DOI: 10.5061/dryad.gtht76hmh
title: Preoperative electrophysiological evaluation and postoperative clinical and functional outcomes in brachial plexus injury after surgical neurolysis

description: Introduction/Aims: Electrophysiological and clinical Correlation of pre-
 and post-operative analysis in BPI surgical management through the use of
 Neurolysis. Methods: An ambilective quasi-experimental analytical study
 was carried out. In order to determine the prognostic value of the
 preoperative electrophysiological analysis in the clinical and functional
 recovery after surgical intervention. the study was approved by the
 Hospital's research and bioethics committee (DI/16/403/03/152), the
 informed consents were obtained and signed by all the patients included. A
 Wilcoxon test was performed in search of significant clinical and
 functional changes after surgery, and a Spearman Correlation test was
 realized between the preoperative electrophysiological variables and
 postoperative clinical and functional outcomes. Value α = 0.05 and β =
 0.01. Results: Twenty patients were studied. Postoperative clinical
 evaluation showed significant changes in terms of pain (∆79.95%, p =
 0.034), upper limb functional recovery (∆31.53%, p = 0.029), and
 subjective perception of general health (∆15.83%, p = 0.007). Correlation
 analysis showed that the stronger relationship was observed in the
 association between fibrillation potentials with the recovery of
 postoperative pain (R = 0.997, p = &lt;0.001), polyphasic units with
 the increase in the patient's subjective perception of their general
 health measured (R = 0.999, p &lt;0.001), and the amplitude of the
 sensitive nerve action potential with sensorial recovery (R = 0.942, p =
 0.009). Discussion/Conclusion: Neurolysis demonstrated changes in pain and
 functional recovery, related to the presence of polyphasic units and
 fibrillation potentials. The prognostic value of electrophysiology in
 postoperative clinical recovery is uncertain, this study introduces the
 possibility of observing preoperative electrophysiological studies as a
 prognostic tool for clinical and functional recovery in the surgical
 management of BPI.
description: The
 clinical evaluation was carried out by a structured questionnaire at
 consultation. The degree of motor and sensory recovery was classified
 according to the BMRC scales. The decrease in pain was classified
 according to VAS, and functional recovery was evaluated by applying the
 DASH and SF-36 questionnaires. The electrophysiological evaluation was
 carried out through the use of EMG and NC studies (Cadwell Sierra Wave EMG
 System, Nihon Kohden Neuropack M1 MEB-9200, and XLTEK XCalibur LT 10328
 EMG Unit). The tests performed were sensory and motor nerve conductions,
 and needle qualitative EMG. The NC analysis was focused on evaluating the
 amplitudes and latencies of the sensory nerve action potential (SNAP) and
 compound muscle action potential (CMAP), for its analysis the percentage
 of axonal injury was calculated. This percentage was calculated using a
 formula (U-A / U X 100), where "U" corresponds to the values
 ​​of the unaffected limb and "A" to the values ​​of the affected
 limb (reference of the % axonal injury) [7].  Regarding the EMG study, the
 characteristics of the graphs were analyzed in search of denervation data
 (fibrillation Potentials and positive sharp waves), and reinnervation data
 (polyphasic units and MUAP's recruitment). Polyphasic units were
 evaluated as a binomial variable (presence/absence). An average value of
 the other variables obtained by EMG was obtained using ordinal subjective
 scales (full, reduce, discrete or none) for MUAPS's recruitment and
 an ordinal scale (1+ (reproducible potentials in more than 1 area) to 4+
 (obliterating the baselines)) for fibrillation potentials and positive
 sharp waves. In order to establish significant changes after surgery in
 clinical and electrophysiological variables, a Wilcoxon test was performed
 to establish the relationship between the preoperative
 electrophysiological variables and the postoperative clinical variables, a
 Spearman Correlation test was performed looking for the
 electrophysiological variables that had a stronger relationship with each
 of the clinical and functional outcomes evaluated. Statistical comparisons
 of the outcomes involved were performed using SPSS 25.0 for Windows
 software (SPSS, Inc., Chicago, IL). In order to establish significant
 changes after surgery in clinical and electrophysiological variables, a
 Wilcoxon test was performed to establish the relationship between the
 preoperative electrophysiological variables and the postoperative clinical
 variables, a Spearman Correlation test was performed looking for the
 electrophysiological variables that had a stronger relationship with each
 of the clinical and functional outcomes evaluated. Statistical comparisons
 of the outcomes involved were performed using SPSS 25.0 for Windows
 software (SPSS, Inc., Chicago, IL). 
description: The database is divided
 into three relevant sections; <br> 1.- Clinical-Electrophysiological
 Correlation Data. <br> 2.- Clinical Outcomes After
 Surgery.  <br> 3.- Demographic and Procedural
 Characteristics.