scholarly journals Conduction velocity of the rabbit facial nerve: a noninvasive functional evaluation

2003 ◽  
Vol 17 (2) ◽  
pp. 126-131 ◽  
Author(s):  
Belmiro Cavalcanti do Egito Vasconcelos ◽  
Cosme Gay Escoda ◽  
Ricardo José de Holanda Vasconcellos ◽  
Riedel Frota Sá Nogueira Neves
Keyword(s):  
Facial Nerve ◽  
Conduction Velocity ◽  
Nerve Conduction ◽  
Action Potentials ◽  
Functional Evaluation ◽  
Surface Electrodes ◽  
Nerve Grafts ◽  
Synthetic Materials ◽  
Facial Nerves ◽  
The Mean

The aim of this study was to evaluate standardized conduction velocity data for uninjured facial nerve and facial nerve repaired with autologous graft nerves and synthetic materials. An evaluation was made measuring the preoperative differences in the facial nerve conduction velocities on either side, and ascertaining the existence of a positive correlation between facial nerve conduction velocity and the number of axons regenerated postoperatively. In 17 rabbits, bilateral facial nerve motor action potentials were recorded pre- and postoperatively. The stimulation surface electrodes were placed on the auricular pavilion (facial nerve trunk) and the recording surface electrodes were placed on the quadratus labii inferior muscle. The facial nerves were isolated, transected and separated 10 mm apart. The gap between the two nerve ends was repaired with autologous nerve grafts and PTFE-e (polytetrafluoroethylene) or collagen tubes. The mean of maximal conduction velocity of the facial nerve was 41.10 m/s. After 15 days no nerve conduction was evoked in the evaluated group. For the period of 2 and 4 months the mean conduction velocity was approximately 50% of the normal value in the subgroups assessed. A significant correlation was observed between the conduction velocity and the number of regenerated axons. Noninvasive functional evaluation with surface electrodes can be useful for stimulating and recording muscle action potentials and for assessing the functional state of the facial nerve.

Repair of Rabbit Facial Nerve with Amniotic Extracellular Matrix Based on Biological Material

2011 ◽  
Vol 322 ◽  
pp. 169-172
Author(s):  
Zhen Gao ◽  
Xiao Ting Luo ◽  
Nian Sheng Li ◽  
Wei Deng ◽  
Shu Mei Li
Keyword(s):  
Extracellular Matrix ◽  
Facial Nerve ◽  
Nerve Conduction ◽  
Peripheral Nerves ◽  
Nerve Conduction Velocity ◽  
Nerve Fibers ◽  
Nerve Graft ◽  
Nerve Conduit ◽  
Nerve Grafts ◽  
Facial Nerves

Objective: To evaluate the effects of amniotic extracellular matrix (AECM) on the repairation of facial nerve in rabbits. Methods: The transected nerve ends of the facial nerves of rabbits were then repaired with the AECM nerve conduit or an autologous nerve graft. After 3 months, the animals’ neural conductive velocity were determined. The myelinated fibers across the specimen were counted with histological examination. Results: The total count of medullated nerve fibers varied significantly, but the nerve conduction velocity had no significance between the AECM grafts and the autologous nerve grafts. Conclusion: AECM could become the biocompatible material for repairing the peripheral nerves.

scholarly journals Facial nerve electroneurography: variability in normal subjects

1996 ◽  
Vol 54 (3) ◽  
pp. 393-396 ◽  
Author(s):  
Jovany Luis Alves de Medeiros ◽  
João Antonio Maciel Nobrega ◽  
Luiz Augusto Franco de Andrade ◽  
Yara Juliano
Keyword(s):  
Facial Nerve ◽  
Action Potentials ◽  
Normal Values ◽  
Normal Subjects ◽  
Nasolabial Fold ◽  
Confidence Limits ◽  
Muscle Action ◽  
Surface Electrodes ◽  
Normal Individuals ◽  
Compound Muscle Action Potentials

