臂丛神经损伤的膈神经传导测定结果分析

目的 评估膈神经传导功能测定方法的临床应用价值. 方法 对292例臂丛神经损伤患者进行膈神经诱发电位的检测,根据积水潭医院肌电图室建立的正常值将其分为传导功能正常组与传导功能异常组,比较2组膈神经诱发电位的潜伏期和波幅. 结果 传导功能正常组膈神经诱发电位的潜伏期较异常组明显降低,波幅较异常组明显增加,差异有统计学意义(P＜0.05). 结论 膈神经运动传导功能测定方法简便、易行.安全可靠,是一种临床了解膈神经功能的可靠方法.     

Phrenic nerve conduction study in normal subjects

Phrenic nerve conduction studies were performed in 50 phrenic nerves from 25 normal subjects using a technique modified from previously described methods. The normal ranges for latency, amplitude, negative peak area, and duration were established. The latency correlates with age and the amplitude increases with chest circumference. With our method, the amplitude increases and the duration decreases with lung volume. We found good right-left agreement and reproducibility. Therefore, the unaffected side can be used as a reference in unilateral phrenic nerve lesions and previous studies can be used for comparison in serial studies. We recommend that phrenic nerve conduction studies be used routinely to diagnose and monitor patients with respiratory involvement from neuromuscular diseases.© 1995 John Wiley &Sons, Inc.     

Phrenic Nerve Conduction in Healthy Subjects

Introduction: Assessment of diaphragm compound muscle action potential by noninvasive phrenic nerve stimulation at the neck is well described. However, normal values in a large cohort of healthy subjects are lacking. Our objective was to determine reference values of phrenic nerve conduction in healthy subjects. Methods: We recruited 155 healthy subjects (25–79 years old) and measured mean amplitude (PhrenAmp) and latency (PhrenLat) of motor responses according to Bolton's method. Results: The lower limit for PhrenAmp was 0.28 and 0.25 mV and the upper limit for PhrenLat was 8.41 and 8.56 ms for right and left side, respectively. PhrenLat was correlated with age. PhrenAmp, PhrenLat and area were significantly higher in men. Tolerance to phrenic nerve stimulation was excellent. Conclusions: Our study provides normative values of phrenic nerve motor responses in a large cohort of healthy subjects and identifies age and sex as factors of variation. Muscle Nerve 59:451–456, 2019     

Phrenic nerve transfer to the musculocutaneous nerve for the repair of brachial plexus injury: electrophysiological characteristics

Phrenic nerve transfer is a major dynamic treatment used to repair brachial plexus root avulsion. We analyzed 72 relevant articles on phrenic nerve transfer to repair injured brachial plexus that were indexed by Science Citation Index. The keywords searched were brachial plexus injury, phrenic nerve, repair, surgery, protection, nerve transfer, and nerve graft. In addition, we performed neurophysiological analysis of the preoperative condition and prognosis of 10 patients undergoing ipsilateral phrenic nerve transfer to the musculocutaneous nerve in our hospital from 2008 to 201 3 and observed the electromyograms of the biceps brachii and motor conduction function of the musculocutaneous nerve. Clinically, approximately 28% of patients had brachial plexus injury combined with phrenic nerve injury, and injured phrenic nerve cannot be used as a nerve graft. After phrenic nerve transfer to the musculocutaneous nerve, the regenerated potentials first appeared at 3 months. Recovery of motor unit action potential occurred 6 months later and became more apparent at 12 months. The percent of patients recovering ‘excellent' and ‘good' muscle strength in the biceps brachii was 80% after 18 months. At 12 months after surgery, motor nerve conduction potential appeared in the musculocutaneous nerve in seven cases. These data suggest that preoperative evaluation of phrenic nerve function may help identify the most appropriate nerve graft in patients with an injured brachial plexus. The functional recovery of a transplanted nerve can be dynamically observed after the surgery.     

