Caloric Testing

𝗢𝗿𝗶𝗴𝗶𝗻𝗮𝗹 𝗗𝗲𝘀𝗰𝗿𝗶𝗽𝘁𝗶𝗼𝗻: Caloric testing is a peripheral vestibular test which takes advantage of the fact that the labyrinth is sensitive to temperature changes. Warm stimulation causes excitation of the semicircular canals while cold stimulation causes inhibition of the semicircular canals. Caloric testing is performed by providing a warm or cold stimulus (often water or air) to the external ear canal. Patients' eye movements in response to this are recorded and measured. Patients are placed in dark environments with video goggles in order to eliminate fixation thereby accentuating peripheral vestibular nystagmus (Fig 1). The change in temperature of the external auditory canal is transmitted most readily to the horizontal canal due to its proximity to the tympanic membrane and external ear canal. Due to this, the caloric is generally viewed as a test specifically examining the horizontal canal function. 𝗡𝗲𝘂𝗿𝗼-𝗼𝗽𝗵𝘁𝗵𝗮𝗹𝗺𝗼𝗹𝗼𝗴𝘆 𝗮𝗻𝗱 𝗡𝗲𝘂𝗿𝗼-𝗼𝘁𝗼𝗹𝗼𝗴𝘆 𝗧𝗲𝘅𝘁𝗯𝗼𝗼𝗸 𝗟𝗲𝗴𝗲𝗻𝗱: An introduction to caloric testing