Anatomy of the greater occipital nerve: implications in posterior fossa approaches.

PURPOSE: Because of its superficial location in the dorsal regions of the scalp, the greater occipital nerve (GON) can be injured during neurosurgical procedures, resulting in post-operative pain and postural disturbances. The aim of this work is to specify the course of the GON and how its injuries can be avoided while performing posterior fossa approaches. METHODS: This study was carried out at the department of anatomy at Bordeaux University. 4 specimens were dissected to study the GON course. Posterior fossa approaches (midline suboccipital, paramedian suboccipital, retrosigmoid and petrosal) were performed on 4 other specimens to assess potential risks of GON injuries. RESULTS: The GON runs around the obliquus capitis inferior (100%), crosses the semispinalis capitis (100%) and the trapezius (75%) or its aponeurosis (25%). Direct GON injuries can be seen in paramedian suboccipital approaches. Stretching of the GON can occur in midline suboccipital and paramedian suboccipital approaches. We found no evidence of direct or indirect GON injury in retrosigmoid or petrosal approaches. CONCLUSION: Our study provides interesting data regarding the risk GON injury in posterior fossa approaches. Direct GON injuries in paramedian suboccipital approaches can be avoided with careful dissection. Placing retractors in contact with the periosteum and performing a minimal retraction may help to avoid excessive GON stretching in midline suboccipital and paramedian suboccipital approaches. Furthermore, the incision for retrosigmoid approaches should be as lateral as possible and not too caudal. Finally, avoiding extreme patient positioning reduces the risk of GON stretching in all approaches.

WHO grade II meningioma: Epidemiology, survival and contribution of postoperative radiotherapy in a multicenter cohort of 88 patients.

BACKGROUND: Meningioma is the most common primary intracranial tumor, representing 13-36.6% of all primary central nervous system tumors. Meningiomas are benign in about 90% of cases. World Health Organization (WHO) grade II meningioma is associated with a high rate of recurrence and poorer survival than in grade I. The reference treatment is surgery, which should be as complete as possible. Currently, in grade II, there are no recommendations for systematic adjuvant treatment such as radiotherapy. We studied a homogeneous series of grade II meningiomas treated by surgery in two university hospital centers to analyze use of radiotherapy and its efficacy. METHODS: We retrospectively analyzed patients in our database with WHO grade II meningioma, operated on between 2007 and 2010 in the university hospitals of Montpellier and Bordeaux, France. Clinical and radiological data, treatments and survival were analyzed. RESULTS: Eighty-eight patients were included. Five-year overall survival was 89.7%. Nineteen patients received radiotherapy during follow-up, without significant impact on survival (P=0.27). CONCLUSION: In WHO grade II meningioma, it is currently difficult to establish clear recommendations for radiotherapy. The present study is in accordance with the literature that early postoperative radiotherapy is not mandatory in grade II meningioma with macroscopically total resection.

Functional outcome 1 year after aneurysmal subarachnoid hemorrhage due to ruptured intracranial aneurysm in elderly patients.

BACKGROUND: Population aging raises questions about extending treatment indications in elderly patients with aneurysmal subarachnoid hemorrhage (aSAH). We therefore assessed functional status 1 year after treatment. METHODS: This study involved 310 patients, aged over 70 years, with ruptured brain aneurysm, enrolled between 2008 and 2014 in a prospective multicentre trial (FASHE study: NCT00692744) but considered unsuitable for randomisation and therefore analysed in the observational arms of the study: endovascular occlusion (EV), microsurgical exclusion (MS) and conservative treatment. The aims were to assess independence, cognition, autonomy and quality of life (QOL) at 1 year post-treatment, using questionnaires (MMSE, ADLI, IADL, EORTC-QLQ-C30) filled in by independent nurses after discharge. RESULTS: The 310 patients received the following treatments: 208 underwent EV (67.1%), 54 MS (17.4%) and 48 were conservatively managed (15.5%). At 1 year, independence rates for patients admitted with good clinical status (WFNS I-III) were, according to the aneurysm exclusion procedure (EV, MS or conservative), 58.9%, 50% and 12.1% respectively. MMSE score was pathological in 26 of the 112 EV patients (23.2%), 10 of the 25 MS patients (40%) and 4 of the 9 patients treated conservatively (44%), without any statistically significant difference [Pearson's Chi2 test, F ratio=4.29; P=0.11]. Regarding QoL, overall score was similar between the EV and MS cohorts, but significantly lower with conservative treatment. CONCLUSION: Elderly patients in good clinical condition with aSAH should be treated regardless of associated comorbidities. Curative treatment (EV or MS) reduced mortality without increasing dependence, in comparison with conservative treatment.

