Brachial Plexopathy/Nerve Root Avulsion in a Football Player: The Role of Electrodiagnostics

Electromyography (EMG) studies are a useful tool in anatomical localization of peripheral nerve and brachial plexus injuries. They are especially helpful in distinguishing between brachial plexopathy and nerve root injuries where surgical intervention may be indicated. EMG can also assist in providing prognostic information after nerve injury as well as after nerve repair. In this case report, a football player presented with weakness in his right upper limb after a traction/traumatic injury to the right brachial plexus. EMG studies revealed evidence of both pre- and postganglionic injury to multiple cervical roots. The injury was substantial enough to cause nerve root avulsions involving the C6 and C7 levels. Surgical referral led to nerve grafts targeted at regaining function in shoulder abduction and elbow flexion. After surgery, the patient's progress was monitored utilizing EMG to assist in identifying true axonal regeneration.     

Musculocutaneous Neuropathy: Case Report and Discussion

The musculocutaneous nerve arises from the lateral cord of the brachial plexus and contains fibers from the C5, C6, and C7 spinal nerve roots. It innervates such muscles as the biceps brachii and brachialis as well as supply branches to the skin over the lateral cubital and forearm regions via the lateral antebrachial cutaneous nerve. Musculocutaneous neuropathy can arise from exercise, participating in sports, strenuous activity, cast placement, trauma, and surgery in addition to other less understood causes such as Parsonage Turner syndrome. We present the case of a 55-year-old female who complained of numbness, weakness, and pain throughout the arm starting 1 day following a surgical procedure. Electrodiagnostic testing revealed a musculocutaneous neuropathy with significant axonal injury. Symptoms of musculocutaneous neuropathy may be similar to cervical spinal nerve root impingement or brachial plexus lesions. Therefore, magnetic resonance imaging and electrodiagnostic studies may be useful in differentiating between these conditions. Once the diagnosis of musculocutaneous neuropathy has been made, treatments include relative rest, nonsteroidal anti-inflammatory drugs, splinting, physical therapy, and surgical decompression in cases that do not respond to conservative management.     

Restoration of Elbow Flexion by Transfer of the Phrenic Nerve to Musculocutaneous Nerve after Brachial Plexus Injuries

Traumatic brachial plexus injuries are a devastating injury that results in partial or total denervation of the muscles of the upper extremity. Treatment options that include neurolysis, nerve grafting, or neurotization (nerve transfer) has become an important procedure in the restoration of function in patients with irreparable preganglionic lesions. Restoration of elbow flexion is the primary goal in treating patients with severe brachial plexus injuries. Nerve transfers are used when spinal roots are avulsed, and proximal stumps are not available. In the present study, we analyze the results obtained in 20 patients treated with phrenic–musculocutaneous nerve transfer to restore elbow flexion after brachial plexus injuries. A consecutive series of 25 adult patients (21 men and 4 women) with a brachial plexus traction/crush lesion were treated with phrenic–musculocutaneous nerve transfer, but only 20 patients (18 men and 2 women) were followed and evaluated for at least 2 years postoperatively. All patients had been referred from other institutions. At the initial evaluation, eight patients received a diagnosis of C5-6 brachial plexus nerve injury, and in the other 12 patients, a complete brachial plexus injury was identified. Reconstruction was undertaken if no clinical or electrical evidence of biceps muscle function was seen by 3 months post injury. Functional elbow flexion was obtained in the majority of cases by phrenic–musculocutaneous nerve transfer (14/20, 70%). At the final follow-up evaluation, elbow flexion strength was a Medical Research Council Grade 5 in two patients, Grade 4 in four patients, Grade 3 in eight patients, and Grade 2 or less in six patients. Transfer involving the phrenic nerve to restore elbow flexion seems to be an appropriate approach for the treatment of brachial plexus root avulsion. Traumatic brachial plexus injury is a devastating injury that result in partial or total denervation of the muscles of the upper extremity. Treatment options include neurolysis, nerve grafting, or neurotization (nerve transfer). Neurotization is the transfer of a functional but less important nerve to a denervated more important nerve. It has become an important procedure in the restoration of function in patients with irreparable preganglionic lesions. Restoration of elbow flexion is the primary goal in treating patients with severe brachial plexus injuries. Nerve transfers are used when spinal roots are avulsed, and proximal stumps are not available. Newer extraplexal sources include the ipsilateral phrenic nerve as reported by Gu et al. (Chin Med J 103:267–270, 1990) and contralateral C7 as reported by Gu et al. (J Hand Surg [Br] 17(B):518–521, 1992) and Songcharoen et al. (J Hand Surg [Am] 26(A):1058–1064, 2001). These nerve transfers have been introduced to expand on the limited donors. The phrenic nerve and its anatomic position directly within the surgical field makes it a tempting source for nerve transfer. Although not always, in cases of complete brachial plexus avulsion, the phrenic nerve is functioning as a result of its C3 and C4 major contributions. In the present study, we analyze the results obtained in 20 patients treated with phrenic–musculocutaneous nerve transfer to restore elbow flexion after brachial plexus injuries.     

