Molecular revolution in the diagnosis of microbial brain abscesses.

A brain abscess is a life-threatening infection, frequently with serious sequelae. Culture-based methods present many limitations and do not enable an exhaustive documentation of the bacterial flora. 16S rRNA-based amplification, cloning, and high-throughput sequencing have dramatically increased the number of identified agents of brain abscesses, showing that the causative flora is polymicrobial in up to 40 % of cases, with the presence of at least one anaerobic bacterium. In contrast, real-time polymerase chain reaction (PCR) technology is an appealing alternative to culture-based methods for diagnosing brain abscesses due to its speed, sensitivity, and specificity. Molecular typing is available for several bacterial and fungal genera, and this user-friendly tool is accessible for the clinical microbiology laboratory to diagnose microbes involved in a brain abscess. This article reviews the applications of the currently available tools for the etiological diagnosis of a brain abscess.

Guillain-Barré syndrome following severe head trauma and spine surgery.

Guillain-Barré syndrome (GBS) is an acute-onset inflammatory polyradiculoneuropathy usually triggered by an infectious disease. In some cases, GBS can occur without any preceding infectious episode, like after vaccination, epidural anaesthesia or surgery. A 73 years old woman had head and spine trauma. Body-TDM showed bilateral temporal and right frontal haematomas and fracture of the first lumbar vertebrae. Sextant and kyphoplasty were performed. She presented 14 days after surgery tetraparesis, swallowing difficulties and bilateral facial palsy. Electromyography was consistent with demyelinating neuropathy. Cerebrospinal fluid examination found albumino-cytological dissociation. Viral and bacterial serology and antiganglioside antibodies were negative. She was treated with intravenous immunoglobulins. Four months after discharge she had fully recovered except left peripheral facial palsy. GBS can rarely be triggered by head trauma or spine surgery. Physician must keep in mind this diagnosis whenever their patients present acute-onset neurological worsening in such context.

Results of a French pilot database of standard of care of chronic subdural hematoma.

BACKGROUND: A registry of chronic subdural hematoma does not exist in France yet. OBJECTIVE: To present a monocentric pilot project of a French registry of surgical management of chronic subdural hematoma. METHOD: A monocentric pseudonymized formal database was created. From May 2020 to May 2021, all patients undergoing surgical evacuation of chronic subdural hematoma were entered into the database. RESULTS: One hundred and twenty four surgeries from 113 patients were entered in the database. Patients' demographic and surgical data as well as follow-up are described. CONCLUSION: A local database is easy to implement. We propose a national registry of chronic subdural hematoma management.

[Clinical presentation suggesting Bickerstaff encephalitis and intracranial hypertension]. / Tableau d'encéphalite de Bickerstaff et hypertension intracrânienne.

A 20-year-old man had progressive headache, neck pain and visual loss after upper airway infection. After 3 weeks, he developed ophtalmoplegia, ataxia, areflexia, autonomic failure, four limbs paresis with impaired consciousness. Brain and cervical MRI were normal. Ophthalmological examination confirmed bilateral papilledema. Cerebro-spinal fluid pressure was high, cell count was normal and proteins were mildly elevated. Electromyography showed presence of both proximal and distal demyelination. Electroencephalogram was slowed, with diffuse delta and theta waves. Anti-GM1 and GQ1b antibodies were negative. The patient was treated with intravenous immunoglobulins (0.4 g/kg/day) for 5 days, associated with high doses of acetazolamide and corticosteroids for papilledema. His neurological condition improved for gait, strength, pain, ophtalmoplegia and ataxia. He kept severe visual loss with optic atrophy. Diagnosis is discussed: Bickerstaff encephalitis with intracranial hypertension or malignant pseudotumor cerebri?

Sustainable neurosurgical training around the globe. A review and outline.

Sharing an equal and quality neurosurgical training across the globe without exclusion may seem utopian. However, such training is possible through educational opportunities and the ongoing digital revolution. The aim is to present the current state of neurosurgery training and education methods indicating strengths, weaknesses and opportunities. The thoughts, comments and suggestions of the authors are based on their academic experiences, training missions around the world and particularly in low- and middle-income countries by pointing out the French experience. The learning must be interactive and programmed over time, integrating varied courses and activities. Virtual reality and neurosurgical simulation need to be developed. The content of the teaching including e-learning must be evidence-based and peer-reviewed. Pedagogical training of trainers is fundamental. It is critical to evaluate the training under real working conditions. The optimization of human resources should create economies of scale that would attenuate the financial burden. The commitment of the teams, tutoring are success factors.

