Upper end of the central canal of the human spinal cord: Quantitative anatomical study and 3D modeling.

The upper end of the central canal of the human spinal cord has been repeatedly implicated in the pathogenesis of various diseases, yet its precise normal position in the medulla oblongata and upper cervical spinal cord remains unclear. The purpose of this study is to describe the anatomy of the upper end of the central canal with quantitative measurements and a three-dimensional (3D) model. Seven formalin-embalmed human brainstems were included, and the central canal was identified in serial axial histological sections using epithelial membrane antigen antibody staining. Measurements included the distances between the central canal (CC) and the anterior medullary fissure (AMF) and the posterior medullary sulcus (PMS). The surface and perimeter of the CC and the spinal cord were calculated, and its anterior-posterior and maximum lateral lengths were measured for 3D modeling. The upper end of the CC was identified in six specimens, extending from the apertura canalis centralis (ACC) to its final position in the cervical cord. Positioned on the midline, it reaches its final location approximately 15 mm below the obex. No specimen showed canal dilatation, focal stenosis, or evidence of syringomyelia. At 21 mm under the ACC in the cervical cord, the median distance from the CC to the AMF was 3.14 (2.54-3.15) mm and from the CC to the PMS was 5.19 (4.52-5.43) mm, with a progressive shift from the posterior limit to the anterior third of the cervical spinal cord. The median area of the CC was consistently less than 0.1 mm2. The upper end of the CC originates at the ACC, in the posterior part of the MO, and reaches its normal position in the anterior third of the cervical spinal cord less than 2 cm below the obex. Establishing the normal position of the upper end of this canal is crucial for understanding its possible involvement in cranio-cervical junction pathologies.

Descriptive Epidemiology of Ependymal Tumors in Gironde, France: Results from the Gironde Registry for the 2000-2018 Period.

BACKGROUND: The Gironde Central Nervous System (CNS) Tumor Registry, in collaboration with the French National Cancer Institute, is the largest population-based registry focused exclusively on primary CNS tumors in France and represents a population of 1.62 million. This report focuses on ependymal tumors to refine current knowledge and provide up-to-date data on the epidemiology of these rare tumors. MATERIAL AND METHODS: All of the ependymal tumors were extracted from the Gironde CNS Tumor Registry for the years 2000-2018. Demographic and clinical characteristics, incidence rates, and time trends as well as survival outcomes were analyzed. RESULTS: One hundred forty-four ependymal tumors were retrieved, which represented 2.3% of all the CNS tumors recorded in the same period. Histological subtype was significantly dependent on age and topography in the CNS. The median age at diagnosis was 46 years. The annual incidence rates varied between 0.15/100,000 (2004) and 0.96/100,000 (2016), with a significant increase over the study period by 4.67% per year. Five-year and 10-year OS rates were 87% and 80%, respectively. CONCLUSION: An increase in the incidence of ependymal tumors was observed over the past two decades. Further studies are needed to confirm this result and provide etiological clues.

Skin landmarks as ideal entry points for ventricular drainage, a radiological study.

PURPOSE: Ventricular drainage remains a usual but challenging procedure for neurosurgical trainees. The objective of the study was to describe reliable skin landmarks for ideal entry points (IEPs) to catheterize brain ventricles via frontal and parieto-occipital approaches. METHODS: We included 30 subjects who underwent brain MRI and simulated the ideal catheterization trajectories of lateral ventricles using anterior and posterior approaches and localized skin surface IEPs. The optimal frontal target was the interventricular foramen and that for the parieto-occipital approach was the atrium. We measured the distances between these IEPs and easily identifiable skin landmarks. RESULTS: The frontal IEP was localized to 116.8 ± 9.3 mm behind the nasion on the sagittal plane and to 39.7 ± 4.9 mm lateral to the midline on the coronal plane. The ideal catheter length was estimated to be 68.4 ± 6.4 mm from the skin surface to the interventricular foramen. The parieto-occipital point was localized to 62.9 ± 7.4 mm above the ipsilateral tragus on the coronal plane and to 53.1 ± 9.1 mm behind the tragus on the axial plane. The ideal catheter length was estimated to be 48.3 ± 9.6 mm. CONCLUSION: The IEP for the frontal approach was localized to 11 cm above the nasion and 4 cm lateral to the midline. The IEP for the parieto-occipital approach was 5.5 cm behind and 6 cm above the tragus. These measurements lightly differ from the classical descriptions of Kocher's point and Keen's point and seem relevant to neurosurgical practice while using an orthogonal insertion.

