Nerve Lesions In Continuity Research Articles

P 71 Optical coherence tomography – a future imaging technique of peripheral nerves?

Object: Owing to their complex topography, their long courses and their small diameters peripheral nerves are challenging structures for radiological diagnostics. However, imaging techniques in the area of peripheral nerve diseases have undergone unexpected development in recent decades. They include magnetic-resonance imaging (MRI) and high-resolution sonography (HRS). Yet none of those imaging techniques reaches a resolution comparable to that of histological sections. Fascicles are the smallest discernable structure. Optical-coherence tomography (OCT) is the first imaging technique that is able to depict a nerve’s ultrastructure at micrometer resolution. Methods: OCT measurement was performed in 32 patients with different peripheral nerve pathologies, i.e. nerve compression syndromes. The nerves were examined during surgery after exposing. Only the sural nerve was twice examined ex vivo . The OCT systems Thorlabs Callisto and Thorlabs Ganymede were used. For intra-operative use, a hand probe was covered with a sterile foil. Different post-processing imaging techniques were applied and evaluated. Results: The intra-operative use of OCT is easy and intuitive. Image artifacts are mainly caused by motion and the sterile foil. If they are kept at a low level, the hyporeflecting bundles of nerve fascicles and their inner parts can be displayed. In the Haralick evaluation the second angular moment (SAM) is most suitable to depict the connective tissue. Conclusion: OCT is a new imaging technique which has shown to be promising in peripheral nerve surgery for particular questions. Its resolution exceeds that provided by recent radiological possibilities such as MRI and HRS. Since its field of view is relatively small, faster acquisition times would be highly desirable. Currently, the method resembles an optical biopsy and can be a supplement to intra-operative sonography, giving high-resolution insight into a suspect area which has been located by sonography in advance. This could be especially helpful in surgery of peripheral nerve lesions in continuity.

Supercharge End-to-Side Nerve Transfer: Systematic Review.

Background: To decrease the time to reinnervation of the intrinsic motor end plates after high ulnar nerve injuries, a supercharged end-to-side (SETS) anterior interosseous to ulnar motor nerve transfer has been proposed. The purpose of this study was to compile and review the indications, outcomes, and complications of SETS anterior interosseous to ulnar motor nerve transfer. Methods: A literature search was performed, identifying 73 papers; 4 of which met inclusion and exclusion criteria, including 78 patients. Papers included were those that contained the results of SETS between the years 2000 and 2018. Data were pooled and analyzed focusing on the primary outcomes: intrinsic muscle recovery and complications. Results: Four studies with 78 patients met inclusion and exclusion criteria. Most patients (33.3%) underwent SETS for an ulnar nerve lesion in continuity, the average age was 46.5 years, and the average follow-up was 10 months. The average duration of symptoms before surgery was 99 weeks, all patients had weakness and numbness, nearly all (96%) had atrophy, and half (53%) had pain. Grip and key pinch strength improved 202% and 179%, respectively, from the preoperative assessment. The vast majority (91.9%) recovered intrinsic function at an average of 3.7 months. Other than 8% of patients who did not recover intrinsic strength, no other complications were reported in any of the 78 patients. Conclusions: The SETS is a successful procedure with low morbidity, which may restore intrinsic function in patients with proximal nerve injuries.

Diffusion tensor imaging to visualize axons in the setting of nerve injury and recovery

Successful management of peripheral nerve trauma relies on accurate localization of the injury and grading of the severity of nerve injury to determine whether surgical intervention is required. Existing techniques, such as electrodiagnostic studies and conventional imaging modalities, provide important information, but are limited by being unable to distinguish severe nerve lesions in continuity that will recover from those that will not. Diffusion tensor imaging (DTI) and tractography of peripheral nerves provide a novel technique to localize and grade nerve injury, by assessing the integrity of the nerve fibers across the site of nerve injury. Diffusion tensor imaging and tractography also hold promise as markers of early nerve regeneration, prior to clinical and electrodiagnostic evidence of recovery. In the present review, the techniques of peripheral nerve DTI and tractography are discussed with respect to peripheral nerve trauma, with illustrative cases demonstrating potential roles of these novel approaches.

