CPT® Code 92537

Caloric vestibular test with recording, bilateral; bithermal (ie, one warm and one cool irrigation in each ear for a total of four irrigations)

The caloric vestibular test, identified by CPT® Code 92537, is a specialized diagnostic procedure designed to assess the vestibulo-ocular reflex, which is crucial for maintaining balance and stable vision. This test is particularly useful in diagnosing asymmetrical functioning of the peripheral vestibular system, which can lead to symptoms such as dizziness and balance disorders. During the procedure, the patient is positioned supine at a 30-degree incline, which optimally aligns the horizontal semi-circular canals of the inner ear into a vertical orientation, enhancing the accuracy of the test results. To conduct the test, electrodes are strategically placed on the skin surrounding the forehead and eyes to measure the corneo-retinal potential through electro-nystagmography (ENG). This setup allows for precise tracking of eye movements in response to vestibular stimulation. Alternatively, video-nystagmography (VNG) employs infra-red goggles to monitor pupil eye movement, providing another layer of data collection. The test involves the irrigation of each external auditory canal with water, utilizing a nozzle or syringe to deliver the fluid. This irrigation is performed in a controlled manner, with the patient engaged in 'tasking' activities, such as counting or naming objects, to facilitate natural eye movements during the test. For the bithermal caloric vestibular testing, which is the focus of CPT® Code 92537, warm water is first used for irrigation, followed by cold water, with each ear receiving a total of four irrigations (one warm and one cool in each ear). A minimum rest period of five minutes is mandated between each irrigation to ensure accurate measurement of the vestibulo-ocular reflex response.