Skin landmarks to main cerebral structures: how to identify the main cerebral sulci? A radiological study about lateral, central, and parietooccipital sulci.

PURPOSE: In a previous cadaveric work, we identified and described useful and reproducible surface skin landmarks to lateral sulcus, central sulcus and preoccipital notch. Potential limitations of this cadaveric study have been raised. Thus, the objective of this study was to confirm radiologically the accuracy of these previously described surface skin landmarks on brain magnetic resonance imaging (MRI) of healthy subjects. METHODS: Healthy adult volunteers underwent a high-resolution brain MRI and measurements of the orthogonal skin projection (OSP) of the anterior sylvian point (AsyP), the superior Rolandic point (SroP) and the parietooccipital sulcus were made from nasion, zygomatic bone and inion, respectively. These measures were compared to our previous cadaveric findings. RESULTS: Thirty-one healthy volunteers were included. ASyP was 33 ± 2 mm above the zygomatic arch, and 32.3 ± 3 mm behind the orbital rim. The lateral sulcus was 63.5 ± 4 mm above the tragus. The SRoP was 196.9 ± 6 mm behind the nasion. The superior point of the parietooccipital sulcus was 76.0 ± 4 mm above the inion. These measurements are comparable to our previously described cadaveric findings. CONCLUSION: We here described three useful, simple and reproducible surface skin landmarks to lateral, central and parietooccipital sulci. Knowledge of these major landmarks is mandatory for Neurosurgical practice, especially in an emergency setting.

Increasing incidence of central nervous system (CNS) tumors (2000-2012): findings from a population based registry in Gironde (France).

BACKGROUND: Although some countries have observed a stabilization in the incidence of CNS, an increasing incidence has been reported from multiple studies. Recent observations point out to the heterogeneity of incidence trends according to histological subtypes, gender and age-groups. Using a high-quality regional CNS tumor registry, this article describes the trends of CNS tumor incidence for main histological subtypes, including benign and malignant tumors, in the French department of Gironde from 2000 to 2012. METHODS: Crude and age-standardized incidence rates were calculated globally, by histological subtypes, malignant status, gender and age groups. For trends, annual percent changes (APC) were obtained from a piecewise log-linear model. RESULTS: A total of 3515 CNS tumors was registered during the period. The incidence of overall CNS tumors was 19/100000 person-years (8.3/100000 for neuroepithelial tumors and 7.3/100000 for meningeal tumors). An increased incidence of overall CNS tumors was observed from 2000 to 2012 (APC = + 2.7%; 95%-confidence interval (CI): 1.8-3.7). This trend was mainly explained by an increase in the incidence of meningiomas over the period (APC = + 5.4%, 95%-CI: 3.8-7.0). The increased incidence rate of CNS tumors was more pronounced in female and in older patients even though the incidence rate increased in all age groups. CONCLUSIONS: Part of the temporal variation may be attributed to improvement in registration, diagnosis and clinical practices but also to changes in potential risk factors. Thus, etiological studies on CNS tumors are needed to clarify this rising trend.

Prognostic factors for survival in adult patients with recurrent glioblastoma: a decision-tree-based model.

