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.

Postoperative compensation after neurotomy in Meniere's disease: Retrospective study of 15 cases.

INTRODUCTION: Vestibular neurotomy is a functional surgery for Meniere's disease in the event of medical treatment failure. The aim of the study was to assess the efficacy and complications of vestibular neurotomy, and to address the question of postoperative compensation. MATERIAL AND METHOD: All patients included in this retrospective study underwent a vestibular neurotomy at our center between 2009 and 2016. A preoperative evaluation was performed including MRI, audiometry, and videonystagmography. The functional level of disability was evaluated by the Dizziness Handicap Inventory (DHI) score. In all patients suboccipital retrosigmoid approach was performed. All patients underwent early postoperative vestibular rehabilitation. One month and two years after surgery, we assessed the effectiveness of treatment on dizziness, disability and imbalance. At the time of this study (2 to 8 years), DHI and patients' satisfaction by patient's global impression of change (PGIC) scale were evaluated. RESULTS: Fifteen patients aged between 42 and 74 years of age were included in our study. Postoperative complications occurred in two patients (meningitis and a wound infection). At one month, all patients had a dramatic clinical improvement with decreased vertigo. Two years after surgery, 85% of the patients were cured and had no dizziness or balance disorder. Only one patient experienced bilateralization and only one had a persistent poor compensation. CONCLUSION: Vestibular neurotomy is a very effective treatment in the case of Meniere's disease resistant to medical treatment, with very good functional results and an extremely low failure rate.

[Chronic subdural hematoma infected by Campylobacter fetus: case report]. / Infection d'hématome sous-dural chronique à Campylobacter fetus : à propos d'un cas.

We report here a rare case of chronic subdural hematoma infected by Campylobacter fetus in a 86-year-old woman. She was admitted for confusion and disorientation in a context of high fever and diarrhoea. After two surgeries, the evolution was finally good with a combination of antibiotics (amoxicillin and clindamycin). Chronic subdural hematoma is a potential site for bacterial infection. Our case suggests that C. fetus infection should be suspected in elderly patients presenting with fever and enteritis. The frequency of such cases may be underestimated, due to the difficult diagnosis of C. fetus. It is also suspected that C. fetus could play a role in the recurrence of hematoma, because of its vessel tropism.

Intraoperative use of the Medtronic O-arm for deep brain stimulation procedures.

The purpose of this study was to analyze the feasibility and utility of 3D imaging to help lead positioning during a deep brain stimulation (DBS) procedure. A bilateral subthalamic DBS procedure was conducted in 2 patients for idiopathic Parkinson's disease. Subthalamic nucleus targeting was based on preoperative stereotactic MRI. We used the Medtronic O-arm to perform 2D-imaging control (frontal and lateral) as well as quick (<30 s) 3D acquisition. This allowed us to check the positioning of micro-macro electrodes and definite electrodes. 3D images were fused with postoperative CT to assess their accuracy, and with preoperative MRI to visualize the anatomical location of the electrodes. 3D imaging is a quick and safe method to ensure perioperative control of lead placement during DBS procedures.

[Method and results of lumbar infusion test in normal pressure hydrocephalus: review of the literature]. / Méthode et résultats du test de perfusion dans l'hydrocéphalie à pression normale : revue de la littérature.

INTRODUCTION: The cerebrospinal (CSF) infusion test is used to analyze the dynamics of CSF circulation. We describe the technique and report test results obtained in subjects with normal pressure hydrocephalus. STATE OF THE ART: The CSF infusion test is based on pressure monitoring during a continuous infusion of saline solution into the CSF space via a lumbar puncture. The main parameters are: intracranial pressure, resistance to CSF outflow (Rout), and compliance of the cranial enclosure estimated by the pressure-volume index. Our review of the recent literature dealing with the results of infusion test in normal pressure hydrocephalus indicates that the positive predictive value is about 80 % for Rout greater than 12 mmHg/ml per minute, i.e. shunt response is observed in 80 % of patients. The information available in the literature for assessing negative predictive value of Rout and usefulness of compliance is limited. PERSPECTIVES AND CONCLUSION: The CSF infusion test may be helpful for the diagnosis of normal pressure hydrocephalus, as supplemental testing when the diagnosis is not certain. We propose a procedure, which includes the infusion test, for identifying shunt-responsive patients.

