GEHS Neurophysiological Classification System for Patients with Carpal Tunnel Syndrome

Median neuropathy at or distal to the wrist or carpal tunnel syndrome (CTS) is one of a number of muscle, tendon, and nerve-related disorders that affect people performing intensive work with their hands. Following a thorough history and physical examination, electrophysiological examination including both nerve conduction studies (NCS) and electromyography (EMG) testing may be performed and currently serve as the reference standard for the diagnosis of CTS. The EMG and NCS exams should identify the peripheral nerve, specific location in the nerve pathway, involvement of sensory and/or motor axons, and the presence of myelinopathy and/or axonopathy neuropathic process. Clinical electrophysiologists now have 2 neurophysiological classification systems for patients with CTS from which to choose when preparing their electrophysiological testing reports. The Bland (2000) and GEHS (2012) neurophysiological classification systems for patients with CTS are discussed. Two case studies of patients with electrophysiological evidence of CTS are presented. Application and comparison of categorizations by the Bland and GEHS neurophysiological classification systems are incorporated into the presentation and discussion of these case studies. This article describes 2 neurophysiological classification systems for patients with CTS. The Bland system documents the distribution of patients with CTS on a scale based upon nerve conduction study findings, but it does not include any EMG findings in its grading scale. The GEHS neurophysiological classification system includes findings for both the NCS and EMG components of the electrophysiological examination. The GEHS classification system provides electrophysiological evidence of myelinopathy and/or axonopathy for patients with CTS. Additional research comparing the psychometric properties and prognostic utility of the Bland and GEHS neurophysiologic classifications is warranted.