可逆性周围神经损伤特点分析(附7例报道)

目的:总结7例可逆性周围神经损伤的特点。方法:分析7例患者周围神经损伤的原因、临床表现和治疗结果。结果:7例患者中,桡神经损伤3例,原因分别为拄拐杖压迫、酒后头压迫、打网球。2例尺神经损伤,原因分别为弹钢琴、打字。尺神经合并正中神经损伤1例,原因为牵拉上肢引起。坐骨神经损伤1例,为坐硬物引起。结论:周围神经受到不严重的压迫、牵拉、疲劳损伤,不会轻易发生神经结构永久性破坏,往往在半年之内能够恢复。     

肋间神经重复电刺激在激素冲击治疗重症肌无力中的应用

目的探讨肋间神经重复电刺激(IRNS)和膈神经重复电刺激(PRNS)对激素冲击治疗时重症肌无力(MG)患者呼吸受累的预测价值.方法治疗开始前3天内检测36例MG患者PRNS和IRNS,同时观察用力肺活量(FVC)、MG临床评分、治疗中临床呼吸症状变化.结果大剂量激素治疗后2～13天14例(40%)患者出现呼吸功能受累或原有呼吸困难加重,呼吸功能恶化患者与未恶化患者相比,上述参数及MG临床类型均有明显差异.Lo-gistic回归分析显示3Hz及5Hz的IRNS双侧波幅衰减均值超过30%时比不超过时发生呼吸困难或原有呼吸困难加重的相对危险度均为19.523.结论治疗中呼吸功能受累与上述指标及MG临床分型均有关系,IRNS可以预测是否发生呼吸功能恶化.     

Simultaneous gradual lengthening of both proximal and distal nerve stumps for repair of peripheral nerve defect in rats

We investigated nerve regeneration following the repair of a segmental nerve defect induced by direct end-to-end neurorrhaphy after simultaneous gradual lengthening of both proximal and distal nerve stumps in rats. A 15-mm-long nerve segment was resected from the sciatic nerve of each rat. The proximal and distal nerve stumps, respectively, were directly lengthened at a rate of 1 mm/day using a custom-made external nerve-lengthening device. After being lengthened for 14 days, both nerve stumps were refreshed, and direct end-to-end neurorrhaphy was performed. For a control, 15-mm nerve grafting was performed immediately after nerve resection. Nerve regeneration was evaluated by motor nerve conduction velocity, muscle contraction force, and histological studies at 6, 8, and 14 weeks after initial nerve resection in both groups. As a result, at 8 and 14 weeks, the motor nerve conduction velocity was significantly higher in the nerve-lengthening group than in the autografting group. In addition, at 14 weeks, the tetanic force and wet weight of the gastrocnemius muscle were significantly higher in the nerve-lengthening group than in the autografting group. Histologically, the mean axonal diameter of myelinated nerve fibers and the total number of myelinated nerve fibers were also significantly higher in the nerve-lengthening group than in the autografting group for each evaluation period. It appears that the simultaneous gradual lengthening of both proximal and distal nerve stumps might have potential application in the repair of peripheral nerve defects.     

Interfascicular suture with nerve autografts for median, ulnar and radial nerve lesions

Interfascicular nerve suture with autografts is the operation of choice for repairing peripheral nerve injuries because it ensures more precise alignment of the fasciculi and so better chances of reinnervation of the sectioned nerve. The procedure as described by Millesi et al has been used at the Istituto Neurologico di Milano in 30 patients with traumatic lesions of the median, ulnar and radial nerves. All have been followed up for 2 to 7 years since operation. The results obtained are compared with those of other series obtained with interfascicular suture and with epineural suture. Microsurgery is essential. The best time to operate is discussed.

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Sommario La sutura nervosa interfascicolare con innesti autoplastici è la tecnica di elezione per ripara le lesioni traumatiche dei nervi periferici, dato che essa garantisce un più preciso allineamento dei fascicoli e quindi una maggiore possibilità di reinnervazione del moncone periferico. Questa tecnica, come è stata descritta da Millesi, è stata adottata all'Istituto Neurologico di Milano in 30 pazienti, affetti da lesioni traumatiche dei nervi mediano, ulnare e radiale. Tutti i pazienti sono stati controllati a distanza di tempo variabile da due a sette anni dall'intervento. I risultati ottenuti sono paragonati a quelli di altre casistiche, ottenuti sia con la tecnica della sutura interfascicolare che con la sutura epineurale; viene anche discussa la tecnica microchirurgica e il momento ottimale per l'intervento.

