Saccadic Hypermetria and Ipsipulsion (Behind Closed Eyelids and with Vertical Saccades)

𝗢𝗿𝗶𝗴𝗶𝗻𝗮𝗹 𝗗𝗲𝘀𝗰𝗿𝗶𝗽𝘁𝗶𝗼𝗻: This is a 40-year-old woman who experienced oscillopsia and vertical diplopia, due to spontaneous torsional nystagmus and a skew deviation (right hypotropia), respectively. The symptom onset was 7 months prior to these videos. MRI demonstrated ill-defined T2 and FLAIR hyperintensity signal changes involving subcortical white matter and throughout the midbrain and ventral medulla suggestive of a demyelinating, vasculitic or inflammatory condition. Although there was no discrete right sided lateral medullary lesion, she had 1) hypermetric saccades to the right, 2) a rightward trajectory with vertical saccades, and 3) rightward ocular lateropulsion (i.e., eyes drift to the right with eyelid closure, also apparent on her MRI), as well as the torsional nystagmus. These are features that are commonly seen with a (right) lateral medullary syndrome (in addition to her right hypotropia), as the climbing fibers connecting (left) inferior olive to (right) dorsal vermis are injured. See diagram of the normal pathways (https://collections.lib.utah.edu/ark:/87278/s6c8649n), and what happens with a lateral medullary lesion (https://collections.lib.utah.edu/ark:/87278/s67h5cjg). Further work-up (including cerebrospinal fluid analysis) is ongoing, although HIV, SS-A/B, ACE, ANCA, GAD-65, SPEP, NMO, ANA, RPR, and Lyme were negative or normal. For an example of characteristic neurologic and ocular motor findings in a lateral medullary (Wallenberg) syndrome, see https://collections.lib.utah.edu/ark:/87278/s6963fhm. 𝗡𝗲𝘂𝗿𝗼-𝗼𝗽𝗵𝘁𝗵𝗮𝗹𝗺𝗼𝗹𝗼𝗴𝘆 𝗮𝗻𝗱 𝗡𝗲𝘂𝗿𝗼-𝗼𝘁𝗼𝗹𝗼𝗴𝘆 𝗧𝗲𝘅𝘁𝗯𝗼𝗼𝗸 𝗟𝗲𝗴𝗲𝗻𝗱: This patient experienced oscillopsia and vertical diplopia, due to spontaneous torsional nystagmus and a skew deviation (right hypotropia), respectively. The pattern of saccadic dysmetria and ocular lateropulsion localized to the right lateral medulla including: 1) hypermetric saccades to the right, 2) a rightward trajectory with vertical saccades, and 3) rightward ocular lateropulsion (i.e., eyes drift to the right with eyelid closure, also apparent on her MRI), as well as the torsional nystagmus. These are features that are commonly seen with a (right) lateral medullary syndrome (in addition to her right hypotropia), as the climbing fibers connecting (left) inferior olive to (right) dorsal vermis are injured in the (right) inferior cerebellar peduncle. https://collections.lib.utah.edu/ark:/87278/ s64r24wd