[Educational assessment of the first computerized national ranking exam in France in 2016: Opportunities for improvement]. / Analyse docimologique des premières Épreuves classantes nationales informatisées (ECNi) de 2016 : propositions d'amélioration.

In June 2016, 8124 medical students in their sixth year of graduation passed the first computerized national ranking exam (CNRE) in France after which they will have to choose what medical specialty they will be practicing all their life. We conducted the first educational assessment of this CNRE according to two criteria: the relevance of the questions and the cognitive domain mainly required to answer these questions. We propose two improvements for the future CNRE: promote student reasoning in the multiple choices questions, reduce to 10 the number of multiple choice questions in the progressive clinical cases and increase by 9 their total number (from 18 to 27), and use a majority of mini-clinical cases for isolated multiple choice questions in order to focus students on reasoning instead of simple knowledge restitution.

A randomized controlled study assessing outcome, cognition, autonomy and quality of life in over 70-year-old patients after aneurysmal subarachnoid hemorrhage.

BACKGROUND: Current aging of the population with good physiological status and the increasing incidence of subarachnoid hemorrhage (SAH) in elderly patients has enhanced the benefit of treatment in terms of independence and long-term quality of life (QoL). METHODS: From November 1, 2008 to October 30, 2012, 351 patients aged 70 years or older with aneurysmal SAH underwent adapted treatment: endovascular coiling (EV) for 228 (65%) patients, microsurgical clipping (MS) for 75 (29.3%) or conservative treatment for 48 (13.7%). Forty-one of these were randomized to EV (n=20) or to MS (n=21). The objectives were to determine the proportion of patients with modified Rankin Scale score≤2 (independence) at 1 year, and, secondarily, to compare cognitive function on the Mini-Mental State Examination (MMSE), autonomy on the Activities of Daily Living Index (ADLI) and Instrumental Activities of Daily Living scale (IADL), and QoL, in the prospective and randomized arms, at 1 year. RESULTS: At 1 year, with 1 loss to follow-up in the EV arm, 11 patients (55%) were independent after EV occlusion and 8 (38.1%) after MS exclusion, without significant difference (P=0.29). Mortality was higher after MS during the first 2 postoperative months, and thereafter the difference between MS and EV ceased to be significant. Cognitive function and autonomy scores were similar in both arms. CONCLUSION: In elderly patients treated for aneurysmal SAH, approximately 50% were independent at 1 year, with conserved cognition and autonomy. EV and MS are valid procedures in this population, with similar results at 1 year in terms of independence, cognition, autonomy, and QoL.

Vertebral artery (V2) pseudo-aneurysm after surgery for cervical schwannoma. How to prevent it and a review of the literature.

STUDY DESIGN: Case report and review of the literature. OBJECTIVE: To prevent and manage a suspected iatrogenic vertebral artery injury during a cervical spine anterior approach. SUMMARY OF BACKGROUND DATA: The anterior spine approach is a common surgery with few complications. One of the rare but significant risks is vertebral artery injury. Consequences of vertebral artery injuries are often delayed. Therefore, it is essential to prevent this complication and to know how when exploring after a suspected vertebral artery injury. METHODS: Report of a case and review of the literature. A 61-year-old woman presented with a cervical schwannoma involving the C5-C6 foramen. She had undergone surgery 22 years before by the posterior approach. We performed an anterior cervical approach. After 12 days, a vertebral artery pseudo-aneurysm occurred. Our review of the literature is focalized on vertebral artery injuries during cervical surgery by the anterior approach. RESULTS: The patient was treated by coil embolization with a good outcome. To our knowledge, only 6 cases of vertebral artery pseudo-aneurysm after surgery have been reported in the literature. CONCLUSION: According to the literature, vertebral artery pseudo-aneurysms resulting in anterior cervical approach are rare but their consequences could be severe. Prevention begins by detailed surgical planning. Peroperative imaging is helpful. Any suspected vertebral artery injury should postpone a contralateral approach before angiographic imaging.