The presigmoid retrolabyrinthine approach: Technical note.

BACKGROUND: The retrolabyrinthine approach is classified among the posterior petrosectomies. Its goal is to achieve an enlarged mastoidectomy while sparing the intrapetrous neurotologic structures in order to offer maximal exposure of the posterior cerebellopontine angle compound. METHODS: The stages of the procedure are subsequently the skeletonization of the sigmoid sinus, wide opening of the mastoid antrum and exposure of the semicircular canals. We present herein the technique, indications and limitations of the retrolabyrinthine approach. CONCLUSION: The retrolabyrinthine approach is a demanding technique. Nowadays the retrolabyrinthine approach is routinely combined to additional resections of the petrous bone, so-called "combined petrosectomies", to target the jugular foramen or the petroclival area.

T1 Mapping for Microstructural Assessment of the Cervical Spinal Cord in the Evaluation of Patients with Degenerative Cervical Myelopathy.

BACKGROUND AND PURPOSE: Although current radiologic evaluation of degenerative cervical myelopathy by conventional MR imaging accurately demonstrates spondylosis or degenerative disc disease causing spinal cord dysfunction, conventional MR imaging still fails to provide satisfactory anatomic and clinical correlations. In this context, we assessed the potential value of quantitative cervical spinal cord T1 mapping regarding the evaluation of patients with degenerative cervical myelopathy. MATERIALS AND METHODS: Twenty patients diagnosed with mild and moderate-to-severe degenerative cervical myelopathy and 10 healthy subjects were enrolled in a multiparametric MR imaging protocol. Cervical spinal cord T1 mapping was performed with the MP2RAGE sequence procedure. Retrieved data were processed and analyzed regarding the global spinal cord and white and anterior gray matter on the basis of the clinical severity and the spinal canal stenosis grading. RESULTS: Noncompressed levels in healthy controls demonstrated significantly lower T1 values than noncompressed, mild, moderate, and severe stenotic levels in patients. Concerning the entire spinal cord T1 mapping, patients with moderate-to-severe degenerative cervical myelopathy had higher T1 values compared with healthy controls. Regarding the specific levels, patients with moderate-to-severe degenerative cervical myelopathy demonstrated a T1 value increase at C1, C7, and the level of maximal compression compared with healthy controls. Patients with mild degenerative cervical myelopathy had lower T1 values than those with moderate-to-severe degenerative cervical myelopathy at the level of maximal compression. Analyses of white and anterior gray matter confirmed similar results. Strong negative correlations between individual modified Japanese Orthopaedic Association scores and T1 values were also observed. CONCLUSIONS: In this preliminary study, 3D-MP2RAGE T1 mapping demonstrated increased T1 values in the pathology tissue samples, with diffuse medullary alterations in all patients with degenerative cervical myelopathy, especially relevant at C1 (nonstenotic level) and at the maximal compression level. Encouraging correlations observed with the modified Japanese Orthopaedic Association score make this novel approach a potential quantitative biomarker related to clinical severity in degenerative cervical myelopathy. Nevertheless, patients with mild degenerative cervical myelopathy demonstrated nonsignificant results compared with healthy controls and should now be studied in multicenter studies with larger patient populations.

Toward the development of 3-dimensional virtual reality video tutorials in the French neurosurgical residency program. Example of the combined petrosal approach in the French College of Neurosurgery.