We assessed prognostic factors in relation to OS from progression in recurrent glioblastomas. Retrospective multicentric study enrolling 407 (training set) and 370 (external validation set) adult patients with a recurrent supratentorial glioblastoma treated by surgical resection and standard combined chemoradiotherapy as first-line treatment. Four complementary multivariate prognostic models were evaluated: Cox proportional hazards regression modeling, single-tree recursive partitioning, random survival forest, conditional random forest. Median overall survival from progression was 7.6 months (mean, 10.1; range, 0-86) and 8.0 months (mean, 8.5; range, 0-56) in the training and validation sets, respectively (p = 0.900). Using the Cox model in the training set, independent predictors of poorer overall survival from progression included increasing age at histopathological diagnosis (aHR, 1.47; 95% CI [1.03-2.08]; p = 0.032), RTOG-RPA V-VI classes (aHR, 1.38; 95% CI [1.11-1.73]; p = 0.004), decreasing KPS at progression (aHR, 3.46; 95% CI [2.10-5.72]; p < 0.001), while independent predictors of longer overall survival from progression included surgical resection (aHR, 0.57; 95% CI [0.44-0.73]; p < 0.001) and chemotherapy (aHR, 0.41; 95% CI [0.31-0.55]; p < 0.001). Single-tree recursive partitioning identified KPS at progression, surgical resection at progression, chemotherapy at progression, and RTOG-RPA class at histopathological diagnosis, as main survival predictors in the training set, yielding four risk categories highly predictive of overall survival from progression both in training (p < 0.0001) and validation (p < 0.0001) sets. Both random forest approaches identified KPS at progression as the most important survival predictor. Age, KPS at progression, RTOG-RPA classes, surgical resection at progression and chemotherapy at progression are prognostic for survival in recurrent glioblastomas and should inform the treatment decisions.

Impact of direct epispinal stimulation on bladder and bowel functions in pigs: A feasibility study.

AIMS: This study assesses the potential of epispinal (subdural) stimulation application in the treatment of urinary and bowel neurological disorders. Acute experiments were performed on a large animal model - the domestic pig - to develop a new methodology facilitating future results and technology transfers to human. METHODS: After rectal and bladder catheterization, four Landrace pigs (45-50 kg) underwent spinal cord surgery - that is, lumbosacral incision, laminectomy [L4-S4], dural opening and microsurgical arachnoid dissection. Three successive electrical stimulation sessions were carried out: 1) nerve roots stimulation, 2) epispinal stimulation with a matrix electrode, 3) epispinal stimulation with a small diameter needle electrode. Changes in rectal and bladder pressures were monitored throughout the various procedures to identify spinal areas inducing responses while evaluating the influence of electrode contacts size in the measured responses amplitudes. RESULTS: An interesting area was identified in the upper portion of the spinal myelomeres (ie, spinal cord segment delimited by two successive pairs of spinal roots) directly adjoining root with best pressures (either rectal or vesical). Significant responses (up to 40 cmH2 O) were also obtained with a needle electrode. Furthermore, bowel evacuation was triggered in one of the animals. Despite the use of smaller electrode contacts, no detrusor or rectum selective responses were observed in none of the sessions. CONCLUSION: This study showed, for the first time, that epispinal stimulation causes significant detrusor and rectal responses in pigs and allows considering further studies with the objective of treating urinary and rectal disorders in spinal cord injury patients.

Recurrent glioblastomas in the elderly after maximal first-line treatment: does preserved overall condition warrant a maximal second-line treatment?

