Ocular Bobbing Due to Hepatic Encephalopathy

𝗢𝗿𝗶𝗴𝗶𝗻𝗮𝗹 𝗗𝗲𝘀𝗰𝗿𝗶𝗽𝘁𝗶𝗼𝗻: This is a 55-year-old man presented with hepatic encephalopathy, and found to have ocular bobbing. Head CT did not show any acute changes. Ocular bobbing almost always localizes to the pons, although cerebellar pathology has also (rarely) been identified as a cause. Typical bobbing consists of rhythmic, downward jerks followed by a slower return to primary position. Horizontal eye movements are usually absent. Other patterns may be seen include: atypical bobbing, which is similar to typical bobbing, but with some residual horizontal gaze; pretectal V-pattern pseudo-bobbing, which consists of downward and convergent jerks with a slow return to primary gaze (usually related to obstructive hydrocephalus; reverse bobbing, which consists of a rapid upward jerks with a slow return to primary position; ocular dipping or inverse bobbing, which consists of slow downward movements over 2 seconds, remaining in downgaze for 2-10 seconds followed by a rapid movement upward to primary gaze; converse bobbing, which consists of an initial slow upward movement over 1-5 seconds, remaining in upgaze for 1-10 seconds followed by a rapid movement downward to primary gaze. 𝗡𝗲𝘂𝗿𝗼-𝗼𝗽𝗵𝘁𝗵𝗮𝗹𝗺𝗼𝗹𝗼𝗴𝘆 𝗮𝗻𝗱 𝗡𝗲𝘂𝗿𝗼-𝗼𝘁𝗼𝗹𝗼𝗴𝘆 𝗧𝗲𝘅𝘁𝗯𝗼𝗼𝗸 𝗟𝗲𝗴𝗲𝗻𝗱: This patient with hepatic encephalopathy developed abnormal eye movements consistent with ocular bobbing. Head CT did not show any acute changes. Ocular bobbing almost always localizes to the pons, although cerebellar pathology has also (rarely) been identified as a cause. Typical bobbing consists of rhythmic, downward jerks followed by a slower return to primary position. Horizontal eye movements are usually absent. Other patterns may be seen include: atypical bobbing, which is similar to typical bobbing, but with some residual horizontal gaze; pretectal V-pattern pseudo-bobbing, which consists of downward and convergent jerks with a slow return to primary gaze (usually related to obstructive hydrocephalus; reverse bobbing, which consists of a rapid upward jerks with a slow return to primary position; ocular dipping or inverse bobbing, which consists of slow downward movements over 2 seconds, remaining in downgaze for 2-10 seconds followed by a rapid movement upward to primary gaze; converse bobbing, which consists of an initial slow upward movement over 1-5 seconds, remaining in upgaze for 1-10 seconds followed by a rapid movement downward to primary gaze. (Video courtesy of Dr. Stephen Reich) https://collections.lib.utah.edu/ark:/87278/s6vx45c3