Phrenic nerve conduction study in patients with traumatic brachial plexus palsy

Phrenic nerve conduction studies were performed to assess the ipsilateral nerve in 100 patients with traumatic brachial plexus palsy. Open exploration and intraoperative recordings of somatosensory evoked potentials and nerve action potentials were used to confirm the level of root lesions. The relationship between C-5 preganglionic root lesion and the functional integrity of the ipsilateral phrenic nerve was examined. The phrenic nerves were normal in 80 cases, partially injured in 7, and severely injured in 13. We found C-5 preganglionic root lesions in 13 (100%) patients with severely injured, 5 (71.4%) with partially injured, and 24 (30%) with normal phrenic nerves. This correlation suggests phrenic nerve conduction study is a useful tool in the diagnosis of C-5 preganglionic root lesions in patients with traumatic brachial plexopathy.     

Improved C3-4 transfer for treatment of root avulsion of the brachial plexus upper trunk Animal experiments and clinical application

Experimental rats with root avulsion of the brachial plexus upper trunk were treated with the improved C3-4 transfer for neurotization of C5-6.Results showed that Terzis grooming test scores were significantly increased at 6 months after treatment,the latency of C5-6 motor evoked potential was gradually shortened,and the amplitude was gradually increased.The rate of C3 instead of C5 and the C4 + phrenic nerve instead of C6 myelinated nerve fibers crossing through the anastomotic stoma was approximately 80%.Myelinated nerve fibers were arranged loosely but the thickness of the myelin sheath was similar to that of the healthy side.In clinical applications,39 patients with root avulsion of the brachial plexus upper trunk were followed for 6 months to 4.5 years after treatment using the improved C3 instead of C5 nerve root transfer and C4 nerve root and phrenic nerve instead of C6 nerve root transfer.Results showed that the strength of the brachial biceps and deltoid muscles recovered to level III-IV,scapular muscle to level III-IV,latissimus dorsi and pectoralis major muscles to above level III,and the brachial triceps muscle to level 0-III.Results showed that the improved C3-4 transfer for root avulsion of the brachial plexus upper trunk in animal models is similar to clinical findings and that C3-4 and the phrenic nerve transfer for neurotization of C5-6 can innervate the avulsed brachial plexus upper trunk and promote the recovery of nerve function in the upper extremity.     

肌萎缩侧索硬化患者膈神经传导的电生理分析

目的 通过分析肌萎缩侧索硬化(Amyotrophic Lateral Sclerosis,ALS)患者膈神经传导检测,并结合其它神经电生理资料,为该病提供更深入的认识,进一步指导临床诊疗。方法 研究范围为武汉大学人民医院2014年1月-2021年12月就诊的ALS患者共88例,收集患者的一般资料、主要症状及体征、肌萎缩侧索硬化改良量表(ALSFRS-R)评分、运动神经传导检测中的复合肌肉动作电位(CMAP)波幅和远端运动潜伏期(DML)等指标。结果(1)运动神经传导检测中CMAP波幅降低192条(43.6%),膈神经波幅异常率为35.2%; 远端潜伏期延长116条(26.4%),膈神经DML异常率为77.3%;(2)膈神经DML在性别方面存在明显差异(P<0.01);(3)ALSFRS-R评分与膈神经、尺神经、正中神经、腓总神经、胫神经的CMAP波幅呈正相关(r=0.393,P<0.01; r=0.375,P<0.01; r=0.413,P<0.01; r=0.251,P<0.05; r=0.442,P<0.01);(4)膈神经DML及CMAP波幅在起病部位方面存在明显差异(P<0.05; P<0.05);(5)膈神经DML在判断病情中度和轻度之间的最佳界点为9.095 ms,敏感性为85.7%,特异性为80.2%。结论 ALS患者的运动神经传导可表现异常,CMAP波幅下降占比较大,但膈神经中潜伏期延长比CMAP波幅降低更多见。膈神经传导检测存在一定程度的性别差异。行运动神经传导检测时多条神经CMAP波幅变化可反映ALS患者病情严重程度。膈神经潜伏期变化可更敏感地反映ALS的病情严重程度,以期指导临床诊断与治疗。     

Respiratory weakness in neuralgic amyotrophy: report of two cases with phrenic nerve involvement