Twenty normal individuals were submitted to facial nerve electroneurography using different techniques in order to determine the most accurate to obtain the latencies and amplitudes of the compound muscle action potentials (CMAP) of the facial muscles. First of all it was determined in which muscle or muscle group highest amplitude CMAP could be recorded with the lowest variability between sides and in test-retest. Different techniques were studied in order to determine which could give the best results. This was shown to be an arrangement of bipolar surface electrodes fixed to a plastic bar. The records with higher amplitude where obtained from the nasolabial fold muscles. Therefore 65 normal volunteers were examined using this technique and recording the potentials obtained over the nasolabial fold muscles. Normal values were determined (latency lower than 4.5 ms and amplitude larger than 2 mV - 95% confidence limits).

scholarly journals Estimation of Intraoperative Stimulation Threshold of the Facial Nerve in Patients Undergoing Microvascular Decompression

2019 ◽  
Vol 80 (06) ◽  
pp. 599-603
Author(s):  
Rafey A. Feroze ◽  
Michael M. McDowell ◽  
Jeffrey Balzer ◽  
Donald J. Crammond ◽  
Partha Thirumala ◽  
...  
Keyword(s):  
Trigeminal Neuralgia ◽  
Facial Nerve ◽  
Microvascular Decompression ◽  
Nerve Conduction ◽  
Tumor Burden ◽  
Constant Current ◽  
Facial Weakness ◽  
Stimulation Threshold ◽  
Compound Muscle Action Potentials ◽  
Facial Nerves

Introduction Facial weakness can result from surgical manipulation of the facial nerve. Intraoperative neuromonitoring reduces functional impairment but no clear guidelines exist regarding interpretation of intraoperative electrophysiological results. Most studies describe subjects with facial nerves encumbered by tumors or those with various grades of facial nerve weakness. We sought to obtain the neurophysiological parameters and stimulation threshold following intraoperative facial nerve triggered electromyography (t-EMG) stimulation during microvascular decompression for trigeminal neuralgia to characterize the response of normal facial nerves via t-EMG. Methods Facial nerve t-EMG stimulation was performed in seven patients undergoing microvascular decompression for trigeminal neuralgia. Using constant current stimulation, single stimulation pulses of 0.025 to 0.2 mA intensity were applied to the proximal facial nerve. Compound muscle action potentials, duration to onset, and termination of t-EMG responses were recorded for the orbicularis oculi and mentalis muscles. Patients were evaluated for facial weakness following the surgical procedure. Results Quantifiable t-EMG responses were generated in response to all tested stimulation currents of 0.025, 0.05, 0.1, and 0.2 mA in both muscles, indicating effective nerve conduction. No patients developed facial weakness postoperatively. Conclusions The presence of t-EMG amplitudes in response to 0.025 mA suggests that facial nerve conduction can take place at lower stimulation intensities than previously reported in patients with tumor burden. Proximal facial nerve stimulation that yields responses with thresholds less than 0.05 mA may be a preferred reference baseline for surgical procedures within the cerebellopontine angle to prevent iatrogenic injury.

scholarly journals Facial Nerve Schwannomas Mimicking as Vestibular Schwannomas

2017 ◽  
Vol 78 (04) ◽  
pp. 283-287
Author(s):  
Sean Wise ◽  
David Cohen ◽  
Jason Bell ◽  
Dennis Bojrab ◽  
Michael LaRouere ◽  
...  
Keyword(s):  
Facial Nerve ◽  
Outcome Measures ◽  
Action Potentials ◽  
Internal Auditory Canal ◽  
Vestibular Schwannomas ◽  
Tumor Capsule ◽  
Spontaneous Action ◽  
The Mean ◽  
Spontaneous Action Potentials ◽  
Stimulation Of

Objective The objective of this study was to identify preoperative and intraoperative findings that may aid in distinguishing facial nerve schwannomas (FNS) from vestibular schwannomas (VSs), particularly in cases limited to the internal auditory canal (IAC) and cerebellopontine angle (CPA). Study Design This was a retrospective study. Setting This study was set at a Tertiary Referral Center. Patients Seventeen cases from October 2002 to July 2015 with an IAC/CPA mass presumed to be a VS who were found to have a FNS intraoperatively. Main Outcome Measures The main outcome measures included preoperative presentation, intraoperative findings, and subsequent intervention. Results Preoperative hearing loss and imbalance were seen in 70.5 and 64.7%, respectively. Suspicious intraoperative findings included: facial nerve incorporated intimately with the tumor capsule in 12 cases; spontaneous action potentials noted while drilling the bony IAC in 3 cases; and action potentials noted on stimulation of the entire tumor capsule in 10 cases. The mean long-term facial function was House–Brackmann grade II and the mean length of follow-up was 4.86 years. Conclusion FNSs are rare and may be difficult to distinguish from VS preoperatively. Surgical findings that should raise concern include spontaneous action potentials during drilling the bony IAC, absence of a plane of dissection between the facial nerve and tumor, or stimulation of the tumor capsule.

