Periodic Alternating Nystagmus Due to Spinocerebellar Ataxia Type 6

𝗢𝗿𝗶𝗴𝗶𝗻𝗮𝗹 𝗗𝗲𝘀𝗰𝗿𝗶𝗽𝘁𝗶𝗼𝗻: This 50-yo-man complained of imbalance for several years and more recently oscillopsia. On examination, there was saccadic pursuit and VOR suppression in addition to gaze-evoked nystagmus with rebound, raising suspicion for a vestibulocerebellar localization. Additionally, there was periodic alternating nystagmus (localizing to the nodulus/uvula) - every 90-120 seconds or so, there was a transition from right-beating to left-beating, etc. Baclofen lessened his oscillopsia, and genetic testing for SCA 6 was positive. 𝗡𝗲𝘂𝗿𝗼-𝗼𝗽𝗵𝘁𝗵𝗮𝗹𝗺𝗼𝗹𝗼𝗴𝘆 𝗮𝗻𝗱 𝗡𝗲𝘂𝗿𝗼-𝗼𝘁𝗼𝗹𝗼𝗴𝘆 𝗧𝗲𝘅𝘁𝗯𝗼𝗼𝗸 𝗟𝗲𝗴𝗲𝗻𝗱: This patient presented with imbalance for several years and more recently oscillopsia. On examination, there was saccadic pursuit in addition to gaze-evoked nystagmus with rebound, raising suspicion for a cerebellar flocculus/paraflocculus localization. Additionally, there was PAN, which localizes to the nodulus/ventral uvula. Every 90-120 seconds there was a transition from right-beating to left-beating, etc. Baclofen lessened his oscillopsia, and genetic testing for SCA 6 was positive. https:// collections.lib.utah.edu/ark:/87278/s6np5spp