Lattice dynamics of oligo(phenylenethienylene)s: a far-infrared and inelastic neutron scattering study.

New promising oligo(phenylenethienylene)s have been synthesized to realize suitable materials for improving electronic transport properties, particularly in organic field effect transistors (OFETs). Far-infrared and incoherent neutron scattering measurements have been performed to assign their phonon modes. The assignment of the main low-frequency phonon modes of these materials has been performed experimentally by using a filiation procedure. Assuming a small frequency dispersion of the high-frequency modes, the main intramolecular phonon modes of a model oligomer have been assigned by using first-principles calculations on its isolated molecule. These assignments constitute the preliminary work for a better understanding of these new promising materials in electronic and opto-electronics applications.

[Creation of self-assessment tools for on-line continuing medical education. Modelization of a training session]. / Création d'outils d'autoévaluation pour une formation médicale continue en ligne. Modélisation à propos d'une formation.

BACKGROUND: For several years, the sessions of continuing medical education organized within the framework of the Société française de neurochirurgie have been recorded on the "campus de neurochirurgie" website, accessible in a form called in "videostreaming" which structures the training session. PURPOSE: Using modern educational methods, how can we transform the scientific productions of our meetings into effective tools for on-line continuing education? METHODS: The article describes the experience gained while creating self-assessment tools starting from the teaching material transmitted by the person in charge of a continuing medical education session, selected and an example for demonstration. RESULTS: We present the various written tools for self-assessment: multiple-choice test and script concordance test (SC). These SC were based partly on a clinical case with various test formats: units of diagnosis, investigation and therapeutics. In connection with the example chosen, we propose a model for constructing on-line continuing medical education sessions, which could be used by persons in charge of such training sessions in neurosurgery and in other specialties. CONCLUSIONS: With the availability of on-line self-assessment tests round-tables videostreaming, this teaching method can be used to fulfil mandatory continuing medical education requirements.

[Giant intradiploic infratentorial epidermoid cyst]. / Quiste epidermoide intradiploico infrastentorial gigante.

Epidermoid cysts are benign, uncommon lesions (1% of all intracranial tumors). Their localization is intradiploic in 25% of cases, and exceptionally subtentorial. We report here a rare case of giant intradiploic infratentorial epidermoid cyst. A 74-year old patient presented with recent diplopia and sindrome cerebellar. CT scan and MR imaging revealed a giant osteolytic extradural lesion of the posterior fossa (5.2 cm x 3.8 cm) with a small area of peripheral enhancement after contrast injection. Retrosigmoid suboccipital craniectomy allowed a satisfactory removal of the tumor, followed by an acrylic cranioplasty. The outcome was good. Neuropathological examination confirmed an epidermoid cyst. We review the literature and discuss our case.

Quiste epidermoide intradiploico infratentorial gigante / Giant intradiploic infratentorial epidermoid cyst

Los quistes epidermoides son lesiones congénitas benignas, de lento crecimiento, que representan el 1% de todos los tumores intracraneales. En un 25% tienen una localización intradiploica y excepcionalmente infratentorial. Presentamos un caso clínico poco frecuente de un quiste epidermoide intradiploico gigante infratentorial. El paciente consultó por una diplopia y un síndrome cerebeloso. La tomografía computarizada y la resonancia magnética mostraron una lesión gigante lítica extradural de la fosa posterior de 5,2 cm x 3,8 cm, con realce periférico con el contraste. Utilizamos un abordaje suboccipital retrosigmoideo para realizar una exéresis completa tumoral y una resección incompleta capsular, debido a la adherencia de ésta al seno lateral. La evolución posoperatoria fue favorable. Realizamos una revisión bibliográfica de la literatura y discusión de nuestro caso