     

The anatomy and physiology of nerve injury

Nerves have a structure of considerable complexity with features of special relevance to nerve injury and nerve regeneration. These include variations in the cross-sectional areas devoted to fascicular and epineurial tissue, the fascicular redistribution and mixing of different branch fibers brought about by fascicular plexuses, and the numbers of nerve fibers representing individual branches. The elasticity and tensile strength of nerve trunks and their capacity to resist traction deformation reside in the fascicular tissue, while the epineurium provides a protective cushion against compression. The microstructure of nerve trunks provides the basis for a classification of nerve injuries into five degrees of severity with partial and mixed types--each with a clearly defined pathology and distinguishing clinical features. Following a transection injury, changes occur in the severed axons, endoneurial tubes, fasciculi, and nerve trunk. The type of injury and the nature of these changes determine the outcome of axon regeneration.     

Effect of applied electrical fields on sprouting of intact saphenous nerve in adult rat

Saphenous nerve sprouting was measured behaviorally and histologically after chronic sciatic denervation in the adult rat. The effect of electrical stimulation (either weak DC fields, or stronger AC fields) on the rate of sprouting of the intact saphenous was studied. Sprouting was enhanced by DC fields (1 μA) if the cathode was placed distal to the growth tips, but was unaffected by anode stimulation. Sprouting was also enhanced by AC fields (1000 μA per pulse) given at 20 Hz and 0.1 ms duration. In the discussion we postulate that separate mechanisms might mediate the AC and DC results. The DC effects are the first demonstration in mammals of results previously observed in lower vertebrates.     

Sciatic nerve compression by an aneurysm of the internal iliac artery

A 73-year-old female with severe sciatica suffered from an aneurysm of the left internal iliac artery. At first minimal caudographic abnormalities suggested intervertebral disc herniation and lumbar root compression but at exploratory surgery the diagnosis had to be rejected. Once the correct diagnosis was established by echography, CT-scanning and angiography surgical treatment of the aneurysm resulted in complete recovery. Because sciatic nerve lesions due to aneurysms in the pelvic region very seldom occur and may be the cause of diagnostic confusion, symptoms and treatment of these aneurysms are discussed.     

The development of a normalization method for comparing nerve regeneration effectiveness among different graft types

The inability to compare directly different nerve grafts has been a significant factor hindering the advance of nerve graft development. Due to the abundance of variables that exist in nerve graft construction and multiple assessment types, there has been limited success in comparing nerve graft effectiveness among experiments. Using mathematical techniques on nerve conduction velocity (NCV) autograft data, a normalization function was empirically derived that normalizes differences in gap lengths. Further analysis allowed for the development of the relative regeneration ratio (RRR). The RRR function allows researchers to directly compare nerve graft results based on the NCV data from their respective studies as long as the data was collected at the same post‐operation time. This function also allows for comparisons between grafts tested at different gap lengths. Initial testing of this RRR function provided confidence that the function is accurate for a continuum of gap lengths and different nerve graft types.     

Foot pad skin biopsy in mouse models of hereditary neuropathy

Numerous transgenic and knockout mouse models of human hereditary neuropathies have become available over the past decade. We describe a simple, reproducible, and safe biopsy of mouse skin for histopathological evaluation of the peripheral nervous system (PNS) in models of hereditary neuropathies. We compared the diagnostic outcome between sciatic nerve and dermal nerves found in skin biopsy (SB) from the hind foot. A total of five animal models of different Charcot-Marie-Tooth neuropathies, and one model of congenital muscular dystrophy associated neuropathy were examined. In wild type mice, dermal nerve fibers were readily identified by immunohistochemistry, light, and electron microscopy and they appeared similar to myelinated fibers in sciatic nerve. In mutant mice, SB manifested myelin abnormalities similar to those observed in sciatic nerves, including hypomyelination, onion bulbs, myelin outfolding, redundant loops, and tomacula. In many strains, however, SB showed additional abnormalities--fiber loss, dense neurofilament packing with lower phosphorylation status, and axonal degeneration-undetected in sciatic nerve, possibly because SB samples distal nerves. SB, a reliable technique to investigate peripheral neuropathies in human beings, is also useful to investigate animal models of hereditary neuropathies. Our data indicate that SB may reveal distal axonal pathology in mouse models and permits sequential follow-up of the neuropathy in an individual mouse, thereby reducing the number of mice necessary to document pathology of the PNS.     

