Anatomie fonctionnelle du nerf trijumeau

The cranial nerve (CN) V is a mixed nerve that consists primarily of sensory neurons. It exits the brain on the lateral surface of the pons, entering the trigeminal ganglion within a few millimeters. Three major branches emerge from the trigeminal ganglion. The first division (V1, the ophthalmic nerve) exits the cranium through the superior orbital fissure, entering the orbit to innervate the globe and skin in the area above the eye and forehead. The second division (V2, the maxillary nerve) exits through a round hole, the foramen rotundum, into a space posterior to the orbit, the pterygopalatine fossa. It then re-enters a canal running inferior to the orbit, the infraorbital canal, and exits through a small hole, the infraorbital foramen, to innervate the skin below the eye and above the mouth. The third division (V3, the mandibular nerve) exits the cranium through an oval hole, the foramen ovale. The third division also has an additional motor component, which may run in a separate fascial compartment. Most fibers travel directly to their target tissues. Sensory axons innervate skin on the lateral side of the head, the tongue, and the mucosal wall of the oral cavity. Motor fibers innervate the muscles that are attached to the mandible. Some sensory axons enter in the mandible to innervate the teeth and emerge from the mental foramen to innervate the skin of the lower jaw.     

双神经卡压综合征

目的：研究双神经卡压征的病因及手术治疗方法。方法：分析了自１９８８年以来同时诊断为腕管综合征和肘管综合征２６例３４侧的临床资料。全部患者均作两处神经松解术，平均随访１７个月。疗效评定标准，根据术后症状、体征的改善程度分优、良、可和无效四级。结果：２５侧术后疗效优良，占７３．６％（２５／３４）。结论：双神经卡压征手术治疗效果较好。当双神经卡压同时合并颈部神经卡压时，建议优先考虑远端的神经减压。当远端神经减压后未能改善近端神经卡压症状时，才考虑近端神经减压     

Repair and reconstruction of peripheral nerve injuries

Axonal regeneration after transection is a complex biological process. It is not merely a process of tissue repair, but rather of cellular repair of a large number of nerve cells. Regeneration involves restoration of the original morphology of each single cell, rather than proliferation. Techniques in microneurosurgical reconstruction of peripheral nerve injuries have improved over the last two decades, with subsequent improvement in functional results. Nerve autografts are now routinely used to guide the regrowth of the proximal nerves to distal nerve segments. However, the limited source of expendable cutaneous nerves restricts the use of nerve grafting techniques and is associated with significant morbidity. With extensive injuries there is an insufficient quantity of nerve autograft material to facilitate optimal repair. In future, the use of artificial conduits or nerve allografts could provide a limitless source of material to reconstruct otherwise irreparable traumatic nerve injuries. Establishment of appropriate strategies to suppress host-immune reaction or donor antigenicity would facilitate clinical allogeneic nerve transplantation. Guest lecture presented at the 69th Annual Meeting of the Japanese Orthopaedic Association in Tokyo on April 13, 1996.     

Repair of peripheral nerve defect with direct gradual lengthening of the proximal nerve stump in rats.

We investigated the effect of direct gradual lengthening on the proximal nerve stump and subsequent nerve regeneration in rats. A 10-mm-long nerve segment was resected from the sciatic nerve of each rat. The proximal nerve stump was directly lengthened at a rate of 1 mm/day using an original external nerve distraction device. Experiment I: After distraction periods of 10, 15, and 20 days, the length of each nerve was evaluated, and the lengthened nerve stump was also examined by immunohistochemical analysis. Experiment II: After a distraction period of 20 days, both nerve stumps were refreshed and direct end-to-end neurorrhaphy was performed. For control, 10-mm nerve grafting was immediately performed after nerve resection. Nerve regeneration was evaluated electrophysiologically and histologically 7, 9, and 15 weeks after nerve resection in both groups. The whole proximal nerve stump, including the endoneurium and the axon, could be lengthened in proportion to the distraction period. There were no significant differences in motor nerve conduction velocity and tetanic muscle contraction force between both groups. Histologically, the total number of myelinated fibers was significantly greater in the nerve lengthening group than in the autografting group. This study demonstrated that the whole proximal nerve stump including the endoneurium and the axon could be lengthened by direct gradual distraction, and that this method might have potential application in the repair of peripheral nerve defects.     