A growing literature supports maximal safe resection followed by standard combined chemoradiotherapy (i.e. maximal first-line therapy) for selected elderly glioblastoma patients. To assess the prognostic factors from recurrence in elderly glioblastoma patients treated by maximal safe resection followed by standard combined chemoradiotherapy as first-line therapy. Multicentric retrospective analysis comparing the prognosis and optimal oncological management of recurrent glioblastomas between 660 adult patients aged of < 70 years (standard group) and 117 patients aged of ≥70 years (elderly group) harboring a supratentorial glioblastoma treated by maximal first-line therapy. From recurrence, both groups did not significantly differ regarding Karnofsky performance status (KPS) (p = 0.482). Oncological treatments from recurrence significantly differed: patients of the elderly group received less frequently oncological treatment from recurrence (p < 0.001), including surgical resection (p < 0.001), Bevacizumab therapy (p < 0.001), and second line chemotherapy other than Temozolomide (p < 0.001). In multivariate analysis, Age ≥70 years was not an independent predictor of overall survival from recurrence (p = 0.602), RTOG-RPA classes 5-6 (p = 0.050) and KPS at recurrence <70 (p < 0.001), available in all cases, were independent significant predictors of shorter overall survival from recurrence. Initial removal of ≥ 90% of enhancing tumor (p = 0.004), initial completion of the standard combined chemoradiotherapy (p = 0.007), oncological treatment from recurrence (p < 0.001), and particularly surgical resection (p < 0.001), Temozolomide (p = 0.046), and Bevacizumab therapy (p = 0.041) were all significant independent predictors of longer overall survival from recurrence. Elderly patients had substandard care from recurrence whereas age did not impact overall survival from recurrence contrary to KPS at recurrence <70. Treatment options from recurrence should include repeat surgery, second line chemotherapy and anti-angiogenic agents.

Anterior cervical intradural arachnoid cyst, a rare cause of spinal cord compression: a case report with video systematic literature review.

PURPOSE: Mostly seen at the thoracic level, arachnoid cysts are a very rare cause of cervical spinal cord compression. Generally treated by laminectomy and cyst fenestration, this approach does not allow removing the cyst in its entirety without manipulating the weakened spinal cord. The aim of this report is to present the case of a cervical intradural arachnoid cyst surgically removed by an anterior approach with corporectomy. METHODS: Here is the case of an 18-year-old amateur boxer presenting with a voluminous cervical intradural anterior arachnoid cyst, extending from C2 to C5. Symptoms were cervical pain, quadriparesis, and clumsiness of both arms which had appeared just after a traffic accident. An anterior approach was chosen, through a C5 corporectomy. RESULTS: The patient totally recovered from his sensitive symptoms at discharge and from his motor symptoms 6 weeks later. Early as well as 3-years post-operatively, MRI confirmed expansion of the spinal cord without any centro-medullar signal. The patient remained asymptomatic 3 years after surgery. Since the first report in 1974, 16 cases of symptomatic cervical intradural arachnoid cysts were treated via a posterior approach, one by MRI-guided biopsy, and one was re-operated on through an anterior approach. For 14 patients, their conditions had improved, while one died of pneumonia, one presented a condition worsened, and one had a stable neurological status. CONCLUSION: Using an anterior approach is a safe procedure that allows resection of a cervical arachnoid cyst without any manipulation of the weakened spinal cord, while giving the best possible view.

When to discharge patients following a neuronavigation-assisted brain biopsy for supratentorial lesion? A single-center experience.

OBJECTIVE: Most brain biopsies are performed using the frame-based stereotactic technique and several studies describe the time taken and rate of complications, often allowing an early discharge. In comparison, neuronavigation-assisted biopsies are performed under general anesthesia and their complications have been poorly described. We examined the complication rate and determined which patients will worsen clinically. METHODS: All adults who underwent a neuronavigation-assisted brain biopsy for a supratentorial lesion from Jan, 2015, to Jan, 2021, in the Neurosurgical Department of the University Hospital Center of Bordeaux, France, were analyzed retrospectively in accordance with the Strengthening the Reporting of Observational studies in Epidemiology (STROBE) statement. The primary outcome of interest was short-term (7 days) clinical deterioration. The secondary outcome of interest was the complication rate. RESULTS: The study included 240 patients. The median postoperative Glasgow score was 15. Thirty patients (12.6 %) showed acute postoperative clinical worsening, including 14 (5.8 %) with permanent neurological worsening. The median delay was 22 h after the intervention. We examined several clinical combinations that allowed early postoperative discharge. A preoperative Glasgow prognostic score of 15, Charlson Comorbidity Index ≤ 3, preoperative World Health Organization Performance Status ≤ 1, and no preoperative anticoagulation or antiplatelet treatment predicted postoperative worsening (negative predictive value, 96.3 %). CONCLUSION: Optical neuronavigation-assisted brain biopsies might require longer postoperative observation than frame-based biopsies. Based on strict preoperative clinical criteria, we consider to plan postoperative observation for 24 h a sufficient hospital stay for patients who undergo these brain biopsies.

