Translaminar Full Endoscopic Technique with Tom Shidi Needles for Highly- and Dorsally-Migrated Lumbar Disc Herniations.

BACKGROUND: Thirty years have passed since Kambin's first clinical series of lumbar disc herniations (LDH) treated by arthroscopic microdiscectomy. Despite several advances in this interim, sequestrated LDHs over the dorsal aspect of the dura, and high-grade up- or downward disc migration have been a relative limitation of the transforaminal endoscopic technique. The interlaminar window was the next step to deal with such highly migrated LDHs. Favorable outcomes were obtained in 70-90% of the patients in the long-term, but recurrence rates remained high (approximately 12%), and the approach could be limited by the size of the interlaminar window. Few relevant studies have addressed the role of translaminar full endoscopic technique for migrated LDHs. To describe an innovative modification of the translaminar full endoscopic approach with Tom Shidi needles. METHODS: This technical modification is presented in a detailed fashion for treating these challenging LDHs and illustrated through a clinical case. RESULTS: The patient underwent successful translaminar full endoscopic technique with complete pain resolution postoperatively. The postprocedural course was uneventful. A follow-up imaging showed no evidence of residual LDHs fragments. CONCLUSIONS: Translaminar full endoscopic technique with Tom Shidi needles is a promising modification of the previously presented interlaminar and translaminar endoscopic routes in the treatment of migrated LDHs to fasten surgical procedures and increase the safety of spinal canal manipulation.

Spontaneous radial nerve palsy with hourglass-like constriction.

Hourglass-like constriction (HLC) is an uncommon spontaneous mononeuropathy that is typically characterised by a sudden onset of pain followed by palsy, affecting branches of the radial (posterior interosseous nerve) and median nerves (anterior interosseous nerve). HLC of the radial nerve (RN) is rare, with only a few reported cases. Here, we report a case of a man who presented with acute wrist and finger drop due to the HLC of the RN. Surgery was recommended 5 months after clinical observation, when the lesion was resected and primarily repaired, resulting in satisfactory recovery. There is still much that remains unknown about HLC, especially for RN. The current understanding points out an inflammatory disease that should be treated conservatively for 3-7 months. The surgical technique depends mostly on the severity and extent of constriction; however, considering only RN constrictions, primary repair by neurorrhaphy or nerve grafts resulted in better functional outcomes.

Volumetric measurement of intracranial meningiomas: a comparison between linear, planimetric, and machine learning with multiparametric voxel-based morphometry methods.

PURPOSE: To compare the accuracy of three volumetric methods in the radiological assessment of meningiomas: linear (ABC/2), planimetric, and multiparametric machine learning-based semiautomated voxel-based morphometry (VBM), and to investigate the relevance of tumor shape in volumetric error. METHODS: Retrospective imaging database analysis at the authors' institutions. We included patients with a confirmed diagnosis of meningioma and preoperative cranial magnetic resonance imaging eligible for volumetric analyses. After tumor segmentation, images underwent automated computation of shape properties such as sphericity, roundness, flatness, and elongation. RESULTS: Sixty-nine patients (85 tumors) were included. Tumor volumes were significantly different using linear (13.82 cm3 [range 0.13-163.74 cm3]), planimetric (11.66 cm3 [range 0.17-196.2 cm3]) and VBM methods (10.24 cm3 [range 0.17-190.32 cm3]) (p < 0.001). Median volume and percentage errors between the planimetric and linear methods and the VBM method were 1.08 cm3 and 11.61%, and 0.23 cm3 and 5.5%, respectively. Planimetry and linear methods overestimated the actual volume in 79% and 63% of the patients, respectively. Correlation studies showed excellent reliability and volumetric agreement between manual- and computer-based methods. Larger and flatter tumors had greater accuracy on planimetry, whereas less rounded tumors contributed negatively to the accuracy of the linear method. CONCLUSION: Semiautomated VBM volumetry for meningiomas is not influenced by tumor shape properties, whereas planimetry and linear methods tend to overestimate tumor volume. Furthermore, it is necessary to consider tumor roundness prior to linear measurement so as to choose the most appropriate method for each patient on an individual basis.

