Biomedical
Electrophysiological grading scale for polyneuropathy severity
Abstract
Objective To establish a simple electrophysiological scale for patients with distal symmetric axonal polyneuropathy, in order to promote standardized and informative electrodiagnostic reporting, and understand the complex relationship between electrophysiological and clinical polyneuropathy severity. Methods We included 76 patients with distal symmetric axonal polyneuropathy, from a cohort of 151 patients with polyneuropathy prospectively recruited from November 2016 to May 2017. Patients underwent nerve conduction studies (NCS), were evaluated by the Toronto Clinical Neuropathy Score (TCNS), and additional tests. The number of abnormal NCS parameters was determined, within the range of 0–4, considering low amplitude or conduction velocity in the sural and peroneal nerve. Results Higher number of NCS abnormalities was associated with higher TCNS, indicating more severe polyneuropathy. Polyneuropathy severity per the TCNS was most frequently (63%-70%) mild in patients with a low (0–1) number of NCS abnormalities, and most frequently (57%-67%) severe in patients with a high number (3–4) of NCS abnormalities, while patients with an intermediate (2) number of NCS abnormalities showed mainly mild and moderate severity with equal distribution (40%). Conclusions A simple NCS classification system can objectively grade polyneuropathy severity, although significant overlap exists especially at the intermediate range, underscoring the importance of clinical based scoring.
Key Questions
1. What is the purpose of the proposed electrophysiological grading scale?
The scale aims to standardize electrodiagnostic reporting and enhance the understanding of the relationship between electrophysiological findings and clinical severity in polyneuropathy.
2. How is the severity of polyneuropathy determined using this scale?
Severity is assessed based on the number of abnormal nerve conduction study (NCS) parameters, with a higher count indicating more severe polyneuropathy.
3. What is the significance of the intermediate range in the grading scale?
The intermediate range (2 abnormal NCS parameters) shows significant overlap between mild and moderate severity, highlighting the necessity of clinical evaluation alongside electrophysiological findings.
Summary
Abraham and Bril's study presents a simple electrophysiological grading scale for distal symmetric axonal polyneuropathy, utilizing nerve conduction study abnormalities to categorize severity. The research involved 76 patients and found that a higher number of NCS abnormalities correlates with increased clinical severity, as measured by the Toronto Clinical Neuropathy Score. However, the intermediate range of the scale exhibited significant overlap between mild and moderate severity, underscoring the importance of integrating clinical assessments with electrophysiological data for accurate severity classification.