P605: Peroneal nerve damage after knee dislocation. Clinic, neurophysiology and ultrasound in diagnosis, prognosis, treatment and rehabilitation

P605: Peroneal nerve damage after knee dislocation. Clinic, neurophysiology and ultrasound in diagnosis, prognosis, treatment and rehabilitation

Intraoperative high-resolution ultrasound in the managment of traumatic nerve lesions: a new technique

Surgical treatment of nerve lesion in continuity remains difficult even in the most experienced hands. Their regenerative potential is evaluated either by intraoperative electrophysiology and/or intraneural dissection. The values of preoperative ultrasound is often hampered due to low tissue penetration and trauma related artifacts. Therefore the present study for the first time examines feasibility and value of intraoperative high-frequency ultrasound as an imaging tool in the management of traumatic nerve lesions in continuity.

Reparatur- und Rekonstruktionsverfahren der Nn. lingualis und alveolaris inferior

Peripheral nerve lesions in continuity with physically intact external appearance are distinguished from injuries with loss of continuity. The 3-type injury grading system of Seddon or preferably the 5 or 6 degree Sunderland classification are the most used predictors of peripheral nerve damage, their capacity for spontaneous regeneration and the need for surgically assisted recovery. Peripheral nerve lesions caused by local neurotoxic effects are lesions in continuity with blocks through the perineurium due to scar tissue formation that precludes axonal sprouting and regeneration. The presented articles deal with the repair and reconstruction of lingual nerve injuries in different scenarios (trauma and tumor resection) with focus on accidental (iatrognic) lesions. Part 1 presents the classification of nerve injuries and terminology, the diagnostic evaluation as well as particular anatomical features and details of the surgical approaches.

Intraoperative high-resolution ultrasound: a new technique in the management of peripheral nerve disorders

Surgical treatment of nerve lesions in continuity remains difficult, even in the most experienced hands. The regenerative potential of those injuries can be evaluated by intraoperative electrophysiological studies and/or intraneural dissection. The present study examines the value of intraoperative high-frequency ultrasound as an imaging tool for decision making in the management of traumatic nerve lesions in continuity. Intraoperative high-frequency ultrasound was applied to 19 traumatic or iatrogenic nerve lesions of differing extents. The information obtained was correlated with intraoperative electrophysiological, microsurgical intraneural dissection, and histopathological findings in resected nerve segments. The intraoperative application of high-resolution, high-frequency ultrasound enabled morphological examination of nerve lesions in continuity, with good image quality. The assessment of the severity of the underlying nerve injury matched perfectly with the judgment obtained from intraoperative electrophysiological studies. Both intraneural nerve dissection and neuropathological examination of the resected nerve segments confirmed the sonographic findings. In addition, intraoperative ultrasound proved to be very time efficient. With intraoperative ultrasound, the extent of traumatic peripheral nerve lesions can be examined morphologically for the first time. It is a promising, noninvasive method that seems capable of assessing the type (intraneural/perineural) and grade of nerve fibrosis. Therefore, in combination with intraoperative neurophysiological studies, intraoperative high-resolution ultrasound may represent a major tool for noninvasive assessment of the regenerative potential of a nerve lesion.

INTRAOPERATIVE NERVE ACTION POTENTIAL RECORDINGS

The purpose of this article is to provide our experience with intraoperative nerve action potential (NAP) recordings. In particular, we focus on a discussion of the technical considerations of intraoperative NAP with emphasis on identifying and remedying problems and pitfalls.We report, perhaps, the largest operative series of peripheral nerve lesions in continuity with intraoperative NAP recording derived from 1736 patients with 3459 lesions in continuity with operative outcomes. We pay special attention to patients for whom we felt that NAP recordings were either difficult or misleading.A positive NAP across a lesion resulting in neurolysis gave grade 3 or better function using the Louisiana State University Health Science Center grading system in 94.7% of neural elements. Differential fascicular recordings resulted in split repair in 62 nerves with recovery in 58. The absence of an NAP correlated histologically with a neurotmetic lesion. With resultant repair, 1111 of 1975 nerves recovered to grade 3 or better.Visual inspection of a nerve lesion in continuity can be misleading. Although there is no "head-to-head" comparison of our data with data obtained without the use of intraoperative NAP recordings, we feel strongly that with experience and knowledge of the problems and pitfalls regarding intraoperative recording techniques, one may take advantage of the great benefits of this very useful and informative surgical tool.