Preoperative diagnosis and surgical indication in traumatic injuries of the brachial plexus

Summary The precise preoperative clinical and electrophysiological evaluation of the brachial plexus as well as an exact rediological evaluation are the keystones for the treatment of traumatic injuries of the brachial plexus. Furthermore, surgical management and prognosis of traction injuries of the brachial plexus depend on the accurate diagnosis of root avulsion from the spinal cord. Myelography, myelo-computed tomography and recently magnetic resonance imaging are the main radiological methods for preoperative diagnose of cervical root avulsions. Surgical experience shows that in may cases, extraspinal findings diverge from intradural findings. Consequently, only correlation with the intradural surgical findings will allow us to define the factual accuracy of myelo-CT and MRI studies. Accuracy of the preoperative myelo-CT based diagnosis related to the intraoperative intradural findings was 85 %. On the other hand, MRI showed an accuarcy of only 52 %. Therefore, myelo-CT scans with 1 to 3 mm axial slices proves to be the most reliable method to evaluate preoperatively the presence of complete or partial root avulsion in traumatic brachial plexus injuries. However in 15 % of the cases preoperative exact radiological diagnosis is unfortunately not reliable. In these special cases intraspinal surgical exposure of the cervical roots will provide the accurate diagnosis of root avulsion. Accurate clinical evaluation and exact assessment of intraspinal root avulsion simplify enormously the decision concerning the choice of donor nerves for transplantation and/or neurotization during brachial plexus surgery.      

Brachial plexus injury: a survey of 100 consecutive cases from a single service

OBJECTIVE: We analyzed the epidemiology, preoperative management, operative findings, operative treatment, and postoperative results in a group of 99 patients who sustained 100 injuries to the brachial plexus. METHODS: The charts of 100 consecutive surgical patients with brachial plexus injuries were reviewed. RESULTS: The patient group comprised 80 males and 19 females ranging from 5 to 70 years of age. One male patient had bilateral brachial plexus palsy. Causes of injury were largely sudden displacement of head, neck, and shoulder and included 27 motorcycle accidents. There were 23 open wounds, including 8 gunshot wounds, 6 other penetrating wounds, and 9 wounds caused by operative or iatrogenic trauma. Loss was exhibited at C5-C6 in 19 patients, at C5-C7 in 15 patients, and at C5-T1 in 39 patients, and 8 patients had another spinal root pattern of injury. Nineteen patients had injury at the cord or the cord to nerve level. Associated major trauma was present in 59 patients. Emergency surgery for vessel or nerve repair was necessary in 18 patients. Myelography (n = 57) or magnetic resonance imaging (n = 7) revealed at least one root abnormality in 52 patients. The median interval from trauma to operation was 7 months. Operative exposures used included anterior supraclavicular, infraclavicular, combined supra- and infraclavicular, or a posterior approach in 5, 14, 77, and 4 patients, respectively. The surgical procedures performed included neurolysis alone in 12 patients and nerve grafting, end-to-end anastomosis, and/or neurotization in 81, 5, and 47 patients, respectively. Postoperative follow-up of at least 36 months was conducted in 78% of the patients. Grade 3 recovery according to Louisiana State University Medical Center criteria means contraction of proximal muscles against some resistance and of distal muscles against at least gravity. Among the 18 patients with open wounds, 14 (78%) recovered to a Grade 3 or better level, as did 35 (58%) of 60 patients with stretch injuries. In all cases of C5-C6 stretch injuries repaired by nerve grafting (n = 10), the patients recovered useful arm function. CONCLUSION: Brachial plexus injury represents a severe, difficult-to-handle traumatic event. The incidence of such injuries and the indications for surgery have increased during recent years. Graft repair and neurotization procedures play an important role in the treatment of patients with such injuries.     