Use of diffusion tensor imaging as a prognostic biomarker after decompression surgery for carpal tunnel syndrome.

BACKGROUND: Magnetic resonance diffusion tensor imaging (MR-DTI) has been increasingly applied for carpal tunnel syndrome (CTS) diagnosis, but relatively little is known about the effect of CTS treatment on median nerve (MN) integrity and functional outcome prediction. PURPOSE: To assess how structural changes in MR-DTI of the MN correlates with symptom severity, functional status, and electrophysiological parameters in patients suffering from CTS before and after decompression surgery. MATERIAL AND METHODS: Nine wrists were prospectively enrolled to perform MR-DTI pre- and postoperatively. The apparent diffusion coefficients (ADC) and fractional anisotropy (FA) of the MN were examined in three different regions-distal radioulnar joint, pisiform bone, and hamate bone-and correlated with clinical and electrophysiological parameters. RESULTS: Postoperatively, mean Boston Carpal Tunnel Questionnaire scores decreased 1.55 points (range = 0.08-3; P = 0.0172) and 1.01 points (-0.13 to 1.88; P = 0.0381) in the symptomatic and functional domains, respectively. Postoperative clinical improvement was reflected in proximal FA elevation (P = 0.0078), but not in diffusivity in comparison to baseline examination. Preoperative electrophysiological parameters were correlated with a reduction in the pre- (sensory latencies [rho = -0.6826; P = 0.0312]) and postoperative (motor latencies [rho = -0.7488; P = 0.0325]) distal FA values. Higher sensory amplitudes indicated higher postoperative proximal FA values (rho = 0.7618; P = 0.0280) ​​and lower postoperative proximal ADC values (rho = -0.9047; P = 0.0020). CONCLUSION: Our study demonstrated that pre- and postoperative proximal FA values are useful biomarkers for the structural evaluation of the MN in patients with CTS. Symptomatic improvement can be better predicted by analyzing FA changes.

Trochlear nerve: celebrating 500 years of description / Nervo troclear: comemorando 500 anos de descrição

The history of the description and classification of the cranial nerves has paralleled the development of anatomy and its role in providing rationality to medicine. About five hundred years ago, the "Anatomical Notes by the Great Alexander Achillinus of Bologna" (1520) provided the first description of the trochlear nerve. In this article, we review the most important macroscopic achievements through different epochs and pioneers such as Herophilus of Chalcedon, Galen of Pergamon, Andreas Vesalius, Bartolomeo Eustachi, Realdo Colombo, Gabriele Falloppio, Antonio Molinetti, Caspar Bartholin, Thomas Willis and Samuel Thomas von Soemmerring. Each of them contributed to a better understanding of the cranial nerves as we know today. Galen's classification was enduring through his seven pairs of cranial nerves. Realdo Colombo coined the name pathetic nerve or nervus oculorum pateticos to the trochlear nerve in 1559, and Molinetti, nervus trochlearis, in 1669. The term trochlear nerve is derived from the Latin word pulley, trochlea, as it innervates the superior oblique muscle that ends in a tendon that bends through a pulley of connective tissue. Besides description and naming, the inclusion into current cranial nerve classification system and how such knowledge applies to current microsurgical understanding is also discussed.

