Thoracodorsal to long thoracic nerve transfer in a patient with traumatic injury: A case report.

Background: Traumatic injury to the long thoracic nerve causes paralysis of the serratus muscle, clinically expressed as winged scapula and functional impairment of the shoulder girdle. Treatment varies according to the severity of the injury, with a focus on early intervention for best results; however, the therapeutic approach remains a challenge at present. Case Description: We present the case of a 32-year-old male patient, athlete, right-handed, presented with bilateral paresis predominantly in the right arm, associated with paresthesia and changes in the coloring of the upper limbs. After being diagnosed with Thoracic Outlet Syndrome and undergoing surgery, vascular symptoms persisted with a significant loss of strength in the right shoulder. Winged scapula was observed and structural lesions were excluded on magnetic resonance imaging. Electromyographic studies confirmed the presumption of traumatic nerve involvement of the long thoracic nerve. Notwithstanding 6 months of physical therapy, there was no improvement, so a nerve transfer from the thoracodorsal nerve to the right long thoracic nerve was chosen. At 12 months, complete resolution of the winged scapula and functional recovery were observed. The patient also experienced a decrease in preoperative pain from 5/10 to 2/10 on the visual analog scale. Conclusion: Nerve transfer from the thoracodorsal nerve to the long thoracic nerve is a safe and effective technique to treat winged scapula due to long thoracic nerve injury.

Brain plasticity in neonatal brachial plexus palsies: quantification and comparison with adults' brachial plexus injuries.

PURPOSE: To compare two populations of brachial plexus palsies, one neonatal (NBPP) and the other traumatic (NNBPP) who underwent different nerve transfers, using the plasticity grading scale (PGS) for detecting differences in brain plasticity between both groups. METHODS: To be included, all patients had to have undergone a nerve transfer as the unique procedure to recover one lost function. The primary outcome was the PGS score. We also assessed patient compliance to rehabilitation using the rehabilitation quality scale (RQS). Statistical analysis of all variables was performed. A p ≤ 0.050 set as criterion for statistical significance. RESULTS: A total of 153 NNBPP patients and 35 NBPP babies (with 38 nerve transfers) met the inclusion criteria. The mean age at surgery of the NBPP group was 9 months (SD 5.42, range 4 to 23 months). The mean age of NNBPP patients was 22 years (SD 12 years, range 3 to 69). They were operated around sixth months after the trauma. All transfers performed in NBPP patients had a maximum PGS score of 4. This was not the case for the NNBPP population that reached a PGS score of 4 in approximately 20% of the cases. This difference was statistically significant (p < 0.001). The RQS was not significantly different between groups. CONCLUSION: We found that babies with NBPP have a significantly greater capacity for plastic rewiring than adults with NNBPP. The brain in the very young patient can process the changes induced by the peripheral nerve transfer better than in adults.

Brain plasticity and age after restoring elbow flexion with distal nerve transfers in neonatal brachial plexus palsy and nonneonatal traumatic brachial plexus injury using the plasticity grading scale.

