Diabetes, Metabolic Syndrome and Obesity (Nov 2020)
Diabetic Peripheral Neuropathy Increases Electrical Stimulation Threshold of Sciatic Nerve: A Prospective Parallel Cohort Study
Abstract
Guang Ying Zhang, Yi Feng Chen, Wei Xin Dai, Dan Zhang, Yi Huang, Wen Zheng He, Cheng Xin Lin Department of Anesthesiology, The First Affiliated Hospital of Guangxi Medical University, Nanning, People’s Republic of ChinaCorrespondence: Cheng Xin Lin; Wen Zheng HeDepartment of Anesthesiology, The First Affiliated Hospital of Guangxi Medical University, No. 6 Shuangyong Road, Qingxiuqu, Nanning 530022, People’s Republic of ChinaEmail [email protected]; [email protected]: To investigate the impact of diabetic peripheral neuropathy and its severity on the threshold of sciatic nerve electrical stimulation in diabetic patients.Patients and Methods: The case–control study included 60 patients that were divided into non-diabetic patients (control group, n = 26) and diabetic patients (diabetes group, n = 34). All the patients who were scheduled for lower leg, foot, and ankle surgery received a popliteal sciatic nerve block. We recorded the minimum current required to produce motor activity of the sciatic nerve during ultrasound-guided popliteal sciatic nerve block.Results: Among the 60 patients, the sciatic nerve innervated muscle contractile response was successfully elicited in 57 patients (dorsiflexion of foot, plantar flexion, foot valgus or adduction, toe flexion, etc.) under electric stimulation. We failed to elicit the motor response in three patients with diabetic peripheral neuropathy, even when the stimulation current was 3 mA. The average electrical stimulation threshold (1.0 ± 0.7 mA) in the diabetes group was significantly higher than that of the control group (0.4 ± 0.1 mA). Diabetic patients with peripheral neuropathy had a higher electrical stimulation threshold (1.2 ± 0.7 mA) than patients without peripheral neuropathy (0.4 ± 0.1 mA). Furthermore, the electrical stimulation threshold of the sciatic nerve in diabetic patients had a linear dependence on the Toronto Clinical Scoring System (TCSS) peripheral neuropathy score (electrical stimulation threshold [in mA] = 0.125 TCSS score) (P < 0.001).Conclusion: The threshold of electrical stimulation to elicit a motor response of the sciatic nerve was increased in diabetic patients, and the threshold of electrical stimulation of the sciatic nerve increased with the severity of diabetic nerve dysfunction.Keywords: diabetes mellitus, peripheral neuropathy, electrical stimulation threshold, nerve block
