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Introduction: We describe a new nerve conduction study technique with reference values for the 3 branches of the supraclavicular nerve (SCN) in young healthy subjects and application of it in 2 patients., Methods: The recording electrode was placed on the posterior border of the sternocleidomastoid muscle, 6-7 cm from the sternoclavicular joint. SCN branches were stimulated below the clavicle, 2.5, 7, and 10.5 cm lateral to the sternoclavicular joint., Results: Twenty healthy volunteers (10 men), 19-38 years, mean 25.9 years (SD 6.3), and 2 patients with SCN lesions were studied. The mean conduction velocities of the SCN branches were 70-78 m/s (SD 8-10 m/s), and amplitudes 3-4 µV (SD 0.9-2.0 µV). There were no side-to-side or gender differences., Discussion: The 3 SCN branches could be studied in all subjects. We provide reference values for young subjects. This new method was useful in verifying SCN lesions in 2 patients. Muscle Nerve 58: 300-303, 2018., (© 2018 Wiley Periodicals, Inc.)

In order to evaluate the risk of nerve injury and to prevent iatrogenic damage at different stages of bilateral sagittal-split osteotomy (BSSO) of the mandible, we monitored the function of the inferior alveolar nerve (IAN) continuously on both sides in 13 orthognathic patients undergoing BSSO. The IAN was stimulated at the mental foramen with two monopolar needle electrodes fixed to the dental splint, and the orthodromic sensory nerve action potentials (SNAP) of the IAN were recorded with a silver-wire electrode inserted near the oval foramen on each side. The latencies, amplitudes, and sensory nerve conduction velocities at baseline, after medial opening, sawing, splitting, eventual manipulation, and fixation of the mandible were analyzed. The monitoring method functioned technically well in 25 of 26 nerves. Both the surgical technique and the duration of medial opening had conspicuous effects on the function of the IAN, which led us to modify the medial approach. When finer instruments were used for retraction and the duration of medial opening was shortened to less than 10 min, the SNAP of the IAN was always preserved at this stage. Monitoring of the IAN also prevented nerve injury during splitting and fixation. This technique for intraoperative monitoring of the IAN seems to be a feasible and promising tool for objective evaluation of intraoperative events and for prevention of nerve injury during BSSO., (Copyright 2000 John Wiley & Sons, Inc.)

A new electrophysiological technique for recording the sensory conduction velocity (SNCV) of the inferior alveolar nerve (IAN) is described. Bilateral orthodromic recordings were done in 21 healthy adults. The sensory responses of the IAN were obtained in all 42 nerves examined with silver wire or monopolar needle electrodes inserted beneath the zygomatic arc in front of the temporomandibular joint to a depth of 4-4.5 cm, near the oval foramen. A small bipolar surface electrode was used for stimulation at the mental foramen. In 3 subjects, the stimuli were additionally delivered via two monopolar needle electrodes to reduce the stimulus artifact. Single responses were usually sufficient for analysis, but, in some cases, averaging was adopted to improve the signal-to-noise ratio. Response latencies and amplitudes, SNCVs, and interside differences were measured, and the 97.5% upper and 2.5% lower prediction limits calculated for reference limits in clinical practice. This new technique provides a sensitive and objective diagnostic tool for the examination of IAN injuries, and may also be used for intraoperative monitoring of the IAN during mandibular surgery.

Purpose: This article evaluates a new intraoperative recording technique for measuring the sensory nerve conduction velocity (SNCV) of the human inferior alveolar nerve (IAN) during orthognathic surgery of the mandible to assess the effects of intraoperative strain on function of the IAN., Materials and Methods: The new test was successfully applied in 10 patients during bilateral sagittal split osteotomy of the mandible (20 IANs). The recordings were made with active wire electrodes at foramen ovale and stimulation was done at the mental foramen with two monopolar needle electrodes. The sensory nerve action potentials (SNAP) were recorded intraoperatively at three stages: 1) before the split, 2) after splitting of the mandible and possible mobilization of the IAN from the proximal bone fragment, and 3) at the end of the operation after fixation of the proximal and distal fragments with screws., Results: The SNCV values (mean 64.1 m/sec) were obtained in all 20 nerves at stage 1, with no significant differences between the sides in latency or amplitude of the SNAPs. The sNAPs remained stable in the IANs not exposed during the operation. In the remaining nerves, the most obvious and statistically significant changes indicating nerve injury occurred between stages and 1 and 2. Partial transsection and mobilization of the IAN were equally potent in bringing about abnormal results in objective neurophysiologic tests as well as subjective sensory disturbances. The results of the intraoperative SNCV recordings correlated well with the findings of the mental nerve blink reflex tests conducted 2 weeks after the operation, whereas comparison of the results of clinical neurosensory testing with the intraoperative events and SNCVs were more inconsistent., Conclusions: Recording of the SNCV offers a useful objective tool for the examination of the IAN both intraoperatively and in clinical diagnosis.

Objective The pathophysiology of primary burning mouth syndrome ( BMS) has remained enigmatic, but recent studies suggest pathology within the nervous system at multiple levels. This study aimed to investigate in detail the contribution of either focal or generalized alterations within the peripheral nervous system ( PNS) in the etiopathogenesis of BMS. Subjects and methods Intraepithelial nerve fiber density ( IENFD) of tongue mucosa was assessed in 10 carefully characterized BMS, and the results were compared to 19 age- and gender-matched cadaver controls, 6 with lifetime diabetes. Extensive neurophysiologic and psychophysical examinations of the trigeminal system and distal extremities were performed to profile PNS function in BMS. Results Patients with BMS had significantly fewer intraepithelial nerve fibers (0,27, s.e. 0,18 mm−1; P = 0.0253) than non-diabetic controls (0,92, s.e. 0,15 mm−1). In the subepithelial space, the amount of nerve fibers did not differ between the groups. The majority (9/10) of patients with BMS showed neurophysiologic or psychophysical signs of a more generalized PNS dysfunction. Conclusions Our results in neurophysiologically optimally characterized BMS patients confirm that pure focal small fiber neuropathy of the oral mucosa has a role in the pathophysiology of primary BMS. Furthermore, BMS may be related to a more generalized, yet subclinical peripheral neuropathy. [ABSTRACT FROM AUTHOR]