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Introduction: Surgical resection of supratentorial cavernous angiomas located in eloquent areas poses a significant risk to the patient of postoperative neurological impairment and justifies intraoperative functional monitoring., Methods: Multicentre retrospective series of adult patients with cavernous angiomas located within eloquent areas and treated with functional-based surgical resection according to functional boundaries under intraoperative functional cortico-subcortical monitoring under awake conditions., Results: Fifty patients (18 males, mean 36.3±10.8 year-old) underwent surgical resection with intraoperative cortico-subcortical functional mapping using direct electrostimulation under awake conditions for a cavernous angioma located in eloquent areas with a mean postoperative follow-up of 21.0±21.2 months. At presentation, the cavernous angioma had previously resulted in severe impairment (neurological deficit in 34%, seizures in 70%, uncontrolled seizures in 34%, reduced Karnofsky Performance Status score of 70 or less in 24%, inability to work in 52%). Functional-based surgical resection allowed complete removal of the cavernous angioma in 98% and of the haemosiderin rim in 82%. Postoperative seizures and other complications were rare, and similarly so across all centres included in this series. Postoperatively, we found functional improvement in 84% of patients (reduced Karnofsky Performance Status score of 70 or less in 6%, uncontrolled seizures in 16%, and inability to work in 11%)., Conclusion: Functional-based surgical resection aids the safe and complete resection of cavernous angiomas located in eloquent areas while minimizing the surgical risks. Functional mapping has to be considered in such challenging cases., (Copyright © 2016 Elsevier Masson SAS. All rights reserved.)

Introduction: The indication for awake brain surgery depends on a prerequisite, i.e. recognition that the brain area concerned is truly eloquent, and identification of one or more functions that must be preserved. These functions are determined preoperatively in collaboration with the patient, and neuropsychological tests considered to be the most relevant are performed in the operating room according to each team's technical preferences., Operating Environment: The neurosurgeon must choose transfer equipment considered to be relevant. Although a minimal technological environment is an option, a surgical team with great human wealth is essential, composed of specialized personnel with complementary skills., Choice and Implementation of Intraoperative Tests: The choice of intraoperative tests, which can be relatively simple for certain primary functions, can be much more difficult for high-level cognitive functions. No consensus has been reached concerning these tests, which must therefore be selected on an individual basis. Intraoperative testing must be based on preoperative multidisciplinary decisions made jointly by the neurosurgeon, neurologist, speech therapist and neuropsychologist., Conclusions: Numerous operating tools and technology transfers are available for neurosurgical teams performing awake brain surgery but none - or very few - of them constitutes a mandatory prerequisite. In contrast, the transition from the concept of eloquent brain area to that of brain functions that must be preserved requires highly skilled multidisciplinary human resources. This goal will be more likely achieved in centers highly specialized in functional oncological neurosurgery., (Copyright © 2017. Published by Elsevier Masson SAS.)

Peripheral nerve tumors are most often benign tumors of the nerve sheath; uncommonly they come from the nerve cells or are metastatic tumors. A precise diagnosis is required for well-adapted and effective treatment, as is good knowledge of fibromatosis diseases. In some cases, the diagnosis of the nerve tumor will lead to a diagnosis of phakomatosis. Surgical treatment must be clearly discussed, which, in case of schwannomas gives very good functional results. Primitive malignant tumors remain an unsolved therapeutic problem.

Muscle fiber action participates in a true contractile machinery associated with noncontractile components providing mechanical stability. The myofibril, the muscle fiber subentity, has an extremely consistent architecture, composed of longitudinal cylindrical units called sarcomeres, the skeletal muscle length functional unit, a highly important place in the transduction of chemical signal into mechanical contractile energy, for the most part mediated by calcium. The sarcoplasmic reticulum is the other major component of muscle fiber and is dedicated to calcium storage, liberation and distribution to the fiber, under the influence of action potential propagation. This phenomenon is called excitation-contraction coupling. This paper explores muscle anatomy from its main embryologic stages of development to its histochemical specificity, including its molecular constitution, and details the main morphofunctional relations supporting muscle contraction.

Synapse formation is probably the key process in neural development allowing signal transmission between nerve cells. As an interesting model of synapse maturation, we considered first the neuromuscular junction (NMJ), whose development is particularly dependent on intercellular interactions between the motor nerve and the skeletal muscle. Nerve and muscle have distinct roles in synaptic compartment differentiation. The initial steps of this differentiation and motor endplate formation require several postsynaptic molecular agents including agrin, the tyrosine kinase receptor MuSK and rapsyn. The agrin or motoneuron dependence of this process continues to be debated while the following steps of axonal growth and postsynaptic apparatus maintenance essentially depend on neuronal agrin and a neuron-specific signal dispersing ectopic AChR aggregate remainders, possibly mediated by acetylcholine itself. Neuregulin is essentially involved in Schwann's cell survival and guidance for axonal growth. In this paper, we will discuss the similarities between Central Nervous System (CNS) synaptic formation and Motor innervation. The limited ability of the CNS to create new synapses after nervous system injury will be then discussed with a final consideration of some new strategies elaborated to circumvent the limitations of lesion extension processes.

