Traumatic Brachial Plexus Lesions Research Articles

The impact of SARS-Covid-19 pandemic on peripheral nerve surgery – A single centre report

ObjectiveSARS-Cov-19 pandemic totally changed daily routine work in German hospitals. As hospital capacity was reduced, many surgeries were postponed or even cancelled. On March 25th 2020 the German Society of Neurosurgery (DGNC) published a statement in which urgent non-elective surgeries were defined for each neurosurgical domain, whereas elective interventions were deferred. The present work examines the impact of these Covid strategies focusing on patients with peripheral lesions who were conducted to our department during this period of time. MethodsAll patients who underwent any peripheral nerve surgery at our department from January 2018 until December 2022, were included. The complete range of surgeries including peripheral nerve lesions was examined encompassing compression syndromes, traumatic lesions of brachial plexus, traumatic lesions and tumors of single peripheral nerves. The numbers of surgical procedures were compared before, during and after pandemic. Pearson correlation coefficient was analysed. ResultsFrom 2018 to 2022 the total number of surgical procedures involving peripheral nerves included 2422 procedures. Compression syndromes made up the largest proportion (1433 operations, 59%), followed by peripheral nerve lesions (445 operations, 18%), peripheral nerve tumors (344 operations, 14%) and lesions of the brachial plexus (142 operations, 6%). The average was 40,5 interventions per month, the range was 7–63. Two declines in the number of peripheral nerve surgeries were noted during this period. The first was in April and May 2020 with an average drop of 65% and 41% respectively. In these months the average number of operations was 37. The second decrease was from October 2021 until January 2022, where number of surgeries was reduced by 16%, 36%, 83% and 18% with an average number of 50 operations. Both declines showed a significant and strong correlation with the lower number of compression syndrome treatments (r = 0.952, p < 0.001 and r = 0.968, p < 0.001), while no drop and no significant correlation was found in the treatment of traumatic peripheral nerve injuries (p = 0.769, r = 0.095 and p = 0.243, r = 0.366) and traumatic brachial plexus injuries (p = 0.787, r = 0.088 and p = 0.780, r = 0.09). A weak significant correlation was seen in the treatment numbers of peripheral nerve tumors (p = 0.017, r = 0.672 and p = 0.015, r = 0.67). ConclusionCovid-19 pandemic lead to a significant decrease in the number of nerve decompressions, since, according to the German Society of Neurosurgery, those were considered as elective surgeries.

Clinic-Electrophysiologic Correlations in Rehabilitation of Adult Patients with Traumatic Brachial Plexus Lesions

Nerve-transfer surgery is the treatment of choice for traumatic brachial plexus injuries (tBPIs). Combined electromyography (EMG) follow-ups and results obtained by transcranial magnetic stimulation (TMS) may provide useful follow-up of rehabilitation outcomes of elbow flexion in C5-C7 tBPIs. A total of 11 patients with complex tBPIs, operated by the Oberlin surgical technique, were assessed clinically (British Medical Research Council’s score—MRC) and by EMG + TMS after undergoing neuromuscular electrical stimulation and proprioceptive neuromuscular facilitation. Dynamometer quantitative muscle strength (DQMS) was also assessed for overall grip strength evaluation. Six patients continued rehabilitation three times a week, whereas five patients did not follow recommendations for continuous physical therapy (PT). All patients were assessed after 6 months as planned. Following a 6-month PT protocol, clinical improvements correlated with decreases of the Motor Evoked Potential (MEP) latency recorded at the first dorsal interosseous muscle, biceps brachii, and cortical level in the sublot group with continuous PT protocol compliance. We obtained significant amelioration of MEP latency and needle EMG signs of amelioration in these six patients. These cases also correlated to the MRC improvement in elbow flexion, as well as DQMS parameters. TMS parameters also mildly and inconstantly improved in the other five patients who limited themselves just to PT after surgery; however, there was no correlation with the EMG findings or MRC scaling. PT influences the cortical representation within the motor area of the upper limb when performed continuously. The electrical signals within the motor cortex promote the utility adherence to long-term PT protocols.

