Electrodiagnostic Features of Sciatic Neuropathy: Six-year Referral Center Experience

Introduction: Sciatic neuropathy is one of the most important neuropathies of the lower extremity. Although electromyography (EMG) is useful for detecting and localizing neurologic damage, assessing the severity of neuropathy, determining prognoses, and detecting confounding or accompanying neurologic pathologies, electrodiagnostic analyses of sciatic neuropathy are rare in the literature. Methods: The EMG database between 2017 and 2022 was reviewed. Neurophysiologic data of 58 patients who were electrophysiologically diagnosed as having sciatic neuropathy were included in the study. The adult patient group was divided into three groups, injection trauma, noninjection trauma, and other etiologies for subgroup analyze. Pediatric patients were not divided into subgroups because of their limited number. Results: Sciatic neuropathy was found in nine patients in the pediatric group, and 48 patients in the adult group. Sciatic neuropathy was left sided in six (66.7%) pediatric patients and 25 (52%) adult patients. It was bilateral in one adult patient. There was no significant difference between the groups in terms of nerve conduction studies. No statistically significant difference was found in the needle EMG of the gastrocnemius medialis, tibialis anterior (TA), and biceps femoris short-head muscles (P = 0.78, P = 0.32, and P = 0.14, respectively). In both injection and noninjection trauma patients, the most common needle EMG findings in the gastrocnemius medialis muscle were detected as grade 2. Grades 3 and 4 findings were observed predominantly in peroneal division innervated TA and biceps femoris short-head muscles. Conclusion: The most common etiology of sciatic neuropathy in adults was injection-related trauma. The peroneal division is more prone to injury in sciatic neuropathy in the context of sciatic variations. Consequently, we considered that the degree of damage in noninjection traumas might be higher in both distal and proximal segments compared with injection traumas.