Effect of microorganisms isolated by preoperative osseous sampling on surgical site infection after autologous cranioplasty: A single-center experience.

PURPOSE: The most frequent postoperative complication in autologous cranioplasty (AC) is infection. European recommendations include osseous sampling before cryogenic storage of a bone flap. We evaluated the clinical impact of this sampling. METHODS: All patients who underwent decompressive craniectomy (DC) and AC in our center between November 2010 and September 2021 were reviewed. The main outcome was the rate of reoperation for infection of the cranioplasty. We evaluated risk factors for bone flap infection, rate of reoperation for any reason (hematoma, skin erosion, cosmetic request, or bone resorption), and radiological evidence of bone flap resorption. RESULTS: A total of 195 patients with a median age of 50 (interquartile range: 38.0-57.0) years underwent DC and AC between 2010 and 2021. Of the 195 bone flaps, 54 (27.7%) had a positive culture, including 48 (88.9%) with Cutibacterium acnes. Of the 14 patients who underwent reoperation for bone flap re-removal for infection, 5 and 9 had positive and negative bacteriological cultures, respectively. Of patients who did not have bone flap infection, 49 and 132 had positive and negative bacteriological cultures, respectively. There were no significant differences between patients with and without positive bacteriological culture of bone flaps in the rates of late bone necrosis and reoperation for bone flap infection. CONCLUSIONS: A positive culture of intraoperative osseous sampling during DC is not associated with a higher risk of re-intervention after AC.

Sacral Anterior Root Stimulation and Visceral Function Outcomes in Spinal Cord Injury-A Systematic Review of the Literature Over Four Decades.

OBJECTIVE: Sacral anterior root stimulation (SARS) was developed 40 years ago to restore urinary and bowel functions to individuals with spinal cord injury. Mostly used to restore lower urinary tract function, SARS implantation is coupled with sacral deafferentation to counteract the problems of chronic detrusor sphincter dyssynergia and detrusor overactivity. In this article, we systematically review 40 years of SARS implantation and assess the medical added value of this approach in accordance with the PRISMA guidelines. We identified 4 axes of investigation: 1) impact on visceral functions, 2) implantation safety and device reliability, 3) individuals' quality of life, and 4) additional information about the procedure. METHODS: A systematic review was performed. Three databases were consulted: PubMed, EBSCOhost, and Pascal. A total of 219 abstracts were screened and 38 articles were retained for analysis (1147 implantations). RESULTS: The SARS technique showed good clinical results (85.9% of individuals used their implant for micturition and 67.9% to ease bowel movements) and improved individual quality of life. Conversely, several sources of complications were reported after implantation (e.g., surgical complications and failure). CONCLUSIONS: Despite promising results, a decline in implantations was observed. This decline can be linked to the complication rate, as well as to the development of new therapeutics (e.g., botulinum toxin) and directions for research (spinal cord stimulation) that may have an impact on people. Nevertheless, the lack of alternatives in the short-term suggests that the SARS implant is still relevant for the restoration of visceral functions after spinal cord injury.

Intramedullary Spinal Cord Lesions: A Single-Center Experience.

