Provocative Maneuvers (Removal of Fixation, Vibration, Head-Shaking) to Accentuate Peripheral Vestibular Nystagmus)

𝗢𝗿𝗶𝗴𝗶𝗻𝗮𝗹 𝗗𝗲𝘀𝗰𝗿𝗶𝗽𝘁𝗶𝗼𝗻: With an acute destructive process like vestibular neuritis that causes significant unilateral vestibular loss, spontaneous nystagmus is always present. However, over days to months, spontaneous nystagmus should resolve completely. In a patient with vestibular neuritis involving the right side, left-beating mixed horizontal-torsional spontaneous nystagmus will be seen acutely. Over weeks, compensatory processes will take place (centrally and peripherally) and the patient may only have mild left-beating nystagmus with removal of fixation - e.g., while wearing the infrared video goggles (such as used in this video). Certain provocative maneuvers will transiently increase vestibular imbalance, causing an increase in left-beating nystagmus in a patient post right vestibular nystagmus. These maneuvers are ideally performed with fixation removed since peripheral vestibular nystagmus is maximal under this condition. Vibration-induced nystagmus is usually a sign of vestibular asymmetry. Vibration is applied to each mastoid and to the vertex of the cranium. Bony transmission of vibration (when the vibrator is placed on one mastoid or over the vertex) simultaneously stimulates the right and left vestibular apparatus. In a patient with right unilateral vestibular loss, vibration will cause (or accentuate) a rightward (ipsilateral) slow phase, and this is followed by a leftward (contralateral) fast phase. Head-shaking nystagmus is assessed after 10-15 cycles of 2 Hz head-shaking in the horizontal and vertical planes (also see video, https://collections.lib.utah.edu/details?id=187675). Nystagmus can be induced with either central or peripheral vestibular disease. In a patient with right unilateral vestibular loss, horizontal head-shaking will cause (or accentuate) a rightward (ipsilateral) slow phase, and this is followed by a leftward (contralateral) fast phase. In central disorders, a spontaneous horizontal nystagmus may reverse directions (usually lateral medullary syndrome) or a vertical (usually downbeat with lesions involving the flocculus) nystagmus may be seen after horizontal head shaking. NOTE: This video is intended to demonstrate the techniques for examination using provocative maneuvers. The subject depicted does not have nystagmus in this demonstration. 𝗡𝗲𝘂𝗿𝗼-𝗼𝗽𝗵𝘁𝗵𝗮𝗹𝗺𝗼𝗹𝗼𝗴𝘆 𝗮𝗻𝗱 𝗡𝗲𝘂𝗿𝗼-𝗼𝘁𝗼𝗹𝗼𝗴𝘆 𝗧𝗲𝘅𝘁𝗯𝗼𝗼𝗸 𝗟𝗲𝗴𝗲𝗻𝗱: With an acute destructive process like vestibular neuritis that causes significant unilateral vestibular loss, spontaneous nystagmus is always present. However, over days to months, spontaneous nystagmus should resolve completely. In a patient with vestibular neuritis involving the right side, left-beating mixed horizontal-torsional spontaneous nystagmus will be seen acutely. Over weeks, compensatory processes will take place (centrally and peripherally) and the patient may only have mild left-beating nystagmus with removal of fixation-e.g., while wearing the infrared video goggles (such as used in this video). Certain provocative maneuvers will transiently increase vestibular imbalance, causing an increase in left-beating nystagmus in a patient post right vestibular nystagmus. These maneuvers are ideally performed with fixation removed since peripheral vestibular nystagmus is maximal under this condition. Vibration-induced nystagmus is usually a sign of vestibular asymmetry. Vibration is applied to each mastoid and to the vertex of the cranium. Bony transmission of vibration (when the vibrator is placed on one mastoid or over the vertex) simultaneously stimulates the right and left vestibular apparatus. In a patient with right unilateral vestibular loss, vibration will cause (or accentuate) a rightward (ipsilateral) slow phase, and this is followed by a leftward (contralateral) fast phase. Head-shaking nystagmus is assessed after 10-15 cycles of 2 Hz head-shaking in the horizontal and vertical planes. Nystagmus can be induced with either central or peripheral vestibular disease. In a patient with right unilateral vestibular loss, horizontal head-shaking will cause (or accentuate) a rightward (ipsilateral) slow phase, and this is followed by a leftward (contralateral) fast phase. In central disorders, a spontaneous horizontal nystagmus may reverse directions (usually lateral medullary syndrome) or a vertical (usually downbeat with lesions involving the flocculus) nystagmus may be seen after horizontal head shaking. NOTE: This video is intended to demonstrate the techniques for examination using provocative maneuvers. The subject depicted does not have nystagmus in this demonstration https://collections.lib.utah.edu/details?id=1307321. (Video and legend created with the assistance of Dr. Tony Brune and Justin Bosley)