Radiological Investigations and Intra-operative Evoked Potentials for the Diagnosis of Nerve Root Avulsion: Evaluation of Both Modalities by Intradural Root Inspection

Summary  Fourteen patients with traumatic brachial plexus injuries underwent intradural inspection of cervical nerve roots to evaluate radiological and intra-operative electrophysiological findings concerning cervical nerve root avulsion from the spinal cord. Four neurosurgeons of our department assessed independently from each other both myelography and CT-myelography concerning intradural nerve root lesions. Each neurosurgeon assessed a total of 26 cervical nerve roots. Two investigators assessed 6/26 and 2 investigators 7/26 nerve roots falsely concerning ventral or/and dorsal root lesions compared with the findings on intradural inspection (23% and 27% false findings). There was a considerable variance concerning the assessibility and findings among the 4 neurosurgeons. Reconstructive surgery was performed after a mean interval of 6.5 months following trauma and 2 weeks following intradural inspection. After exposure of the brachial plexus and the cervical nerve roots in question via a ventral approach, 13 cervical nerve roots were stimulated electrically close to the neuroforamen and cortical evoked potentials (root-SEPs) were recorded from the contralateral postcentral region. All 5 roots with SEPs were intact (no root lesion) and all 8 roots without SEPs showed interrupted (ventral or/and dorsal) rootlets on intradural inspection. Our results demonstrate that false radiological findings concerning root lesions are possible. Intra-operative root-SEPs seem to be a useful aid for evaluation of cervical nerve root lesions. However, more electrophysiological data are necessary to ascertain, if this modality is able to replace intradural inspection in unclear radiological cases in the future.     

Evaluation of traumatic cervical nerve root injuries by intraoperative evoked potentials

OBJECTIVE: To evaluate intraoperative evoked potentials as a diagnostic tool in traumatic brachial plexus injuries. METHODS: Thirteen patients with traumatic brachial plexus injuries were investigated by intradural nerve root inspection (n = 28 roots) via cervical hemilaminectomy to assess or rule out nerve root avulsion from the spinal cord. Two to 8 weeks later, evoked potentials from neck and scalp were recorded after direct electrical nerve root stimulation close to the vertebral foramen during operative brachial plexus repair via an anterior (supraclavicular and infraclavicular) approach. Recordings were performed without and after full muscle relaxation. RESULTS: There was a clear relationship between the state of the root as documented by intradural root inspection and the result of intraoperative recording of evoked potentials: the absence of evoked muscle action potentials from neck muscles demonstrated a 100% sensitivity for anterior root lesions, whereas sensory evoked potentials from the scalp demonstrated a 100% sensitivity for posterior root lesions. Moreover, roots could be identified with preserved continuity that did not conduct, suggesting a nerve lesion in continuity. CONCLUSION: Intraoperative evoked muscle action potentials and sensory evoked potentials after electrical nerve root stimulation allow selective functional evaluation of anterior and posterior nerve roots in patients with traumatic brachial plexus injuries. The high sensitivity and reliability of this test obviate the need for additional diagnostic surgery.     

