Transcutaneous and Direct Electrical Stimulation of Mouse Sciatic Nerve Accelerates Functional Recovery After Nerve Transection and Immediate Repair.

BACKGROUND: Electrical stimulation can accelerate peripheral nerve regeneration after injury and repair. Clinically, direct electrical stimulation (DES) may involve longer operating times, increasing risks of perioperative complications. Transcutaneous electrical stimulation (TCES) is a noninvasive alternative. In this study, we investigate how transcutaneous and DES compare for accelerating functional nerve recovery in a mouse sciatic nerve model. METHODS: Twenty-eight mice were divided into sham (n = 4), axotomy (n = 8), DES (n = 8), and TCES (n = 8) groups. After sciatic nerve transection and repair, the proximal nerve was subjected to DES or TCES at 20 Hz for 1 hour. Sciatic functional index was measured before the injury, and at weeks 1, 2, 4, 6, 8, 10, and 12 by walking-track analysis. Electrophysiological measures were taken at week 12. RESULTS: Kinematic studies showed significant improvement from the 8th week to the 12th week for both electrical stimulation groups compared with the axotomy group (P < 0.05), with no difference between the electrical stimulation groups. At the 12th week, both DES and TCES groups had significantly faster average conduction velocity than the axotomy group. CONCLUSIONS: Functional recovery was significantly better from 8 weeks onward in mice receiving either DES or TCES stimulation when compared with axotomy and repair alone. Transcutaneous electrical stimulation is a minimally invasive alternative treatment for accelerating functional recovery after peripheral nerve injury.

Comparison of student examiner to faculty examiner scoring and feedback in an OSCE.

OBJECTIVES: to help reduce pressure on faculty staff, medical students have been used as raters in objective structured clinical examinations (OSCEs). There are few studies regarding their ability to complete checklists and global rating scales, and a paucity of data on their ability to provide feedback to junior colleagues. The objectives of this study were: (i) to compare expert faculty examiner (FE) and student-examiner (SE) assessment of students' (candidates') performances on a formative OSCE; (ii) to assess SE feedback provided to candidates, and (iii) to seek opinion regarding acceptability from all participants. METHODS: year 2 medical students (candidates, n = 66) participated in a nine-station formative OSCE. Year 4 students (n = 27) acted as SEs and teaching doctors (n = 27) served as FEs. In each station, SEs and FEs independently scored the candidates using checklists and global rating scales. The SEs provided feedback to candidates after each encounter. The FEs evaluated SEs on the feedback provided using a standardised rating scale (1 = strongly disagree, 5 = strongly agree) for several categories, according to whether the feedback was: balanced; specific; accurate; appropriate; professional, and similar to feedback the FE would have provided. All participants completed questionnaires exploring perceptions and acceptability. RESULTS: there was a high correlation on the checklist items between raters on each station, ranging from 0.56 to 0.86. Correlations on the global rating for each station ranged from 0.23 to 0.78. Faculty examiners rated SE feedback highly, with mean scores ranging from 4.02 to 4.44 for all categories. There was a high degree of acceptability on the part of candidates and examiners. CONCLUSIONS: student-examiners appear to be a viable alternative to FEs in a formative OSCE in terms of their ability to both complete checklists and provide feedback.