Lumbosacral plexus and pudendal nerve magnetic resonance tractography: A systematic review of the clinical applications for pudendal neuralgia.

Diffusion tensor imaging (DTI) is commonly used to establish three-dimensional mapping of white-matter bundles in the supraspinal central nervous system. DTI has also been the subject of many studies on cranial and peripheral nerves. This non-invasive imaging technique enables virtual dissection of nerves in vivo and provides specific measurements of microstructural integrity. Adverse effects on the lumbosacral plexus may be traumatic, compressive, tumoral, or malformative and thus require dedicated treatment. DTI could lead to new perspectives in pudendal neuralgia diagnosis and management. We performed a systematic review of all articles or posters reporting results and protocols for lumbosacral plexus mapping using the DTI technique between January 2011 and December 2023. Twenty-nine articles published were included. Ten studies with a total of 351 participants were able to track the lumbosacral plexus in a physiological context and 19 studies with a total of 402 subjects tracked lumbosacral plexus in a pathological context. Tractography was performed on a 1.5T or 3T MRI system. DTI applied to the lumbosacral plexus and pudendal nerve is feasible but no microstructural normative value has been proposed for the pudendal nerve. The most frequently tracking parameters used in our review are: 3T MRI, b-value of 800 s/mm2, 33 directions, 3 × 3 × 3 mm3, AF threshold of 0.1, minimum fiber length of 10 mm, bending angle of 30°, and 3DT2 TSE anatomical resolution. Increased use of DTI could lead to new perspectives in the management of pudendal neuralgia due to entrapment syndrome, whether at the diagnostic, prognostic, or preoperative planning level. Prospective studies of healthy subjects and patients with the optimal acquisition parameters described above are needed to establish the accuracy of MR tractography for diagnosing pudendal neuralgia and other intrapelvic nerve entrapments.

Prognostic factors for progression-free survival of the filum terminale ependymomas in adults.

OBJECTIVE: To define the prognostic factors for progression and to determine the impact of the histological grading (according to the World Health Organization) on the progression-free survival (PFS) of filum terminale ependymomas. METHODS: A retrospective chart review of 38 patients with ependymoma of the filum terminale was performed, focusing on demographic data, preoperative symptoms, tumor size, quality of resection, presence of a tumor capsule, and histological grade. RESULTS: Gross total resection (GTR) was achieved in 30 patients (78.9%). Histopathological analysis found 21 (55.3%) myxopapillary grade I ependymoma (MPE), 16 (42.1%) ependymoma grade II (EGII), and 1 (2.6%) ependymoma grade III. There was no significant difference between the mean±SD volume of MPE (5840.5±5244.2mm3) and the one of EGII (7220.3±6305.9mm3, p=0.5). The mean±SD follow-up was 54.1±38.4 months. At last follow-up, 30 (78.9%) patients were free of progression. In multivariate analysis, subtotal resection (p=0.015) and infiltrative tumor (p=0.03) were significantly associated with progression. The PFS was significantly higher in patients with encapsulated tumor than in patients with infiltrative tumor (log-rank p=0.01) and in patients who had a GTR in comparison with those who had an incomplete resection (log-rank p=0.05). There was no difference in PFS between patient with MPE and EGII (p=0.1). CONCLUSION: The progression of ependymoma of the filum terminale highly depends on the quality of resection, and whether the tumor is encapsulated. Except for anaplastic grade, histopathological type does not influence progression.

Headholders' - complications in neurosurgery: A review of the literature and recommendations for its use.

Several types of headholders are routinely used in neurosurgical practice to secure the head in a precise position, providing better security during surgical dissection as well as an absence of eye compression during prone positions. Nevertheless, potentially lethal complications might occur. We performed a review of the literature via PubMed and Google Scholar using the terms "Mayfield skull clamp", "Sugita headholders", "headholder complications" and "skull clamp complications". Twenty-six complications directly related to the use of headholders were identified through 19 papers published from 1981 to 2014: mainly skull fractures with or without a dural laceration (50%), epidural hematomas (23.8%), skull fractures with or without a dural laceration (50%), and air embolism (9.5%). The authors propose recommendations for the safe use of headholders.

The minimally invasive endoscopic management of septated chronic subdural hematomas: surgical technique.

BACKGROUND: Fibrin membranes and compartmentalization within the subdural space are a frequent cause of failure in the treatment of chronic subdural hematomas (CSH). This specific subtype of CSH classically requires craniotomy, which carries significant morbidity and mortality rates, particularly in elderly patients. In this work, we describe a minimally invasive endoscopic alternative. METHODS: Under local scalp anesthesia, a rigid endoscope is inserted through a parietal burr hole in the subdural space to collapse fibrin septa and cut the internal membrane. It also allows cauterization of active bleedings and the placement of a drain under direct visualization. CONCLUSIONS: The endoscopic treatment of septated CSH represents a minimally invasive alternative to craniotomy especially for the internal membranectomy.

[Surgery of high-grade gliomas guided by fluorescence: a retrospective study of 22 patients]. / Exérèse neurochirurgicale optimale des gliomes de haut grade guidée par fluorescence : mise au point à partir d'une série rétrospective de 22 patients.

BACKGROUND AND PURPOSE: Optimal surgical resection improves the prognosis of glioblastomas. However, this goal is far from being achieved due to its invasive nature. Several studies have already shown the efficacy of fluorescence-guided surgery, in improving the quality of resection of glioblastoma. We report herein our experience through a retrospective serie and describe the principles, limitations and advantages of this technique. METHODS: Between 2006 and 2009, 22 patients underwent resection of a glioblastoma guided by fluorescence. Following operations, all patients underwent sequential clinical examination and radiological monitoring using multimodal MRI. The extent of resection was assessed by the surgeon during the procedure and by the radiologist on MRI. The curves of progression-free clinical survival (SSP) and overall survival (SG) were analyzed. The prognostic value of the extent of resection was studied. RESULTS: We obtained 68.2% of complete resection according to the absence of residual fluorescence as assessed by the surgeon, and 75% according to the absence of residual tumor on early MRI. The median SSP was 10.75 months and the median SG was 17 months. Complete tumoral resection confirmed by loss of fluorescence significatively increases the median SSP of 6.7 months to 12.9 months (p=0.001559) and the median SG of 12.3 months to 20.9 months (p=0.000559). After 1 year, 81.8% of patients were still alive. CONCLUSIONS: Our study confirms the use of fluorescence as an effective method to allow optimal resection of glioblastoma. In addition to neuronavigation, surgical experience, vision and proprioception, fluorescence contributes to achieve a complete tumor resection.