OBJECTIVE: Ulnar and/or median nerve fascicle to musculocutaneous nerve (MCN) transfers are used to restore elbow flexion following severe neonatal and nonneonatal brachial plexus injuries (BPIs). Restoring volitional control requires plastic changes in the brain. To date, whether the potential for plasticity is influenced by a patient's age remains unknown. METHODS: Patients who had presented with a traumatic upper (C5-6 or C5-7) BPI were divided into two groups: neonatal brachial plexus palsies (NBPPs) and nonneonatal traumatic BPIs (NNBPIs). Both groups underwent ulnar or median nerve transfers to the MCN for elbow flexion restoration between January 2002 and July 2020. Only those who attained a British Medical Research Council strength rating of 4 were reviewed. The primary comparison between the two groups was the plasticity grading scale (PGS) score to determine the level of independence of elbow flexion (target) from forearm motor muscle movement (donors). The authors also assessed patient compliance with rehabilitation using a 4-point Rehabilitation Quality Scale. Bivariable and multivariable analyses were used to identify intergroup differences. RESULTS: In total, 66 patients were analyzed: 22 with NBPP (mean age at surgery 10 months) and 44 with NNBPI (age range at surgery 3-67 years, mean 30.2 years; mean time to surgery 7 months, p < 0.001). All NBPP patients obtained a PGS grade of 4 at the final follow-up versus just 47.7% of NNBPI patients (mean 3.27, p < 0.001). On ordinal regression analysis, after nature of the injury was excluded because of excessive collinearity with age, age was the only significant predictor of plasticity (ß = -0.063, p = 0.003). Median rehabilitation compliance scores were not statistically different between the two groups. CONCLUSIONS: The extent of plastic changes that occur for patients to regain volitional control over elbow flexion after upper arm distal nerve transfers following BPI is influenced by patient age, with complete plastic rewiring more likely in younger patients and virtually ubiquitous in infants. Older patients should be informed that elbow flexion after an ulnar or median nerve fascicle transfer to the MCN might require simultaneous wrist flexion.

Femoral intraneural ganglion cyst: the first confirmed case report.

BACKGROUND: Ganglion cysts affecting nerve are rare causes of neuropathy. The formation of intraneural ganglion cysts, once controversial, has recently been clarified. We describe the first modern description of a femoral intraneural ganglion cyst at the hip region. METHODS: A patient presented with a 1 year history of radiating pain, quadriceps weakness and anteromedial leg numbness was found to have a femoral intraneural cyst with a hip joint connection on MRI. RESULTS: Surgical disconnection of the articular branch led to improvement of the neuropathy and resolution of the cyst on postoperative MRI. CONCLUSIONS: The unifying articular (synovial) theory describes the joint origin of intraneural cysts, even when they occur in unusual locations, and their propagation into the parent nerve. Knowledge of this theory can improve outcomes; surgery needs to address the joint origin or capsulolabral defect lest recurrence ensue.

Nerve Graft Length and Recovery of Elbow Flexion Muscle Strength in Patients With Traumatic Brachial Plexus Injuries: Case Series.

BACKGROUND: Traumatic brachial plexus injuries cause long-term maiming of patients. The major target function to restore in complex brachial plexus injury is elbow flexion. OBJECTIVE: To retrospectively analyze the correlation between the length of the nerve graft and the strength of target muscle recovery in extraplexual and intraplexual nerve transfers. METHODS: A total of 51 patients with complete or near-complete brachial plexus injuries were treated with a combination of nerve reconstruction strategies. The phrenic nerve (PN) was used as axon donor in 40 patients and the spinal accessory nerve was used in 11 patients. The recipient nerves were the anterior division of the upper trunk (AD), the musculocutaneous nerve (MC), or the biceps branches of the MC (BBs). An index comparing the strength of elbow flexion between the affected and the healthy arms was correlated with the choice of target nerve recipient and the length of nerve grafts, among other parameters. The mean follow-up was 4 yr. RESULTS: Neither the choice of MC or BB as a recipient nor the length of the nerve graft showed a strong correlation with the strength of elbow flexion. The choice of very proximal recipient nerve (AD) led to axonal misrouting in 25% of the patients in whom no graft was employed. CONCLUSION: The length of the nerve graft is not a negative factor for obtaining good muscle recovery for elbow flexion when using PN or spinal accessory nerve as axon donors in traumatic brachial plexus injuries.

Differences in strength fatigue when using different donors in traumatic brachial plexus injuries.

