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.

Use of ultrasound and targeted physiotherapy to manage nerve sutures placed under joint flexion: a case series.

BACKGROUND: Joint flexion to diminish the gap and avoid nerve grafts fell into disuse for decades, but recently attention for using this technique was regained. We report a case series of nerve suture under joint flexion, ultrasound monitoring, and physiotherapy. Our main objective was to determine how effective this multimodality treatment is. METHODS: A retrospective review of 8 patients treated with direct repair with joint flexion was done. Depending on the affected nerve, either the knee or the elbow was flexed intraoperatively to determine if direct suturing was possible. After surgery, the limb was held immobilized. Through serial ultrasounds and a physiotherapy program, the limb was fully extended. If a nerve repair rupture was observed, the patient was re-operated and grafts were used. RESULTS: Of the eight nerve sutures analyzed, four sustained a nerve rupture revealed by US at an early stage, while four did not show any sign of dehiscence. In the patients in whom the nerve suture was preserved, an early and very good response was observed. Ultrasound was 100% accurate at identifying nerve suture preservation. Early detection of nerve failure permitted early re-do surgery using grafts without flexion, ultimately determining good final results. CONCLUSIONS: We observed a high rate of dehiscence in our group of patients treated with direct repair and joint flexion. We believe this was due to an incorrect use of the immobilization device, excessive movement, or a broken device. In opposition to this, we observed that applying direct nerve sutures and joint flexion offers unusually good and fast results. If this technique is employed, it is mandatory to closely monitor suture status with US, together with physiotherapy providing progressive, US-guided extension of the flexed joint. If nerve rupture occurs, the close monitoring dictated by this protocol should ensure the timely application of a successful graft repair.

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.

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.

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.

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.

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.

Treatment of complete facial palsy in adults: comparative study between direct hemihypoglossal-facial neurorrhaphy, hemihipoglossal-facial neurorrhaphy with grafts, and masseter to facial nerve transfer.

BACKGROUND: The hypoglossal (with or without grafts) and masseter nerves are frequently used as axon donors for facial reinnervation when no proximal stump of the facial nerve is available. We report our experience treating facial nerve palsies via hemihypoglossal-to-facial nerve transfers either with (HFG) or without grafts (HFD), comparing these outcomes against those of masseteric-to-facial nerve transfers (MF). METHOD: A total of 77 patients were analyzed retrospectively, including 51 HFD, 11 HFG, and 15 MF nerve transfer patients. Both the House-Brackmann (HB) scale and our own, newly-designed scale to rate facial reanimation post nerve transfer (quantifying symmetry at rest and when smiling, eye occlusion, and eye and mouth synkinesis when speaking) were used to enumerate the extent of recovery. RESULTS: With both the HB and our own facial reanimation scale, the HFD and MF procedures yielded better outcome scores than HFG, though only the HGD was statistically superior. HGD produced slightly better scores than MF for everything but eye synkinesis, but these differences were generally not statistically significant. Delaying surgery beyond 2 years since injury was associated with appreciably worse outcomes when measured with our own but not the HB scale. The only predictors of outcome were the surgical technique employed and the duration of time between the initial injury and surgery. CONCLUSIONS: HFD appears to produce the most satisfactory facial reanimation results, with MF providing lesser but still satisfactory outcomes. Using interposed grafts while performing hemihypoglossal-to-facial nerve transfers should likely be avoided, whenever possible.

Transferencia tendinosa de tibial posterior en parálisis del nervio peróneo común: ¿El fin del pie caído? / Tendinous transfer of posterior tibial in paralysis of the common peroneal nerve: The end of the fallen foot?