The peripheral nerve provides the pathway for motor, sensory and vegetative axons belonging to the peripheral nervous system. It transmits information between these neurons and their peripheral effectors in both directions (sensory receptors, skeletal muscles and viscera). The afferences to the periphery correspond to the nerve motor content, whereas efferences from the periphery, in charge of delivering information to the central integrators, correspond to nerve-sensitive content. This information support depends on intrinsic properties of the nerve itself. Recent advances in cellular and molecular biology have provided a better understanding of nerve physiology, which are reviewed here as an indispensable basis to the study of its pathology.

Peripheral nerve injuries are frequent and generate significant deficits. Their treatment sometimes leads to functional recovery but is mostly incomplete or unpredictable, despite the regular use of sophisticated repair techniques. The clinician must clearly understand the peripheral nervous system's responses to injury, which reveal surprising degenerating and spontaneous regenerating abilities. This potential recovery is a peripheral nervous system specificity and follows a relatively complex process. Peripheral neurons depend on glial cell structure and metabolism, inducing a global and dynamic response of the whole axon environment, even in cases of focal lesion, modulated by the initial type and mechanism of injury. Today's progress remains insufficient to improve functional prognosis significantly, but a better understanding of peripheral nerve regenerating processes has opened the door to new medical and surgical advances.

The neuromuscular junction is made up of the apposition of highly differentiated domains of three types of cell: the motor neuronal ending, the terminal Schwann cell and the muscle postsynaptic membrane. These three components are surrounded by a basal lamina, dedicated to molecular signal exchanges controlling neuromuscular formation, maturation and maintenance. This functional and structural differentiated complex conducts synaptic neurotransmission to the skeletal muscle fiber. Nerve and muscle have distinct roles in synaptic compartment differentiation. The initial steps of this differentiation and the motor endplate formation require several postsynaptic molecular agents including agrin, the tyrosine kinase receptor MuSK. Neuregulin is essentially involved in Schwann cell survival and guidance for axonal growth.

The sarcoplasmic reticulum (SR) plays a fundamental role in excitation-contraction coupling, which propagates the electric signal conversion along the muscle fiber's plasmic membrane to a mechanical event manifested as a muscle contraction. It plays a crucial role in calcium homeostasis and intracellular calcium storage control (storage, liberation and uptake) necessary for fiber muscle contraction and then relaxation. These functions take place at the triad, made up of individualized SR subdomains where the protein-specific organization provides efficient and fast coupling. Ryanodine receptors (RyR) and dihydropyridine receptors (DHPR) mainly act in calcium exchanges in the SR. This particular structural and molecular architecture must be correlated to its functional specificity.

Neuromuscular transmission results from a double signal transduction from electric impulses to chemical messengers, taking place at a highly differentiated region, the neuromuscular junction (NMJ). A nerve cell responds to a specific stimulus by modifications of its plasmic membrane properties, generating an action potential (AP). This electric signal is transmitted along the axon to the NMJ, where it induces the voltage-gated calcium channels to open. Intracellular calcium entry leads to acetylcholine release in the synaptic space at the active zones but all scientists do not consider it the major release factor. Acetylcholine binding with its receptor at the muscle membrane generates an endplate potential when the induced depolarization is greater than the sodium voltage channel opening threshold. Muscle AP causes a muscle contraction involving the three phases. This paper will successively review the electrophysiological and molecular mechanisms involved at the pre-, inter- and postsynaptic levels. The last part of the article will discuss electromechanical considerations directly affecting the mechanical properties of the muscle fiber, most particularly the factors influencing the predetermined involvement of motor units, motor neuron electrical properties determining responses to synaptic inputs and finally the impact of recruited motor neurons and their electrical impulse rates on muscle contraction strength and velocity.

This paper explores the specific roles of sprouting stimuli, perisynaptic Schwann cells and neuromuscular activity in axonal sprouting at the neuromuscular junction in partially denervated muscles. As for sprouting stimuli, insulin-like growth factor II which is generated from inactive muscle fibers in partially denervated and paralysed skeletal muscle is described. Likewise, perisynaptic Schwann cells can induce and guide axonal sprouting in partially denervated muscles. Finally, excessive neuromuscular activity significantly reduces bridging of the perisynaptic Schwann cell processes between denervated and innervated endplates and thereby inhibits axonal sprouting in partially denervated muscle. The lack of neuromuscular activity is also harmful in axonal sprouting, probably by impeding calcium influx into the nerve.

Background and Purpose: Recent developments in molecular biology have provided the clinician with opportunities to investigate a number of new biomarkers. This has led to an abundant literature reporting the biological role, the relation to survival, and the predictive value of treatment responses in adult glioma patients. Consequently, the clinician must assimilate a large amount of information, raising the question of the genuine role of these biomarkers in the daily care of these patients., Methods: The authors report the data on biomarkers from the literature relevant to this context., Discussion: Molecular biology today sheds new and valuable light on the natural history of adult glioma, bringing to the forefront a number of therapeutic principles for glioma patients as a group. However, each of these biomarkers does not have sufficient power to amount to a criterion for individual patient therapeutics., Conclusions: Biomarkers are not pertinent today for decision making, but the authors believe that the principle of including this approach in adult glioma workups must be encouraged as a promising means of study in the years to come.