C5/C6 brachial plexus palsy reconstruction using nerve surgery: long-term functional outcomes

IntroductionIn traumatic proximal brachial plexus lesions (i.e., C5/C6), reconstruction of the musculocutaneous, axillary and suprascapular nerves yields satisfactory short- and medium-term functional outcomes. HypothesisEarly functional outcomes after nerve surgery will be maintained in the long-term. MethodsA retrospective analysis was done using the medical records of 29 patients with C5/C6 palsy treated by nerve surgery. Active range of motion and strength at the elbow (i.e., flexion) and shoulder (i.e., flexion, abduction, external rotation with the elbow at the side of the body and with the arm 90° abducted ) were evaluated clinically using a goniometre and the British Medical Research Council grading scale, respectively. ResultsAt a mean follow-up of 46±15 months (25;76), the mean active elbow flexion was 126°±18° (90;150) and the mean strength was 3.8±0.5 (2;4). At the shoulder, mean active flexion, abduction, external rotation with the elbow at the side of the body and with the arm 90° abducted were 109°±39° (0;180), 99°±38° (0;180°), 12°±34° (−80;70) and 3°±21° (−40;50), while mean strength was 3.6±0.8 (0;4), 3.6±0.8 (0;4), 3.4±0.9 (0;4) and 2.5±1.2 (0;4), respectively. DiscussionIn cases of C5/C6 palsy, early nerve surgery yields satisfactory functional outcomes that are maintained over time for elbow flexion and shoulder elevation. However, when the teres minor is not reinnervated, it is difficult to restore satisfactory shoulder external rotation. Level of evidenceIV, Retrospective case study.

Effects of a robotic rehabilitation treatment in a patient with traumatic lesion of the right brachial plexus measured by means of motion analysis: A case stud

Effects of a robotic rehabilitation treatment in a patient with traumatic lesion of the right brachial plexus measured by means of motion analysis: A case stud

Quantitative MR neurography of brachial plexus lesions based on diffusivity measurements

ObjectivesNew magnetic resonance imaging (MRI) based on 3D fat-suppressed techniques provide high accuracy for evaluation of brachial plexus and peripheral nerve lesions from a qualitative point of view. However, this qualitative evaluation often demonstrates overlapping features among different pathologies (Pullman et al., 2013). Diffusion weighted imaging (DWI) and diffusion tensor imaging (DTI) are functional MRI techniques that have been successfully applied in the imaging of central nervous system lesions, and now are being imported, with promising results for peripheral nerve and plexus evaluation. Several derived parameters from DWI and DTI studies such as apparent diffusion coefficient (ADC) or fractional anisotropy (FA), can be used as potential biomarkers of neural damage by providing information about axonal flow, fiber organization or myelin integrity (Andreou et al., 2015). In this study we assess the role of DW and DT based quantitative measures in characterization of traumatic and non traumatic lesions of brachial plexus and peripheral nerve and its influence on therapeutic management and outcome. Methods34 patients with features ofbrachialplexopathy and peripheral neuropathy were included in the study. MR neurography examinations included conventional MR sequences and unidirectional DW-MRN with background suppression (DWIBS) and DTI. The images were independently reviewed by two radiologists and the findings were recorded at different levels of thebrachial plexus: ganglia, roots, trunks, divisions and cords. Mean ADC and FA values were determined within each lesion and within contra lateral homologous unaffected segment of the plexus. The Mann-Whitney Test was used to calculate the differences in ADC&FA values between diseased and normal sides and the One way ANOVA test between diseased segments of different pathologies with p-values <0.05 being considered statistically significant. Resultspatients were classified according to etiologic causes into four categories: traumatic, compressive degenerative disk, radiation induced plexitis and neoplastic nerve compression or invasion. T2 high signal intensity and swelling of the affected nerve, muscular denervation and complication such as pseudo meningeocele and neuroma were the major findings in qualitatitve sequences. A statistically significant difference in ADC and FA values were found between diseased and normal sides as well as across the traumatic and non traumatic groups and between benign compressive and malignant infiltrative etiologies. ConclusionThe resulted values of newly designed quantitative protocols give us functional and numerical marker by which the diagnosis and differentiation of different pathologies of peripheral nerves and brachial plexus will be more suitable.