A história da descrição e da classificação dos nervos cranianos acompanhou o desenvolvimento da anatomia e o seu papel na racionalidade da medicina. Cerca de quinhentos anos atrás, as "Notas Anatômicas do Grande Alexandre Achillini de Bolonha" (1520) forneceram a primeira descrição do nervo troclear. Neste artigo, revisamos as realizações macroscópicas mais importantes em diferentes épocas e damos crédito aos pioneiros como Herófilo de Calcedônia, Galeno de Pérgamo, Andreas Vesalius, Bartolomeo Eustachi, Realdo Colombo, Gabriele Falloppio, Antonio Molinetti, Caspar Bartholin, Thomas Willis e Samuel Thomas von Soemmerring. Cada um deles contribuiu para uma melhor compreensão dos nervos cranianos, como os conhecemos hoje. A classificação de Galeno perdurava através de seus sete pares de nervos cranianos. Realdo Colombo cunhou o nome nervo patético ou nervus oculorum pateticos para o nervo troclear em 1559, e Molinetti, nervus trochlearis, em 1669. O termo nervo troclear é derivado da palavra latina polia, tróclea, pois inerva o músculo oblíquo superior que termina em um tendão que se dobra através de uma polia de tecido conjuntivo. Além da descrição e da nomenclatura, também é discutida a inclusão do nervo troclear no atual sistema de classificação de nervos cranianos e como esse conhecimento se aplica à compreensão microcirúrgica atual.

"Million dollar nerve" magnetic resonance neurography: first normal and pathological findings.

OBJECTIVES: To evaluate prospectively the feasibility of magnetic resonance neurography (MRN) in identifying the anatomical characteristics of thenar muscular branch (TMB) of the median nerve, also known as the "million dollar nerve," in patients and controls. METHODS: Thirteen patients affected by carpal tunnel syndrome (CTS) and four healthy controls had their hands scanned on a 3-T MR imaging scanner for TMB visualization. Median nerve anatomical variations were classified into four groups according to Poisel's classification system modified by Lanz. TMB signal intensity and diameter were assessed for the diagnosis of neuropathy. RESULTS: TMB was successfully identified in all patients and subjects by using MRN. The most suitable pulse sequences to identify and measure nerve diameter were 3D DW-PSIF and T2-FS-TSE. The axial oblique and sagittal oblique planes are complementary in demonstrating its entire course. TMB had mostly an extraligamentous course with radial side origin (93.8%, each). All patients experienced increased T2 signal intensity (p < 0.001) and thickened nerves. Mean TMB diameters were 1.27 ± 0.21 mm (range, 1.02-1.74 mm) and 0.87 ± 0.16 mm (0.73-1.08 mm) (p = 0.008) in the patient and control groups, respectively. CONCLUSION: MRN is a reliable imaging technique for identification and anatomical characterization of TMB in patients affected by CTS. This innovative imaging workup may therefore be included in the preoperative evaluation of patients scheduled for carpal tunnel release, especially in CTS with TMB involvement or even in isolated TMB neuropathy. KEY POINTS: • Magnetic resonance neurography allows precise visualization of the thenar muscular branch of the median nerve. • Thenar muscular branch anatomical variations can be correctly identified. • Preoperative scanning can contribute to reducing the risk of iatrogenic injuries during carpal tunnel release, especially in carpal tunnel syndrome with thenar muscular branch involvement or even in isolated thenar muscular branch neuropathy.

Osseous morphology of the medial epicondyle: an anatomoradiological study with potential clinical implications.

PURPOSE: The cubital tunnel is limited anteriorly by the medial epicondyle (ME), laterally by the medial collateral ligament, and superiorly by Osborne's fascia and the cubital tunnel retinaculum. Previous studies were mostly dedicated to the roof of the cubital tunnel, in the way that the study of the groove for ulnar nerve and ME anatomy is relatively scarce in the literature. We sought to describe the radiological anatomy of the groove for ulnar nerve and ME in healthy volunteers with multiplanar computed tomography (CT). METHODS: We analyzed 3D CT images of 30 healthy volunteers (mean age 39 years, range 18-66 years). Nine variables were measured from the right elbow, including sizes, areas and angles in two different planes (coronal and axial). RESULTS: Mean ME width and length were 17.3 ± 3.5 mm and 31.7 ± 4.5 mm, respectively. According to categorical correlation studies, ME width (X) was deemed the most representative morphological characteristic because of the positive correlation to five other different anatomical measurements. A three-tiered anatomical classification was proposed based on data distribution. CONCLUSION: Large individual variation is found in the shape of ME, both in coronal and axial planes. The knowledge of individual osseous morphology is of great value potentially contributing to the surgical decision-making in patients affected by cubital tunnel syndrome.