[The relationship between aneurysmal subarachnoid hemorrhage and meteorological parameters based on a series of 236 French patients]. / Relations entre hémorragies sous-arachnoïdiennes par rupture anévrysmale et paramètres météorologiques à partir d'une série française de 236 patients.

Subarachnoid hemorrhage (SAH) is a sudden and potentially severe event with mortality rates ranging between 24 and 30 % depending on the initial clinical condition. Studies have attempted to assess the possible influence of meteorological parameters on the occurrence of SAH. However, this idea remains very controversial and the results vary widely from one study to another. Our study is the second largest French series, and first performed in a homogeneous series of patients. The aim of our study was to attempt to establish a relationship between the weather (i.e.) temperature variations and daily variations of atmospheric pressure in the days before the onset of SAH and the same day and the occurrence of non-traumatic SAH in a homogeneous population of 236 patients from a single center, over a period of 7 years (2002 to 2008). This retrospective study does not suggest any relationship between the occurrence of SAH and meteorological data studied. Moreover, no relationship was observed between mean changes in temperature or pressure and the occurrence of SAH, that the day of the bleeding or the days preceding the SAH. However, a female predominance was observed and a relatively high mortality rate of 18.3 %. The distribution of the occurrence of an SAH was random. As it seems impossible to provide logistics and organization of care for non-traumatic SAH, the care system must remain vigilant throughout the year.

[Hepatic artery aneurysm rupture after lumbar stenosis surgery. Medico-legal thinking]. / Rupture d'un anévrisme de l'artère hépatique après chirurgie de canal lombaire étroit. Réflexions médico-légales.

INTRODUCTION: Distinguishing between therapeutic contingency and surgical complication is sometimes not easy, especially when rare events occur. We report the case of a patient who presented with an intraperitoneal haemorrhage following laminectomy and discuss the implications of surgery in this complication. CASE REPORT: A 77-year-old woman, suffering from radiculopathy due to lumbar stenosis underwent a laminectomy in the prone position. On admission she presented with high blood pressure and obesity as significant comorbidities. A few hours after surgery, she collapsed and underwent a thoraco-abdominal CT-scan. The examination revealed a ruptured hepatic artery aneurysm. It is the first case published in the medical literature after lumbar surgery. The aim of this article was to discuss the responsibility of the surgeon and surgery, particularly the surgical positioning of the ruptured aneurysm. CONCLUSION: After reviewing the literature we did not find any evidence to attribute the rupture of this hepatic artery aneurysm to lumbar surgery. This adverse event could be attributed to therapeutic contingency. In cases of patient complaint, this situation depends on national solidarity.

[Intracranial hemorrhage in adults: place of antithrombotic treatment]. / Hémorragies intracrâniennes de l'adulte : implication de plus en plus importante des traitements antithrombotiques ?