Sensory disturbances and pain complaints after brachial plexus root injury: a prospective study involving 150 adult patients

After injury of the brachial plexus, sensory disturbance in the affected limb varies according to the extent of root involvement. The goal of this study was to match sensory assessments and pain complaints with findings on CT myelo scans and surgical observations. One hundred fifty patients with supraclavicular stretch injury of the brachial plexus were operated upon within an average of 5.4 months of trauma. Preoperatively, upper limb sensation was evaluated using Semmes-Weinstein monofilaments. Pain complaints were recorded for each patient. With lesions affecting the upper roots of the brachial plexus, hand sensation was largerly preserved. Sensory disturbances were identified over a longitudinal bundle on the lateral arm and forearm. In C8-T1 root injuries, diminished protective sensation was observed on the ulnar aspect of the hand. If the C7 root also was injured, sensation in the long finger was impaired. Eighty-four percent of our 64 patients with total palsy reported pain, versus just 47% of our 72 patients with upper type palsies. This rate dropped to 29% in the 14 patients with a lower-type palsy. C8 and T1, when injured, always were avulsed from the cord; when avulsion of these roots was the only nerve injury, pain was absent. Hand sensation was largely preserved in patients with partial injuries of the brachial plexus, particularly on the radial side. Even when T1 was the only preserved root, hand sensation was mostly spared. This indicates that overlapping of the dermatomal zones seems much more widespread than previously reported.     

Outcomes of surgical treatment of brachial plexus injuries using nerve grafting and nerve transfers

Between 1993 and 1998, 32 male patients with brachial plexus injuries were surgically treated. Eighteen interfascicular grafting and 71 extraplexal neurotization procedures were performed separately or in combination. Donor nerves were the intercostals, spinal accessory, phrenic, contralateral C7, and cervical plexus, in order of frequency. Patients were followed for a minimum of 24 (average, 35) months. Biceps function was best following grafting the musculocutaneous nerve itself, or neurotization with the phrenic nerve (100 percent grade 4), followed by neurotization with the intercostals (89.5 percent grade 3 or more) and last, grafting the C5 root or upper trunk (grade 3 in one of three patients). Phrenic to suprascapular neurotization produced the best results of shoulder abduction (40 to 90 degrees), followed by combined neurotization of the spinal accessory to suprascapular and phrenic to axillary (20 to 90 degrees). Sensory recovery over the lateral forearm and palm varied from S2 to S3+, according to the method of reconstruction.     

Free muscle transplantation combined with intercostal nerve crossing for reconstruction of elbow flexion and wrist extension in brachial plexus injuries.

Complete paralysis due to traumatic brachial plexus injury is extremely difficult to treat when the injury affects whole nerve roots and when motor function fails to show any signs of recovery. Seddon has suggested that arthrodesis of the shoulder and amputation at the humerus, combined with the use of a functional upper extremity prosthesis, was the most practical procedure available. Since 1965, in cases of irreparable lesions such as complete root avulsion type injuries, we have performed direct intercostal nerve crossing to the musculocutaneous nerve without free nerve graft to achieve elbow flexion. However, it is necessary to operate on the patient within 6 months following the injury to obtain good results. In the past there was no procedure for dealing with delayed cases of complete brachial plexus palsy. However, with the advent of microsurgical techniques, new approaches have become open to us. Since 1978, we have reconstructed the elbow flexor by the combined surgery of free muscle transplantation with intercostal nerve crossing in delayed cases of complete paralysis. This article introduces the operative technique and the results we have obtained.     

Brachial plexus injury: factors affecting functional outcome in spinal accessory nerve transfer for the restoration of elbow flexion

