Indications for surgical evacuation of cerebellar intracerebral hemorrhage: consensus guidelines from the French Society of Neurosurgery (SFNC) and the French Society of Vascular Neurology (SFNV)

BACKGROUND

Cerebellar intracerebral hemorrhage (ICH) is associated with poor functional prognosis and high mortality. Surgical evacuation has been proposed to improve outcome. The purpose of this review was to determine the benefit of surgical evacuation of cerebellar ICH and to establish guidelines for when it should be performed.

METHOD

The writing committee comprised 9 members of the SFNV and the SFNC. Recommendations were established based on a literature review using the PICO questions. The American Heart Association (AHA) classification was used to define recommendation level. In case of insufficient evidence, expert opinions were provided.

RESULTS

Levels of evidence were low to moderate, precluding definitive recommendations. Based on available data, surgical hematoma evacuation is not recommended to improve functional outcome (Class III; Level B NR). However, based on subgroup analysis, surgical evacuation may be considered in strictly selected patients (Class IIb; Level C-EO): hematoma volume 15-25 cm3, GCS 6-10, and no oral anticoagulation or antiplatelet therapy. Moreover, surgical evacuation is recommended to decrease risk of death (Class IIa; Level B NR) in patients with a hematoma volume >15 cm3 and GCS score <10.

CONCLUSION

These guidelines were based on observational studies, limiting the level of evidence. However, except for strictly selected patients, surgical evacuation of cerebellar ICH was not associated with improved functional outcome, limiting indications. Data from RCTs are needed in this field.

First results about ProAKAP4 concentration in stallion semen after cryopreservation in two different freezing media

The quality of fresh or thawed sperm in stallions has been generally determined by the viability and total and progressive motility of the sperm. Today, the expression of ProAKAP4, a protein present in the flagellum of spermatozoa, appears to be an innovative and relevant functional marker to assess semen quality and male fertility. This study aims to compare the concentration of ProAKAP4 in the semen from 5 stallions frozen with two different extenders immediately after thawing (T0) and 4 h post-thawing (T4). Viability, total and progressive motility were measured in parallel. Significant differences for sperm viability and total motility were observed between the two extenders, as was the concentration of ProAKAP4 both at T0 and T4. At T4, all quality parameters and ProAKAP4 content significantly decreased compared to T0, but with a considerably slower decrease in one extender than the other. These preliminary results suggest that measuring the concentration of ProAKAP4 is a promising tool for the comparison of different extenders and the selection of the optimal freezing medium for each stallion ejaculate.

Seizures after decompressive hemicraniectomy for large middle cerebral artery territory infarcts: Incidence, associated factors, and impact on long-term outcomes

BACKGROUND AND PURPOSE

Decompressive hemicraniectomy (DH) reduces mortality of large middle cerebral artery (MCA) territory infarcts. Survivors are at high risk of poststroke seizures (PSSs). This study aims to describe the incidence of PSSs, to identify associated factors, and to assess their impact on long-term outcomes.

METHODS

We included consecutive patients who underwent DH for large MCA infarcts from May 2005 to December 2019 at Lille University Hospital. Patients were followed up at 3 months, 1 year, and 3 years. We analysed (i) the incidence and associated factors of early onset PSSs (EPSSs) with logistic regression models; (ii) the incidence and associated factors of late onset PSSs (LPSSs) in survivors at 7 days with a univariate Cox proportional hazard regression model for interval-censored data; and (iii) the impact of PSSs (EPSSs and LPSSs) on mortality with univariate and multivariate Cox proportional hazard regression models and modified Rankin Scale at 1 and 3 years, with univariate and adjusted multivariate ordinal logistic regression analyses.

RESULTS

Of 248 patients (150 men, 60.5%; mean age = 50.4 ± 9.6 years), 106 (42.7%) presented PSSs (six inaugural seizures, 22 EPSSs, 78 LPSSs) during follow-up. The PSS cumulative incidence was 12.3% at 7 days, 24.9% at 3 months, 49.8% at 1 years, and 54.8% at 3 years. No predictor was significantly associated with either EPSSs or LPSSs. PSSs did not significantly impact mortality and long-term functional outcome.