BACKGROUND: The purpose of this study was to assess the results of elbow flexion strength fatigue, rather than the maximal power of strength, after brachial plexus re-innervation with phrenic and spinal accessory nerves. We designed a simple but specific test to study whether statistical differences were observed among those two donor nerves. METHOD: We retrospectively reviewed patients with severe brachial plexus palsy for which either phrenic nerve (PN) or spinal accessory nerve (SAN) to musculocutaneous nerve (MCN) transfer was performed. A dynamometer was used to determine the maximal contraction strength. One and two kilograms circular weights were utilized to measure isometrically the duration of submaximal and near-maximal contraction time. Statistical analysis was performed between the two groups. RESULTS: Twenty-eight patients were included: 21 with a PN transfer while 7 with a SAN transfer for elbow flexion. The mean time from trauma to surgery was 7.1 months for spinal accessory nerve versus 5.2 for phrenic nerve, and the mean follow-up was 57.7 and 38.6 months, respectively. Statistical analysis showed a quicker fatigue for the PN, such that patients with the SAN transfer could hold weights of 1 kg and 2 kg for a mean of 91.0 and 61.6 s, respectively, while patients with transfer of the phrenic nerve could hold 1 kg and 2 kg weights for just a mean of 41.7 and 19.6 s, respectively. Both differences were statistically significant (at p = 0.006 and 0.011, respectively). Upon correlation analysis, endurances at 1 kg and 2 kg were strongly correlated, with r = 0.85 (p < 0.001). CONCLUSIONS: Our results suggest that phrenic to musculocutaneous nerve transfer showed an increased muscular fatigue when compared with spinal accessory nerve to musculocutaneous transfer. Further studies designed to analyze this relation should be performed to increase our knowledge about strength endurance/fatigue and muscle re-innervation.

Comparison Between Supraclavicular Versus Video-Assisted Intrathoracic Phrenic Nerve Section for Transfer in Patients With Traumatic Brachial Plexus Injuries: Case Series.

BACKGROUND: The phrenic nerve has been extensively reported to be a very powerful source of transferable axons in brachial plexus injuries. The most used technique used is supraclavicular sectioning of this nerve. More recently, video-assisted thoracoscopic techniques have been reported as a good alternative, since harvesting a longer phrenic nerve avoids the need of an interposed graft. OBJECTIVE: To compare grafting vs phrenic nerve transfer via thoracoscopy with respect to mean elbow strength at final follow-up. METHODS: A retrospective analysis was conducted among patients who underwent phrenic nerve transfer for elbow flexion at 2 centers from 2008 to 2017. All data analysis was performed in order to determine statistical significance among the analyzed variables. RESULTS: A total of 32 patients underwent supraclavicular phrenic nerve transfer, while 28 underwent phrenic nerve transfer via video-assisted thoracoscopy. Demographic characteristics were similar in both groups. A statistically significant difference in elbow flexion strength recovery was observed, favoring the supraclavicular phrenic nerve section group against the intrathoracic group (P = .036). A moderate though nonsignificant difference was observed favoring the same group in mean elbow flexion strength. Also, statistical differences included patient age (P = .01) and earlier time from trauma to surgery (P = .069). CONCLUSION: Comparing supraclavicular sectioning of the nerve vs video-assisted, intrathoracic nerve sectioning to restore elbow flexion showed that the former yielded statistically better results than the latter, in terms of the percentage of patients who achieve at least level 3 MRC strength at final follow-up. Furthermore, larger scale prospective studies assessing the long-term effects of phrenic nerve transfers remain necessary.

¿Cómo entrenar para el uso del exoscopio? Utilización de un novedoso simulador de exoscopíade bajo costo por residentes de neurocirugía / How to train for the use of the exoscope? Use of a novel low-cost exoscopy simulator by neurosurgery residents