INTRODUCCIÓN: la lesión del nervio peróneo común es la más frecuente del miembro inferior, resultando en pie caído y marcha en steppage. La reconstrucción nerviosa tiene un resultado desfavorable en la mayoría de las series. Una alternativa terapéutica a dicha reconstrucción es la transferencia del tendón del músculo tibial posterior, cuyo objetivo es lograr la dorsiflexión activa del pie. El objetivo de este trabajo es analizar los resultados obtenidos con esta cirugía. MATERIAL Y MÉTODOS: se analizaron una serie de pacientes a los que se realizó una transferencia de tendón de tibial posterior por pie caído, entre los meses de enero 2008 y junio 2012. Sólo se incluyeron en el análisis aquellos que presentaban un seguimiento de al menos 12 meses. La técnica empleada en todos los procedimientos fue la vía subcutánea, circunferencial, con fijación tendón-tendón, y usando como blanco los tendones del tibial anterior, extensor propio del hallux, extensor común de los dedos y peróneos laterales. La escala de Stanmore fue empleada para analizar los resultados. RESULTADOS: en el período analizado, fueron realizadas 22 transferencias de tibial posterior, de los cuales 19 poseían un seguimiento adecuado. Diez de esos 19 pacientes mostraron un resultado excelente (52,3%), cinco bueno (26,7%), dos pacientes regular (10,5%) y dos malo (10,5 %), de acuerdo a la escala mencionada. Sólo una complicación se verificó en un caso, la pérdida de tensión de la sutura tendinosa, que requirió una nueva cirugía. CONCLUSIÓN: la transferencia tendinosa de tibial posterior es un procedimiento con una alta tasa de éxito, tanto es nuestra serie como en otras publicadas en la literatura. Atento a los resultados generalmente pobres que posee la reconstrucción nerviosa primaria directa, consideramos que en casos seleccionados la técnica de transferencia tendinosa es la primera elección en el pie caído

INTRODUCTION: common peroneal nerve injury is the most frequent nerve deficit affecting the lower limbs, resulting in foot drop and stepagge. Primary surgical nerve repair has an unfavorable outcome in most series. An alternative is posterior tibial tendon transfer, a procedure designed to achieve active dorsiflexion. The aim of this paper is to analyze the results obtained with this surgery. METHODS: between January 2008 and June 2012, all patients submitted for posterior tibial tendon transfer with a minimum follow-up of 12 months, were analyzed. Subcutaneous route was used for the transfer, and tendon-to-tendon suture was employed, using as targets the anterior tibial, extensor hallucis longus, extensor digitorum longus and peroneal tendons. Stanmore scale was used for analysis. RESULTS: a total of 22 patients were operated in the studied period, but 19 who had a minimum follow-up were included in these analysis. The results were excellent in 10 patients (52,3%), good in 5 (26,7%), fair in in 2 patients (10,5%) and poor in 2 (10,5%), according to Stanmore scale. CONCLUSIONS: this tendon transfer has a high rate of success, both in our series and in the literature. Considering the poor results that primary nerve repairs has, we believe that posterior tibial tendon transfer is the first choice for the treatment of foot drop in selected cases

Artrodesis de hombro vs cirugía primaria de reconstrucción en pacientes con lesiones graves de plexo braquial: estudio comparativo / Shoulder arthrodesis vs. primary reconstruction surgery in patients with serious brachial pexus injuries: comparative study

Objetivo: La cirugía de reparación nerviosa es la primera elección en lesiones del plexo braquial. La artrodesis de hombro estabiliza y otorga cierta abducción por desplazamiento de la escápula. El objetivo del presente trabajo es: comparar la artrodesis de hombro versus la transferencia del nervio espinal accesorio al supraescapular. Materiales y métodos: se analizaron en forma retrospectiva 20 pacientes con parálisis completa del miembro superior y avulsión radicular de al menos 4 raíces. Diez fueron artrodesados, y en los otros 10 se realizó una única transferencia nerviosa para el hombro, antes citada. El seguimiento mínimo fue de 2 años. Se determinó la abducción en grados y se describió una escala para estudiar los resultados de ambas técnicas. Los resultados fueron comparados estadísticamente. Resultados: en los pacientes artrodesados el promedio, según la escala, fue 4,5 puntos, mientras que en los transferidos fue 4,8. La media de abducción en grados fue de 37 en artrodesados y 43,5 en transferidos. No se encontraron diferencias estadísticamente significativas entre ambos grupos. Conclusiones: los resultados de ambas técnicas son semejantes. La artrodesis escápulo-humeral es una posibilidad terapéutica aceptable del hombro paralizado en los pacientes con lesiones muy graves del plexo braquial y escasez de donantes nerviosos.