Epidermoid cysts are benign, uncommon lesions(1% of all intracranial tumors). Their localization is intradiploic in 25% of cases, and exceptionally subtentorial. We report here a rare case of giant intradiploicinfratentorial epidermoid cyst. A 74-year old patient presented with recent diplopia and sindrome cerebellar. CT scan and MR imaging revealed a giant osteolytic extradural lesion of the posterior fossa (5,2 cm x 3,8 cm)with a small area of peripheral enhancement after contrast injection. Retro sigmoid suboccipital craniectomy allowed a satisfactory removal of the tumor, followed by an acrylic cranioplasty. The outcome was good. Neuropathological examination confirmed an epidermoidcyst. We review the literature and discuss our case

[Less invasive calibration of lumbar canal stenosis. Results with a tubular muscle retraction system used in 35 patients]. / Recalibrage moins invasif des sténoses canalaires lombaires. A propos de 35 patients opérés en utilisant un système tubulaire de rétraction musculaire.

BACKGROUND: The purpose of this study was to evaluate retrospectively the indications, surgical technique, and postoperative findings in a series of 35 patients presenting lumbar canal stenosis due to osteoarthritic degeneration who underwent surgery using a tubular system for muscle retraction. METHODS: This retrospective analysis included 35 patients, 28 with lumbar canal stenosis on a single level and seven with stenosis on two levels. On the stress images, 8 of these 35 patients presented stable degenerative spondylolisthesis. The surgical technique consisted in using a tubular system for muscle retraction. This enabled access for magnification and microsurgery of the canal, which was opened via an interlaminal approach. Concentric endocanal treatment was thus achieved without laminectomy. The same surgeon performed these 35 operations. The following variables were noted: patient age, level of canal narrowing, initial symptoms, duration of the operation, postoperative pain, use of analgesics, duration of hospital stay, clinical outcome at one and six months. RESULTS: The postoperative period (mean postoperative stay 2.5 days) was generally uneventful with little pain (mean VAS 0.8). This can be explained by the absence of invasive dissection. Disinsertion of the paravertebral muscles and use of elevators can induce muscle ischemia. The spine is not destabilized since laminectomy is avoided. The six-month outcome showed relief of the initial symptom for 84% of patients. There were two dural breaches with no clinical impact and one patient required revision surgery because of destabilization of a degenerative spondylolisthesis. One other patient also required revision for complementary laminectomy. CONCLUSION: The short-, mid-, and long-term results of spinal canal recalibration using a less invasive approach to lumbar canal stenosis via a tubular system for muscle retraction has provided encouraging results in terms of symptom relief. The early postoperative period is short and uneventful allowing earlier resumption of daily activities. This technique reduces the cost of hospitalization and drugs and is adapted for geriatric patients. The long-term outcome with this technique should be assessed in terms of spinal stability after recalibration.

A report of a desmoplastic ganglioglioma in a 12-year-old girl with review of the literature.

Desmoplastic infantile ganglioglioma is a supratentorial tumor that typically occurs in infants below the age of 24 months. Rare tumors with the same radiological and histological characteristics have been described in older subjects. We report a case of desmoplastic ganglioglioma in a 12-year-old girl with a 13 years follow-up. The patient presented with an inaugural generalized seizure. CT scan demonstrated a large superficial parieto-occipital mass, attached to the dura with solid and cystic components. Surgical resection was macroscopically complete. No adjuvant treatment was given. Thirteen years after surgery, the patient is symptom free. Histological examination revealed a pleomorphic tumor involving the meningeal space and the cortex. Meningeal portion was made of neoplastic astrocytes enmeshed in a dense network of connective tissue. The cortical component showed abnormal neurons, tumoral astrocytes and small foci of poorly differentiated cells with rare mitoses. Our observation and the seven others found in the literature indicate that desmoplastic gangliogliomas can occur in children and even in young adults. Despite some worrisome radiological and histological features, these tumors should not be misdiagnosed as malignant glioma. Like infantile cases, non-infantile desmoplastic gangliogliomas seem to have a favorable prognosis without additional therapy, if a total surgical resection can be performed.

