Neural correlates of consciousness and related disorders: From phenotypic descriptors of behavioral and relative consciousness to cortico-subcortical circuitry.

We report a review of medical aspects of the consciousness. The behavioral dimension, phenotypic descriptors, relative consciousness and neural correlates of consciousness and related disorders were addressed successively in a holistic and chronological approach. Consciousness is relative, specific to each individual across time and space. Historically defined as the perception of the self and the environment, it cannot be separated from behaviors, entailing an idea of conscious behavior with metapractic and metagnostic aspects. Observation of spontaneous and evoked overt behavior distinguishes three main types of disorder of consciousness (DoC): coma, vegetative state or unresponsive wakefulness, and minimally conscious or relationally impoverished state. Modern functional exploration techniques, such as imaging, increase the understanding of DoCs and consciousness. Whether consciousness is a superior function and/or an instrumental function is discussed. Neural correlates can be subdivided into two wakefulness pathways (superior thalamic cholinergic and inferior extra-thalamic), and cortico-subcortical circuitry. The deep brain structures are those described in the well-known sensorimotor, associative and limbic loops, as illustrated in the mesolimbic model of DoC. The cortices can be segregated into several overlapping networks: (1) a global workspace including thalamo-cortical loops; (2) the default mode network (DMN) and related intrinsic connectivity networks (i.e., central executive, medial DMN and salience networks); (3) a 3-fold network comprising the fronto-parietal control system and its dorsal and ventral attentional sub-networks, the fronto-parietal executive control network, and the cingulo-opercular salience network; (4) the internal and external cortices, respectively medial, turned toward the self, and lateral, turned toward the environment. The network dynamics is the reflection of consciousness, notably anticorrelations such as the decrease in activity of the posterior cingulate-precuneus regions during attentional tasks. Thanks to recent advances in DoC pathophysiology, further significative therapeutic progress is expected, taking into account the societal context. This depends notably on the dissemination of medical knowledge and its transfer to a wider public.

[Medico-economic analysis of a neurosurgery department at a university hospital]. / Analyse médico-économique d'un service de neurochirurgie en centre hospitalier et universitaire.

OBJECTIVE: Economic and societal constraints require to take into account the economic dimension and medical performance of hospital departments. We carried out a self-assessment study, which we thought could be useful to share with the neurosurgical community. MATERIAL AND METHODS: Care and research activities were assessed from 2009 to 2013. We used institutional and assessment-body parameters in order to describe activities and perform a financial evaluation. It was a retrospective descriptive study based on the guidelines of the DHOS/O4 circular No. 2007/390 of October 29, 2007. RESULTS: The average annual, analytic income statement was +1.39 millions euros, for 63 beds with a 92% occupancy rate, including 6.7 full-time equivalent neurosurgeons (and assistants), for 2553 patients and 1975 surgeries. The average mortality rate was 2.74%. The annual mean length of stay was 6.82 days. Per year, on average 15.6% of patients were admitted in emergency and 76.9% returned home. The annual, act-related-pricing and publication-related incomes represented 77% and 0.6%, respectively of the total funding. Difficulties to find downstream beds for the most severe patients induced 1401 "waiting days" in 2012. CONCLUSION: Medico-economic analysis of a neurosurgery department at a university hospital was useful in order to take into account the care, teaching and research activities, as well as its related financial value.

[An optic nerve glioma in a 4-month-old child]. / Gliome du nerf optique chez un enfant de 4 mois.

The optic nerve glioma is a relatively rare pathology in children and only a few cases have been described in infants. This paper reports the symptoms of this exceptional case in a 4-month-old child and reviews the differential diagnoses at this age. Finally, we discuss the diagnosis and therapeutic possibilities.

[Cervical and para-pharyngeal bone tumors: two cases report]. / Tumeurs cervicales et para-pharyngées d'origine osseuse.

OBJECTIVE: The purpose of the study was to report two cases of cervical and para-pharyngeal bone tumors. MATERIAL AND METHODS: Patients were two 29 and 67-year-old men. Presentation of the lesions included respectively a right cervical mass and a left para-pharyngeal mass. Clinical features and radiological, anatomopathological and therapeutic characteristics of the tumors were retrospectively studied. RESULTS: A cervical approach was made in both cases. Tumor biopsies revealed a vertebral aneurismal cyst and a corporeo-pedicular chordoma respectively. CONCLUSION: Vertebral bone tumors with cervical expression are very uncommon entities. Diagnosis could be systematically evoked in patients with a cervical or para-pharyngeal tumor presenting vertebral lysis.