BACKGROUND: The present study developed 3D video tutorials with commentaries, using virtual reality headsets (VRH). VRHs allow 3D visualization of complex anatomy from the surgeon's point of view. Students can view the surgery repeatedly without missing the essential steps, simultaneously receiving advice from a group of experts in the field. METHODS: A single-center prospective study assessed surgical teaching using 3D video tutorials designed for French neurosurgery and ENT residents participating in the neuro-otology lateral skull-base workshop of the French College of Neurosurgery. At the end of the session, students filled out an evaluation form with 5-point Likert scale to assess the teaching and the positive and negative points of this teaching tool. RESULTS: Twenty-two residents in neurosurgery (n=17, 81.0%) and ENT (n=5) were included. Eighteen felt that the 3D video enhanced their understanding of the surgical approach (81.8%). Fifteen (68.2%) thought the video provided good 3D visualization of anatomical structures and 20 that it enabled better understanding of anatomical relationships (90.9%). Most students had positive feelings about ease of use and their experience of the 3D video tutorial (n=14, 63.6%). Twenty (90.9%) enjoyed using the video. Twelve (54.5%) considered that the cadaver dissection workshop was more instructive. CONCLUSIONS: 3D video via a virtual reality headset is an innovative teaching tool, approved by the students themselves. A future study should evaluate its long-term contribution, so as to determine its role in specialized neurosurgery and ENT diploma courses.

Chiari malformations in adults: A single center surgical experience with special emphasis on the kinetics of clinical improvement.

BACKGROUND: The Chiari malformation type I (CM-I) is the most commonly found type in adults. The efforts to further improve the treatment offered for these malformations are hampered by the existence of controversial methods and the absence of a uniform scoring system to evaluate clinical outcomes. OBJECTIVES: The goal of our study is to analyze the clinical and radiological data concerning patients operated for CM and to expose surgical techniques. PATIENTS AND TREATMENT: This is a retrospective study concerning patients of more than 16 years of age, operated on (from 2000 to 2016) in our institution. These patients underwent bony decompression of the cervico-occipital junction, with a duraplasty enlargement. Clinical and radiological follow-up was assessed sequentially. RESULTS: The mean age of patients included in this study was 39. Headaches (n=19) and sensory disturbances (n=17) were the most common presenting complaints. Furthermore, syringomyelia symptoms were present in 34.5% of the cases (n=10). Twenty-three patients displayed a Chiari malformation of type I (79.3%), and six patients were classified as Chiari malformation type I.5 (20.7%). A syringomyelia was present in 58.6% of the cases (n=17). The postoperative complications that were encountered were: one case of pseudo-meningocele, two cases of cerebrospinal fluid leakage, two cases of meningitis, and one case of delayed wound healing. The mean follow-up period was 18 months, which showed beneficial outcomes in 82.8% of the cases (20.7% cured, and 62.1% improved) and an unfavorable outcome in 17.2% of the cases (13.8% stable patients and 3.4% worsened outcomes). Syringomyelia symptoms were improved in 60% of the patients. Among the patients who presented without a syrinx, 82.3% had good outcomes; and those who presented with a syrinx, 83.4% had good outcomes. Symptoms improved for 69% of patients within 3 months. CONCLUSION: An optimal craniocervical osteo-dural decompression plus duraplasty offered early and sustainable good clinical results in symptomatic CM-I and CM-I.5 patients.

Long term surgical results of 154 petroclival meningiomas: A retrospective multicenter study.

BACKGROUND: Outcomes of petroclival meningiomas (PCM) (morbidity, permanent cranial nerves deficit, tumor removal and recurrence) are inconsistent in the literature, making it a challenge to predict surgical morbidity. METHODS: A multicenter study of patients with PCMs larger than 2.5cm between 1984 and 2017 was conducted. The authors retrospectively reviewed the patients' medical records, imaging studies and pathology reports to analyze presentation, surgical approach, neurological outcomes, complications, recurrence rates and predictive factors. RESULTS: There were 154 patients. The follow-up was 76.8 months on average (range 8-380 months). Gross total resection (GTR) was achieved in 40 (26.0%) patients, subtotal resection (STR) in 101 (65.6%), and partial resection in 13 (8.3%). Six (2.6%) perioperative deaths occurred. The 5-year, 10-year and 15-year progression-free survival (PFS) of GTR and STR with radiation therapy (RT) was similar (100%, 90% and 75%). PFS of STR without adjuvant radiation was associated with progression in 71%, 51% and 31%, respectively. Anterior petrosectomy and combined petrosectomy were associated with higher postoperative CN V and CN VI deficits compared to the retrosigmoid approach. The latter had a significantly higher risk of CN VII, CN VIII and LCN deficit. Temporal lobe dysfunction (seizure and aphasia) were significantly associated with the anterior petrosectomy approach. CONCLUSIONS: Our study shows that optimal subtotal resection of PCMs associated with postoperative RT or stereotactic radiosurgery results in long-term tumor control to equivalent radical surgery. Case selection and appropriate intraoperative judgement are required to reduce the morbidity.