Advances in the repair of segmental nerve injuries and trends in reconstruction

Despite advances in surgery, the reconstruction of segmental nerve injuries continues to pose challenges. In this review, current neurobiology regarding regeneration across a nerve defect is discussed in detail. Recent findings include the complex roles of nonneuronal cells in nerve defect regeneration, such as the role of the innate immune system in angiogenesis and how Schwann cells migrate within the defect. Clinically, the repair of nerve defects is still best served by using nerve autografts with the exception of small, noncritical sensory nerve defects, which can be repaired using autograft alternatives, such as processed or acellular nerve allografts. Given current clinical limits for when alternatives can be used, advanced solutions to repair nerve defects demonstrated in animals are highlighted. These highlights include alternatives designed with novel topology and materials, delivery of drugs specifically known to accelerate axon growth, and greater attention to the role of the immune system.     

Long-term observation on the changes of somatotopy in the facial nucleus after nerve suture in the cat: Morphological studies using retrograde labeling

To examine the time course of plasticity of the cranial nucleus during axonal regeneration, we followed the topographical reorganization of the cat facial nucleus (FN) up to 24 months after facio-facial nerve suture using retrograde labeling methods. The trunk of the temporal-zygomatico-orbital and both superior and inferior buccolabial branches (defined as main branch) of the facial nerve was cut and sutured again under ketamine hydrochloride anesthesia. At 11-722 days after nerve suture, Fast Blue (FB) and 1,1'-dioctadecyl-3, 3, 3', 3'-tetramethylindocarbocyanine perchlorate (Dil) or horseradish peroxidase (HRP) were injected into the distal part of the sutured main branch and the unoperated posterior auricular branch, respectively. Until about 3 months after suture, the topographical pattern in FN was similar to that observed in normal cats. At about 4 months after suture, FB-labeled motoneurons were distributed not only in the lateral part (including intermediate, dorsal and ventrolateral divisions) but also in the medial subdivision of FN. After a survival period of 18-24 months, FB-labeled neurons were found all over the FN, and their number increased significantly. Interestingly, in the longer survival cases, we noticed that the Dil- or HRP-labeled posterior auricular branch motoneurons also showed a tendency to distribute outside the medial region. The present study showed that somatotopic disorganization starts at around 4 months after suture, which seems to be somewhat slower than that in rats, and continues until a much later postoperative period. Furthermore, we suggested a possibility that the regeneration of one branch may affect the somatotopy of the unoperated nerve branch. These phenomena may contribute to aberrant facial nerve functions such as abnormal associated movement and facial spasm observed after nerve injury.     

Electroneurographic investigation of the mandibular nerve in lingual neuropathy

We developed a method for determination of motor conduction along the mandibular and sensory conduction along the lingual and inferior alveolar nerves in 10 controls and 6 patients with lingual neuropathy following lower wisdom tooth extraction. Patients with lingual neuropathy had reduced/absent or delayed compound sensory action potentials and normal conduction along the fibers of the inferior alveolar nerve and mandibular nerve. The method provides a useful electrophysiological means of evaluating lingual nerve lesions. © 1998 John Wiley-Liss, Inc. Muscle Nerve 21:410–412, 1998.     

Anatomical feasibility of vagus nerve esophageal branch transfer to the phrenic nerve

This study measured the vagus and phrenic nerves from 12 adult cadavers. We found that the width and thickness of the vagus and phrenic nerves were different in the chest. The distance from the point of the vagus nerve and phrenic nerve on the plane of the inferior border of portal pulmonary arteries (T point) was approximately 7 cm to the diaphragm and was approximately 10 cm to the clavicle level. The number of motor fibers in the vagus nerves was 1 716 ± 362, and the number of nerve fibers was 4 473 ± 653. The number of motor fibers in the phrenic nerves ranged from 3 078 ± 684 to 4 794 ± 638, and the number of nerve fibers ranged from 3 437 ± 642 to 5 071 ± 723. No significant difference was found in the total number of nerve fibers. The results suggest that width, thickness, and total number of nerve fibers are similar between the vagus and phrenic nerves, but the number of motor fibers is different between them.     

