High-voltage Stimulation (HVS) in Plexus Lesions

Purpose: Usually electrodiagnosis of plexus lesions comprises EMG to find axonal damage and SEPs to prove impairment of the sensory fibers. Acute or dominant demyelinating lesions lack to show denervation activity in EMG. Particularly motor deficits can not be detected by SEPs. Conventional neurography (so as MEP) fails in plexopathies due to the impossibility of supramaximal stimulation. F-waves and H-reflexes are not able to localize the site of the lesion. The 2nd motoneuron can be stimulated supramaximally with high-voltage stimulation (HVS) from nerve root to distal extremities. So it provides proximal nerv…