Late Nerve Repairs in Brachial Plexus Lesions

Objectives: It is a common opinion that surgical repair of brachial plexus later than 1 year from the lesion cannot lead to real functional results. This is probably true for repair by means of multiple grafts which need specially in root’s lesions a long time for reinnervation: This fact and the frequent delay in repair reduce in a substantial way the possibility to obtain good results in brachial plexus surgery. The continuous development of nerve transfers allowed shortening the time of recovery by means of very distal repairs, near to the mainly motor targets. The shortening of recovery time gives today the possibility to move forward the classical limits for nerve repair. Materials and Methods: The authors present the results obtained in 93 nerve transfers in 52 patients who underwent nerve repair after more than 1 year from the lesion. The series consists of 22 children with obstetric brachial plexus palsy and 30 adults with traumatic brachial plexus lesions all of them repaired after 1 year from the lesion with a maximum delay of 7 years. The nerve repaired by means of late transfers had been the suprascapular, the musculocutaneous, and the axillary. In all the cases, a previous electromyography detected the presence of fibrillation in the muscles that are planned to be reinnervated. Fibrillation is actually considered as a prerequisite to indicate a late nerve transfer. Results: Evaluation of results has been separate between children and adult patients. In adult patients, the results for biceps have been 30% of failures, 42% of partial results (M2/M3−), and 28% of good results (M3+/M4). The results for suprascapular have been 23% of failures, 45% of partial results, and 32% of good results. In children, the results for biceps have been 15% of failures and 85% of good results (&lt;M3+). The results for suprascapular have been 25% of failures, 25% of partial results, and 50% of good results. No result can be reported for deltoid due to the too reduced number of operated cases. Conclusions: Nerve transfers allow in a considerable number of cases to obtain functional results, in some case even after several years of delay. A part for late observed cases we can offer in this way a second option in cases of lack of recovery from primary surgery. Actually nerve transfer is nowadays a new possibility placed in between primary microsurgical repair and classic palliative surgery. Undoubtedly better results have been obtained in children, but surprisingly useful results could be obtained in adults even if in a more reduced percentage of cases.

Diagnosis of closed injury and neoplasm of the brachial plexus by ultrasonography

To evaluate the feasibility and accuracy of high-frequency sonography (US) in diagnosing traumatic brachial plexus (BP) lesions and neoplasms in the adult. Eleven patients with suspected BP closed trauma, 6 patients with BP neoplasm, and 12 healthy volunteers were scanned. The US findings were compared with surgical findings. The interscalene space and intervertebral foramina were useful anatomic markers in identifying the BP. In the 24 sites examined in the normal group (12 subjects examined on both sides), the fifth to seventh cervical nerve roots (C5-7, including upper and middle trunk) were seen, whereas the eighth cervical and first thoracic nerve roots (C8, T1, including the lower trunk) were seen in 91.7% (22/24) of the subjects. The BP appeared as three or four discrete rounded hypoechoic nodules between the anterior scalene and middle scalene muscle in transverse views at the C5-7 level, representing the trunks in the sagittal oblique section. In the BP trauma group (n = 11), the normal nerve trunk was interrupted, and lesions were shown as thickening and swelling with indistinct inner structures. In the neoplasm group (n = 6), masses were shown as hypoechoic masses. High-frequency US is valuable in diagnosing BP closed injuries and neoplasms.

