Pseudonystagmus Due to Bilateral Vestibular Loss and Head Tremor

𝗢𝗿𝗶𝗴𝗶𝗻𝗮𝗹 𝗗𝗲𝘀𝗰𝗿𝗶𝗽𝘁𝗶𝗼𝗻: This is a 65-yo-woman with complaints of imbalance, dizziness, and horizontal oscillopsia. On exam, she had a high frequency, low amplitude (mainly horizontal) head tremor, and with ophthalmoscopy, the optic nerve was clearly oscillating back and forth at the same frequency as her head tremor, which was responsible for her horizontal oscillopsia. In her case, she also had bilateral vestibular loss demonstrated by + head impulse testing in the planes of right and left horizontal canals (also in anterior and posterior canals, not seen in this video). If a patient with a head tremor has an impaired or absent vestibulo-ocular reflex (VOR), the eyes will move with the head with each head oscillation, and oscillopsia will result. The term "pseudonystagmus" has been used to indicate oscillopsia (not due to nystagmus) that results from bilateral vestibular loss and head tremor. 𝗡𝗲𝘂𝗿𝗼-𝗼𝗽𝗵𝘁𝗵𝗮𝗹𝗺𝗼𝗹𝗼𝗴𝘆 𝗮𝗻𝗱 𝗡𝗲𝘂𝗿𝗼-𝗼𝘁𝗼𝗹𝗼𝗴𝘆 𝗧𝗲𝘅𝘁𝗯𝗼𝗼𝗸 𝗟𝗲𝗴𝗲𝗻𝗱: This patient presented with complaints of imbalance, dizziness, and horizontal oscillopsia. On exam, she had a high frequency, low amplitude (mainly horizontal) head tremor, and with ophthalmoscopy, the optic nerve was clearly oscillating back and forth at the same frequency as her head tremor, which was responsible for her horizontal oscillopsia. In her case, she also had bilateral vestibular loss demonstrated by abnormal head impulse testing in the planes of right and left horizontal canals (also in anterior and posterior canals, not seen in this video). If a patient with a head tremor has an impaired or absent vestibulo-ocular reflex (VOR), the eyes will move with the head with each head oscillation, and oscillopsia will result. The term "pseudonystagmus" has been used to indicate oscillopsia (not due to nystagmus) that results from the combination of bilateral vestibular loss and head tremor https://collections.lib.utah.edu/ark:/87278/s62z4z8g