scholarly journals Limb-Specific Features and Asymmetry of Nerve Conduction Velocity and Nerve Trunk Size in Human

2020 ◽  
Vol 11 ◽  
Author(s):  
Ayaka Nobue ◽  
Yoko Kunimasa ◽  
Hiromu Tsuneishi ◽  
Kanae Sano ◽  
Hiroyuki Oda ◽  
...  
Keyword(s):  
Conduction Velocity ◽  
Nerve Conduction ◽  
Action Potentials ◽  
Electric Stimulation ◽  
Nerve Conduction Velocity ◽  
Lower Limbs ◽  
Upper Limbs ◽  
Cross Sectional ◽  
Nerve Ultrasonography ◽  
Human Nerve

This study aimed to simultaneously examine the differences of human nerve conduction velocity (NCV) and nerve cross-sectional area (nCSA) between the upper and lower limbs and between different regions of the upper and lower limbs. Thirty healthy subjects volunteered for the study. NCV and nCSA of the ulnar and tibial nerves were measured with the dominant and non-dominant arms and the supporting and reacting legs using supramaximal electric stimulation and peripheral nerve ultrasonography at three regions for ulnar and tibial nerves, respectively. Supramaximal electric stimulation was superficially applied to the ulnar and tibial nerves at each point. These action potentials were recorded from the digiti minimi and soleus muscles for the ulnar and tibial nerves, respectively. Our results clearly showed that the NCV, nCSA, and circumference of the ulnar and tibial nerves were higher and greater in the lower limbs than in the upper limbs. The greater the circumference, the greater the nCSA for both the upper and lower limbs. However, unlike the upper limbs, the supporting leg did not have higher NCV than the reacting leg despite its greater circumference. Therefore, nCSA can be related to the circumference but not necessarily function for NCV developments of the lower limbs. These various aspects between the upper and lower limbs suggest that NCV does not depend on the nCSA sizes or upper and lower limb circumference; the results indicate the existence of limb-specific NCV but not nCSA developments.

Possible Lateralization of Peripheral Nerve Conduction Associated with Gender

1995 ◽  
Vol 81 (3) ◽  
pp. 939-943 ◽  
Author(s):  
Meliha Tan ◽  
Üner Tan
Keyword(s):  
Peripheral Nerve ◽  
Conduction Velocity ◽  
Nerve Conduction ◽  
Nerve Conduction Velocity ◽  
Right Hand ◽  
Sensory Conduction ◽  
The Mean ◽  
The Right ◽  
Right And Left Hands

Lateralization of peripheral nerve conduction velocity was studied in right-handed men ( n = 40) and women ( n = 48). Sensory and motor velocities were measured in ulnar and median nerves of the right and left hands. In women, the mean sensory velocity was significantly faster in the left than the right hand. There were no significant right-left differences in men. The mean sensory velocity from the right hand was significantly slower in women than men, creating an asymmetric organization of sensory conduction in women. Estradiol in women and testosterone in men were suggested as playing a role in asymmetric and symmetric nerve conductions, respectively.

scholarly journals Rabbit Facial Nerve Anastomosis with Fibrin glue: Nerve Conduction Velocity Evaluation

2007 ◽  
Vol 73 (2) ◽  
pp. 196-201 ◽  
Author(s):  
Francisco Aurelio Lucchesi Sandrini ◽  
Cosme Gay-Escoda ◽  
Edwaldo Dourado Pereira-Júnior
Keyword(s):  
Facial Nerve ◽  
Fibrin Glue ◽  
Conduction Velocity ◽  
Nerve Conduction ◽  
Nerve Conduction Velocity ◽  
Nerve Anastomosis
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