Reference data for ulnar nerve short segment conduction studies at the elbow

Continuous Scanning and Inching in Ultrasonographic Localisation of Ulnar Neuropathy: A Comparative Study of Sensitivity

Background: This study compares the sensitivity of continuous ultrasonographic scanning and ultrasonographic inching in the localisation of ulnar neuropathy at the elbow to diagnose the two common entrapment sites: retroepicondylar groove and cubital tunnel. Methods: The charts of 30 patients who were diagnosed with ulnar neuropathy of the elbow and underwent ultrasonographic examinations using the inching and the continuous technique between April 2015 and September 2019 were reviewed. Sensitivities of ultrasonographic inching and continuous scanning were compared. Results: A total of 34 elbows from 30 patients were examined. The sensitivities of continuous ultrasonographic scanning method and ultrasonographic inching were 85% and 71%, respectively, but this was not significant (p = 0.06). The maximum cross-sectional areas (CSAs) in continuous scanning were mainly found within the area from the medial epicondyle to the 2-cm distal point in the cubital tunnel entrapment, while a majority of the largest CSAs in ultrasonographic inching was observed at the medial epicondyle level in both entrapment sites. The mean of the maximum CSAs in continuous scanning (17.04 ± 6.75 mm²) was higher than that in ultrasonographic inching (14.13 ± 6.63 mm²), although this difference remained non-significant (p = 0.08). However, continuous scanning differed more significantly (p < 0.0001) from the cut-off value than the ultrasonographic inching (p < 0.0066). Conclusions: Continuous scanning might be more suitable than ultrasonographic inching to localise ulnar neuropathy, which inherently has variations in the cubital tunnel anatomy and its entrapment points, when selecting optimal treatment based on the entrapment site. Level of Evidence: Level III (Diagnostic).

Preliminary study on the lesion location and prognosis of cubital tunnel syndrome by motor nerve conduction studies

Background:

To study lesions’ location and prognosis of cubital tunnel syndrome (CubTS) by routine motor nerve conduction studies (MNCSs) and short-segment nerve conduction studies (SSNCSs, inching test).

Methods:

Thirty healthy subjects were included and 60 ulnar nerves were studied by inching studies for normal values. Sixty-six patients who diagnosed CubTS clinically were performed bilaterally by routine MNCSs and SSNCSs. Follow-up for 1-year, the information of brief complaints, clinical symptoms, and physical examination were collected.

Results:

Sixty-six patients were included, 88 of nerves was abnormal by MNCS, while 105 was abnormal by the inching studies. Medial epicondyle to 2 cm above medial epicondyle is the most common segment to be detected abnormally (59.09%), P < 0.01. Twenty-two patients were followed-up, 17 patients’ symptoms were improved. Most of the patients were treated with drugs and modification of bad habits.

Conclusions:

(1) SSNCSs can detect lesions of compressive neuropathy in CubTS more precisely than the routine motor conduction studies. (2) SSNCSs can diagnose CubTS more sensitively than routine motor conduction studies. (3) In this study, we found that medial epicondyle to 2 cm above the medial epicondyle is the most vulnerable place that the ulnar nerve compressed. (4) The patients had a better prognosis who were abnormal in motor nerve conduction time only, but not amplitude in compressed lesions than those who were abnormal both in velocity and amplitude. Our study suggests that SSNCSs is a practical method in detecting ulnar nerve compressed neuropathy, and sensitive in diagnosing CubTS. The compound muscle action potentials by SSNCSs may predict prognosis of CubTS.

New treatment alternatives in the ulnar neuropathy at the elbow: ultrasound and low-level laser therapy

Ulnar nerve entrapment at the elbow (UNE) is the second most common entrapment neuropathy of the arm. Conservative treatment is the treatment of choice in mild to moderate cases. Elbow splints and avoiding flexion of the involved elbow constitute majority of the conservative treatment; indeed, there is no other non-invasive treatment modality. The aim of this study was to investigate the efficacy of ultrasound (US) and low-level laser therapy (LLLT) in the treatment of UNE to provide an alternative conservative treatment method. A randomized single-blind study was carried out in 32 patients diagnosed with UNE. Short-segment conduction study (SSCS) was performed for the localization of the entrapment site. Patients were randomized into US treatment (frequency of 1 MHz, intensity of 1.5 W/cm(2), continuous mode) and LLLT (0.8 J/cm(2) with 905 nm wavelength), both applied five times a week for 2 weeks. Assessments were performed at baseline, at the end of the treatment, and at the first and third months by visual analog scale, hand grip strength, semmes weinstein monofilament test, latency change at SSCS, and patient satisfaction scale. Both treatment groups had significant improvements on clinical and electrophysiological parameters (p < 0.05) at first month with no statistically significant difference between them. Improvements in all parameters were sustained at the third month for the US group, while only changes in grip strength and latency were significant for the LLLT group at third month. The present study demonstrated that both US and LLLT provided improvements in clinical and electrophysiological parameters and have a satisfying short-term effectiveness in the treatment of UNE.

Recovery features in ulnar neuropathy at the elbow

[Purpose] This study evaluated the effect of age, sex, and entrapment localization on recovery time in patients treated conservatively for ulnar neuropathy at the elbow. [Subjects] Thirty-five patients (16 women and 15 men) who were diagnosed with ulnar neuropathy at the elbow using short segment conduction studies were evaluated retrospectively. [Methods] Definition of recovey was made based on patient satisfaction. The absence of symptoms was considered as the marker of recovery. Patients who recovered within 0–4 weeks were in Group 1, and patients who recovered within 4 weeks to 6 months were in Group 2. The differences between Group 1 and Group 2 in terms of age, sex and entrapment localization were investigated. [Results] Entrapment was most frequent in the retroepicondylar groove (54.3%). No significant difference was found in terms of age and entrapment localizations between Groups 1 and 2. There was a statistically significant difference between the groups for the male sex. [Conclusion] In ulnar neuropathy at the elbow, age and entrapment localization do not affect recovery time. However, male sex appears to be associated with longer recovery time.