[The combined petrosal approach. Anatomical principles, surgical technique and indications]. / La pétrectomie combinée Bases. anatomiques, technique chirurgicale et indications.

Management of large petroclival tumors requires the use of extensive surgical approaches that usually jeopardize the intrapetrous neuro-otologic structures. To confirm the interest of the combined petrosal approach in this indication, we describe the relevant anatomy and the surgical steps of this procedure. After making a periauricular skin incision and muscle elevation, an occipitotemporal bone flap is shaped. Then a retrolabyrinthine exposure is undertaken, with optimal skeletonization of the semicircular canals. Around the internal auditory canal, the retromeatal area and the petrous apex are resected. The retrosigmoid dura is opened followed by the incision of the subtemporal and posterior fossa dura along the superior petrosal sinus. The sinus is coagulated and divided. The tentorium is sectioned transversally toward its free edge behind the porus of the trochlear nerve. The combined petrosal approach is able to provide a wide multidirectional corridor toward the ventral surface of the pons, the basilary trunk and the ipislateral cranial nerves from the oculomotor to the lower cranial nerves. This study confirms that despite a significant extra time needed for proper achievement, the combined petrosal approach is a valuable conservative approach when the petroclival area, ventral brain stem and basilary trunk are targeted. This approach should be included in the panel of the transpetrous routes available by expert skull base teams.

Long-term results of Gamma-knife stereotactic radiosurgery for vestibular schwannomas in patients with type 2 neurofibromatosis.

INTRODUCTION: The aim of this study was to analyze the long-term results of Gamma-knife radiosurgery treatment of vestibular schwannomas in type 2 neurofibromatosis patients. MATERIALS AND METHODS: A cohort of 129 treatments for vestibular schwannomas in 103 patients was selected from a prospectively-maintained clinical database. Tumor control was assessed by volumetric analysis of the tumor at the last follow-up. Any need of a further procedure such as microsurgical removal or second treatment was regarded as a failure of tumor control. Hearing function was assessed based on Gardner-Robertson classification. Progression-free survival and functional hearing preservation rates were estimated using the Kaplan-Meier method. RESULTS: The median age at treatment was 34 years with no gender predominance. The median tumor volume was 1.5cm3. At a median clinical follow-up of 5.9 years, five patients had died, four underwent a second radiosurgical procedure and eight underwent microsurgical resection. Progression-free survival was 88 and 75% respectively at 5 and 10 years. Hearing was considered serviceable in 70 ears and remained functional in 28 ears. Kaplan-Meier estimates for 5 and 10 years functional hearing was 47 and 34%, respectively. Three patients developed new facial nerve palsy after radiosurgery at 15 days, 6 and 19 months respectively and only one partially recovered. Five patients complained of a subjective instability worsening. Four cases developed trigeminal neuropathy. No predictive factors were found to be statistically correlated with a better hearing outcome or an improved tumor growth control. CONCLUSION: Results prove less satisfying than in sporadic unilateral schwannomas. However, the lower rate of mortality and morbidity compared with microsurgical resection may support a proactive role of Gamma-knife in this pathology.

Delayed hemorrhagic complication after complete embolization of a brain arteriovenous malformation.

Endovascular embolization is an essential therapeutic approach in the multidisciplinary management of cerebral arteriovenous malformations (AVM). However, it rarely occludes the AVM in its entirety. It is often combined with surgery or stereotactic radiosurgery. The aim of embolization is to reduce the size of the nidus and the intra-nidal flow in order to facilitate the microsurgical or the radiosurgical procedure. We report the case of a 61-year-old patient with a right frontal hemorrhagic AVM treated with complete embolization in a single session. Initially, a surgical procedure for excision of the AVM was scheduled 24hours post-embolization. This surgery was canceled due to a good angiographic result of the embolization. Eight days post-embolization, there was a massive re-bleed of the AVM which justified emergency surgical management. This case illustrates a delayed post-embolization hemorrhagic complication of an occluded AVM and prompts a review of the therapeutic strategy of the cerebral AVM to select the most effective and least morbid procedure or combination of procedures.