[Venous embolization of dural arterio-venous fistulas. Transcranial approach under neuronavigation]. / Embolisation de fistules artério-veineuses durales par voie veineuse.

OBJECT: Transvenous embolization is an effective treatment for dural arterio-venous fistulas. In the event of dural sinus thrombosis, embolization can be performed by direct puncture via craniectomy. We report our experience with transcranial venous embolization in two patients. METHODS: Two patients underwent transcranial venous embolization of a type-III dural arterio-venous fistula of the transverse sinus. The craniectomy was performed with neuronavigation assistance. RESULTS: The surgical approach consisted in a minimal exposure of the sinus with a drill. Neuronavigation allowed accurate placement of the craniectomy. The endovascular treatment was performed in a second stage, enabling complete and stable occlusion of the fistula in both patients. CONCLUSION: This combined treatment of dural AVFs associating craniectomy and transcranial puncture of the sinus is simple and efficient when retrograde navigation through the internal jugular vein cannot be achieved. Neuronavigation is helpful in accurately positioning the craniectomy.

Mutations within the programmed cell death 10 gene cause cerebral cavernous malformations.

Cerebral cavernous malformations (CCMs) are hamartomatous vascular malformations characterized by abnormally enlarged capillary cavities without intervening brain parenchyma. They cause seizures and cerebral hemorrhages, which can result in focal neurological deficits. Three CCM loci have been mapped, and loss-of-function mutations were identified in the KRIT1 (CCM1) and MGC4607 (CCM2) genes. We report herein the identification of PDCD10 (programmed cell death 10) as the CCM3 gene. The CCM3 locus has been previously mapped to 3q26-27 within a 22-cM interval that is bracketed by D3S1763 and D3S1262. We hypothesized that genomic deletions might occur at the CCM3 locus, as reported previously to occur at the CCM2 locus. Through high-density microsatellite genotyping of 20 families, we identified, in one family, null alleles that resulted from a deletion within a 4-Mb interval flanked by markers D3S3668 and D3S1614. This de novo deletion encompassed D3S1763, which strongly suggests that the CCM3 gene lies within a 970-kb region bracketed by D3S1763 and D3S1614. Six additional distinct deleterious mutations within PDCD10, one of the five known genes mapped within this interval, were identified in seven families. Three of these mutations were nonsense mutations, and two led to an aberrant splicing of exon 9, with a frameshift and a longer open reading frame within exon 10. The last of the six mutations led to an aberrant splicing of exon 5, without frameshift. Three of these mutations occurred de novo. All of them cosegregated with the disease in the families and were not observed in 200 control chromosomes. PDCD10, also called "TFAR15," had been initially identified through a screening for genes differentially expressed during the induction of apoptosis in the TF-1 premyeloid cell line. It is highly conserved in both vertebrates and invertebrates. Its implication in cerebral cavernous malformations strongly suggests that it is a new player in vascular morphogenesis and/or remodeling.

Pre-irradiation chemotherapy for newly diagnosed high grade astrocytoma.

The purpose of this work was to determine the response rate and toxicity of a combination of Carmustine and Cisplatin administered before radiation in patients with newly diagnosed high grade astrocytoma. A good response rate has been published with this association in primary cerebral high grade tumor. This protocol was administered in a homogeneous population of 37 adult patients with measurable tumor on magnetic resonance imaging (MRI) or CT scan. After biopsy or subtotal resection, the patients received BCNU 40 mg/m2/d and CODP 40 mg/m2/d, for 3 days every 28 days for 3 cycles. Evaluation was performed before each cycle. Radiation therapy began 4 weeks after completing the chemotherapy or immediately if there was evidence of tumor progression on chemotherapy. Seven out of 37 (19%) demonstrated tumor regression with a median duration to progression of 11 months. Median survival was 6 months. Myelosuppression was the predominant but manageable toxicity. This work indicated that the first chemotherapy protocol gave poor results in a homogeneous group of patients, with bad prognosis.