The epidemiology of adult traumatic brachial plexus lesions in a large metropolis

Adult traumatic brachial plexus lesions are devastating injuries. Their real incidence is difficult to ascertain, but are certainly growing due to the increasing number of high-speed motor-vehicle accidents, especially in big cities. Analysis of the epidemiological characteristics of patients with traumatic brachial plexus lesions in São Paulo, Brazil, the sixth largest city in the world. This was a retrospective analysis of the epidemiological characteristics of patients submitted to surgical treatment of traumatic brachial plexus lesions in the Peripheral Nerve Surgery Unit of the Department of Neurosurgery of the University of São Paulo Medical School. In the period from 2004 to 2012, 406 patients underwent surgery. There were 384 (94.6%) men and 22 (5.4%) women. In 45.9% the compromised plexus was the right and in 54.1%, the left. The average age was 28.38years. Among the causes, the most frequent was motorcycle accidents (79%). Most of the lesions were supraclavicular. In 46.1% of cases the lesions were complete, in 30.1% the lesions compromised C5/C6 roots, in 20.9% the C5/C6/C7 roots were lesioned and in 2.9% the lesion was in the lower roots, C8/T1. Among the associated lesions the most prevalent were head trauma, observed in 34.2% of the cases; lesions of long bones in 38.8%; clavicle fractures in 25.9%; and thoracic trauma in 12.9%. In a population of adult patients with brachial plexus lesions with surgical indication, most of them comprise young male adults involved in high-energy motorcycle accidents.

Schraubenarthrodese der Schulter

The aim of the procedure is arthrodesis of the shoulder by osteosynthesis of the glenohumeral and the acromiohumeral joint each with three screws, which results in preservation of scapulothoracic motion and pain relief. Traumatic brachial plexus lesions, palsy in infancy, poliomyelitis with preserved or restorable function of the elbow and the hand. Paralysis of the deltoid muscle and the rotator cuff. Nonrestorable vast defect of the rotator cuff with pseudoparalysis. Chronic infectious arthritis resistant to therapy. Unsuccessful attempts to treat glenohumeral instability. Alternative procedure to shoulder arthroplasty in young patients with omarthrosis, who perform hard physical work. Insufficient strength of the scapular muscles (< grade4, <75% of normal strength). Insufficient scapulothoracic passive motion. Inadequate soft tissue coverage after burns, excessive previous surgery or radiotherapy. Incomplete rehabilitation (<3years) after neurosurgical interventions (neurolysis, nerve transplantation). Cases of resection of the proximal humerus. Acampsia of the shoulder joint in 20° of abduction, 30° of anteversion, and 40° of internal rotation using three glenohumeral and three acromiohumeral spongiosa screws as a compression arthrodesis. Thorax-arm-abduction splint (20° of abduction, 30° of anteversion, and 40° of internal rotation) until the week6 postoperatively with removal for physiotherapy and personal hygiene. Assisted active and passive motion exercises for the elbow, hand, and fingers after the postoperative day1. Weaning from the splint after the end of the week6 postoperatively, full range of motion allowed. In a prospective study from January 2007 to September 2008, 4patients with a medium age of 35.7years underwent screw arthrodesis of the shoulder with a follow-up of 1.0 (0.6-1.5)year. Primary fusion of all arthrodesis surfaces was achieved in all patients; no revision surgery was necessary. All patients improved in shoulder function with an average range of motion of 60° abduction and 40° anteversion.

Differential Diagnosis between Pre- and Postganglionic Adult Traumatic Brachial Plexus Lesions by Ultrasonography

The goal of this study was to prospectively investigate the feasibility of preoperative ultrasonography evaluation in the differentiation between pre- and postganglionic traumatic brachial plexus lesions. Two expert radiologists employed ultrasonography to observe the morphology of the brachial plexus in 23 patients with suspected traumatic brachial plexus lesions and 40 healthy volunteers. The detection rate was 100% (126/126) for the C5 through C7 nerve roots and upper and middle trunks and three fascicles, 84% (106/126) for the C8 roots and the lower trunks and 64% (81/126) for T1 roots in all subjects. Surgical inspections found 58 lesions in 23 patients (40 preganglionic lesions and 18 postganglionic lesions). Ultrasonography detected most of the brachial plexus lesions (56/58) but misjudged two preganglionic and two postganglionic lesions. The rate of differentiation was 93% (52/56). This study demonstrated that ultrasonography is a useful but experience-dependent supplemental imaging technique for preoperative diagnosis of brachial plexus lesions and differentiation between pre- and postganglionic brachial plexus lesions.

