Findings of Electrodiagnostic Studies in Moderate to Severe Lumbar Central Spinal Stenosis—Electrodiagnostic Studies in Lumbar Central Spinal Stenosis

Purpose: The purpose of this study was to investigate the findings of electrodiagnostic studies (nerve conduction study (NCS) and electromyography (EMG)) in patients with moderate and severe lumbar central spinal stenosis (LCSS). Methods: We retrospectively reviewed the medical records of Ulsan University Hospital and identified 32 consecutive patients (mean age = 66.9 ± 7.4 years; male:female = 8:24) with LCSS. Based on the results of T2 axial magnetic resonance imaging at the level of L4–5, patients were categorized as having severe (n = 14) or moderate LCSS (n = 18). Results from NCS and EMG were retrieved. Additionally, we included 15 age- and sex-matched volunteers without LCSS (mean age = 65.2 ± 8.0 years; male:female = 4:11) to serve as a control group. Results of NCS and EMG were compared between the three groups. Results: We found that, compared to normal subjects, patients with moderate or severe LCSS presented significantly lower distal amplitudes of the compound motor action potential of both peroneal and tibial nerves. Regarding EMG, positive sharp waves and fibrillation potentials were exclusively observed in patients with severe LCSS group (28.6%). Conclusion: Electrodiagnostic studies were significantly altered in patients with moderate and severe LCSS. Our results may be helpful to diagnose LCSS-induced radiculopathy and to differentiate it from other causes of peripheral nerve pathologies.

The comparison of MRN, electrophysiology and progression among typical CIDP and atypical CIDP subtypes

We aimed to compare the electrophysiology and magnetic resonance neurography (MRN) results of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) subtypes and to explore the progression from atypical CIDP to typical CIDP. We collected the medical records of 45 CIDP patients to analyse the rate of progression from atypical CIDP to typical CIDP subtypes. The cerebrospinal fluid (CSF) protein (p = 0.024) and overall disability sum score (ODSS) (p = 0.000) differed among patients with typical CIDP, distal acquired demyelinating symmetric neuropathy (DADS) and Lewis-Sumner syndrome (LSS). The compound motor action potential (CMAP) of typical CIDP was lower than that of the other subtypes (p = 0.016, p = 0.022 and p = 0.012). The cross-sectional area (CSA) of nerve roots in typical CIDP was significantly thicker than that of nerve roots in DADS and LSS. There were fewer DADS and LSS patients who progressed to typical CIDP than those who progressed to pure motor and pure sensory CIDP (p = 0.000), and the progression from pure motor to typical CIDP required a significantly longer time than the progression from pure sensory to typical CIDP (p = 0.007). Typical CIDP was more severe than the other subtypes not only in terms of clinical and electrophysiology factors but also in terms of MRN factors.

Nerve Repair and Orthodromic and Antidromic Nerve Grafts: An Experimental Comparative Study in Rabbit

Purpose. Although many surgeons have anecdotally described reversing the polarity of the autograft with the intent of improving regeneration, the optimal orientation of the autogenous nerve graft remains controversial. The aim of this study was to compare (1) the outcomes of orthodromic and antidromic nerve grafts to clarify the effect of nerve graft polarity and (2) the outcome of either form of nerve grafts with that of nerve repair. Methods. In 14 of the 26 rabbits used in this study, a 1 cm defect was made in the tibial nerve. An orthodromic nerve graft on one side and an antidromic nerve graft on the other were performed using a 1.2 cm long segment of the peroneal nerve. In the remaining 12 rabbits, the tibial nerve was transected completely and then repaired microscopically on one side but left untreated on the other. Electrophysiologic studies were performed in all animals at 8 weeks after surgery, and the sciatic nerves were harvested. Results. Compound motor action potential was visible in all rabbits treated by nerve repair but in only half of the rabbits treated by nerve graft. There was no significant difference in the compound motor action potential, nerve conduction velocity, or total number of axons between the orthodromic and antidromic nerve graft groups. However, in both groups, the outcome was significantly poorer than that of the nerve repair group. Conclusion. There was no significant difference by electromyographic or histologic evaluation between orthodromic and antidromic nerve grafts. Direct nerve repair with moderate tension may be a more effective treatment than nerve grafting.