[Self-assessment for neurosurgery residents by script concordance test (SCT). The process of test elaboration]. / Auto-évaluation des internes en neurochirurgie par tests de concordance de script (TCS). Processus d'élaboration des tests.

BACKGROUND: The script concordance test (SCT) is a new tool to assess clinical reasoning in a context of uncertainty. It was chosen for computer-based self-assessment training for neurosurgery residents. PURPOSE: The aim of this work is to describe the construction of a first series of questions and provide teachers practical information needed to build a SCT. METHOD: The theorical background of the SCT is explained. We review the steps we followed when writing of a series of more than two hundred questions. RESULTS: We present the different steps of our work, including writing clinical cases, validation of questions and elaboration of scoring systems. We explain the main difficulties we encountered. CONCLUSION: The script concordance test is an interesting easy-to-construct assessment tool useful for evaluating clinical competence. This work summarizes our experience in building a SCT, which should be helpful for teachers interested in this new assessment tool, especially in neurosurgery.

Mutations within the MGC4607 gene cause cerebral cavernous malformations.

Cerebral cavernous malformations (CCM) are hamartomatous vascular malformations characterized by abnormally enlarged capillary cavities without intervening brain parenchyma. They cause seizures and focal neurological deficits due to cerebral hemorrhages. CCM loci have already been assigned to chromosomes 7q (CCM1), 7p (CCM2), and 3q (CCM3) and have been identified in 40%, 20%, and 40%, respectively, of families with CCM. Loss-of-function mutations have been identified in CCM1/KRIT1, the sole CCM gene identified to date. We report here the identification of MGC4607 as the CCM2 gene. We first reduced the size of the CCM2 interval from 22 cM to 7.5 cM by genetic linkage analysis. We then hypothesized that large deletions might be involved in the disorder, as already reported in other hamartomatous conditions, such as tuberous sclerosis or neurofibromatosis. We performed a high-density microsatellite genotyping of this 7.5-cM interval to search for putative null alleles in 30 unrelated families, and we identified, in 2 unrelated families, null alleles that were the result of deletions within a 350-kb interval flanked by markers D7S478 and D7S621. Additional microsatellite and single-nucleotide polymorphism genotyping showed that these two distinct deletions overlapped and that both of the two deleted the first exon of MGC4607, a known gene of unknown function. In both families, one of the two MGC4607 transcripts was not detected. We then identified eight additional point mutations within MGC4607 in eight of the remaining families. One of them led to the alteration of the initiation codon and five of them to a premature termination codon, including one nonsense, one frameshift, and three splice-site mutations. All these mutations cosegregated with the disease in the families and were not observed in 192 control chromosomes. MGC4607 is so far unrelated to any known gene family. Its implication in CCMs strongly suggests that it is a new player in vascular morphogenesis.

Endoscopic endonasal management of invasive skull base mucocele: report of two cases.

Two cases of massive erosive skull base sphenoid mucocele are reported. Even if intra-sphenoid mucoceles are an ENT pathology, when extensive they become of neurosurgical interest. An endoscopic minimally invasive procedure was performed in both cases with an excellent outcome. Patient 1 presented with several years of retro-orbital bilateral pain and several months of purulent pharyngeal leak. CT scan and MRI imaging showed an extensive erosive intra-sphenoid mass, with peripheral contrast enhancement. Patient 2 was referred because of several months of frontal headache and decreased left visual acuity. A wide intra-sphenoid mass was evident at CT scan and MRI. This mass included an anterior compartment, hyperintense on both T (1)- and T (2)-weighted images, and a posterior part, hypointense on T (1)- and hyperintense on T (2)-weighted images. A pure endoscopic endonasal one nostril pure procedure was performed in both cases. Endoscopic technique has been shown to be an easy and minimally invasive procedure. It should be the treatment of choice in case of invasive skull base mucocele in order to avoid blind damage of vasculo-nervous structures which are not protected by the bone, extensively eroded by the lesion.