Nerve transfers in brachial plexus palsies

It has been many years now since the introduction of nerve transfers for repair of traumatic brachial plexus lesions and more recently, we have seen its application in the field of obstetric brachial plexus palsy. These nerve transfers do not represent an alternative to anatomical repair by means of nerve grafting, but represent an additional possibility to increase the reconstructive options and improve the final results. This pushes the surgeon to decide: which function is to be restored by nerve grafting, which one by nerve transfer? What is the more reliable procedure? Does the age of the patient, the delay after the accident, or the type of accident influence this choice? If we add in the possibilities of palliative treatment, one can state that many therapeutic options are available today for brachial plexus reconstruction, and that no real consensus does exist. But some tendencies, some trends are apparent.

TRAUMATIC LESIONS OF THE BRACHIAL PLEXUS

To analyze retrospectively the outcomes of primary as well as secondary functional reconstructions in 49 patients with traumatic brachial plexus lesions from a single service. Guidelines for treatment might be extracted from this analysis. Among 152 cases of traumatic lesion of the brachial plexus presented to our clinic, 58 underwent primary brachial plexus reconstructive surgery. On exploration, all patients showed stretching and scarring of plexus elements; root avulsions were found in 28 patients (48%). Outcome evaluation was carried out in 49 of these patients with a follow-up period of 1 year or longer (mean follow-up, 27.9 mo; range, 12-72 mo). A total of 43 secondary reconstructive procedures to improve functionality of the involved arm were performed at a later stage in 25 of 58 patients. Outcomes of the secondary functional restorative procedures were evaluated (mean follow-up, 11.5 mo; range, 3-60 mo in 43 procedures). Patients with neurolysis as a stand-alone procedure (11 patients) showed an outcome grade of 4 or 5. The average outcome of the 19 patients with C5, C6, and C7 grafting was Grade 3, the same as in patients with nerve transfers to the upper plexus elements (C5-C6 root avulsions, 13 patients). Patients with multiple root avulsions (five cases) showed an overall poor outcome (Grades 0-2). Secondary functional restorative surgery was performed in 43% of the patients and helped improve individual outcomes, providing a favorable effect on the general functionality of the arm. Among the restorative operations performed, the Steindler procedure, wrist extension restoration, claw hand correction, and free functional muscle flap transfer to the arm and forearm were the most rewarding. A combination of primary brachial plexus reconstruction and carefully evaluated, selected, and planned function-restorative secondary procedures might offer favorable outcomes in patients with partial or total brachial plexus lesions.

Treatment of deafferentation pain by high-frequency intervention on the dorsal root entry zone

From August 1980 to May 1981, high-frequency lesions of the dorsal root entry zone of the spinal cord were performed on 35 patients with chronic deafferentiation pains. Among them were 15 patients with traumatic transverse cord lesions, 5 with non-traumatic transverse lesions and 7 with cervical root tears or traumatic brachial plexus lesions, 6 with stump or phantom pain after amputation, and 1 each with sciatic paralysis or spinal arachnopathy. Treatment results were best in complete transverse lesions, cervical root avulsion and brachial plexus lesion, less so for stump or phantom pain of the lower extremities. It failed in patients with sciatic-nerve lesion and arachnopathy. Thus best results are to be expected if the method is limited to genuine deafferentiation pain.

High-resolution ultrasound of the supraclavicular brachial plexus—can it improve therapeutic decisions in patients with plexus trauma?