Introducción: Analizar el impacto del entrenamiento en una estación de simulación en exoscopía (ESA) de bajo costo, utilizado por un grupo de residentes de neurocirugía. Materiales y métodos: Se reclutaron 6 residentes de neurocirugía, todos ellos sin experiencia previa en exoscopía. Se desarrolló una estación de simulación en exoscopía compuesta por una computadora, una webcam y una fuente de luz. Todos los participantes realizaron un tutorial introductorio, un ejercicio inicial de 5 suturas (cada sutura fue clasificada en forma binaria como correcta e incorrecta), evaluando el tiempo necesario para completar dicho ejercicio y la eficacia (definida como la relación entre suturas correctas y el total). Posteriormente se realizaron 3 sesiones de entrenamiento semanal de 1 hora cada una y una evaluación final con las mismas características que la inicial. Ambas evaluaciones fueron estudiadas por un neurocirujano senior que realizó un análisis, así como la puntuación de cada ejercicio de los participantes. Resultados: El tiempo promedio de realización del ejercicio inicial fue de 31 minutos con 59 segundos, con una eficacia promedio del 70%. Luego del entrenamiento el promedio de tiempo fue 18 minutos y 12 segundos, con una eficacia del 80%. Conclusión: El entrenamiento en este simulador demostró una notable mejoría en los tiempos y la calidad de la técnica exoscópica si se compara el principio del entrenamiento con su final. Por los beneficios obtenidos y su bajo costo creemos que será útil su implementación para acercar dicha técnica a todos los neurocirujanos que se encuentren interesados en ella.

Introduction: To analyze the impact of training in a low-cost simulation station of exoscopy, used by residents of neurosurgery. Materials and methods: Six residents of neurosurgery were recruited, all of them having no previous experience in the use of the exoscope. An exoscopy simulation station, including a computer, a webcam and a light source, was developed. All the participants performed an introductory tutorial, an initial exercise of 5 sutures (each suture was classified as correct and incorrect), evaluating the time to complete this exercise and the efficacy (defined as the relation between correct sutures and the total). Posteriorly, 3 training sessions of 1 hour and a final evaluation with the same characteristics as the initial one were performed by all the participants. Both evaluations were studied by a senior neurosurgeon who gave individualized punctuation and feedback to the participant. Results: The average time of the initial exercise was 31 minutes 59 seconds, with an average efficiency of 70%. After training, the average time was 18 minutes, 12 seconds, with an efficiency of 80%. Conclusion: The simulator training demonstrated the improvement of the exoscopic technique of the evaluated residents. Because of the benefits that were observed, and also its low cost, we believe that the implementation of this device will be useful to all neurosurgeons interested in this technique

A Comparison of Patients from Argentina and Germany to Assess Factors Impacting Brachial Plexus and Brain Injury.

Background Traumatic brachial plexus injuries (BPIs) represent a major cause of disability in young patients. The purpose of this study was to compare two populations (from Argentina and Germany) who suffered a traumatic BPI after a motorcycle accident to identify predictors of BPI and brain injury severity. Methods Univariate and multivariable intergroup comparisons were conducted, and odds ratios were calculated to assess the associations between the different demographic, morphometric, and trauma-related variables, and the type and severity of patients' injuries. Pearson correlation coefficients were generated to identify statistically significant correlations. Results A total of 187 patients were analyzed, 139 from Argentina and 48 from Germany. The two countries differed significantly in age and several morphometric and trauma-related variables. The clinical presentation was also convincingly different in the two countries. The following three variables remained as statistically significant predictors of a complete (vs. partial) BPI: living in Argentina ( p < 0.001), presenting prior to 2015 ( p = 0.004), and greater estimated speed at the time of impact ( p = 0.074). As for BPIs, a disproportionate percentage (85.6%) of more severe brain injuries occurred in Argentinian patients ( p < 0.001) and among those whose accident involved striking a stationary vertical object. Conclusions This study identified several factors that might be considered when planning governmental policies and education initiatives to reduce BPI and brain injuries related to motorcycle use. Level of evidence II-2 (evidence obtained from case-control studies).

Treatment of neuropathic pain after peripheral nerve and brachial plexus traumatic injury.