An isolated affection of the phrenic nerve is a rare feature in patients with neuralgic amyotrophy. We report 1 case each of bilateral and unilateral phrenic neuropathy. The first patient presented a sudden onset of severe respiratory failure without pain. The second patient developed intense pain in the neck and in the right shoulder followed by dyspnea on mild effort and orthopnea. Chest X-rays showed elevation of the diaphragm. Needle electromyography revealed denervation restricted to the diaphragm. The phrenic nerve conduction was within the normal range. The diagnosis of neuralgic amyotrophy may be particularly difficult when the palsy of the phrenic nerve appears without brachial plexus involvement or the typical shoulder pain of acute onset. In our patients, electrophysiological evaluation combined with radiographic studies, ventilatory parameters and biochemical analyses were helpful in establishing the diagnosis. Received: 18 March 2000 / Accepted in revised form: 26 May 2000     

Abnormalities of proximal conduction in acute idiopathic polyneuritis: comparison of short latency evoked potentials and F-waves.

Motor and sensory conduction studies, F-wave latency, and the latency of evoked potentials from the brachial plexus and cervical spine in response to median nerve stimulation were examined in 17 patients with acute idiopathic polyneuropathy. Short latency evoked potentials provided a higher yield of evidence of abnormalities of proximal conduction than did the F-wave latency. Both methods of studying conduction in the proximal segments of a peripheral nerve may be normal, however, in a small number of patients who have significant pathological lesions.     

Phrenic nerve conduction in the early stage of Guillain-Barre syndrome might predict the respiratory failure

OBJECTIVE: To investigate whether phrenic nerve conduction in the early phase of Guillain- Barre syndrome (GBS) predicts the need for respiratory assistance during the subsequent clinical course. MATERIAL AND METHODS: We performed electrophysiological examinations of conventional peripheral nerve conduction and phrenic nerve conduction for GBS patients within 14 days from the onset. We excluded patients who had already been treated with immuno-related therapy and respiratory assistance. RESULTS: Fifteen patients were enrolled. Three patients with the sum of phrenic nerve latency longer than 30 ms and the sum of bilateral diaphragmatic compound muscle action potential amplitude smaller than 0.3 mV required respiratory assistance after the conduction test. CONCLUSION: Our findings showed that not only delayed distal latency but also decreased amplitude may predict the need for respiratory assistance during the subsequent disease course.     

Analysis of reflex activity in cardiac sympathetic nerve induced by myelinated phrenic nerve afferents

Electrical stimulation of the phrenic nerve afferents evoked excitatory responses in the right inferior cardiac sympathetic nerve in chloralose-anaesthetized cats. The reflex was recorded in intact and spinal cats. The latency and threshold of the volley recorded from the phrenic nerve as well as of the cord dorsum potentials evoked by electrical stimulation of the phrenic nerve indicated that group III afferents were responsible for this reflex. The phrenicocardiac sympathetic reflex recorded in intact cats was followed by a silent period. The maximum amplitude of the reflex discharges was 800 microV, the latency was 83 ms and the central transmission time 53 ms. Duration of the silent period lasted up to 0.83 s. In spinal cats the reflex was recorded 5.5-8 h after spinalization. The maximum amplitude of the spinal reflex discharges ranged from 22 to 91 microV and the latency from 36 to 66 ms.     

Aging of phrenic nerve conduction in the elderly.

OBJECTIVE: We elucidated the possible relationship between age and conduction parameters of phrenic nerve in subjects above the sixth decade, comparing with the data from middle-age controls. METHODS: Diaphragmatic action potentials (DAPs) were recorded on bilateral hemithoraces of 41 volunteers aged 60-101 years (old group) and 25 volunteers aged 35-55 years (middle-age group). Statistical analyses were performed to assess the effects of aging on latency, latency corrected by size (Lat/Dist), amplitude, and the right-left difference of these DAP parameters. RESULTS: In all 61 subjects, age showed a significant quadratic correlation with latency and with Lat/Dist, and a linear correlation with amplitude. The right-left differences ranged from 0.0 to 14.5% for latency and from 6.5 to 112.4% for amplitude in the elderly. CONCLUSIONS: The normal ranges of DAP parameters should be determined according to age. The left-right difference may be a useful reference in diagnosing unilateral phrenic nerve lesion. SIGNIFICANCE: The precise normal ranges of phrenic nerve conduction parameters presented will encourage investigations of neuropathies in subjects aged above 60.     

Respiratory electrophysiological studies in Guillain-Barré syndrome.