BACKGROUND AND PURPOSE: Antithrombotic (anticoagulants and antiplatelets) are responsible for iatrogenic accidents, with a specific impact in neurosurgery. Bleeding complications are the most common and best-known. But the link to antiplatelet or to dual association of antithrombotic treatment with intracranial haemorrhage is not complete yet. We studied the proportion of patients under antithrombotic treatment, when an intracranial hemorrhage occurred, as well as the morbi-mortality of each group of patients (with or without antithrombotic treatment). Finally, we studied the proportion of off-label prescriptions. METHODS: We conducted a monocentric and comprehensive prospective study on a group of patients. All patients that had been admitted for intracranial hemorrhage to our hospital, in a 5-month period were included in the study. RESULTS: One hundred and sixty patients admitted for an intracranial hemorrhage were included during 70days of call. Seventy-four of these patients (46.25%) were under antithrombotic treatment: 40 under antiplatelet treatment (54%), 29 under anticoagulant treatment (39.2%), four under dual antithrombotic treatment (5.4%), and one under Arixtra(®). Half of the patients under antithrombotic treatment had poor prognosis as compared to 40% of patients without antithrombotic treatment. Off-label antithrombotic therapy was estimated at 27.3% of all prescriptions. CONCLUSIONS: The prevalence of antithrombotic therapy in patients is high when intracranial hemorrhage occurs. Some complications could be avoided by decreasing the number of off-label prescriptions and by better controlling their use (using standardized INR). Antiplatelet treatments and new antithrombotic therapies require better drug monitoring which could be part of the establishment of a specific register.

Delayed hypoglossal nerve palsy following unnoticed occipital condyle fracture.

Occipital condylar fractures (OCFs) are rare and difficult to diagnose. The routine use of computed tomography (CT) scan in traumatology has however now made their diagnosis easier, with an estimated frequency of 4 to 19% of craniospinal traumatized patients and 0.4 to 0.7% of all severe traumatized patients in emergencies. This paper describes a patient who was not diagnosed with OCF during his first hospitalization after a road accident. However, 15 days later a left sided hypoglossal nerve palsy occurred. In this case report, we underline that an examination of the cranial nerve is a quick and easy procedure to screen each head trauma patient for occipital foramen fractures. Also, careful attention must be paid to X-Rays, CT scans and magnetic resonance imaging of the craniocervical junction.

[Orbital tumors. Neurosurgical activity]. / Tumeurs orbitaires. Activité neurochirurgicale.

In this chapter, we report the results of orbital tumor management in a few neurosurgical departments and compare it to a Paris neurosurgical department that has developed a close relation with an ophthalmological department. These departments' activity is quite low, treating mainly sphenoorbital meningiomas. Other tumor groups are unequally and sporadically managed.

Junction between the great cerebral vein and the straight sinus: an anatomical, immunohistochemical, and ultrastructural study on 25 human brain cadaveric dissections.

The cerebral venous system is poorly understood, and best appreciated under macroscopic anatomical considerations. We present an anatomical and immunohistochemical studies to better define the morphological characteristics of the junction between the great cerebral vein and the straight sinus. Twenty-five cadaveric specimens from the anatomy laboratory of the University Victor Segalen of Bordeaux were studied. The observation of the venous junctions with the straight sinus was performed under an operating microscope. The smooth muscular actin immunohistochemical staining was performed for 18 veno-sinosal junctions. Five venous junctions were observed using an electron microscope. We observed 3 different anatomic aspects: type 1 was a junction with a small elevation in its floor and a posterior thickening (14 cases); type 2 was a junction with an outgrowth on the floor like a cornice (7 cases); and type 3 was a junction presenting a nodule. Microscopic study of type 1 and 2 junctions showed a positive coloration to orceine attesting the presence of elastic fibers. Immunohistochemistry revealed the presence of smooth muscular actin and S 100 protein attesting the presence of smooth muscular fibers and nervous fibers. We observed in the ultrastructural study, a morphological progression of the endothelium. The venous orifice of the great cerebral vein into the straight sinus could be anatomically assimilated as a true "sphincter." Its function in the regulation of the cerebral blood flow needs further exploration.

Peritumoral edema and prognosis in intracranial meningioma surgery.