Fibular Nerve Repair by Lateral Sural Cutaneous Nerve Graft: Anatomic Feasibility Study and Clinical Results.

OBJECTIVE: The common fibular nerve (CFN) is the most frequently injured nerve in the lower limbs. Surgical management is necessary in approximately two thirds of patients and includes neurolysis, suture, graft repair, or nerve transfer. The distal sural nerve is the preferred donor for grafting, but it is not without complications and requires a second incision. We sought to study the surgical anatomy of the lateral sural cutaneous nerve (LSCN) with the aim of repairing CFN injuries through the same incision and as a potential source for grafting in other nerve injuries. METHODS: The popliteal fossa was dissected in 11 lower limbs of embalmed cadavers to study LSCN variations. Four patients with CFN injuries then underwent surgical repair by LSCN grafting using the same surgical approach. RESULTS: At the medial margin of the biceps femoris, the LSCN emerged from the CFN approximately 8.15 cm above the fibular head. The LSCN ran longitudinally to the long axis of the popliteal fossa, with an average of 3.2 cm medial to the fibular head. The mean LSCN length and diameter were 9.61 cm and 3.6 mm, respectively. The LSCN could be harvested in all patients for grafting. The mean graft length was 4.4 cm. Motor function was consistently recovered for foot eversion but was recovered to a lesser extent for dorsiflexion and toe extension. All patients recovered sensitive function (75% of S3). Hypoesthesia was recognized at the calf. CONCLUSIONS: LSCN harvest is a viable alternative for nerve grafting, especially for repairing short CFN injuries, thereby avoiding the need for a second incision.

Delayed Transfer of the Extensor Carpi Radialis Brevis Branch of the Radial Nerve to the Anterior Interosseous Nerve for Restoration of Thumb and Index Finger Flexion: Case Report.

High median nerve injuries (HMNIs) are rare lesions involving the upper extremities and affect the median nerve from its origin to the emergence of the anterior interosseous nerve (AIN). Proximal reconstruction has long been considered the gold standard in treating HMNI, but thumb and index flexion and pinch and grip weakness are consistently not recovered. We report the surgical results of a patient affected by an HMNI with partial spontaneous recovery after a gunshot wound. AIN function was successfully restored in a delayed fashion by transferring the radial nerve branch to the extensor carpi radialis brevis to the AIN.

Endovascular Intervention Versus Surgery in Ruptured Intracranial Aneurysms in Equipoise: A Systematic Review.

Background and Purpose- The benefits of endovascular intervention over surgery in the treatment of ruptured aneurysms of anterior circulation remains uncertain. Recently, published studies did not find superiority of endovascular intervention, challenging earlier evidence from a clinical trial. The earlier evidence also had a higher than average proportion of patients in good clinical status, leading to uncertainty about external validity of earlier trials. Methods- We performed a systematic review of studies after 2005 under a protocol published in the International Prospective Register of Systematic Reviews. Primary outcomes were posttreatment rebleeding and adverse events (procedural complications). Secondary outcomes were dependency at 3 to 6 and 12 months, delayed cerebral ischemia, and seizures. Results- Rebleeding was more frequent after endovascular intervention (Peto OR, 2.18 [95% CI, 1.29-3.70]; 3104 participants; 15 studies; I2=0%, Grading of Recommendations, Assessment, Development and Evaluation: very low certainty of evidence). Fewer adverse events were reported with the endovascular intervention (RR, 0.71 [95% CI, 0.53-0.95]; 1661 participants; 11 studies; I2=14%, Grading of Recommendations, Assessment, Development and Evaluation: low certainty of evidence). Three to six months dependency (RR, 0.82 [95% CI, 0.73-0.93]; 4081 participants; 18 studies; I2=15%, Grading of Recommendations, Assessment, Development and Evaluation: low certainty of evidence) and 12-month dependency (RR, 0.76 [95% CI, 0.66-0.86]; 1981 participants; 10 studies; I2=0%, Grading of Recommendations, Assessment, Development and Evaluation: low certainty of evidence) were lower after endovascular intervention. Conclusions- This study found consistent results between recent studies and the earlier evidence, in that endovascular intervention results in lower chance of dependency compared with surgery for repair of ruptured anterior circulation aneurysms. A lower proportion of patients in good clinical status in this review supports the application of the earlier evidence. Registration- URL: https://www.crd.york.ac.uk/PROSPERO. Unique identifier: CRD42018090396.

