Vestibular-evoked myogenic potential (VEMP) triggered by galvanic vestibular stimulation recorded in the lower limbs v1

Galvanic vestibular stimulation (GVS) is a method that stimulates the vestibular afferents with a small current, triggering a motor reflex response in the posture-controlling muscles. This response can be captured by electromyography (EMG) and is called vestibular evoked myogenic potential (VEMP). The VEMP triggered by GVS (galvanic-VEMP) assesses the central pathways of the vestibular system. When the EMG responses are recorded in the lower limbs, galvanic-VEMP provides information about the function of the vestibulospinal tract extending from the cervical to the lumbar spine. Galvanic-VEMP is a safe, low-cost, and easily performed test which has been used to investigate spinal cord function in cases of trauma, tumor, ischemia, and infection. Our research group has been using galvanic-VEMP to follow patients with diseases that cause postural disabilities, such as Human T-cell lymphotropic virus type 1-associated myelopathy (HAM), Schistosomal myeloradiculopathy, and Parkinson’s disease. This protocol aims at showing how to perform VEMP triggered by galvanic vestibular stimulation with the EMG responses being recorded in the lower limbs.