Axillary nerve injury in young adults—An overlooked diagnosis? Early results of nerve reconstruction and nerve transfers

Abstract

An injury to the axillary nerve from a shoulder trauma can easily be overlooked. Spontaneous functional recovery may occur, but occasionally reconstructive surgery is required. The time frame for nerve reconstruction procedures is from a neurobiological view crucial for a good functional outcome. This study presents a group of operatively and non-operatively treated young adults with axillary nerve injuries caused by motorcycle accidents, where the diagnosis was set late. Ten young men (median age at trauma 13 years, range 9–24) with an axillary nerve injury were diagnosed by examination of shoulder function and electromyography (EMG). The patients had either a nerve reconstruction procedure or were treated conservatively and their recovery was monitored. The axillary nerve was explored and reconstructed at a median of 8 months (range 1–22 months) after trauma in 8/10 patients. Two patients were treated non-operatively. In 4/8 cases, a reconstruction with sural nerve graft was performed and in 1/8 case only exploration of the nerve was made (minor neuroma). In 3/8 cases a radial nerve branch transfer to the axillary nerve was chosen as the procedure. The shoulder was mobilised after 3 weeks with physiotherapy and the patients were monitored regularly. Functional recovery was observed in 9/10 cases (median follow up 11 months, range 7–64) with EMG signs of reinnervation in seven patients. Axillary nerve function should not be overlooked in young patients with a minor shoulder trauma. Nerve reconstruction can successfully recreate function.     

Current concepts in diagnosis and management of common upper limb nerve injuries in children

Peripheral nerve injuries (PNI) of the upper limb are a common event in the paediatric population, following both fractures and soft tissues injuries. Open injuries should in theory be easier to identify and the repair of injured structures performed as soon as possible in order to obtain a satisfying outcome. Conversely, due to the reduced compliance of younger children during clinical assessment, the diagnosis of a closed nerve injury may sometimes be delayed. As the compliance of patients is influenced by pain, anxiety and stress, the execution of the clinical manoeuvres intended to identify a loss of motor function or sensibility, can be impaired. Although the majority of PNI are neuroapraxias resulting in spontaneous recovery, there are open questions regarding certain aspects of closed PNI, e.g. when to ask for electrophysiological exams, when and how long to wait for a spontaneous recovery and when a surgical approach becomes mandatory. The aim of the article is therefore to analyse the main aspects of the different closed PNI of the upper limb in order to provide recommendations for timely and correct management, and to determine differences in the PNI treatment between children and adults.     

Long-term results of transplantations to repair median, ulnar, and radial nerve lesions by a microsurgical interfascicular autogenous cable graft technique

A comprehensive analysis of 187 patients (78 median, 86 ulnar, and 23 radial nerve lesions) treated by an interfascicular autogenous nerve grafting technique is presented. After a follow-up of at least 18 months good motor recovery was achieved in 72% of median nerve lesions, 77% of ulnar nerve lesions, and 57% of radial nerve lesions. Good functional sensory recovery was found in 36% of median, 45% of ulnar, and 48% of radial nerve lesions. It appears by multivariate analysis that the results obtained generally were better in younger patients, in patients with a shorter preoperative delay, and in cases with a shorter transplant.     

Comparison of assessment tools to score recovery of function after repair of traumatic lesions of the median nerve

In this paper the recovery after repair of the median nerve has been used to compare different assessment tools for evaluation of peripheral nerve function: touch (moving 2-point discrimination (2PD); Semmes-Weinstein (SW) monofilament, motor (Medical Research Council (MRC) scale), combined motor and sensory (Dellon modification of the Moberg pick up test; Moberg Recognition test), and pain (visual analogue scale; pinprick-test). The mean (SD) age of our 28 patients was 28 (12) years. The mean (SD) follow-up period was 5 years, 2 months (2 years, 8 months). On the operated side three patients (11%) had a moving 2PD of less than 4 mm. The results of the moving 2PD were compared with those of the SW monofilaments, but with a poor correlation. The MRC score correlated well with opposition movement of the thumb and muscle wasting (p<0.01). We recommend a number of tests to evaluate (the chronological return of) peripheral nerve function.     