Rhabdomyolysis and spine surgery: A systematic review of the literature.

Rhabdomyolysis is characterized by the rupture of skeletal muscles due to a lot of reasons such as exercise, drug addiction, toxins, infections, trauma and some medications. The etiology of postoperative rhabdomyolysis is potentially multifactorial and has been documented in several types of surgery. The lysis of cell membrane releases organic and inorganic intracellular components that can be toxic and life threatening. Creatinephosphokinase (CPK) is one of the components and it is the most sensitive indicator of myocyte injury. The classic triad of symptoms is characterized by myalgia, weakness and brown-red urine. There is not a clearly agreed level of serum CPK that is evident for diagnosis of rhabdomyolysis. However, a CPK level higher than 5 times of its normal value is accepted by many authors as diagnostic criteria. Acute kidney injury is the most serious complication of rhabdomyolysis in the days following initial presentation and develops in 33% of patients. The objective of this study was to perform a review of the literature, aiming at a better understanding about the changes in CPK levels and the frequency of rhabdomyolysis in spine surgery, with special attention in posterior lumbar fusion. Nineteen studies were selected for analysis. The studies had different characteristics considering patients age, body mass index, comorbidities and type of surgery. The best available evidence points out to the prognosis depend on the extension and clinical severity of rhabdomyolysis, as well as on the early and prompt medical intervention.

Predictive Factors for Muscle Injury After Posterior Lumbar Spinal Surgery.

OBJECTIVE: The aims of this study were to evaluate the risk factors for muscle injury in patients undergoing posterior lumbar spinal surgery and the clearance of postoperative biochemical changes following lumbar fusion and secondarily to evaluate the timing for monitoring postoperative biochemical serum levels and potential clinical correlation. METHODS: The study prospectively enrolled 39 patients with degenerative disease of the lumbar spine. Biochemical markers (creatine phosphokinase [CPK], creatinine, and hemoglobin) were analyzed in 5 predefined stages. All relevant clinical data were collected. Rhabdomyolysis (RML) was defined as a postoperative 5-fold increase of the baseline CPK value. RESULTS: Patients from the lumbar fusion group had the highest postoperative CPK ratio. Overall, the rate of RML was 43.6%. CPK and creatinine activity reached their maximum on the first postoperative day in 69.2% and 87.5% of patients, respectively. Lumbar fusion (P = 0.005), surgical time >270 minutes (P = 0.028), and fall in hemoglobin levels >3 g/dL (P = 0.034) were identified as independent factors associated with higher risk of RML. CONCLUSIONS: The risk of RML increases with prolonged and invasive surgery with higher bleeding potential. Knowing the clearance of postoperative biochemical changes permits a standardized strategy with measurements in precise intervals, thereby avoiding unnecessary costs. The clinical significance is still undetermined.

Predictors of Outcomes and Complications After Microsurgical and Endovascular Treatment of 1300 Intracranial Aneurysms.