Objective: Primary nerve reconstruction surgery is the gold standard in brachial plexus injuries. Shoulder arthrodesis stabilizes and abducts the shoulder by the movement of the scapula. The goal of the present study is to compare shoulder arthrodesis versus spinal nerve transfer to supraescapular nerve. Materials y methods: 20 patients with complete brachial plexus palsy (flail arm) and at least 4 roots avulsions were analyzed retrospectively. Ten were submitted to shoulder arthrodesis, while in the other 10, only one nerve transfer was performed to reinervate the shoulder. Minimum follow-up was 2 years. The results were determined in degrees of abduction, also measured in a scale, and compared statistically. Results: the mean result in the patients with shoulder arthrodesis was 4.5, and 4.8 in the nerve transferred. Mean final abduction was 37 degrees in arthrodesis and 43.5 in nerve transfer. No statistical significant difference was found between groupsConclusions: the results of both techniques are similar. Shoulder arthrodesis is a viable option in severely injured brachial plexus patients where donor nerve are scarce.

Forámenes craneales en abordajes a base de cráneo / Skull foramina in surgical approaches to the skull base

Introducción: el objetivo del presente trabajo es determinar la distancia entre los abordajes neuroquirúrgicos ás utilizados y los forámenes de base de cráneo. Estos datos pueden ser de utilidad tanto para el planeamiento prequirúrgico como para navegaión intraoperatoria. Materiales y métodos: se estudiaron 72 hemicráneos secos, 36 derechos y 36 izquierdos, 7 bases de cráneo formolizadas y 14 hemicráneos. Se emplearon calibradores y las medidas se expresan en mm. Resultados: La distancia entre el abordaje Ptrerional y el punto de salida dural del III par fue d 55 mm en promedio. La distancia entre el abordaje Petrosectomía Presignmoidea Posterior y el punto de salida dural del IV par fue 57.3 mm. LA distancia entre el abordaje de la Petrosectomía Presigmoidea Posterior y el punto de salida dural del V par fue 33.71 mm e promedio. LA distancia entre el abordaje Subtemporal y los amos del nervio trigémino fue en promedio de 61 mm para V1 (mínimo 56 mm y máximo 67 mm), 57 mm para V2 mínimo 50 mm y máximo 63 mm) y 48 mm para V3 (mínimo 35 mm y máximo 56 mm). La distancia entre el abordaje de la petrosectomía Presigmoide Posterior y el punto de saluda dural del VI par fue 59.85 mm en promedio. La distancia entre ewl abordaje suboccipital lateral superior y el punto de saluda dural de los pares VII y VIII fue 34. 5 mm. La distancia entre el abordaje de la Petrosectomía Presigmoidea Posterior y el punto de salida dural de los pares IX, X y XI fue 2179 mm. La distancia entre el abordaje Transcondilar y el XII par fue de 50.58 mm en promedio. Conclusión: se describió la anatomía de los forámenes de base de cráneo y su relación con los abordajes, con el objetivo de brindar el conocimiento necesario para el planeamiento de las complejas estrategias neuroquirúrgicas. (AU)

Introduction: This paper aims at establishing the distance between the most frequently used neurosurgical approaches and the skull base foramina. These data can be useful both for presurgical planning and for intrasurgical navigation. Materials and methods: 72 dried skull halves were examined, 36 right and 36 left halves, 7 in formaldehyde solution skull bases and 14 skull halves. Gages were used and measurements are expressed in mm.Results: The distance between the Pterional approach and the dural opening of the III pair was 55mm in average. The distance between the posterior Petrosectomy with presigmoidal approach and the dural opening of the IV pair was 57.3mm. The distance between the posterior Petrosectomy with presigmoidal approach and the dural opening of the V pair was 33.71mm in average. The distance between the Subtemporal approach and the trigeminal nerve branches was 61mm, in average, for V1 (56mm minimum and 67mm maximum), 57mm for V2 (50mm minimum and 63mm maximum) and 48mm for V3 (35mm minimum and 56mm maximum). The distance between the posterior Petrosectomy with presigmoidal approach and the dural opening of the VI pair was 59.85mm in average. The distance between the upper lateral suboccipital approach and the dural opening of the VII and VIII pairs was 34.5mm. The distance between the posterior Petrosectomy with presigmoidal approach and the dural opening of pairs IX, X and XI was 21.79mm. The distance between the Transcondilar approach and the XII pair was 50.58mm in average.Conclusion: The anatomy of skull base foramina was described together with their relation to the different approaches, with the aim of providing the necessary knowledge for planning the complex neurosurgical strategies. (AU)

Forámenes craneales en abordajes a base de cráneo / Skull foramina in surgical approaches to the skull base