Patients with major traumatic brachial plexus lesions benefit from early surgery, but they are seldom isolated by today's diagnostic workup. Subjects with ambiguous findings after such workups usually undergo a trial of conservative treatment and those without improvement delayed surgery. Our study focuses on this problem. Hence, the purpose of this study was to evaluate the impact of high-resolution ultrasound (HR-US) on patient recruitment for non-delayed surgery. Twelve patients after blunt shoulder trauma and standardized HR-US assessment who underwent plexus surgery were included in this prospective observational study. Thereby, a total of 168 plexus elements were evaluated. All findings were compared to electrophysiological data if available and tested statistically against the gold-standard, i.e., surgical validation. Major plexus lesions were correctly detected by HR-US in nine patients (20 plexus elements). In two patients (five plexus elements), the lesion was underestimated by HR-US in relation to the gold standard (surgical inspection). Our analysis showed a high positive (1.0) and an acceptable negative predictive value (0.92) for the grading of traumatic plexus lesions with HR-US. Based on HR-US findings alone, 9 of 11 patients with objective major lesions would have undergone early surgery. In conclusion, HR-US proved a valuable tool for the triage of patients with traumatic lesions into surgical and non-surgical candidates.

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.

The brachial plexus lesion. Management, consequences of palsy and reconstructive operations

The treatment of traumatic brachial plexus lesions follows sequential steps. After acute therapy (phase I), neurological diagnostics (phase II), neurosurgery and postoperative treatment (phase III/IV), reconstructive operations (phase V) can be indicated and performed. In most cases an insufficient grade of muscle power remains. Within 6 months after injury, neurosurgery must be performed in patients with brachial plexus palsy. After malfunction of the muscles, taking into account the individual neuromuscular defects, passive joint function and bony deformities, different procedures such as muscle transposition, arthrodesis and corrective osteotomy can be performed to improve the function of the upper extremity. The treatment of patients suffering from brachial plexus lesion requires interdisciplinary teamwork.

Significance of sensory evoked potentials in determination of the level of brachial plexus injuries

The aim of this work is to show the highlights of electrophysiological diagnostics, i.e. its potentials in level diagnostics of traumatic disfunction of brachial plexus (BP). In that manner we have analyzed the results of electrophysiological research, made on 53 patients with different levels and grades of traumatic lesion of brachial plexus. We have also analyzed the authors' opinions and points of view who have contributed in solving these problems. Brachial plexus is a complex, vulnerable nerve structure that is often, in life, exposed to direct or indirect influence of mechanical force. Preserved integrity of bone structures of a shoulder protects BP from longitudinal forces, which are the most common causes of injury of this structure. Traction mechanism of the injury is always up to date in the cases of fractures and dislocation of the skeleton in this region. In the early childhood, mechanical injuries of brachial plexus are caused by distocia in the second delivery period, while in adulthood most common injuries are caused by sudden and intensive forces, which cause disfunction of plexus by traction mechanism (dislocation of a shoulder and clavicular fracture) and by direct action (stabing and piercing injuries). Slowly progressive, expansive, degenerative and inflammatory processes of neighbouring organs are causing the disfunction of the plexus as well. Traction actions are aimed mostly at radiculars as a vulnerable structure that is placed between relatively mobile shoulder joint and rigid cervical part of vertebral column. Complex anatomical structure and mutual overlapping of radicular motor and sensitive innervation of muscles and dermatoms, make the diagnostics of disfunction of this periphery nerve structure very difficult and complicated. Disfunction of neighboring bone, vascular and muscle elements as well as the nearness of vital organs, which complicates even more the diagnostics. Taking into account the general analysis of all electrophysiological results of the research on 53 patients with an PB injury, we have concluded that none of the functional methods is not sovereign, i.e. the contribution of this research is complementary also with roentgenological results. Clinical data are unavoidable, but they are not enough without good argumentation, especially for the level of lesion, pre- or postganglionary. Electromiography gives reliable results for the phase and the grade of denervation of particular muscle groups, and that way it is possible to conclude, indirectly, which part of the plexus is in disfunction. Special attention should be paid to EMG of paraspinal muscles, where the signs of denervation are aleays indicating intradural lesion of the radicular. In the examined group, 52% of the patients with radicular disfunction had the signs of denervation in paraspinal muscles. Examination of the sensitive action potentials is another method by which we can see the disfunction level of the plexus in an anesthetical region. In a group with preganglionary root disfunction, 48% of the patients had preserved sNAP response. In a group with postganglionary disfunction, 36% of the patients had no sNAP response. Somatosemsory evoked potentials are addition to EMG and ENG research and they are efficient in the primary phase, when electromyographic and electroneurographic examinations are not offering relevant data. Checking of the early diagnostics of the pre- and postganglionary lesions with somatosensory evoked potentials wasn't possible in this group because the first examinations of these patients in our laboratory were mostly made couple of months after the injury. Disfunction of the ratio amplitudes N9 and P/N13 in the group with preganglionary lesion was found in 31%, with postganglionary in 42.2% and with both in 10% of the patients.

