 𝗟𝗲𝗴𝗲𝗻𝗱: This is a 70-year-old man who experienced the gradual onset of oscillopsia over weeks about 3 months prior to this video recording. Examination demonstrated elliptical pendular nystagmus which was atypical for infantile nystagmus or oculopalatal tremor (no palatal tremor on exam, and no inferior olivary hyperintensity on MRI). The remainder of the ocular motor and neurologic exam was normal. Contrastenhanced MRI months prior was normal. Consistent with APN, the movements briefly suppressed following blinks, and suppressed to a more significant degree following saccades. One theory for APN is that it is due to an unstable neural integrator. In this case, blinking and saccades may serve to reset this unstable system, albeit transiently. This patient remained stable and work-up remained unremarkable for at least 6 months. https://collections.lib.utah.edu/ark:/87278/s6673nxw