OBJECTIVE: Spinal cord tumors constitute a small part of spinal surgery owing to their rarity. This retrospective study describes their current management. METHODS: Forty-eight patients were treated for an intramedullary tumor between 2014 and 2020 at a single institution. Patients' files were retrospectively studied. We detailed clinical status according to neurological deficit and ambulatory ability using the modified McCormick Scale, radiological features like number of levels, associated syringomyelia, surgical technique with or without intraoperative electrophysiological monitoring, pathological findings, and postoperative outcome. RESULTS: The median age of this population was 43 years, including 5 patients under 18 years. The median delay before first neurosurgical contact was 3 months after the first clinical complaint. Treatment was gross total resection in 43.8%, subtotal resection in 50.0%, and biopsy in 6.2%. A laminectomy was performed for all the patients except 2 operated using the laminoplasty technique. Pathological findings were ependymoma in 43.8%, hemangioblastoma in 20.8%, and pilocytic astrocytoma in 10.4%. Six patients were reoperated for a tumor recurrence less than 2 years after the first surgical resection. One patient was reoperated for a postoperative cervical kyphosis. CONCLUSION: Intramedullary tumors are still a challenging disease and they are treated by various surgical techniques. They must be managed in a specialized center including a trained surgical, radiological, electrophysiological, and pathological team. Arthrodesis must be discussed before performing extensive laminectomy to avoid postoperative kyphosis.

Inflammation induced neurological handicap processes in multiple sclerosis: new insights from preclinical studies.

Multiple sclerosis (MS) is described as originating from incompletely explained neuroinflammatory processes, dysfunction of neuronal repair mechanisms and chronicity of inflammation events. Blood-borne immune cell infiltration and microglia activation are causing both neuronal destruction and myelin loss, which are responsible for progressive motor deficiencies, organic and cognitive dysfunctions. MRI as a non-invasive imaging method offers various ways to visualise de- and remyelination, neuronal loss, leukocyte infiltration, blood-brain barrier modification and new sensors are emerging to detect inflammatory lesions at an early stage. We describe studies performed on experimental autoimmune encephalomyelitis (EAE) animal models of MS that shed new light on mechanisms of functional impairments to understand the neurological handicap in MS. We focus on examples of neuroinflammation-mediated inhibition of CNS repair involving adult neurogenesis in the sub-ventricular zone and hippocampus and such experimentally observed inhibitions could reflect deficient plasticity and activation of compensatory mechanisms in MS. In parallel with cognitive decline, organic deficits such as bladder dysfunction are described in most of MS patients. Neuropharmacological interventions, electrical stimulation of nerves, MRI and histopathology follow-up studies helped in understanding the operating events to remodel the neurological networks and to compensate the inflammatory lesions both in spinal cord and in cortical regions. At the molecular level, the local production of reactive products is a well-described phenomenon: oxidative species disturb cellular physiology and generate new molecular epitopes that could further promote immune reactions. The translational research from EAE animal models to MS patient cohorts helps in understanding the mechanisms of the neurological handicap and in development of new therapeutic concepts in MS.

Increased Incidence of Intracranial Meningiomas in Patients With Acromegaly.

BACKGROUND: An increased incidence of various neoplasms has been described in patients with acromegaly, and there is evidence to suggest that growth factors are risk factors for the development of meningiomas. OBJECTIVE: To study if patients with acromegaly are more at risk for developing intracranial meningiomas. METHODS: We conducted an observational study on 221 consecutive acromegalic patients recruited between January 1, 2000 and December 31, 2015, and 357 consecutive patients with a nonsomatotropic pituitary adenoma recruited between March 1, 2015 and December 31, 2016, in our institution. Patients underwent a gadolinium-enhanced 3D T1 brain magnetic resonance imaging to look for meningiomas. The proportion of meningiomas was compared between the 2 groups, and the standardized incidence ratio (SIR) was computed from the incidence rates of meningiomas observed in the population of acromegalic patients and compared to that of the general population given by the local registry of central nervous system tumors. RESULTS: Patients with acromegaly had a significant risk for developing intracranial meningiomas as compared to patients without acromegaly (7.7% vs 2.2%, P = .005, OR = 3.45 [1.46; 8.15]). There was a significant increased incidence of intracranial meningiomas in patients with acromegaly (SIR = 126 [25; 367]) as compared to the general population. CONCLUSION: Our study suggests strongly that patients with acromegaly are more at risk for developing intracranial meningiomas.