Introducción: el objetivo del presente trabajo es determinar la distancia entre los abordajes neuroquirúrgicos ás utilizados y los forámenes de base de cráneo. Estos datos pueden ser de utilidad tanto para el planeamiento prequirúrgico como para navegaión intraoperatoria. Materiales y métodos: se estudiaron 72 hemicráneos secos, 36 derechos y 36 izquierdos, 7 bases de cráneo formolizadas y 14 hemicráneos. Se emplearon calibradores y las medidas se expresan en mm. Resultados: La distancia entre el abordaje Ptrerional y el punto de salida dural del III par fue d 55 mm en promedio. La distancia entre el abordaje Petrosectomía Presignmoidea Posterior y el punto de salida dural del IV par fue 57.3 mm. LA distancia entre el abordaje de la Petrosectomía Presigmoidea Posterior y el punto de salida dural del V par fue 33.71 mm e promedio. LA distancia entre el abordaje Subtemporal y los amos del nervio trigémino fue en promedio de 61 mm para V1 (mínimo 56 mm y máximo 67 mm), 57 mm para V2 mínimo 50 mm y máximo 63 mm) y 48 mm para V3 (mínimo 35 mm y máximo 56 mm). La distancia entre el abordaje de la petrosectomía Presigmoide Posterior y el punto de saluda dural del VI par fue 59.85 mm en promedio. La distancia entre ewl abordaje suboccipital lateral superior y el punto de saluda dural de los pares VII y VIII fue 34. 5 mm. La distancia entre el abordaje de la Petrosectomía Presigmoidea Posterior y el punto de salida dural de los pares IX, X y XI fue 2179 mm. La distancia entre el abordaje Transcondilar y el XII par fue de 50.58 mm en promedio. Conclusión: se describió la anatomía de los forámenes de base de cráneo y su relación con los abordajes, con el objetivo de brindar el conocimiento necesario para el planeamiento de las complejas estrategias neuroquirúrgicas.

Introduction: This paper aims at establishing the distance between the most frequently used neurosurgical approaches and the skull base foramina. These data can be useful both for presurgical planning and for intrasurgical navigation. Materials and methods: 72 dried skull halves were examined, 36 right and 36 left halves, 7 in formaldehyde solution skull bases and 14 skull halves. Gages were used and measurements are expressed in mm.Results: The distance between the Pterional approach and the dural opening of the III pair was 55mm in average. The distance between the posterior Petrosectomy with presigmoidal approach and the dural opening of the IV pair was 57.3mm. The distance between the posterior Petrosectomy with presigmoidal approach and the dural opening of the V pair was 33.71mm in average. The distance between the Subtemporal approach and the trigeminal nerve branches was 61mm, in average, for V1 (56mm minimum and 67mm maximum), 57mm for V2 (50mm minimum and 63mm maximum) and 48mm for V3 (35mm minimum and 56mm maximum). The distance between the posterior Petrosectomy with presigmoidal approach and the dural opening of the VI pair was 59.85mm in average. The distance between the upper lateral suboccipital approach and the dural opening of the VII and VIII pairs was 34.5mm. The distance between the posterior Petrosectomy with presigmoidal approach and the dural opening of pairs IX, X and XI was 21.79mm. The distance between the Transcondilar approach and the XII pair was 50.58mm in average.Conclusion: The anatomy of skull base foramina was described together with their relation to the different approaches, with the aim of providing the necessary knowledge for planning the complex neurosurgical strategies.

Asterion: frontera anatómica en los abordajes supra e infra tentoriales / Asterion: anatomical landmark in posterior fossa approaches

Resultados: la distancia entre el asterion y los puntos seleccionados (inion, CAE, mastoides) se mantiene dentro de rangos acotados. En la distancia Asterion-CAE se aprecia la menor variación en los valores medidos, mientras que en la distancia Asterion - Inion se objetiva la mayor variación entre los ejemplares estudiados. Por lo tanto, las distancias Asterion - CAE y Asterion- mastoides serian las mas seguras y confiables para la determinación de una referencia en la ubicación del asterion, sin que se halle expuesta la superficie ósea y guiándonos solo con puntos palpables.Conclusión: Hemos encontrado una fuerte correlación entre la posición del asterion y del seno transverso, por lo tanto, los orificios de trépano deberían situarse alejados de este punto craneométrico. A la vez, hemos observado que las distancias entre el asterion y los puntos seleccionados (inion, CAE, mastoides) se mantienen dentro de rangos acotados, lo cual permite su utilización en la práctica clínico- quirúrgica para la localización del asterion sin exponer la superficie ósea.(AU)