Indication,technique and results of facial nerve reconstruction

Summary 160 patients with various intraor extracranial pathologies were treated by microsurgical facial nerve reconstruction at Nordstadt Neurosurgical Clinic between 1978 and 1993. Facial nerve reconstruction was accomplished along the anatomical course of the facial nerve from its origin at the brainstem, within the mastoid, at the stylomastoid foramen and within the face. Mostly, reconstruction was indicated because of nerve discontinuity (n=61), whereas facial nerve reanimation with a donor nerve such as the contralateral facial nerve or the ipsilateral hypoglossal nerve was indicated in 99 cases of loss of a proximal nerve stump. Depending on the site of the lesion reinnervation started at 5 to 15 months postoperatively lasting for 2 to 3 years with overall satisfactory results. 69% of all the patients regained good symmetry on rest, complete eye closure equivalent to House-Brackmann-Score III: Patients with complete failures either suffered of non-related diseases such as cancer leading to death before the estimated time of recovery or were exposed to radiation or received facial nerve reconstruction after long-standing facial deficit and marked muscular atrophy. The indication of the adequate method depends on the clinical course with or without preexisting facial paresis, on considering the intraoperative state of the facial nerve, the identification and microsurgical preparation of adequate nerve stumps, as well as on the adaptation techniques and the postoperative guidance of the patient. We conclude that facial nerve reconstruction by transplantation at either site of the nerve course or by reanimation with a donor nerve are effective and reliable procedures of treatment leading to satisfactory functional and cosmetic results.     

多种移植体修复周围神经的比较实验研究

修复神经缺损的材料甚多，但至今尚未见各种材料的比较研究。为了比较自体神经、肌肉、静脉、肌腱及硅橡胶修复神经缺损的效果，选用ＳＤ大白鼠，切断腓总神经，制成０．６ｃｍ缺损，分别用不同移植物桥接缺损。于术后６周、１２周在电生理、胫前肌称重、远端轴突计数及组织学等方面进行综合分析评价。结果表明：自体神经移植在各方面均优于其它移植体，而静脉组又优于另外３组。对各种移植体中神经再生的特点及其成熟过程进行了讨论，并探讨了形成这种差别的有关神经再生微环境的影响。     

USE OF THE DISTALLY-BASED RADIAL FOREARM FLAP SUPPLIED BY THE DORSAL CARPAL ARCH,OR PALMAR CARPAL ARCH,OR BOTH,IN MUTILATING INJURIES: Two case reports

The distally-based radial forearm flap is safe, easy, and versatile as a regional, one-stage procedure to reconstruct soft tissue defects of the hand. However, there is a general perception that the deep and superficial palmar arches have to be intact to raise a distally-based radial forearm flap. We successfully used two flaps supplied by the dorsal carpal arch, or the palmar carpal arch, or both, despite the fact that the deep and the superficial palmar arches were damaged in mutilating injuries.     

Long-term local corticosteroid application does not influence nerve transmission or structure

The long-term effects of a locally applied depot form of a corticosteroid on the electrical properties and structure of nerves were investigated in an animal experimental model.
The conduction in electrically stimulated A-fibres of the plantar nerve was monitored by a bipolar volley recording of the sciatic nerve whereas the conduction in C-fibres of the plantar nerve was measured through a C-fibre evoked segmental flexion reflex in the anaesthetized rat. Droplets of either methylprednisolone acetate or vehicle were placed under direct observation on the plantar nerve. Saline was used as a control on the contralateral side. One to two weeks after the application both the A-fibre volley of the sciatic nerve and the C-fibre evoked reflex discharge of flexor motoneurons were recorded.
No difference was found between the nerves treated with corticosteroid, constituent vehicle or saline. Light and electron microscopic analysis of the nerves showed no changes in the nerve fibres or in the intraneural connective tissue in either the corticosteroid treated or the control nerves.
It is concluded that locally applied corticosteroids in limited amounts have no long-term effects on the electrical and structural properties of peripheral nerves.