Respiratory failure is a common and potentially life threatening complication in patients with Guillain-Barré syndrome. The incidence of phrenic nerve involvement and the predictive value of phrenic nerve conduction and diaphragmatic needle EMG were studied in 40 patients with Guillain-Barré syndrome within the first three days of admission to hospital. The negative peak onset latency of the diaphragmatic compound muscle action potential (CMAP), and its amplitude, duration, and area were abnormal in 83%. The need for ventilation was correlated with diaphragmatic CMAP amplitude (P = 0.005), and area (P = 0.001), but not with latency or duration. Abnormalities in diaphragmatic needle EMG were found in 45%, mainly a decreased number of motor unit potentials. The abnormalities correlated with the need for ventilation (P = 0.013). Of the 40% who required ventilation, all had either abnormal phrenic conduction, abnormal diaphragmatic needle EMG, or both. Eighty one per cent of the ventilated patients had abnormal forced vital capacity on the day of the electrophysiological examination. The results indicate that phrenic nerve conduction studies and diaphragmatic EMG are useful in detecting respiratory involvement in patients with Guillain-Barré syndrome and in identifying those at risk of respiratory failure.     

Conduction along the articular branch of the suprascapular nerve

The maximum sensory conduction velocity was measured along the articular branch of the suprascapular nerve. The potential was evoked by stimulating in the perception area of the nerve above the glenohumeral joint and recorded by an electrode near the suprascapular nerve in the supraclavicular fossa. The maximum conduction velocity averaged 42 m/s, SD 4.6 m/s (20 normal subjects); it decreased slightly with age. When correcting for the error in distance arising from the measurement by obstetric calipers (20%), the maximum conduction velocity averaged 50 m/s. The peak-to-peak amplitude of the main component of the sensory potential was 0.8 muV, SD 0.5 muV. In one of seven patients with a pain syndrome in the shoulder secondary to a brachial plexus neuropathy the velocity and the amplitude of the sensory potential was diminished. In five other patients with pain in the region of the shoulder the conduction velocity was normal but the amplitude was diminished.     

A comprehensive electrophysiological evaluation of phrenic nerve injury related to open-heart surgery

A prospective electrophysiological study of phrenic nerve was performed in 59 subjects undergoing open-heart surgery. The nerve was stimulated percutaneously at the neck and the diaphragmatic response was recorded with surface electrodes placed over the 8th intercostal space. The latency, amplitude, duration and area of the evoked response were measured before and after the operation. Post-operatively no response was elicited in 2 patients bilaterally, in 5 from the left and in 2 from the right. Comparison of the post-operative with the pre-operative group values in the remaining subjects showed that the amplitude and area of the left phrenic were lower in the post-operative study, indicating that some of the nerve fibres were not conducting. There were no statistically significant differences between pre and post-operative values of latency or duration on the left or any of the parameters on the right. Our findings suggest that the amplitude and area of the diaphragmatic response are more sensitive than latency in detecting phrenic nerve paresis associated with open-heart surgery.     

Nerve transfer helps repair brachial plexus injury by increasing cerebral cortical plasticity

In the treatment of brachial plexus injury, nerves that are functionally less important are transferred onto the distal ends of damaged crucial nerves to help recover neuromuscular function in the target region. For example, intercostal nerves are transferred onto axillary nerves, and accessory nerves are transferred onto suprascapular nerves, the phrenic nerve is transferred onto the musculocutaneous nerves, and the contralateral C7 nerve is transferred onto the median or radial nerves. Nerve transfer has become a major method for reconstructing the brachial plexus after avulsion injury. Many experiments have shown that nerve transfers for treatment of brachial plexus injury can help reconstruct cerebral cortical function and increase cortical plasticity. In this review article, we summarize the recent progress in the use of diverse nerve transfer methods for the repair of brachial plexus injury, and we discuss the impact of nerve transfer on cerebral cortical plasticity after brachial plexus injury.     