CONCLUSIONS

The incidence of PSSs after DH is high, reaching more than 50% 3 years after stroke, but PSSs did not influence long-term mortality or functional outcome.

Age-dependent expression of osteochondrosis-related genes in equine leukocytes

INTRODUCTION

Osteochondrosis (OC) is a developmental disease in horses which has a significant impact on the horse's welfare and performance. The early disturbance in the process of endochondral ossification progresses to inflammatory and repair processes in older horses. Previously, differentially expressed genes in leukocytes of OC-affected horses have been identified. The aim of the present study is to detect age-related changes in these differentially expressed genes.

MATERIALS AND METHODS

The expression of OC-related genes was analysed by real-time PCR and subsequent statistical analysis (ΔΔCT) in the leukocytes of 135 Belgian Warmblood horses divided into three different age groups: <12 months (n=47), 18-24 months (n=50) >30 months (n=38).

RESULTS

Relative expression of genes of horses less than 12 months of age showed significant induction of the genes MGAT4A, PRKCG, MHCI, ApoB, ApoB3G, B4GALT6 and a significantly lower expression of the genes OAS3. Horses of 18-24 months of age, showed a significantly higher expression of the genes TBC1D9, MGAT4A, IFIH1, MHCIIa and MMP1. Horses of more than 30 months of age showed a significantly higher expression of the genes MGAT4A, HP, SECTM1 compared with their age-matched control groups.

CONCLUSIONS

The study demonstrates that OC-related genes are differentially expressed in horses of different ages compared with their age-matched controls. Some of the genes may be implicated in cell signalling and differentiation as well as carbohydrate and lipid metabolism and inflammation. However, the causal relationship between the differentially expressed genes and the development and progression of the OC lesions needs to be determined.

Biomechanical wall properties of human intracranial aneurysms resected following surgical clipping (IRRAs Project)

BACKGROUND AND PURPOSE

Individual rupture risk assessment of intracranial aneurysms is a major issue in the clinical management of asymptomatic aneurysms. Aneurysm rupture occurs when wall tension exceeds the strength limit of the wall tissue. At present, aneurysmal wall mechanics are poorly understood and thus, risk assessment involving mechanical properties is inexistent. Aneurysm computational hemodynamics studies make the assumption of rigid walls, an arguable simplification. We therefore aim to assess mechanical properties of ruptured and unruptured intracranial aneurysms in order to provide the foundation for future patient-specific aneurysmal risk assessment. This work also challenges some of the currently held hypotheses in computational flow hemodynamics research.

METHODS

A specific conservation protocol was applied to aneurysmal tissues following clipping and resection in order to preserve their mechanical properties. Sixteen intracranial aneurysms (11 female, 5 male) underwent mechanical uniaxial stress tests under physiological conditions, temperature, and saline isotonic solution. These represented 11 unruptured and 5 ruptured aneurysms. Stress/strain curves were then obtained for each sample, and a fitting algorithm was applied following a 3-parameter (C(10), C(01), C(11)) Mooney-Rivlin hyperelastic model. Each aneurysm was classified according to its biomechanical properties and (un)rupture status.

RESULTS

Tissue testing demonstrated three main tissue classes: Soft, Rigid, and Intermediate. All unruptured aneurysms presented a more Rigid tissue than ruptured or pre-ruptured aneurysms within each gender subgroup. Wall thickness was not correlated to aneurysmal status (ruptured/unruptured). An Intermediate subgroup of unruptured aneurysms with softer tissue characteristic was identified and correlated with multiple documented risk factors of rupture.

CONCLUSION

There is a significant modification in biomechanical properties between ruptured aneurysm, presenting a soft tissue and unruptured aneurysms, presenting a rigid material. This finding strongly supports the idea that a biomechanical risk factor based assessment should be utilized in the to improve the therapeutic decision making.

Ruptured cerebral oncotic aneurysm from choriocarcinoma: report of two cases and review of the literature

The study design involved case reports and review of the literature. Oncotic aneurysm from choriocarcinoma is an extremely rare event that should be known by all neurosurgeons and suspected in women of childbearing age. The purpose of this article is to report the authors' experience and to provide insight on clinical presentation and radiological signs to aware the reader to this entity and then to prevent misdiagnosis. The authors report two cases of ruptured oncotic aneurysm treated at their institution in 2010. A review of the literature was performed to discuss the pathogenesis and the role of the neurosurgeon. Chemotherapy is the treatment of choice making surgery necessary only for patients with large intracerebral haematoma that represents an immediate threat.

