Complete Saccadic Palsy Due to Pulmonary Thrombectomy

𝗢𝗿𝗶𝗴𝗶𝗻𝗮𝗹 𝗗𝗲𝘀𝗰𝗿𝗶𝗽𝘁𝗶𝗼𝗻: This is a 37-year-old woman who underwent pulmonary thrombectomy for a pulmonary embolus. Immediately following the procedure, she was unable to make normal eye movements. This video exam (she is the passenger in a car during a telemedicine appointment) was performed 4 months after the onset. She was unable to make saccades horizontally or vertically, although horizontal and vertical smooth pursuit and the vestibulo-ocular reflexes (VOR) were intact, as was the range of eye movements. When asked to look out the window at passing scenery (i.e., an optokinetic stimulus), the slow phase was clearly present, but because she could not generate a fast phase (saccades), the eyes were pinned to the right side. This could happen while walking and looking to the sides as well. ; ; This patient had a pure saccadic palsy in both horizontal and vertical planes; therefore, this did not localize to the paramedian pontine reticular formation (PPRF) or rostral interstitial medial longitudinal fasciculus (riMLF), respectively. Because the excitatory burst neurons (EBN, responsible for saccades) and the omnipause cells are both ensheathed by the perineuronal nets, and because a patient with this rare disorder at autopsy was shown to have normal EBN and omnipause cells, the prevailing theory for a post-surgery saccadic palsy is that ischemia of the perineuronal nets may be the culprit. ; ; Case reports of this rare occurrence (typically post-cardiac surgery) have demonstrated that deficits are permanent. Fortunately, she was able to adapt by using head movements (the vestibulo-ocular reflex) to move the eyes in the intended direction. 𝗡𝗲𝘂𝗿𝗼-𝗼𝗽𝗵𝘁𝗵𝗮𝗹𝗺𝗼𝗹𝗼𝗴𝘆 𝗮𝗻𝗱 𝗡𝗲𝘂𝗿𝗼-𝗼𝘁𝗼𝗹𝗼𝗴𝘆 𝗧𝗲𝘅𝘁𝗯𝗼𝗼𝗸 𝗟𝗲𝗴𝗲𝗻𝗱: This patient underwent pulmonary thrombectomy for a pulmonary embolus. Immediately following the procedure, she was unable to move her eyes. This video exam (she is the passenger in a car during a telemedicine appointment) was performed 4 months after the onset. She was unable to make saccades horizontally or vertically, although horizontal and vertical smooth pursuit and the vestibulo-ocular reflexes (VOR) were intact, as was the range of eye movements. When asked to look out the window at passing scenery (i.e., an optokinetic stimulus), the slow phase was clearly present, but because she could not generate a fast phase (saccades), the eyes were pinned to the right side. This could happen while walking and looking to the sides as well. She had a pure saccadic palsy in both horizontal and vertical planes; therefore, this did not localize to the paramedian pontine reticular formation (PPRF) or rostral interstitial medial longitudinal fasciculus (riMLF), respectively. Because the excitatory burst neurons (EBN, responsible for saccades) and the omnipause cells are both ensheathed by the perineuronal nets, and because a patient with this rare disorder at autopsy (typically due to cardiac surgery) was shown to have normal EBN and omnipause cells, the prevailing theory for a post-surgery saccadic palsy is that ischemia of the perineuronal nets may be the culprit. Fortunately, she was able to adapt by using head movements (the VOR) to move the eyes in the intended direction. https://collections.lib.utah.edu/ ark:/87278/s68h45z9