Peripheral nerve and brachial plexus injuries typically cause severe impairment in the affected limb. The incidence of neuropathic pain is high, reaching up to 95% of cases, especially if cervical root avulsion has occurred. Neuropathic pain results from damage to the somatosensory system, and its progression towards chronicity depends upon disruptions affecting both the peripheral and central nervous system. Managing these painful conditions is complex and must be accomplished by a multidisciplinary team, starting with first-line pharmacological therapies like tricyclic antidepressants and calcium channel ligands, combined physical and occupational therapy, transcutaneous electrical stimulation and psychological support. For patients refractory to the initial measures, several neurosurgical options are available, including nerve decompression or reconstruction and ablative/modulatory procedures.

Phrenic to musculocutaneous nerve transfer for traumatic brachial plexus injuries: analyzing respiratory effects on elbow flexion control.

OBJECTIVE: In this study, the authors sought to identify the relationship between breathing and elbow flexion in patients with a traumatic brachial plexus injury (TBPI) who undergo a phrenic nerve (PN) transfer to restore biceps flexion. More specifically, the authors studied whether biceps strength and the maximal range of active elbow flexion differ between full inspiration and expiration, and whether electromyography (EMG) activity in the biceps differs between forced maximum breathing during muscular rest, normal breathing during rest, and at maximal biceps contraction. All these variables were studied in a cohort with different intervals of follow-up, as the authors sought to determine if the relationship between breathing movements and elbow flexion changes over time. METHODS: The British Medical Research Council muscle-strength grading system and a dynamometer were used to measure biceps strength, which was measured 1) during a maximal inspiratory effort, 2) during respiratory repose, and 3) after a maximal expiratory effort. The maximum range of elbow flexion was measured 1) after maximal inspiration, 2) during normal breathing, and 3) after maximal expiration. Postoperative EMG testing was performed 1) during normal breathing with the arm at rest, 2) during sustained maximal inspiration with the arm at rest, and 3) during maximal voluntary biceps contraction. Within-group (paired) comparisons, and both correlation and regression analyses were performed. RESULTS: Twenty-one patients fit the study inclusion criteria. The mean interval from trauma to surgery was 5.5 months, and the mean duration of follow-up 2.6 years (range 10 months to 9.6 years). Mean biceps strength was 0.21 after maximal expiration versus 0.29 after maximal inspiration, a difference of 0.08 (t = 4.97, p < 0.001). Similarly, there was almost a 21° difference in maximum elbow flexion, from 88.8° after expiration to 109.5° during maximal inspiration (t = 5.05, p < 0.001). Involuntary elbow flexion movement during breathing was present in 18/21 patients (86%) and averaged almost 20°. Measuring involuntary EMG activity in the biceps during rest and contraction, there were statistically significant direct correlations between readings taken during normal and deep breathing, which were moderate (r = 0.66, p < 0.001) and extremely strong (r = 0.94, p < 0.001), respectively. Involuntary activity also differed significantly between normal and deep breathing (2.14 vs 3.14, t = 4.58, p < 0.001). The degrees of involuntary flexion were significantly greater within the first 2.6 years of follow-up than later. CONCLUSIONS: These results suggest that the impact of breathing on elbow function is considerable after PN transfer for elbow function reconstruction following a TBPI, both clinically and electromyographically, but also that there may be some waning of this influence over time, perhaps secondary to brain plasticity. In the study cohort, this waning impacted elbow range of motion more than biceps muscle strength and EMG recordings.

Age as a Predictor of Long-Term Results in Patients with Brachial Plexus Palsies Undergoing Surgical Repair.