[Management of severe head injuries during the first 24 hours, in the emergency department, in neurosurgery]. / Prise en charge du traumatisé crânien grave dans les 24 premières heures, dans le service des urgences, par la neurochirurgie.

In France, the role of the neurosurgeon in the emergency department depends on local health care policies and geographical constraints. Some departments include a neurosurgical team with a dedicated operating room. In others, a neurosurgeon can be reached by phone, possibly with an image transfer. Whatever the case, it should be possible to remove on site and without delay an intracranial haematoma, which is most often an extradural injury. The management of a haematoma of the posterior fossa or a bleeding dural venous sinus would be difficult for a surgeon not qualified in neurosurgery. The optimal situation is the presence of a neurosurgeon in the medical team admitting patients with a severe head or spine trauma, for assessment of the neurological status, or interpretation of radiological explorations, insertion of an intracranial pressure monitoring device. Besides the extradural haematoma, other injuries such as an acute subdural haematoma, a haematoma associated with a contusion, an acute hydrocephalus, a depressed fracture of the skull, or a craniocerebral wound, also require an emergency decompressive procedure.

[Neurological outcome of 152 surgical patients with spinal metastasis]. / Evolution neurologique de 152 patients opérés de métastases rachidiennes.

BACKGROUND AND PURPOSE: The aim of this study is to evaluate retrospectively the benefit of the surgical spinal decompression in 152 patients with spinal metastasis. METHODS: Based on clinical notes and GP inquiry, we determined the actuarial survival curve, and assessed the pain level one month post-operatively and the motor, the sensory and sphincter distrurbances three months after surgery. RESULTS: Thoraco-lumbar lesions were usually treated using a posterior approach, with a laminectomy and if necessary an osteosynthesis. Cervical lesions were treated with an anterior approach, i.e. a corporectomy and a methylmetacrylate stabilization. Sixty eight percent of patients (103/152) had pre or postoperative radiotherapy. After the surgical decompression for a spinal metastasis, our study demonstrated an improvement in sensory status (31 % of the patients), in motor ability (56 %), in sphincter function (51 %), and a decrease in the pain intensity in 47 % of the patients. Among 83 patients who could not walk on admission (grade A, B and C of Frankel), 52 % recovered a gait function 3 months post operatively. The best benefit after surgery concerned grade C patients, of which 71 % recovered the gait function. Two percent of the patients had postoperative worsening of their motor strength. No operative mortality was noted, and the postoperative mortality rate was 3 % at 7 days and 9 % at 30 days. The analysis of the actuarial survival curve demonstrated a mean follow up of 3.7 years. The mean survival time was 12 months with 25 % of patients surviving 2 years. CONCLUSION: Surgical decompression is effective in relieving neurological symptoms from spinal metastasis. In our experience a complete motor deficit does not seem to be a good surgical indication because of the lack of postoperative improvement.

[Intracranial pressure monitoring in France, and French-speaking Belgium and Switzerland. Retrospective and prospective survey]. / Monitorage de la pression intracrânienne en France, Belgique et Suisse francophones. Enquête rétrospective et prospective.

OBJECTIVE: To assess the use of ICP monitoring in France and French-speaking Belgium and Switzerland. PARTICIPANTS: Neuro-intensive care unit (ICU) and neuroanaesthesia teams. METHODS: Retrospective survey (concerning the year 1995), followed by a prospective one (spread over a period of 4 months in 1996) about policy concerning: frequency, delay, duration, indications, complications and cost of ICP monitoring in their units. Other questions were: type of devices, duration of the device insertion, operators and place of operating. RESULTS: Out of the 77 units which replied, 54 regularly carried out ICP monitoring, corresponding to a total of 2,012 patients in 1995. Only 23 participated in the prospective survey (301 patients). Out of the 54 hospitals, 25 assessed the ICP in more than 50 patients per year. Head trauma was the main indication for ICP monitoring (61%), the second indication was intracranial haemorrhage (23% of patients). The most often monitored patients were young males for head trauma, whereas females were mainly monitored for intracranial haemorrhage. The delay for starting ICP monitoring was 16 hours and was maintained for 7 days in head trauma patients. Intraventricular catheter and fibreoptic devices were chosen in the same proportion, a subdural system was used in 8% of the cases. The devices were inserted by neurosurgeons in 80% of cases, anaesthetists also participated in this operation. Risk of haemorrhage was very low (0.7%), the risk of infection was 4% and always concerned intraventricular catheters. CONCLUSION: ICP monitoring is widely practised in France and French-speaking Belgium and Switzerland, especially for traumatic brain injury in young males. Anaesthetists mainly took part in the operation, especially for the fibreoptic devices.