OBJECT: Between 1994 and 1998, 44 nerve transfers were performed using a graft between a branch of the accessory nerve and musculocutaneous nerve to restore the flexion of the arm in patients with traumatic brachial plexus injuries. A retrospective study was conducted, including statistical evaluation of the following pre- and intraoperative parameters in 39 patients: 1) time interval between injury and surgery; and 2) length of the nerve graft used to connect the accessory and musculocutaneous nerves. METHODS: The postoperative follow-up interval ranged from 23 to 84 months, with a mean +/- standard deviation of 36 +/- 13 months. Reinnervation of the biceps muscle was achieved in 72% of the patients. Reinnervation of the musculocutaneous nerve was demonstrated in 86% of the patients who had undergone surgery within the first 6 months after injury, in 65% of the patients who had undergone surgery between 7 and 12 months after injury, and in only 50% of the patients who had undergone surgery 12 months after injury. A statistical comparison of the different preoperative time intervals (0-6 months compared with 7-12 months) showed a significantly better outcome in patients treated with early surgery (p < 0.05). An analysis of the impact of the length of the interposed nerve grafts revealed a statistically significant better outcome in patients with grafts 12 cm or shorter compared with that in patients with grafts longer than 12 cm (p < 0.005). CONCLUSIONS: Together, these results demonstrated that outcome in patients who undergo accessory to musculocutaneous nerve neurotization for restoration of elbow flexion following brachial plexus injury is greatly dependent on the time interval between trauma and surgery and on the length of the nerve graft used.     

The C5 root dermatome enlarges and modulates hand pain in total brachial plexus palsy

Hand pain is a major complaint in 80% of the patients with complete brachial plexus palsy; and, in 80% of these patients, the C5 root is ruptured and the C6‐T1 roots avulsed from the spinal cord. It has been suggested that pain in brachial plexus injuries may not arise from avulsed roots, but rather from ruptured roots. Traditionally the C5 root dermatome does not extend to the hand. We have hypothesized that in total lesions of the brachial plexus the C5 root dermatome expands, reaching the hand. In 20 patients with confirmed C5 root rupture and C6‐T1 root avulsion, we investigated the distribution of C5 root paresthesia six to eight weeks after grafting. After cervical percussion in search of Tinel's sign, maps related to reported paresthesia were drawn on the affected limb. We observed that paresthesia following C5 root percussion reached the hands and fingers, dermatomes linked to the C6 and C8 roots. Immediately after percussion, for a few seconds, 14 patients who complained of pain during examination reported the augmentation of numbness and pain resolution. After brachial plexus injury, the C5 root dermatome expands and modulates hand pain. © 2013 Wiley Periodicals, Inc. Microsurgery 34:292–295, 2014.     

磁共振对臂丛神经损伤诊断准确率的分析

目的 探讨磁共振(magnetic resonance imaging,MRI)对臂丛神经节前损伤诊断的准确率及影响因素.方法 运用MRI对27例臂丛神经损伤的患者进行多序列扫描,将影像学诊断与手术所见及术中神经电生理检测结果进行比较,统计各神经根损伤诊断的准确率.结果 臂丛神经节前损伤MRI表现的直接征象:冠状面、横断面或多平面重建均见脊神经前后根消失或连续性的中断,脊髓移位(中心点偏移＞1.5mm);间接征象:创伤性脊膜囊肿,椎管内囊状脑脊液积聚,脊髓变形或移位,"黑线征",脊柱旁肌肉信号异常、强化.臂丛神经节后损伤MRI表现的直接征象:神经增粗或离断、扭曲,伴或不伴T2WI信号增高,创伤性神经瘤形成;间接征象:去神经化肌肉的显示.MRI对臂丛C5～T1各神经根撕脱损伤诊断的准确率分别是59.3%、85.2%、100%、88.9%和92.6%.结论 MRI对臂丛各神经根节前损伤的诊断效能不同,影像诊断应与临床及神经电生理检测相结合.