Results: the distance between selected points (inion, EAC, mastoid) and asterion remains within bounded ranges. The EAC-Asterion distance shows the least variation at the measured values while distance between Asterion-Inion manifest the greatest variation at the studied specimens. Therefore, the distances Asterion-EAC and Asterion-mastoid would be the most secures and reliables to locate the Asterion, without bone surface exposure and guided only by tangible points. Conclusion: We found a strong correlation between the position of the asterion and the transverse sinus, therefore, drill holes should be located far away from this point. Also we observed that the distances between asterion and selected points (inion, EAC, mastoid) remains within bounded ranges, allowing their use in clinical-surgical practice for asterion(AU)

Asterion: frontera anatómica en los abordajes supra e infra tentoriales / Asterion: anatomical landmark in posterior fossa approaches

Resultados: la distancia entre el asterion y los puntos seleccionados (inion, CAE, mastoides) se mantiene dentro de rangos acotados. En la distancia Asterion-CAE se aprecia la menor variación en los valores medidos, mientras que en la distancia Asterion - Inion se objetiva la mayor variación entre los ejemplares estudiados. Por lo tanto, las distancias Asterion - CAE y Asterion- mastoides serian las mas seguras y confiables para la determinación de una referencia en la ubicación del asterion, sin que se halle expuesta la superficie ósea y guiándonos solo con puntos palpables.Conclusión: Hemos encontrado una fuerte correlación entre la posición del asterion y del seno transverso, por lo tanto, los orificios de trépano deberían situarse alejados de este punto craneométrico. A la vez, hemos observado que las distancias entre el asterion y los puntos seleccionados (inion, CAE, mastoides) se mantienen dentro de rangos acotados, lo cual permite su utilización en la práctica clínico- quirúrgica para la localización del asterion sin exponer la superficie ósea.

Results: the distance between selected points (inion, EAC, mastoid) and asterion remains within bounded ranges. The EAC-Asterion distance shows the least variation at the measured values while distance between Asterion-Inion manifest the greatest variation at the studied specimens. Therefore, the distances Asterion-EAC and Asterion-mastoid would be the most secures and reliables to locate the Asterion, without bone surface exposure and guided only by tangible points. Conclusion: We found a strong correlation between the position of the asterion and the transverse sinus, therefore, drill holes should be located far away from this point. Also we observed that the distances between asterion and selected points (inion, EAC, mastoid) remains within bounded ranges, allowing their use in clinical-surgical practice for asterion

Transfer of flexor carpi ulnaris branches to selectively restore AIN function in median nerve sections: Anatomical feasibility study and case report.

BACKGROUND: In recent years, distal nerve transfers have become a valid tool for nerve reconstruction. Though grafts remain the gold standard for proximal median nerve injuries, a new distal transfer of flexor carpi ulnaris branches of the ulnar nerve to selectively restore anterior interosseous nerve function, concomitant with median nerve graft repair, could enhance outcomes. The objective of this paper is to anatomically analyze a technique to selectively reinnervate the thumb and index flexors. METHODS: Both the median and ulnar nerves were dissected in 10 cadavers. First and second branches to the flexor carpi ulnaris (FCU) were measured for length at its emergence from the ulnar nerve, and for width. The emergence of the AIN, just proximal to the arch of the flexor digitorum superficialis, was dissected, and the distance measured from this point to its motor entry at the long flexor pollicis and its branch to the long index flexor. A tensionless repair was performed between one FCU branch and the AIN. RESULTS: The mean AIN length was 32.3±8.20 mm and width 2.4±0.49 mm. The first branch from the ulnar nerve to the FCU measured 20.8±2.04 mm and 1.52±0.44 mm, while the second, more distal branch measured 24.3±6.71 and 1.9±0.17 mm, respectively. In all dissections, it was possible to contact both the proximal and distal branches of the ulnar nerve to the FCU with the distal stump of the divided AIN, with no tension or need for interposed nerve grafts. CONCLUSIONS: Though proximal reconstruction remains the gold standard, new distal nerve transfer techniques may improve outcomes.

