Examen clinique versus électromyographie dans les lésions traumatiques du plexus brachial chez l’adulte — Analyse de la précision diagnostique

Abstract

Traumatic brachial plexus injury is one of the most devastating injuries of the upper arm, with great functional, psychological and socioeconomical impact. Evaluation includes a detailed physical examination, imagistic and electrodiagnostic studies. The purpose of this study was to determine the efficacy of preoperatory EMG examination versus physical testing of patients with traumatic brachial plexus injury when comparing with intraoperative findings.

The medical records of 36 patients with traumatic brachial plexus injury from 2020 until 2023 were reviewed. Initially the patients underwent a detailed clinical examination. Then, they were subjected to routine EMG. All of them underwent surgical exploration and the intraoperative findings were correlated. A statistical analysis was performed and P-values < 0.05 were considered statistically significant.

When used alone, clinical examination and routine EMG could not locate the site of the lesion in 3 of 36 and 20 of 36 patients, respectively. The surgical explorations have confirmed 44.44% of EMG results while the physical tests were accurate in 91.66% of cases. Moreover, the predictive rate of EMG alone is low (R² = 10.61%), while the clinical tests alone are very useful if well performed (R² = 84.16%). When used together, the predictive rate doesn’t modify significantly but remains at a high level (R² = 84.28%).

Although there is a consensus that one should not rely only on one type of preoperative evaluation alone but to a combination of clinical examination, electrodiagnostic studies and imaging investigations, problems in diagnosis continue to arise. Previous studies indicate that physical examination is a very accurate tool for assessing the localisation of brachial plexus lesions and suggest that when electrodiagnostic studies and MRI are used in conjunction with it, the diagnostic accuracy is clearly improved. Our study shows that when used together, EMG and physical examination together don’t improve diagnostic accuracy. We have proven that muscle testing, if it is performed by a trained and experienced hand surgeon, can correctly identify the site of the lesion in most of cases and has the highest predictive value. Otherwise, when using EMG alone, the predictability drops to a surprising percentage.

Physical examination is probably the most accurate tool for assessing brachial plexus lesions. When used together, EMG and physical examination together don’t significantly improve diagnostic accuracy. The EMG becomes less reliable in cases of extended upper plexus and total plexus; therefore, the gold standard in detecting the site of the lesions remains surgical exploration with intraoperative neurostimulation.