Validation of an Electromyography and Nerve Conduction Study Protocol for the Analysis of Brachial Plexus Lesions in 184 Consecutive Patients With Traumatic Lesions

To validate a concentric needle electromyography (EMG) and nerve conduction study (NCS) protocol for the preoperative analysis of brachial plexus lesions.METHODS. 184 consecutive patients with traumatic brachial plexus lesions were analyzed. The results of the neurophysiological studies were compared with the final diagnoses based on the results of computed tomography-myelography and findings during the operation. The protocol proved reliable in the analysis of these lesions in 84% of cases. Limitations were that extraforaminal lesions may mask root avulsion or central lesions; paraspinal sampling is of limited value in multiple root lesions because of the overlap in innervation; and sometimes normal sensory nerve action potentials (SNAPs) could occur in an extra foraminal lesion. Lesions outside the plexus were found in 21% of the patients, most of which would not have been expected on clinical grounds. With this protocol, a reliable analysis of traumatic brachial plexus lesions can be made in 84% of the patients, even finding lesions outside the brachial plexus not expected on clinical grounds in 2l degrees of the patients.

Traumatic brachial plexus lesions in the adult: Indications and results

Several types of lesions in adults can be differentiated. The author discusses his experience with 810 operated cases from 1975 to 1994.

Muscle fiber conduction velocity in amyotrophic lateral sclerosis and traumatic lesions of the plexus brachialis

Muscle fiber conduction velocity (MFCV) in biceps brachii was studied in traumatic brachial plexus lesions (16 patients) and amyotrophic lateral sclerosis (ALS) (22 patients) by means of an invasive (I-MFCV) method. After complete denervation an exponential decrease of the mean I-MFCV was found, T 1 2 = 1.1 month. After 4–5 months this resulted in severely reduced conduction velocities (mean 1.4 m/sec, range from 0.5 to 2 m/sec). Simultaneous with signs of reinnervation, fibers with faster conduction velocities were seen. In ALS, a decrease of the mean I-MFCV was found, and slow conducting fibers were found in every patient on at least one side. At the same time muscle fibers with increased I-MFCVs were found. This increased range of velocities seems based on a combination of slow conducting, atrophic fibers, with fast conducting, hypertrophic fibers, compensating the force loss. In some subjects we found these disturbances without clear abnormalities with concentric needle EMG, and with unimpaired muscle force. The surface EMG measurements in the ALS patients revealed increased S-MFCV values in combination with a decrease of the median frequency (F med). We suggest that the opposite finding of an increased S-MFCV is a consequence of the muscle fiber hypertrophy in the surviving, voluntarily recruited, motor units. The simultaneous decrease of the F med seems to be caused mainly by the change in shape of the motor unit potential.