Introduction: As one of the most common complications of diabetes mellitus, diabetic peripheral neuropathy (DPN) has gained worldwide attention for a long time. DPN was traditionally considered as an irreversible condition until the advent of surgical decompression of multiple peripheral nerves. The surgical outcome has varied in different medical centers. However, it is important to note that DPN is a heterogeneous disease. Mechanical allodynia (MA) is a characteristic symptom of neuropathic pain and is not uncommon in patients with painful DPN. According to clinical observations on the outcome of ND for painful DPN, patients with MA appeared more likely to benefit from ND than those without MA. We carried out this retrospective study to focus on the role of MA in predicting the surgical outcome of patients with painful DPN and to discuss the mechanism involved.
Methods: 192 patients with painful DPN were involved (148 patients in the surgical group and 44 patients in the control group). Both groups were further divided into subgroups based on the incidence of mechanical allodynia on admission. Clinical evaluations including a visual analogue scale (VAS), examination of nerve conduction velocity (NCV) and high-resolution ultrasonography (cross-sectional area, CSA) were performed preoperatively and postoperatively.
Results: The levels of VAS, the NCV results and the CSA were all better achieved in the surgical group than the control group (P<0.05). In the surgical group, pain relief, improvement in NCVs and the restoration of the CSA were observed in patients with signs of MA (P<0.05), while no improvement in NCVs was noted in patients without signs of MA (P<0.05). Furthermore, pain relief was better achieved in patients with MA than those without MA (P<0.05).
Conclusions: Better pain relief and improvements in NCVs were achieved in patients with signs of MA, which is thus a reliable predictor of better surgical outcome for painful DPN.
Patient Care: Surgical decompression provide an alternative treatment for patient with painful diabetic peripheral neuropathy and they would benefit from the development of surgical indication provided in this study.
Learning Objectives: By the conclusion of this session, participants should be able to:1) gain practical and valuable information in patient selection of painful DPN for surgical decompression, and 2) have a further understanding on the mechanism of diabetic peripheral neuropathic pain as well as the relevant natural course of diabetic neuropathy.