BACKGROUND: We performed a rigorous statistical analysis of the complications and outcomes of patients with ruptured or unruptured intracranial aneurysms. Our emphasis was on the potential predictive factors when both surgical and endovascular management are offered by a team with balanced microsurgical and endovascular expertise. METHODS: From January 2005 to December 2011, 1297 consecutive patients presenting with ruptured (n=829) or unruptured (n=468) aneurysms were prospectively enrolled in our vascular database. The treatment modality was determined by consensus of the endovascular and microsurgical teams. The patients' medical and neurological conditions and aneurysm characteristics were compared against the postintervention complication rates and outcomes using multivariate analyses. RESULTS: The patients mostly underwent clipping for ruptured (63.7%) or unruptured (56.6%) aneurysms. For ruptured aneurysms, higher Hunt and Hess and Fisher grades on admission were key predictors of increased neurological (P < 0.001 and P < 0.001, respectively) and medical (P < 0.001 and P=0.041, respectively) complication rates. No significant differences in the outcomes were observed between the coiling or clipping groups during the follow-up period. For the unruptured group, a family history of intracranial aneurysms was the most relevant predictor for reducing neurological complication rates and increasing survival at 6 months. Hypertension was, however, the strongest factor associated with complications negatively affecting the outcomes. CONCLUSIONS: For the ruptured and unruptured groups both, the outcomes were generally good, although neurological and medical complications were reasonably more frequent for the ruptured aneurysms. Coiling provided a sustained benefit in lowering the complication rates only in the short term for the unruptured aneurysms. Smoking was associated, paradoxically, with improved outcomes.

Dorsally exophytic glioblastoma of the pons.

Brainstem gliomas are rare tumours in adults, accounting for only 1%-2% of all intracranial gliomas. They are recognised as a heterogeneous group, in which most are malignant tumours. Brainstem gliomas are classified into four major groups according to the growth pattern on imaging, namely diffuse, focal, exophytic and cervicomedullary. Such a classification system is also useful for surgical decision making. The exophytic variant is extremely rare having anecdoctal reports in the literature. We report the case of an adult patient affected by an exophytic glioblastoma of the pons, which was submitted to subtotal resection followed by radiation therapy and chemotherapy with a longer overall survival. To the best of our knowledge, this is the seventh adult patient reported of an exophytic brainstem glioblastoma.

Prognostic significance of mast cell and microvascular densities in malignant peripheral nerve sheath tumor with and without neurofibromatosis type 1.

Malignant peripheral nerve sheath tumors (MPNSTs) are rare and aggressive soft tissue sarcomas with a significant susceptibility to metastasize early in their course. Pathogenesis is yet to be fully elucidated. Recently, the essential role of mast cells in the tumor onset of neurofibromatosis type 1 (NF1)-associated neurofibromas and MPNSTs was confirmed in both experimental and human studies. In this study, we investigate mast cell density (MCD), microvascular density (MVD), and proliferation index (Ki-67) in MPNST. A secondary aim was to correlate histological staining to clinical data and survival in patients with and without NF1. In total, 34 formalin-fixed paraffin-embedded MPNST tissues from 29 patients were eligible. MCD, MVD, and Ki-67 labeling index (LI) were analyzed in all stained tissues by a computer-based quantitative algorithm (Aperio ImageScope). In addition, chart review was performed for clinical data and survival analysis. Overall, MCD, MVD, and Ki-67 LI were evenly distributed throughout tumor tissue. There was a negative correlation of NF1 status (affected, P = 0.037), tumor size (>10 cm, P = 0.023), and MVD in the tumor periphery (higher tercile, P = 0.002) to survival. Multivariate analysis confirmed the association of MVD in the tumor periphery (higher tercile, P = 0.019) with a decreased overall survival. Diverse mast cell and microvascular distributions suggest that angiogenesis in MPNST occurs independently. The role of mast cells in tumor progression is unclear and lacks prognostic value. Higher MVD has prognostic significance with possible therapeutic implications in MPNST.

The Enigma of Orbital Compartment Syndrome After Lumbar Spine Surgery in the Prone Position: Case Report and Literature Review.