Abstract：

Objective To analyze the diagnostic accuracy of MRI in determining brachial plexus preganglionic injury and the factors that affect the accuracy. Methods Twenty-seven patients who presented with brachial plexus root avulsion injuries underwent MRI scanning with multiple sequences before the operation.Images of MRI were reviewed for features that would lead to the diagnosis of a preganglionic injury. MRI diagnosis was then verified and compared with surgical findings and electrophysiological diagnosis. The accuracy rate for individual nerve root avulsion was calculated. Results There were direct signs and indirect signs of MRI features that indicated preganglionic injuries. The direct signs included disappearance or loss of continuity of the ventral and dorsal rootlets of the spinal nerve on coronal plane, axial plane or multiplanal reconstruction, and spinal cord shift (midline shift ＞ 1.5 mm). The indirect signs included traumatic pseudomeningocele, CSF collection in the vertebral canal, spinal cord deformation or shift, "black line" sign, and abnormal signals in the paraspinal muscles. Direct MRI signs of postganglionic injuries included thickening, rupture or distortion of the nerve root, with or without increase signal in T2 weighted images, and neuroma formation. Muscle denervation was also an indirect sign for postganglionic injury. The diagnostic accuracy by MRI of C5 to T1 avualsion was 59.3%,85.2%,100%,88.9% and 92.6% respectively. Conclusion The capability of MRl to evaluate lesions of each nerve root is different. A diagnosis should be made combining MRI, electrophysiological and clinical findings.     

The role of magnetic resonance imaging in the management of traction injuries to the adult brachial plexus

Magnetic resonance imaging (MRI) of the cervical spine and brachial plexus was performed on 26 consecutive patients presenting with traction injuries of the brachial plexus during 1996 and 1997. These included T1 and T2 weighted coronal, sagittal and axial images of the cervical spine and coronal images of the brachial plexus. The results were compared with surgical findings, intraoperative neurophysiology, and subsequent clinical progress. Operations for exploration and repair have been performed in 23 and 26 patients scanned. Evidence of root avulsion was seen in 11 patients in the form of displacement or oedema of the spinal cord, haemorrhage or scarring within the spinal canal, absence of roots in the intervertebral foramena, and meningoceles. Characteristic abnormalities were evident in the MR scans of all cases where exploration confirmed some root avulsions. There were no false positives. MRI underestimated the number of individual roots avulsed; sensitivity was 81%. Post-ganglionic lesions were seen as swelling on T1 images associated with increasing signal on T2 images. It was usually possible to define the level of the injury within the plexus. This study suggests that MR imaging, performed early after traction injury to the brachial plexus, provides useful additional information towards establishing the level of the lesion. It also provides information about injury to the plexus outside the spinal canal.     

Injuries of the brachial plexus and neighboring peripheral nerves in vertebral fractures and other trauma of the cervical spine

On the one hand, out of 115 patients admitted to hospital with 162 various fractures of the cervical spine without injury to the spinal cord, only 3 (2.6%) had an associated lesion to the brachial plexus or nerves in the vicinity. On the other hand, among 500 consecutive patients with injuries to the brachial plexus, 55 (11%) presented fractures of the cervical spine (including T1 and the 1st rib), whiplash injuries, severe distortions and dislocations, and contusions of that vertebral segment. Five (1% resp. 9%) had spinal cord injuries, including four patients with partial Brown-Sequard's syndrome, which was caused by multilevel root avulsions of the brachial plexus. In rather severe trauma to the lower cervical spine and concomitant brachial plexus lesion, root avulsions must be expected in 83% of cases, and in almost half of these patients three or more roots are avulsed from the spinal cord. Fractures around the shoulder-girdle as well as arterial ruptures are also significant for this severe nerve injury. Of these patients 39 (71%), were victims of motorcycle accidents.     

Neurotization via the spinal accessory nerve in complete paralysis due to multiple avulsion injuries of the brachial plexus

The authors report their experience with 21 cases of neurotization via the spinal accessory nerve for multiple nerve root avulsion injuries of the brachial plexus associated with total paralysis of the upper limb. They performed microneuroanastomoses with interposed cable nerve grafts between the spinal accessory nerve taken in the supraclavicular fossa and the musculocutaneous nerve at its entrance into the biceps muscle. Surgical indications depend on the accurate diagnosis of spinal nerve root avulsion, especially C5. The anatomicosurgical basis of this technique is as precise as are the indications. As many as two-thirds of the patients with a neurotized musculocutaneous nerve can be expected to achieve strength of at least Grade 3 on late muscle testing. Nevertheless, these results are always inferior to those obtainable when grafting is performed with carefully selected unavulsed C5 or C6 spinal nerve root fibers in the intervertebral foramina. Therefore, neurotization via donor nerves extrinsic to the plexus should only be considered as a second-choice intervention.     