Reliability of phrenic nerve conduction study: In healthy controls and in patients with primary lateral sclerosis

ObjectivePhrenic nerve conduction study is a marker of hypoventilation in amyotrophic lateral sclerosis. We aimed to evaluate its intra-rater reliability in healthy subjects and in a cohort of Primary Lateral Sclerosis (PLS) patients.MethodsEighteen healthy subjects and 16 PLS patients were included. All subjects underwent three phrenic nerve conduction evaluations (time interval: 1 week for healthy controls; 1 year for PLS patients). We analyzed intra-rater reliability for five parameters of the diaphragmatic motor response: latency; negative-peak duration, area and amplitude; peak-to-peak amplitude.ResultsHealthy subjects showed excellent inter-test reliability for most parameters (coefficients of variation <10%). In PLS patients coefficients of variation resulted <10% for latency and peak-to-peak amplitude, <20% for remaining parameters. Inter-test reliability was excellent for latency and peak-to-peak amplitude [intra-class correlation coefficient (ICC) > 0.9] and good for negative-peak amplitude and area (ICC 0.75 ≥ 0.9); duration was not reliable (ICC = 0.383). Negative peak and peak-to-peak amplitude had the least random error (respectively ±0.136 mV and ± 0.177 mV). All parameters showed homoscedasticity (R2 < 0.1).ConclusionsIntra-rater reliability is high for phrenic nerve study, especially for latency, peak-to-peak and negative-peak amplitude.SignificancePhrenic nerve conduction study is a reliable method to monitor respiratory function.     

Full-length phrenic nerve transfer as the treatment for brachial plexus avulsion injury to restore wrist and finger extension

Introduction: The functional restoration of wrist and finger extension after complete brachial plexus avulsion injury remains an unsolved problem. We conducted a prospective study to elucidate a new method for resolving this injury. Methods: Six patients with complete brachial plexus avulsion injury underwent a new surgical procedure in which the full‐length phrenic nerve was transferred to the medial portion of the radial nerve at the level of the latissimus dorsi insertion via endoscopic thoracic surgery. Results: In 5 patients, extensor carpi ulnaris and extensor carpi radialis strength recovered to Medical Research Council grade ≥M3, and in 4 patients extensor digitorum strength recovered to ≥M3. Conclusions: Neurotization of phrenic nerve to the medial portion of the radial nerve at the level of latissimus dorsi insertion is a feasible means of restoring wrist and finger extension in cases of complete brachial plexus avulsion injury. Muscle Nerve 45: 39–42, 2012     

Retrograde effects of digital nerve severance on somatosensory evoked potentials in man

To determine if retrograde conduction changes might occur long after injury of the most distal peripheral nerves, short-latency somatosensory evoked potentials (SEPs) to median or ulnar nerve stimulation at the wrist were studied in 10 subjects who had sustained traumatic digit amputation 4 months to 15 years previously. SEPs were recorded from Erb's point (N9), the cervical region (N13), and the contralateral scalp hand area (N20). While N9 latency was slightly delayed or not affected, the amplitude was either markedly reduced or undetectable. For N13 and N20 components, latency prolongation and amplitude reduction were mild to moderate, but the central conduction time (N13–N20) remained normal. The present data indicate that even the most distal nerve injury may have profound long-term retrograde effects on parental nerve function which are presumed mainly due to an axonopathy. © 1994 John Wiley & Sons, Inc.     

A comparison of magnetic and electrical stimulation of peripheral nerves

We compared magnetic stimulation using different coil designs (2 rounded coils and a butterfly-prototype coil) with electrical stimulation of the median and ulnar nerves in 5 normal subjects. Using magnetic stimulation we were able to record technically satisfactory maximal sensory and motor responses only with the butterfly coil. Submaximal electrical stimuli preferentially activated sensory rather than motor axons, but submaximal magnetic stimuli did not. The onset latency, amplitude, area and duration of responses elicited electrically or magnetically with the butterfly coil during routine sensory and motor nerve conduction studies were similar, and motor and sensory conduction velocities were comparable when studied over long segments of nerve. However, the motor conduction velocities with magnetic and electrical stimulation differed by as much as 18 m/sec in the across-elbow segment of ulnar nerve. Thus, recent developments in magnetic stimulator design have improved the focality of the stimulus, but the present butterfly coil design cannot replace electrical stimulation for the detection of focal changes in nerve conduction velocity at common entrapment sites, such as in the across-elbow segment of the ulnar nerve.