MGMT (O6 methyl guanine methyl transferase) is a gene involved in DNA repair. Its mechanism of action is to remove alkyl groups created by alkylating chemotherapy and therefore induces chemoresistances. Recent studies show that this gene expression seems to be related to the promoter's methylation, which could predict a possible chemosensitivity. The study of MGMT could be of some therapeutic and prognostic interest. Few series of oligodendrogliomas have been published and their results appear to be controversial. This is probably due to both tumour heterogeneity and multiple parameters associated with chemosensitivity. To date, it thus appears difficult to choose the adjuvant treatment according to the sole status of MGMT.

Objective: The aim of this work is to summarize the elements of the "Cancer Plan" applicable to neurosurgical practice, and to give the results of a national inquiry concerning the daily practice of Neuro-Oncology from the neurosurgical point of view., Method: The Neuro-Oncology Group of the French Society of Neurosurgery has submitted a questionnaire to every department of Neurosurgery in France., Results: The response rate of the public centers was 96.5%. Moreover, responses were available from 7 private centers. The results are detailed in the text., Conclusion: This national survey highlights the interest and implication of French neurosurgeons in the field of Neuro-Oncology. But also, to be in accordance with the guidelines for good clinical practice, the importance of developing official neuro-oncological networks in order to offer the best access to clinical and fundamental data and hence optimise patient's care. The publication of the "Cancer Plan", the creation of a National Neuro-Oncology Group, and the results of this survey (actual multidisciplinary approach, better information and transparency, individualized care of the patients), are in the line with updating our daily practice, even though discrepancies remain among centers. French neurosurgeons must continue along the same path, but at the same time there is a need for additional help to definitely reach a truly, and homogeneous, optimized care of neuro-oncological patients.

During the past years, studies dealing with the pathophysiology of brain injuries have focused on certain agents that seem to be particularly involved in secondary brain lesions. Of them, some amino acids, and particularly glutamate, appears to deserve special attention. We discuss the role of glutamate neurotransmitters, review glutamate metabolism and actions, and then review in the pertinent literature devoted to the role of glutamate in the onset of brain injuries secondary to head trauma.

We report a case of iterative surgery of a spinal chordoma of the 10(th) thoracic vertebra. This kind of neoplasm constitutes 3 to 7% of primary malignant bone tumors. Approximately 50% originate in the sacrum, 35% at the base of the skull and 15% in the true vertebrae. The slow growth delays diagnosis and compromises effective surgical therapy. On the basis of a review of the literature, we advocate an aggressive surgical resection from the beginning, similar to management of solitary vertebral metastasis.

Large series of cauda equina tumors in adults are seldom reported. This study was based on the 231 cases collected in the French neurosurgery units for the congress of the Société Française de Neurochirurgie in October 1996. Schwannomas were the most frequent benign tumor in this series, followed by ependymomas. Very few malignant tumors were recorded, usually malignant neurinomas nearly always arising in patients with neurofibromatosis. Some other rare tumors were also observed including paragangliomas. This series confirms the contribution of pre-therapeutic neurological status to functional prognosis. All schwannomas can be cured while ependymomas and paragangliomas may recur after a very long delay. Surgery must be as complete as possible since adjuvant therapies have proven to have little efficacy. This type of tumor requires a very long follow-up. Prognosis is good for hemangioblastoma. When present, abnormal sphincter function is an argument for poor prognosis. It may appear after primary surgery or more often after treatment of recurrence.

This 67 year-old man experienced the sudden onset of generalized headache followed by visual troubles. Examination showed a poor visual acuity of the right eye with a palsy of the right third nerve and signs of panhypopituitarism confirmed by endocrinologic testing. CT- scan and MRI showed a large sellar tumor with a necrotic portion in the middle, so that the pre-operative diagnosis was: pituitary adenoma. The tumor was removed through a trans-sphenoïdal approach. The pathologic diagnosis was benign schwannoma. A review of the literature showed that this was the second reported case of an intra sellar schwannoma mimicking a pituitary adenoma clinically as well as radiologically. Surgical removal of these lesions by a trans-sphenoïdal approach seems to be more difficult than for an adenoma. The histopathogenic origin of such tumors could be either ectopic schwann cells of peri-vascular schwann cells in the sellar region.

The authors report two cases of brain metastasis of a testicular cancer in two young men. In the first case the histology was an embryonal carcinoma, in the second the association of a seminoma and a teratocarcinoma. The first patient was submitted to chemotherapy, neurosurgery and radiotherapy. The second one to chemotherapy alone. The survival time was respectively of 16 and 58 months. It looked interesting to review the different treatments and their indications in this extremely severe pathology to define the interest of surgery and radiotherapy, and the different prognostic factors. In the literature, among the various treatment, the role of chemotherapy is widely emphasized. The prognosis remains desperately bad when several brain metastasis exist, or if a brain metastasis develops during chemotherapy.