复合式神经移位术治疗臂丛根性撕脱伤

自１９８８年１１月～１９９４年１２月，应用复合式神经移位术治疗臂丛根性撕脱伤８９例。损伤原因为：摩托车撞击伤６３例，机器牵拉伤２１例，直接损伤５例。损伤类型为：上臂丛型４７例，下臂丛型１３例，全臂丛型２９例。伤后至手术时间为３周～６个月。神经移位方式主要根据不同的损伤类型选用相应的移位方式。术后随访时间为１．５～６年。疗效最佳为膈神经移位，有效率达８２．９％；其次为副神经，达６６．７％；颈丛运动支达５５．２％；肋间神经达４８．３％；健侧Ｃ７神经根移位与患侧尺神经吻合，神经再生率达９６．６％。作者认为，复合式神经移位术治疗臂丛根性撕脱伤，尤其是对上臂丛根性撕脱伤，治疗效果是令人满意的。     

MRI在产瘫节前损伤中的诊断价值

目的探讨MRI在产瘫节前损伤中的诊断价值。方法2006年11月-2008年2月,收治产瘫患儿10例。男8例,女2例;年龄2个月～3岁,平均11.4个月。左侧7例,右侧3例。临床分型按Tassin分型:Ⅱ型2例,Ⅲ型6例,Ⅳ型2例。术前均行臂丛神经MRI检查,并与术中探查情况进行比较。结果术前MRI检查1例未见异常,9例创伤性脊膜囊肿。其中脊髓偏移6例,向健侧偏移4例,向患侧偏移2例;脊髓变形6例;撕脱神经根增粗2例。MRI检查神经根为阳性19根中,术中探查真阳性16根,假阳性3根;MRI检查阴性6根中,假阴性2根,真阴性4根。MRI对产瘫节前损伤诊断的敏感性为84.2%、特异性为80.0%和准确性为83.3%,结果具有统计学意义(P<0.05),即MRI检查结果与术中探查结果一致。结论MRI能显示产瘫节前损伤情况,对产瘫的早期诊断及手术时机的选择有参考作用,可作为术前的常规检查。     

Transfer of a flexor digitorum superficialis motor branch for wrist extension reconstruction in C5–C8 root injuries of the brachial plexus: A case series

In brachial plexus injuries, though nerve transfers and root grafts have improved the results for shoulder and elbow reconstruction, wrist extension has received little attention. We operated on three young patients with C5–C8 root injuries of the left brachial plexus, each operated upon within 6 months of trauma. For wrist extension reconstruction, we transferred a proximal branch of the flexor digitorum superficialis to the motor branch of the extensor carpi radialis brevis. Twenty‐four months after surgery, all patients recovered some degree of active wrist motion, from full flexion to near neutral. Independent control of finger flexion and wrist extension was not observed. In C5–C8 root injuries of the brachial plexus, transfer of a flexor digitorum superficialis motor branch to the extensor carpi radialis brevis produces limited recovery. © 2012 Wiley Periodicals, Inc. Microsurgery, 2013.     

Diagnosis of brachial plexus traction lesions by sensory nerve action potentials and somatosensory evoked potentials

Forty-two patients with unilateral brachial plexus traction lesions were investigated by recording sensory nerve action potentials (SNAPs) from the lower arm and somatosensory evoked potentials (SEPs) from the clavicle, the cervical spine and the scalp overlying the contralateral somatosensory cortex, in response to electrical stimulation of peripheral nerves. The median and radial nerves were assumed to derive principally from the C6 and C7 roots, and the ulnar nerve from the C8 and T1 roots. Combination of SEP and SNAP findings suggested a location for the lesion (preganglionic, postganglionic or combining pre- and postganglionic elements) which was found to be accurate in 10 out of 16 operated cases, and substantially accurate in another 3. There was a poor correlation, however, between the presence or absence of SNAPs in the musculocutaneous nerve and the location of the lesion to the C5 root.