Animal models of sacral neuromodulation for detrusor overactivity.

The recent increase in the use of sacral neuromodulation (SN) for the treatment of detrusor overactivity has coincided with improved knowledge of micturition physiology and technological advances in nerve stimulation. Efficacy of SN treatment and patient satisfaction should continue to progress. Nevertheless, the exact mechanism of the action of this technique remains uncertain. Numerous theories have been proposed to explain the mechanism of action, including stimulation of efferents, or direct effect on the muscle, stimulation of the afferents, induction of spinal plasticity, and modifications of cortical activation. In experimental conditions, to evaluate the effects of electrical stimulation, animal models are generally focused on bladder inflammation or spinalization which both induce detrusor overactivity. Recently, experimental autoimmune encephalomyelitis in rats has proven useful to study bladder dysfunction characterized as both detrursor overactivity or acontractile detrursor. The present article reviews experimental approaches for SN for treatment of detrusor overactivity and provides explanations for the potential acting mechanisms.

Validation of a methodology for neuro-urological and lumbosacral stimulation studies in domestic pigs: a humanlike animal model.

OBJECTIVESpinal cord injuries (SCIs) result in loss of movement and sensory feedback, but also organ dysfunction. Nearly all patients with complete SCI lose bladder control and are prone to kidney failure if intermittent catheterization is not performed. Electrical stimulation of sacral spinal roots was initially considered to be a promising approach for restoring continence and micturition control, but many patients are discouraged by the need for surgical deafferentation as it could lead to a loss of sensory functions and reflexes. Nevertheless, recent research findings highlight the renewed interest in spinal cord stimulation (SCS). It is thought that synergic recruitment of spinal fibers could be achieved by stimulating the spinal neural networks involved in regulating physiological processes. Paradoxically, most of these recent studies focused on locomotor issues, while few addressed visceral dysfunction. This could at least partially be attributed to the lack of methodological tools. In this study, the authors aim to fill this gap by presenting a comprehensive method for investigating the potential of SCS to restore visceral functions in domestic pigs, a large-animal model considered to be a close approximation to humans.METHODSThis methodology was tested in 7 female pigs (Landrace pig breed, 45-60 kg, 4 months old) during acute experiments. A combination of morphine and propofol was used for anesthesia when transurethral catheterization and lumbosacral laminectomy (L4-S4) were performed. At the end of the operation, spinal root stimulation (L6-S5) and urodynamic recordings were performed to compare the evoked responses with those observed intraoperatively in humans.RESULTSNervous excitability was preserved despite long-term anesthesia (mean 8.43 ± 1.5 hours). Transurethral catheterization and conventional laminectomy were possible while motor responses (gluteus muscle monitoring) were unaffected throughout the procedure. Consistent detrusor (approximately 25 cm H2O) and sphincter responses were obtained, whereas spinal root stimulation elicited detrusor and external urethral sphincter co-contractions similar to those observed intraoperatively in humans.CONCLUSIONSPigs represent an ideal model for SCS studies aimed at visceral function investigation and restoration because of the close similarities between female domestic pigs and humans, both in terms of anatomical structure and experimental techniques implemented. This article provides methodological keys for conducting experiments with equipment routinely used in clinical practice.

Decompressive Craniectomy in Children with Severe Traumatic Brain Injury: A Multicenter Retrospective Study and Literature Review.