Peritumoral brain edema (PTBE) is often associated with meningiomas. PTBE is probably implicated in the complications occurring in intracranial meningiomas. The goal of this study was to determine the exact implication of PTBE in prognosis. Thirty consecutive patients who underwent surgery for intracranial meningiomas were investigated over a 1-year period. We focused on the clinical and radiological status before and after surgery, and postoperative complications. Multiple regression analysis revealed a close correlation (p<0.05) between PTBE and symptoms, type of arterial supply, difficulty of surgical removal, and postoperative complications. PTBE is likely implicated in the morbidity of intracranial meningiomas. We suggest predictive factors for difficult surgical resection, and emphasise the importance of medical preoperative management and post-operative follow-up.

Sacral neuromodulation as a functional treatment of bladder overactivity.

Sacral neuromodulation, namely the electrical stimulation of the sacral nerves has become an alternative treatment for cases of idiopathic bladder overactivity. The mechanism of action in this type of spinal cord modulation is only partially understood but it seems to involve stimulation of inhibitory interneurons. Temporary sacral nerve stimulation is the first step. It consists of the temporary application of neurostimulation as a diagnostic test in order to check the integrity of the sacral root and determine the best location for the implant. If the test stimulation is successful, a permanent device is implanted. In experienced hands, this is a safe procedure. When the patients are selected on the basis of sound criteria, more than three-quarters of them show a clinically significant improvement with a reduction in the frequency of incontinence episodes by more than 50%; however, the results vary according to each author's method of evaluation. The application of this technique should be combined with careful follow-up and attentive adjustments of the stimulation parameters in order to optimize the coordination of activity between the neurological systems involved.

Dorsal rhizotomy combined with anterior sacral root stimulation for neurogenic bladder.

A spinal cord lesion (traumatic or not) above the sacral micturition center may induce hyperreflexia of the detrusor, spasticity of the sphincter and vesico-sphincter dyssynergia. Eventually, alterations in the upper urinary tract can be associated with increased mortality in this patient population. Sacral rhizotomies combined with implantation of an anterior sacral root stimulator appear to be an effective method not only for the treatment of voiding dysfunction but also for defecation and sexual disorders. The clinical and electrophysiological checks and the surgical technique are described. In most series, the results show a constant improvement in the patient's functional status. Ninety percent of patients gain satisfactory continence and no longer require an incontinence appliance. Bladder capacity and compliance increase dramatically. As a consequence, urinary infection rate decreases. The majority of patients remain dry, and more than 80% have a complete voiding or a post-void residue of less than 50ml and do not require any catheterization. Anterior sacral root stimulation combined with sacral posterior rhizotomy is a valuable method to restore bladder function in spinal cord-injured patients suffering from hyperactive bladder.

beta(2)-Microglobulin amyloidosis caused spinal cord compression in a long-term haemodialysis patient.

STUDY DESIGN: A case report of cervical myelopathy caused by epidural beta (2)-microglobulin (beta2m) amyloid deposits in a 50-year-old woman with haemodialysis treatment. OBJECTIVE: Long-term haemodialysis in patients with end-stage renal disease leads to several complications based on beta2m deposits, which can affect, in the cervical spine, the intervertebral disk, and in rare cases, they may compress the spinal cord and nerves. The objective of this report is to describe the clinical and radiological follow-up preceding the indispensable surgical excision of an amyloid mass in a 50-year-old woman with haemodialysis treatment. Long-term postoperative cervicalgia owing to subcondylian bone cyst-associated atlanto-occipital instability is also described and discussed. SETTING: Department of Neurosurgery A, Hop Pellegrin, Bordeaux, France. CASE REPORT: We present a clinical case of a patient with spinal cord compression. The patient was treated by surgical excision of an amyloid mass subsequent to a C2-C3 laminectomy. The patient experienced clinical improvement with a regression of all of her neurological symptoms. Histological findings confirm the diagnosis of beta2m amyloid deposition. However, 5 years after surgery the subcondylian bone cysts were still observed and atlanto-occipital instability required her to wear a minerva. CONCLUSION: Our case report confirms that surgical excision of beta2m epidural deposits is necessary and relevant when neurological prognosis is discussed, and that pain is still the major symptom of disease evolution. The use of high-flux synthetic membranes could decrease the beta2m blood level and early renal graft is the only method to prevent such complications.