BACKGROUND: Among other factors, like the time from trauma to surgery or the number of axons that reach the muscle target, a patient's age might also impact the final results of brachial plexus surgery. OBJECTIVE: To identify (1) any correlations between age and the 2 outcomes: elbow flexion strength and shoulder abduction range; (2) whether childhood vs adulthood influences outcomes; and (3) other baseline variables associated with surgical outcomes. METHODS: Twenty pediatric patients (under age 20 yr) who had sustained a traumatic brachial plexus injury were compared against 20 patients, 20 to 29 yr old, and 20 patients, 30 yr old or older. Univariate, univariate trend, and correlation analyses were conducted with patient age, time to surgery, type of injury, and number of injured roots included as independent variables. RESULTS: A statistically significant trend toward decreasing mean strength in elbow flexion, progressing from the youngest to oldest age group, was observed. This linear trend persisted when subjects were subdivided into 4 age groups (<20, 20-29, 30-39, ≥40). There were no differences by age group in final shoulder abduction range or the percentage achieving a good shoulder outcome. CONCLUSION: Our data suggest that age is somehow linked to the outcomes of brachial plexus surgery with respect to elbow flexion, but not shoulder abduction strength. Increasing age is associated with steadily worsening elbow flexion outcomes, perhaps indicating the need for earlier surgery and/or more aggressive repairs in older patients.

Fístula dural cavernosa. presentación de 3 casos y revisión bibliográfica / Cavernous dural fistula. presentation of 3 cases and bibliographic review

Objetivo: Describir la etiología, forma de presentación, evolución y conducta terapéutica adoptada en tres casos de fístulas durales cavernosas (FDC) y realizar una revisión bibliográfíca. Materiales y métodos: Se presentan tres casos de FDC, una, post-traumática; otra, secundaria a trombosis del seno cavernoso contralateral; y la tercera sin causa conocida. Todos los pacientes se presentaron con proptosis, diplopía, quemosis, ptosis palpebral e inyección conjuntival. Dos de ellos referían disminución de la agudeza visual. Ante la sospecha clínica, se realizaron estudios por imágenes no invasivos en dos pacientes, y el diagnóstico fue confirmado por angiografía digital cerebral en los tres casos. La conducta terapéutica consistió en la oclusión del seno cavernoso con coils a través de un acceso venoso femoral transoftálmico en el primer caso, anticoagulación como tratamiento de la trombosis de seno cavernoso contralateral en el segundo y compresión ocular diaria por 3 meses en el tercero. Resultados: En todos los casos, se logró la resolución completa de los síntomas. Conclusiones: La FDC es una entidad diferenciada del resto de las fístulas durales. Se dispone de diversas estrategias terapéuticas, con resultados favorables. También se observa una alta tasa de remisión espontánea. En dos de los casos presentados, el manejo de forma conservadora fue eficaz para la resolución del cuadro. En el caso que requirió tratamiento endovascular para el cierre de la fistula, el acceso por vía venosa femoral transoftálmica constituyó un abordaje efectivo para lograr la oclusión de la misma.

Objective: To describe the etiology, presentation, evolution and therapeutic approach adopted in three cases of dural cavernous fistulas (DCCF) and to perform a literature review.Materials and methods: Three cases of DCCF are report, one, post-traumatic lession; another secondary to contralateral cavernous sinus thrombosis; and the third with unknown etiology. All patients presented with proptosis, diplopia, chemosis, ptosis and conjunctival injection. Two of them concerned vision impairment. Noninvasive imaging studies were performed in two patients, and the diagnosis were confirmed by cerebral angiography digital in all three cases. The therapeutic approach consisted of cavernous sinus occlusion with coils through a femoral venous access in the first case, anticoagulation treatment of contralateral cavernous sinus thrombosis in the second and ocular compression daily for 3 months in the third. Results: Complete resolution of symptoms was achieved in all cases.Conclusions: The FDC is a distinct entity from the rest of the dural fistulas. It has several therapeutic strategies, with favorable results. A high rate of spontaneous remission is also observed. In two cases, conservative management was effective in the resolution of the picture. In the case requiring endovascular treatment for closure of the fistula, femoral vein transoftálmic acces was an effective approach to achieve occlusion of it.