A randomized controlled study assessing outcome, cognition, autonomy and quality of life in over 70-year-old patients after aneurysmal subarachnoid hemorrhage.

BACKGROUND: Current aging of the population with good physiological status and the increasing incidence of subarachnoid hemorrhage (SAH) in elderly patients has enhanced the benefit of treatment in terms of independence and long-term quality of life (QoL). METHODS: From November 1, 2008 to October 30, 2012, 351 patients aged 70 years or older with aneurysmal SAH underwent adapted treatment: endovascular coiling (EV) for 228 (65%) patients, microsurgical clipping (MS) for 75 (29.3%) or conservative treatment for 48 (13.7%). Forty-one of these were randomized to EV (n=20) or to MS (n=21). The objectives were to determine the proportion of patients with modified Rankin Scale score≤2 (independence) at 1 year, and, secondarily, to compare cognitive function on the Mini-Mental State Examination (MMSE), autonomy on the Activities of Daily Living Index (ADLI) and Instrumental Activities of Daily Living scale (IADL), and QoL, in the prospective and randomized arms, at 1 year. RESULTS: At 1 year, with 1 loss to follow-up in the EV arm, 11 patients (55%) were independent after EV occlusion and 8 (38.1%) after MS exclusion, without significant difference (P=0.29). Mortality was higher after MS during the first 2 postoperative months, and thereafter the difference between MS and EV ceased to be significant. Cognitive function and autonomy scores were similar in both arms. CONCLUSION: In elderly patients treated for aneurysmal SAH, approximately 50% were independent at 1 year, with conserved cognition and autonomy. EV and MS are valid procedures in this population, with similar results at 1 year in terms of independence, cognition, autonomy, and QoL.

[Temporopolar epidural transcavernous transpetrous approach. Technique and indications]. / Approche épidurale temporopolaire transcaverneuse transpétreuse. Technique chirurgicale et indications.

BACKGROUND AND PURPOSE: Several selective approaches have been recommended for access to the petroclival region (PCR). However, locoregional extension of the tumor may necessitate more extensive procedures. Dissections from injected specimens allowed us to describe the different osteodural triangles that are exposed to provide an extensive access to the PCR. METHOD: The bony step included a temporopterional flap and exposure of the paraclinoid carotid after removal of the anterior clinoid process. The sphenoid wing was then extensively drilled, exposing the foramen rotundum and ovale. An anterior petrosectomy was subsequently performed. The dura propria of the cavernous sinus was elevated as far as the Meckel cave. The sylvian fissure was also opened. Then, the temporobasal dura and the dura from the posterior surface of the petrous bone were opened and the superior petrosal sinus was coagulated and divided. The tentorium was divided toward its free edge. RESULTS: Via this approach, cranial nerves from the olfactory tract to the acousticofacial bundle are exposed. In the same way, the ventral and lateral surface of the pons is identified. CONCLUSION: The epidural temporopolar transcavernous transpetrous approach is useful to expose during the same procedure, elements of the posterior and middle cranial fossa. It is of particular value when managing tumors simultaneously involving the PCR, the parasellar, and the suprasellar regions.

[Value of retrolabyrinthine approach for surgical resection of meningiomas inserted around the lateral sinus between the transverse and sigmoid parts]. / Avantages de l'abord rétro-labyrinthique pour l'exérèse des méningiomes insérés au pourtour du coude du sinus latéral.

