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BackgroundFinite element modeling of the human head offers an alternative to experimental methods in understanding the biomechanical response of the head in trauma brain injuries. Falx, tentorium, and their notches are important structures surrounding the brain, and data about their anatomical variations are sparse.ObjectiveTo describe and quantify anatomical variations of falx cerebri, tentorium cerebelli, and their notches.Methods3D reconstruction of falx and tentorium was performed by points identification on 40 brain CT-scans in a tailored Matlab program. A scatter plot was obtained for each subject, and 8 anatomical landmarks were selected. A reference frame was defined to determine the coordinates of landmarks. Segments and areas were computed. A reproducibility study was done.ResultsThe height of falx was 34.9 ± 3.9 mm and its surface area 56.5 ± 7.7 cm2. The width of tentorium was 99.64 ± 4.79 mm and its surface area 57.6 ± 5.8 cm2. The mean length, height, and surface area of falx notch were respectively 96.9 ± 8 mm, 41.8 ± 5.9 mm, and 28.8 ± 5.8 cm2 (range 15.8–40.5 cm2). The anterior and maximal widths of tentorial notch were 25.5 ± 3.5 mm and 30.9 ± 2.5 mm; its length 54.9 ± 5.2 mm and its surface area 13.26 ± 1.6 cm2. The length of falx notch correlated with the length of tentorial notch (r = 0.62, P < 0.05).ConclusionWe observe large anatomical variations of falx, tentorium, and notches, crucial to better understand the biomechanics of brain injury, in personalized finite element models.

Background A public health student service was set up by the French government in 2018 with the aim of increasing awareness of primary health promotion among the 47,000 students of medicine and other health professions. It is an annual program involving community-based actions on nutrition, physical activity, addiction or sexuality. Our objective was to evaluate its implementation at local level and the different experiences of the stakeholders. Methods A quasi-experimental study using process evaluation was performed in a Faculty of Medicine in Paris. Quantitative and qualitative data were collected from medical students who carried out preventive health actions, in the institutions in which the actions took place and from a subsample of beneficiaries. Results One hundred and eight actions were carried out by 341 students in 23 educational or social institutions, mostly high schools ( n  = 12, 52%). Two thirds of the students did not feel sufficiently prepared to deliver preventive health interventions (65.7%, 224/341); however the beneficiaries found that the interventions were good (278/280, 99,2%). Nineteen (83%) of the host institutions agreed to welcome health service students again, of which 9 required some modifications. For students, the reporting of a satisfactory health service experience was associated with the reporting of skills or knowledge acquisition ( p  < 0.01). Delivering actions in high schools and to a medium-sized number of beneficiaries per week was associated with students’ satisfaction. No effect of gender or theme of prevention was observed. For 248/341 (72.7%) students, the public health service program prompts them to address prevention issues in the future. Conclusion The public health service undertaken by medical students through the program is a feasible and acceptable means of delivering preventive actions. Reinforcement of training and closer interaction with the host institutions would improve results.

Abstract BACKGROUND: The endoscopic removal of third ventricular colloid cysts has been developed as an alternative to microsurgical transcortical-transventricular and transcallosal approaches. OBJECTIVE: To examine the value of endoscopic technique by reviewing the large number of endoscopically treated patients with long-term follow-up in 2 neurosurgical centers. METHODS: A retrospective chart review was conducted for all patients admitted for resection of a third ventricular colloid cyst to the Radboud University Nijmegen Medical Centre (Nijmegen, the Netherlands) and the Hôpital Henri Mondor (Paris, France) between 1994 and 2007. Both clinical and radiological symptoms and operative results were evaluated. RESULTS: Postdischarge clinical follow-up was available for 85 patients over a mean period of 4 years 3 months. Permanent morbidity occurred in 1 patient (persisting preoperative memory deficit). Follow-up imaging of 80 evaluable patients showed that total or nearly total cyst removal was possible in 46 individuals (57.5%). Residual cyst was present in 34 patients (42.5%), and 6 required repeated endoscopic surgery for symptomatic regrowth. Recurrent cysts were mainly seen within the first 2 years after surgery. CONCLUSION: It is debatable whether the higher numbers of recurrent or residual cysts can be justified by the slightly lower complication rates achieved with endoscopic removal. However, results have been improving over the years. Moreover, the modifications observed on control magnetic resonance images justify the need for regular control imaging for at least the first 2 years postoperatively.