BACKGROUND: Severe traumatic brain injury (TBI) is the most common cause of disability in children. Refractory increased intracranial pressure can be a therapeutic challenge. Decompressive craniectomy can be proposed when medical management is insufficient, but its place is not clearly defined in guidelines. The aim of this study was to identify prognostic factors in children with TBI. METHODS: We performed a retrospective, multicenter study to analyze long-term outcomes of 150 children with severe TBI treated by decompressive craniectomy and to identify prognostic factors. RESULTS: A satisfactory neurologic evolution (represented by a King's Outcome Scale for Childhood Head Injury score >3) was observed in 62% of children with a mean follow-up of 3.5 years. Mortality rate was 17%. Prognostic factors associated with outcome were age, initial Glasgow Coma Scale score, presence of mydriasis, neuromonitoring values (maximal intracranial pressure >30 mm Hg), and radiologic findings (Rotterdam score ≥4). CONCLUSIONS: This study in a large population confirms that children with severe TBI treated by decompressive craniectomy can achieve a good neurologic outcome. Further studies are needed to clarify the use of this surgery in the management of children with severe TBI.

Functional Selectivity of Lumbosacral Stimulation: Methodological Approach and Pilot Study to Assess Visceral Function in Pigs.

Nearly all spinal cord injured (SCI) individuals lose bladder control and are prone to kidney complications if intermittent catheterization is not applied. Electrical stimulation of the sacral anterior roots with an implantable neuroprosthesis is one means to restore continence and control micturition. However, only a small percentage of the SCI population benefits from this solution because of its drawbacks, e.g., section of sacral posterior roots with loss of spared sensitivity. There has been renewed interest in spinal cord stimulation in recent years, but most studies have focused on locomotion and only few have reported the impact on visceral functions. Moreover, even though the lumbosacral spinal cord is the location of many pre-cabled neural networks (involved in locomotion, bladder, and bowel management), the functional selectivity of spinal stimulations has never been investigated in detail. Here, we present: 1) a methodology designed to study lumbosacral epispinal-intradural stimulation selectivity; 2) preliminary results assessing the impact of epispinal stimulation on bladder and bowel functions in two domestic pigs; and 3) a comparison of these visceral responses with abdominal and lower limb activities. Our experiments resulted in selective bladder and rectal responses, i.e., without hind paw responses, thus reaffirming the rehabilitation potential of spinal cord stimulation.

A hypothesis of cerebral venous system regulation based on a study of the junction between the cortical bridging veins and the superior sagittal sinus. Laboratory investigation.

OBJECT: The cerebral venous regulation involved in various physiological and pathological processes has received little attention. Here the authors describe the anatomy of the junction between the cortical vein and the superior sagittal sinus (SSS) and propose a new theory of cerebral venous regulation. METHODS: Ten adult human cadaveric heads (20 sides), including five specimens into which stained latex had been injected, were used for anatomical study. Formalin-fixed cadaver heads were dissected to demonstrate the cortical veins along the SSS. The characteristics of the cortical bridging veins and their openings into the SSS were established by anatomical, histological, immunohistochemical, and ultrastructural study of the junction. RESULTS: After their subarachnoid course, the cortical bridging veins penetrated the SSS at different points in the dura mater depending on their rostrocaudal position. The venous endothelium stretched beyond the sinus endothelium. The orientation of the collagen fibers changed at the level of the venous openings, with the luminal diameter becoming narrow and oval-shaped. The major finding was the organization of the smooth-muscle cells at the end of each cortical vein. At this site and particularly in the frontoparietal region, the vessel resembled a myoendothelial "sphincter." The authors hypothesize that this organization is involved in cerebral venous system regulation. CONCLUSIONS: The point of convergence between the cortical veins and the SSS is a key area. The authors also hypothesize that the myoendothelial junction acts as a smooth sphincter and that it plays a role in cerebral venous hemodynamics and pathological conditions.