Electrical stimulation promotes regeneration of injured oculomotor nerves in dogs

Functional recovery atfer oculomotor nerve injury is very poor. Electrical stimulation has been shown to promote regeneration of injured nerves. We hypothesized that electrical stimulation would improve the functional recovery of injured oculomotor nerves. Oculomotor nerve injury models were created by crushing the right oculomotor nerves of adult dogs. Stimulating electrodes were positioned in both proximal and distal locations of the lesion, and non-continuous rectangular, biphasic current pulses (0.7 V, 5 Hz) were administered 1 hour daily for 2 consecutive weeks. Analysis of the results showed that electrophysiological and morphological recovery of the injured oc-ulomotor nerve was enhanced, indicating that electrical stimulation improved neural regeneration. hTus, this therapy has the potential to promote the recovery of oculomotor nerve dysfunction.     

Two approaches to measure amplitude changes of the sensory nerve action potential over a length of nerve

Changes in amplitude of sensory nerve action potentials (SNAPs) over a length of nerve have not been used for diagnostic purposes. We measured such changes for median and ulnar nerves in 25 healthy subjects in two ways. The multiple-stimulation method involved three stimulation sites (palm, wrist, elbow) and one recording site on a finger. The multiple-recording method involved stimulation at the wrist and simultaneous recording from two adjacent sites on a finger. Percentile changes in amplitude could be measured in all subjects for the median nerve, but not for the ulnar nerve due to submaximal stimulation in the palm. For the median nerve, the multiple-recording method resulted in a mean amplitude change of 79% +/- 13%, whereas comparison of wrist to palm stimulation in the multiple-stimulus method resulted in a change of 73% +/- 10%. These values are high enough to encourage study into practical applications of such methods in detecting peripheral nerve disease.     

Lateral femoral cutaneous neuropathy and its surgical treatment: a report of 167 cases

Surgical treatment of lateral femoral cutaneous neuropathy (LFCN) is performed only after failure of conservative management. We reexamined 167 cases (7 bilateral) of LFCN of various etiologies (idiopathic, abdominal surgery, iliac crest bone grafting, trauma, and total hip arthroplasty) operated on between 1987 and 2003. Average follow-up was 98 months (20-212). The intervention was performed under local anesthesia in 139 cases (83%). Surgical release of the nerve was performed in 153 cases (92%) and transection in 14 cases (8%). Surgical treatment of LFCN led to improvement and patient satisfaction in 130 cases (78%). The results depended on several factors, especially the underlying etiology, duration of symptoms before intervention, and integrity of the nerve. Nerve release remains the first-line surgical technique, improving painful symptoms in many cases while preserving sensation of the thigh. It can be performed under local anesthesia by an experienced surgeon.     

Medial plantar nerve testing facilitates identification of polyneuropathy

Many studies have used sural nerve action potential (NAP) as an electrophysiological marker for distal symmetrical polyneuropathy (DSP). We examined the role of medial plantar nerve testing for identifying DSP by comparing amplitudes from sural, superficial peroneal, and medial plantar nerves in 85 participants with symptoms and clinical signs of DSP and 204 participants without DSP. Receiver‐operating characteristic curves were used to determine the sensitivity of all three sensory conduction studies for the diagnosis of DSP. All three nerves could be used to discriminate between subjects with and without DSP with an area under the curve of more than 85% of cases. Sural and superficial peroneal nerve testing sensitivities were about 55%, whereas medial plantar nerve testing sensitivity was more than 90%. These findings suggest that testing the medial plantar nerve may increase the diagnostic yield of nerve conduction studies for DSP. Muscle Nerve 38: 1595–1598, 2008     

Enhancement of peripheral nerve regeneration

Numerous factors external to the nerve cell can support and enhance nerve regeneration after injury. The definition of these factors and the elucidation of their mechanisms of action are the central goals of much contemporary neurobiologic research. This research will hopefully lead to the discovery of factors that will prove to be therapeutically beneficial for patients with either peripheral nervous system (PNS) injury or central nervous system (CNS) injury. This article reviews the biology of the regeneration response of the nerve to injury and discusses many of the factors that enhance nerve growth. Finally, the nerve guide or nerve regeneration chamber model for the evaluation of putative nerve regeneration enhancing agents in vivo is also discussed.