We present an overview of the history, development, technological advancements, current application, and future trends of cranial endoscopy. Neuroendoscopy provides a safe and effective management modality for the treatment of a variety of intracranial disorders, either tumoral or non-tumoral, congenital, developmental, and degenerative, and its knowledge, indications, and limits are fundamental for the armamentarium of the modern neurosurgeon.

Background External ventricular drainage (EVD) is a freehand neurosurgical procedure performed routinely using the anatomical landmarks. Objective The aim of this study was to determine the accuracy of EVD catheter freehand placement. Materials and methods Pre-operative and post-operative computed tomography scans for 66 consecutive EVDs performed in 56 adult patients (26 men, 30 women) in 2008 were retrospectively reviewed. Etiologies of acute hydrocephalus were subarachnoid or intraventricular haemorrhage (43 cases) or miscellaneous (13 cases). Pre-operative lateral ventricular volume, position of the burr hole, length of the catheter and its sagittal and coronal angular variations from a theoretical trajectory were measured. Results The EVD was placed on the right (53 cases) or left (13 cases) side. The mean pre-operative lateral ventricular volume was 51 cc (10–118 cc). The average distance from the burr hole to the midline was 28 mm (10–49 mm) and to the supra-orbital ridge was 101 mm (75–125 mm). The mean intracranial catheter length was 60 mm (from 39–102 mm). Only 50% of the EVDs in the coronal plane and 40% in the sagittal plane were placed with an angular variation of ±5° to the target. The tip was placed outside of the ventricles in three cases; 13 catheters crossed the midline, and five intracranial minor haemorrhages were detected. Conclusion Freehand placement of EVDs does not have sufficient accuracy and may lead to drainage dysfunctions. This data suggests that a guidance system for EVD’s would be required.

Abstract BACKGROUND Supratentorial hemangioblastomas are rare lesions, occurring either sporadically or in von Hippel-Lindau disease. OBJECTIVE Following recent advances in our understanding of the natural history of von Hippel-Lindau–associated cerebellar and spinal hemangioblastomas, we conducted a study of the natural history of supratentorial hemangioblastomas in von Hippel-Lindau disease. METHODS We reviewed a series of 18 supratentorial hemangioblastomas in 13 patients with von Hippel-Lindau disease. Clinical, genetic, and serial imaging data and operative records were analyzed. RESULTS Hemangioblastomas were most commonly seen in the temporal lobe. Only 6 tumors had a cyst at diagnosis or during follow-up, and only 6 patients had associated symptoms at presentation or during follow-up. The most frequent clinical presentations were intracranial hypertension and visual loss. Of 14 tumors with documented serial imaging, 13 demonstrated tumor growth. Rates and patterns of tumor growth were unique to each patient. The mechanism of cyst formation described in other locations was also demonstrated in the supratentorial region. Patterns of peritumoral edema and rate of cyst formation seemed to be influenced by the presence of anatomic barriers. Germline VHL mutation was identified in all patients, but no specific genotype-phenotype correlation was found, although a familial predisposition is suggested. CONCLUSION This series illustrates the wide variation in tumor locations, patterns of growth, and edema progression seen in supratentorial hemangioblastomas and adds to our knowledge of the natural history of hemangioblastomas.

Aims. In spastic subjects, lidocaine is often used to induce a block predictive of the result provided by subsequent surgery. Lidocaine has been demonstrated to inhibit the Hoffmann (H) reflex to a greater extent than the direct motor (M) response induced by electrical stimulation, but the timecourse of these responses has not been investigated. Methods. An animal (rat) model of the effects of lidocaine on M and H responses was therefore developed to assess this time course. M and H responses were recorded in 18 adult rats before and after application of lidocaine to the sciatic nerve. Results. Two to five minutes after lidocaine injection, M responses were markedly reduced (mean reduction of 44%) and H reflexes were completely abolished. Changes were observed more rapidly for the H reflex. The effects of lidocaine then persisted for 100 minutes. The effect of lidocaine was therefore more prolonged on the H reflex than on the M response. Conclusion. This study confirms that lidocaine blocks not only alpha motoneurons but also Ia afferent fibres responsible for the H reflex. The authors describe, for the first time, the detailed time course of the effect of lidocaine on direct or reflex activation of motoneurons in the rat.