PURPOSE: To describe the retrolabyrinthine approach for the resection of 9 meningiomas inserted around the lateral sinus between the transverse and sigmoid parts, to discuss the value of this approach compared to the retrosigmoid approach for resection of meningioma in this localization and to review the literature. METHODS: Retrospective study. Between 1988 and 2002, 9 patients (8 female, mean age 50 years) underwent surgery via the retrolabyrinthine approach for resection of meningiomas inserted around the lateral sinus between the transverse and sigmoid parts. RESULTS: Resection was total (8 Simpson I and 1 Simpson II) in all patients. In the early postoperative course, one patient was treated for meningitidis with an LCR leak and one patient present a temporary paresis of the vagus nerve. Mean follow-up was 5 years (6 months-10 years). All patients continued their pre-treatment occupation after surgery. No recurrence was observed. CONCLUSION: Two approaches can be used for resection of meningiomas in this localization. The retrosigmoid approach is a common neurosurgical approach exposure of the cerobellopontine angle. It is practised by most neurosurgeons. Via this approach, the cerebellar lobe must be pushed back so the arteries feeding the tumor are in the operative field at the end of the procedure. For numerous authors the operative field is too narrow. On the other hand, the retrolabyrinthine approach described in 1972 by Hitselberger and Pulec allows exposure of feeding arteries during the first steps of operation, an easier resection of meningioma insertion and better control of the lateral sinus. This approach can be enlarged to the retrosigmoid or the subtemporal anatomic region.

"Giant cell reparative tumor: An exceptional differential diagnosis for a lytic lesion of the temporal bone".

BACKGROUND AND IMPORTANCE: Giant cell reparative granuloma is a very rare benign osteolytic lesion. It typically arises in the mandible and rarely involves the skull. CLINICAL PRESENTATION: A 25-year-old male was admitted in August 2002 for a painless left preauricular mass of several months duration. CT scan revealed an osteolytic extradural lesion located in the temporal bone, with extension to infratemporal fossa. We performed a surgical partial resection of the tumour via a frontotemporal approach. At 36 months after surgery, the lesion continued growth and subsequently we decided to perform a preauricular infratemporal approach. After a ten year-follow-up, the patient remained asymptomatic and a small tumour remnant was visible and stable. CONCLUSION: Giant cell reparative granulomas that originate from the temporal bone are exceptional. There are no typical radiological features of this disease. Diagnosis is confirmed by analysis of the surgical specimen. Tumor growth requires surgical resection.

Ruptured posterior ethmoidal artery aneurysm and Moyamoya disease in an adult patient. Case report.

The association between Moyamoya disease and intracranial aneurysms is well described. In our case, we describe a unique aneurismal location and its management. We report the case of a 74-year-old woman affected by a Moyamoya disease who displayed a frontal lobe hematoma. The origin of the bleeding came from the rupture of a posterior ethmoidal artery aneurysm that was treated surgically with favourable outcome. This case of a ruptured posterior ethmoidal artery aneurysm in a Moyamoya patient illustrates the polymorphism of the vascular complications encountered in this disease. It stresses the need to obtain information from an angiographic investigation in order to select the best therapeutic option and to reduce procedural complications.

Cerebellopontine angle gangliogliomas: Report of two cases.

BACKGROUND: Gangliogliomas are rare tumors of the central nervous system. We report two unusual cases of gangliogliomas located in the cerebellopontine angle (CPA). POPULATION AND METHODS: The first patient was a 57-year-old woman, who presented with dizziness and harbored a non-enhanced heterogeneous mass located in the cisternal space of the CPA. A partial microsurgical removal was performed, and the pathological examination concluded a grade I ganglioglioma according to the WHO Classification. The postoperative course was uneventful without any adjuvant treatment and the 5-year imaging follow-up indicated a stable remnant tumor. The second patient was a 35-year-old male who presented with acute vertigo and imbalance associated with recent prominent headaches; MR imaging showed a large heterogeneous and post-contrast enhanced tumor mass located in the CPA cistern with a mass effect on the brain. An optimal subtotal surgical resection was performed. The pathologists concluded a WHO grade III ganglioglioma. In spite of adjuvant radiotherapy and chemotherapy, the evolution proved unfavorable and patient died from cancer complications within a 2-year period. In both cases, the precise origin of the tumor could not be clearly identified even if the major component was present in the cisternal space. CONCLUSION: Gangliogliomas growing into the cisternal spaces are exceedingly rare particularly in the CPA. Due to its infiltrating behavior and major difficulties to identify the tumor margins, total resection is not routinely feasible. The histological grading is the most important predictor for oncological prognosis.