BACKGROUND: Perioperative visual loss after spinal surgery is a devastating complication for the patient and the surgical team. Two known major causes are ischemic optic neuropathy and central retinal artery occlusion (CRAO). Traditional understanding of CRAO has been consistently related to occurrence of periocular trauma and signs of increased intraorbital pressure in addition to visual loss. However, such orbital signs are not a feature of any common perioperative visual loss syndrome. CASE DESCRIPTION: A 55-year-old woman underwent prolonged lumbar decompression and fusion for spinal stenosis under general anesthesia in the prone position. At the end of surgery, periocular hyperemia, corneal edema, and a tense orbit on the right side were noted. Complete internal and external ophthalmoplegia was observed on examination. Orbital computed tomography confirmed the clinical diagnosis of orbital compartment syndrome. Bony decompression was performed, but the treated eye remained blind. Resolution of the complete ophthalmoplegia was observed during late follow-up. CONCLUSIONS: In retrospect, patients diagnosed with often misunderstood CRAO and ischemic optic neuropathy with orbital signs after spinal surgery most likely had orbital compartment syndrome. The inclusion of orbital signs in the clinical picture of ischemic optic neuropathy and CRAO is not only incorrect but also gives the impression of therapeutic futility, thereby preventing successful orbital decompression in a timely fashion.

Retroperitoneoscopic Resection of a Lumbosacral Plexus Schwannoma: Case Report and Literature Review.

BACKGROUND AND STUDY AIMS: Schwannomas are benign tumors derived from the Schwann cells of the peripheral nerve sheath that rarely affect the retroperitoneum. When symptomatic, surgical resection is usually recommended via open surgery or the laparoscopic transperitoneal approach. We discuss the retroperitoneoscopic resection of lumbosacral plexus schwannomas through an illustrative case and literature review. A new management classification is also proposed. PATIENTS: A 61-year-old woman affected by schwannomatosis presented with neuropathic pain in her right inguinocrural area for the past 4 years before admission. Preoperative imaging revealed a 2-cm right retroperitoneal tumor lateral to the psoas muscle. The diagnosis of a schwannoma of the ilioinguinal nerve was then suggested. The patient underwent complete tumor resection through retroperitoneoscopy, and no recurrence was observed over the long term. A review of the relevant literature revealed that surgical strategy depends on tumor location, and therefore patients are divided into three groups by tumor position to guide trocar placement: type 1 (paravertebral or over the psoas muscle), type 2 (lateral to the psoas muscle), and type 3 (sacral or pelvic). RESULTS: Four patients were classified as type 1, one as type 2, and three as type 3, thereby guiding trocar placement to a lateral, anterior, or inferior montage, respectively. CONCLUSIONS: Retroperitoneoscopy is a minimally invasive technique that offers some potential advantages in approaching retroperitoneal masses. This new classification is useful to group patients and thus provide guidance on the best retroperitoneoscopic surgical strategy.

Implementing an epilepsy surgery center. Initial experience at a university hospital in Brazil.

OBJECTIVE: Epilepsy is a serious neurological condition, often without a full and effective treatment. In some cases, surgery is beneficial, despite being underused. Our aim herein is to describe the implementation of an epilepsy surgery center in a federal university hospital, sharing the initial experience gained, as well as describing the main challenges and first results. METHODS: Experience report of an epilepsy surgery center implementation. Retrospective review of 13 drug-resistant patients who underwent surgical treatment. RESULTS: Thirteen patients underwent surgical epilepsy treatment, five patients categorized as the International League Against Epilepsy class 1, two in class 2, three in class 3, zero in class 4, and two in class 5; with a 30.76% complication rate. CONCLUSION: Despite the challenges, it was possible to implement an epilepsy surgery center with favorable results and acceptable incidence of complications, which were not higher than the incidences found in more experienced centers.

Foix-Alajouanine syndrome mimicking a spinal cord tumor.

Subacute necrotizing myelopathy (SNM) or Foix-Alajouanine syndrome is a rare disease characterized by progressive neurological dysfunction caused by a spinal dural arteriovenous fistula (AVF). Radiological diagnosis is usually suspected when there is intramedullary nonspecific enhancement and perimedullary flow voids. Ring-enhancement is rarely reported in the scope of AVF, which poses a diagnostic challenge and raises the suspicion of a spinal cord tumor. In such situations, biopsy can be required and delay proper diagnosis. We report the case of a patient with SNM, who underwent biopsy on the assumption of it being a spinal cord tumor.