[...]with World Rugby's operational definition, a concussion following a head injury cannot be excluded until an assessment is completed at 36-48 h post injury. Conor McCarthy (Irish RFU Medical Director), Deborah Robinson (New Zealand Rugby Union Team Physician), Rob Nichol (CEO International Rugby Players' Association), Vincenzo Ieracitano (Chairman Medical Commission of Italian FIR), Mike England (Director English RFU Injured Players Foundation), Paul Watson (Medical Director Rugby Canada); Eanna Falvey (Team Physician Irish Rugby Union), Mark Harrington (IRB Training and Medical Manager-World Rugby representative).

BackgroundDosing regimens of trastuzumab administered by intracerebroventricular (icv) route to patients with HER2-positive brain localizations remain empirical. The objectives of this study were to describe pharmacokinetics (PK) of trastuzumab in human plasma and cerebrospinal fluid (CSF) after simultaneous icv and intravenous (iv) administration using a minimal physiologically-based pharmacokinetic model (mPBPK) and to perform simulations of alternative dosing regimens to achieve therapeutic concentrations in CSF.MethodsPlasma and CSF PK data were collected in two patients with HER2-positive brain localizations. A mPBPK model for mAbs consisting of four compartments (tight and leaky tissues, plasma and lymph) was enriched by an additional compartment for ventricular CSF. The comparison between observed and model-predicted concentrations was evaluated using prediction error (PE).ResultsThe developed mPBPK model described plasma and CSF trastuzumab concentrations reasonably well with mean PE for plasma and CSF data of 41.8% [interquartile range, IQR = -9.48; 40.6] and 18.3% [-36.7; 60.6], respectively, for patient 1 and 11.4% [-10.8; 28.7] and 22.5% [-27.7; 77.9], respectively, for patient 2. Trastuzumab showed fast clearance from CSF to plasma with Cmin,ss of 0.56 and 0.85 mg/L for 100 and 150 mg q1wk, respectively. Repeated dosing of 100 and 150 mg q3day resulted in Cmin,ss of 10.3 and 15.4 mg/L, respectively. Trastuzumab CSF target concentrations are achieved rapidly and maintained above 60 mg/L from 7 days after a continuous perfusion at 1.0 mg/h.ConclusionContinuous icv infusion of trastuzumab at 1.0 mg/h could be an alternative dosing regimen to rapidly achieve intraventricular CSF therapeutic concentrations.

Background Recurrent concussions are suspected to promote the development of long-term neurological disorders. The study was designed to assess the prevalence of major depressive disorder, mild cognitive disorders and headache in a population of retired high-level sportsmen and rugby players and to study the link between scores evaluating these disorders and the number of reported concussions (RCs). Methods A total of 239 retired rugby players (RRPs) and 138 other retired sportsmen (ORSs) who had reached the French national or international championship level between 1985 and 1990 filled in a self-administered questionnaire describing their sociodemographic data, comorbidities and reported history of RC. A phone interview was then conducted using validated questionnaires for the detection of major depressive disorder (PHQ-9), mild cognitive disorders (F-TICS-m) and headache (HIT-6). Results RRPs reported a higher number of RCs than ORSs ( p  < 0.001). A higher rate of major depressive disorder (PHQ-9 score >9) was observed among RRPs compared to ORSs (9% versus 6%) ( p  = 0.04), and the PHQ-9 score increased with the number of RCs regardless of the type of sport ( p  = 0.026). A higher rate of mild cognitive disorders (TICS-m score ≤30) was observed in RRPs compared to ORSs (57% versus 40%, p  = 0.005), but no association was found with the number of RC. The HIT-6 score increased with the number of RCs ( p  = 0.019) Conclusions More than 20 years after the end of their career, RRPs present higher rates of depression and lower F-TICS-m scores in favor of mild cognitive impairment compared with ORSs. PHQ-9 and HIT-6 scores were significantly associated with the number of RCs.