Consideraciones anatomoquirúrgicas sobre el seno sagital superior / Anatomicosurgical considerations regarding the superior sagittal sinus

Objetivo: conocer la anatomía de los senos de la duramadre, especialmente del seno sagital superior (SSS) y sus relaciones con las estructuras lindantes. Material y método: se utilizaron 39 encéfalos inyectados y formalizados, disecándose con técnicas microscópicas y con lupas de 2.5X el seno sagital superior y estructuras lindantes comparándose los resultados con angiografías normales. Resultados: la longitud del SSS osciló entre 20-27 cm (media 23.58 cm). Observamos que el tercio medio mayormente se desplaza a derecha, siendo 100% concordante con la sutura sagital a nivel de su desembocadura distal. En 28 casos (71.8%) había comunicación con el seno sagital inferior, conformando plexos venosos. Las lagunas se posicionaron en forma variable, ubicándose mayormente en relación al tercio medio, y ninguna en el tercio posterior. Las venas emisarias parietales drenan en el tercio medio del seno sagital superior en el 100%, mientras que las venas nasales fueron encontradas sólo en 5 casos (12,82%). Conclusión: consideramos que el conocimiento anatómico del seno sagital superior es vital en la táctica quirúrgica a fin de evitar y prever complicaciones en las cirugías que impliquen patologías de la línea media.

Pain and brachial plexus lesions: evaluation of initial outcomes after reconstructive microsurgery and validation of a new pain severity scale.

BACKGROUND: Peripheral nerve lesions usually are associated with neuropathic pain. In the present paper, we describe a simple scale to quantify pain after brachial plexus injuries and apply this scale to a series of patients to determine initial outcomes after reconstructive surgery. METHODS: Fifty-one patients with traumatic brachial plexus avulsion injuries were treated over the period of one calendar year at one center by the same surgical team. Of these, 28 patients who were available for follow-up reported some degree of neuropathic pain radiating towards the hand or forearm and underwent reconstructive microsurgery and direct pain management, including trunk and nerve neurolysis and repair. A special pain severity rating scale was developed and used to assess patients' pain before and after surgery, over a minimum follow-up of 6 months. An independent researcher, not part of the surgical team, performed all pre- and postoperative evaluations. FINDINGS: Of the 28 patients with brachial plexus traction injuries who met eligibility criteria, 93% were male, and most were young (mean age, 27.6 years). The mean preoperative severity of pain using our scale was 30.9 out of a maximum of 37 (± 0.76 SD), which fell to a mean of 6.9 (± 0.68 SD) 6 months post-procedure. On average, pain declined by 78% across the whole series, a decline that was statistically significant (p < .001). Subset analysis revealed similar improvements across all the different parameters of pain. CONCLUSIONS: We have designed and tested a simple and reliable method by which to quantify neuropathic pain after traumatic brachial plexus injuries. Initial surgical treatment of the paralysis--including nerve, trunk and root reconstruction, and neurolysis--comprises an effective means by which to initially treat neuropathic pain. Ablative or neuromodulative procedures, like dorsal root entry zone, should be reserved for refractory cases.

Medición, clasificación y evolución del dolor provocado por las lesiones nerviosas periféricas traumáticas antes y después de la cirugía de reparación nerviosa / Measurement, classification and follow up of pain caused by traumatic peripheral nervous lesions before and after surgical repair

Objetivo: describir una escala sencilla que cuantifique el dolor provocado por las lesiones nerviosas periféricas traumáticas y su aplicación en un estudio retrospectivo para determinar los efectos de la cirugía sobre los síntomas dolorosas. Material y método: fueron analizados los pacientes con dolor neuropático por lesión nerviosa periférica de origen traumático intervenidos quirúrgicamente entre septiembre 2007 y septiembre 2008 por el Equipo de Nervios Periféricos del Hospital de Clínicas. Se obtuvieron datos del estado preoperatorio y postoperatorio a los 90 días del procedimiento. Resultados: se incluyeron 26 pacientes cuya edad media fue de 28,76 años, con predominancia masculina (80%), siendo 23 lesiones de plexo braquial por tracción y 3 lesiones penetrantes del nervio ciático (88% y 12% respectivamente). La media de puntos para el prequirúrgico fue de 33,8, mientras que el valor medio postquirúrgico fue de 7,1. Estos datos implicaron una mejoría global del 79%, y que cada paciente en promedio mejoró su dolor en 26,7 puntos. Conclusión: la escala aplicada es un método sencillo y confiable para cuantificar el dolor por una lesión nerviosa periférica. Queda demostrada la utilidad de la cirugía para tratar para tratar el dolor de estos pacientes cuando no mejora con la medicación.