Surgical interventions for traumatic lesions of the brachial plexus: a retrospective study of 134 cases

Surgical therapy for traumatic brachial plexus lesions is still a great challenge in the field of peripheral nerve surgery. The aim of this study was to present the results of different surgical interventions in patients with this lesion type. One hundred thirty-four patients with traumatic brachial plexus lesions underwent surgery between January 1991 and September 1999. In more than 50% of the patients, injury was caused by a motorbike accident. Patients underwent surgery a mean of 6.3 months posttrauma. The following surgical techniques were applied: neurolysis for nerve lesions in continuity (27 cases), grafting for lesions in discontinuity (149 cases), and neurotization for root avulsions (67 cases). Sixty-five patients were evaluated for at least 30 months (mean follow up 42.1 months) after surgery. Function was graded using the Louisiana State University Health Sciences Center classification system. Only 2% of the patients had Grade 3 or better function preoperatively, increasing to 52% postoperatively. The effect of surgical measures on the functional results for different muscles were compared (supra- or infraspinatus, deltoid, biceps, and triceps muscles); the best results were obtained for biceps muscle function (57% of patients with Medical Research Council Grades M3-M5 function). Graft reconstruction yielded a better outcome than neurotization. Surgery within 5 months posttrauma clearly resulted in improved recovery of motor function compared with later interventions. Sural nerve grafts (monofascicular nerves) showed better results. The results of neurosurgical interventions for brachial plexus lesions are satisfactory, especially when the operation is performed between 3 and 6 months after trauma.

Surgical management and results of 135 tibial nerve lesions at the Louisiana State University Health Sciences Center.

This retrospective study presents 33 years of clinical and surgical experience with 135 tibial nerve lesions to review operative techniques and their results and to provide management guidelines for the proper selection of surgical candidates. Between 1967 and 1999, 135 patients with tibial nerve lesions at the knee level or below were managed surgically at the Louisiana State University Health Sciences Center. We reviewed these cases. Of the 135 cases, traumatic injury accounted for 71, tarsal tunnel syndrome for 46, and nerve sheath tumor for 18. Of 22 lesions not in continuity, functional recovery of Grade 3 or better was achieved in 4 (67%) of 6 patients who required end-to-end suture repair and 11 (69%) of 16 patients who required graft repair. One hundred thirteen tibial nerve lesions in continuity underwent primarily external or internal neurolysis or resection of the lesions. A few received end-to-end suture or graft repair. Direct intraoperative recording of nerve action potentials guided case management decisions. Among the 113 patients with lesions in continuity, 76 (81%) of 94 patients receiving neurolysis, 5 (83%) of 6 receiving suture repair, and 11 (85%) of 13 receiving graft repair recovered function to Grade 3 or better. Repair results were best in patients with recordable nerve action potentials treated by external neurolysis. Results were poor in a few patients with very lengthy lesions in continuity and in reoperated patients with tarsal tunnel syndrome. Surgical exploration and repair of tibial nerve lesions, including nerve sheath tumors and tarsal tunnel syndromes, achieved excellent outcomes.

Value of nerve action potentials in the surgical management of traumatic nerve lesions.

The goals of the study were to investigate the value of intraoperative electrically evoked nerve action potentials (NAPs) in the surgical treatment of traumatic peripheral nerve injuries (nerve lesions in continuity). Sixty-four patients with 76 traumatic nerve lesions in continuity were investigated intraoperatively by stimulating and recording NAP from the whole nerve across the suspected lesion site. Among the 76 nerves (nerve lesions) were 43 with incomplete and 33 with complete loss of function. In cases (nerves) with complete loss of function (n = 33), the surgical procedure (external neurolysis, internal neurolysis, or nerve repair) was performed according to the microscopic aspect of the nerve and the result of the intraoperative electrophysiological testing. In cases (nerves) with incomplete loss of function (n = 43), the surgical procedure was performed solely according to the microscopic aspect of the nerve and independently from the result of the intraoperative electrophysiological testing. Of 43 nerves with incomplete loss of function, we were able to record reproducible NAPs in 41 (95%) across the lesion site, thus demonstrating a high reliability of the method. Of 33 nerves with complete loss of function, a reproducible NAP could be recorded only in 3. Assuming an axonotmetic lesion in regeneration, we did nothing else on the nerve with excellent clinical results (full recovery). Of the remaining nerves with no NAP, 24 showed a caliber shift of the nerve (in 20 cases a thickening of the nerve, suggesting a neuroma in continuity). A grafting procedure was performed, and the histological evaluation revealed a neurotmetic lesion. However, in six patients with no NAP, there was no clear caliber shift of the nerve. The epineurium was opened and an internal neurolysis performed showing fascicles in continuity. Three patients had good and three had partial (but useful) recovery. In nerve lesions in continuity with complete loss of nerve function, intraoperative NAPs are able to detect axonotmetic lesions in regeneration. Thus, unnecessary further surgical procedures can be avoided. On the other end of the spectrum, no recordable NAP together with a caliber shift of the nerve (suggesting a neuroma in continuity) may facilitate the surgeon's decision for a grafting procedure without a time-consuming internal neurolysis. But there is also evidence from our data that not every nerve lesion in continuity without a NAP needs to be grafted.

Isolated Musculocutaneous Nerve Lesion after Shoulder Dislocation

Case Report A 27 year old soldier suffered an injury to his left nondominant shoulder following a hard rugby tackle. He was seen in the Accident and Emergency Department about two hours after the injury. Radiographs confirmed an anterior dislocation of the shoulder without fracture. There was no history of previous injury to this shoulder. Reduction proved difficult and was eventually carried out under midazolam using Kocher's method. The arm was supported in a sling. When physiotherapy was commenced after three weeks it was noted that biceps brachii could not be voluntarily contracted and that there was diminished sensation in the cutaneous distribution of the musculocutaneous nerve, over the lateral aspect of the forearm. Function was excellent due to compensatory elbow flexion by the pronator teres and brachio-radialis muscles. Muscle stimulation tests using an Orthotron Mk. 5 controlled current stimulator confirmed denervation of the left biceps brachii. Electromyography subsequently undertaken showed pathological spontaneous activity in the biceps characterised by a close succession of positive sharp waves and moderate fibrillation potentials. On supramaximal stimulation of the musculocutaneous nerve at Erbs' point with needle electrode sampling from the biceps brachii muscle, a reduced response potential of 5001-1-V could be generated after 6.3 msec. This was considered to show a denervation ofthe biceps caused by a nerve lesion in continuity. The patient remained untroubled by his disability and was able to return to his work as an avionics technician approximately four weeks after the injury, at which time he had only minor loss of power of elbow flexion.

Nerve fiber planimetry in acute and chronic nerve lesions and in nerve lesions in continuity.

The level of resection of damaged nerve tissue in acute and chronic nerve lesions was determined on the basis of the vascular structure, the consistency of the nerve during palpation, the amount of interfascicular connective tissue, and the mushroom formation of the fascicles. Intraoperative electrophysiologic recordings were performed on the cut nerve ends to determine the function of the axons. Postoperative planimetric analyses of cross sections made through the resected nerve stumps were performed to measure axonal and endoneural tube diameters and to correlate these results with the clinical criteria used through the operating microscope. Axons in the proximal nerve ends of acute and chronic nerve lesions displayed a similar mean diameter. Endoneural tubes in chronic nerve lesions shrunk significantly as nerve repair was delayed. In several nerve lesions in continuity, axons remained present across the injured site despite absence of electrical conduction. When comparing the results of axonal or endoneural tube diameters of chronic nerve lesions to the results of other studies or acute nerve lesions, we demonstrated that careful examination through the operating microscope provided valid information about the proper management and resection level of chronic nerve lesions. Electrophysiologic evaluation aided the surgical management but was not useful for the resection of the distal damaged nerve segment. The presence of an evoked potential in the proximal nerve ends guaranteed a nearly normal nerve fiber diameter distribution, while the absence of such a potential in the distal nerve ends indicated an abnormal, absent, or disturbed endoneural tube diameter histogram.

Nerve Fiber Planimetry in Acute and Chronic Nerve Lesions and in Nerve Lesions in Continuity

Nerve Fiber Planimetry in Acute and Chronic Nerve Lesions and in Nerve Lesions in Continuity

Internal Neurolysis in Traumatic Peripheral Nerve Lesions in Continuity

Internal neurolysis — the division of interfascicular scar tissue in order to relieve instrinsic axonal compression — has proved to be of value only in nerve lesions in continuity. There may be division of the axons with preservation of the continuity of connective tissue elements, or both the axons and connective tissue elements may remain intact but with failure of conduction as a result of injury. The authors’ procedure is described, from initial evaluation and diagnosis to surgical techniques. Case reports illustrate the types of lesions in which the procedure is of benefit.