Validation of a portable equine metabolic measurement system

REASONS FOR PERFORMING STUDY

In equine sports medicine, VO2 has been measured exclusively with stationary systems, in laboratories equipped with a treadmill. Measurement during exercise in field conditions has not previously been reported because of the lack of portable equipment designed for horses.

OBJECTIVES

A commercially available portable metabolic measurement system, based on breath-to-breath gas analysis and flow spirometry, was adapted to the horse's physiology and morphology (Cosmed K4b2 and Equimask) and its validity tested by (1) repeatability of the measures and (2) comparing metabolic data to those obtained by a reference method (RM).

METHODS

To test the reproducibility of the measurements, 5 healthy saddle horses were subjected twice at 2 day intervals to a similar submaximal standardised incremental exercise test on a treadmill. The same horses performed twice at one week interval an incremental treadmill test to fatigue: the oxygen consumption and ventilation were measured once with the K4b2 system and once with the RM. The metabolic and ventilatory data obtained with both systems were compared.

RESULTS

There was a good reproducibility of the metabolic measurements obtained by the K4b2 system at any workload. The VO2 obtained by both systems at any workload was not significantly different. However, the K4b2 expired fraction in CO2 (FETCO2) and carbon dioxide production (VCO2) were significantly lower at high and at maximal workloads. As a consequence, the values of the respiratory exchange ratio were too low and incompatible with normal physiological values.

CONCLUSIONS

The good reproducibility of the metabolic and ventilatory measurements and the fact that the VO2 measurements at any workload were similar to the data obtained with the reference method suggested that this system may be used for comparison of repeated VO2 measurements in practical field conditions.

POTENTIAL RELEVANCE

The K4b2 system could be used to improve knowledge of the energetic cost in different equine sports disciplines and offer the opportunity to undertake performance tests with genuine track conditions, on ridden or harnessed horses, rather than under laboratory conditions.

Surgical anatomy and surgical approaches to the lateral ventricles

This study focuses on the surgical approaches to intraventricular tumors which have developed within the cavity of the lateral ventricle. The first section is dedicated to embryology and describes the wrapping of the telencephalic vesicles around the thalamus and the morphogenesis of basal nuclei and commissures. In the second section, the anatomy of the lateral ventricles is described, along with their arterial and venous vasculature, their relationship with the eloquent cortical areas and cortical sulci, and their relationship with white matter fascicles, especially the optic radiations. In the third part, the main surgical approaches to the frontal horn, to the ventricular atrium and to the temporal horn are detailed.

Radiographic evolution of the forelimb digit in Ardenner horses from weaning to 28 months of age and its clinical significance

Ossification of collateral cartilages is a common radiographic finding in draught horses and indication of a high frequency of interphalangeal osteo-arthropathy have been found in Ardenner horses. This study first aimed at following the evolution of the digits of the forelimbs on radiographic images in a group of 32 Ardenner horses from weaning to 852 +/- 19 days and, secondly, at evaluating the clinical significance of the observed radiographic changes. At 250 +/- 21 days, only 23% of the horses presented a small separate ossification centre of collateral cartilages above the level of the distal sesamoid bone or at the level of the proximal half of the middle phalanx. At 852 +/- 19 days, 100% of the horses presented an ossification of collateral cartilages but at different stages and grades. The presence and the extent of the ossification of the lateral cartilages were not significantly associated with lameness. Phalanges changes appeared at the average age of 1 year and they were represented by entheseophytes on the dorsal surface of the middle and distal phalanges. The frequency of affected horses increased with age as well as the size of the entheseophytes. This may reflect mechanical stresses applied to the interphalangeal joints. A significant association with the presence of lameness was pointed out. The presence and the severity of phalanges changes could be of importance, in combination with a clinical examination, in improving the selection of horses able to assume work and/or leisure activities.

Localisation en IRM des anévrismes carotidiens paraclinoïdiens

AIM

The distal dural ring plane (DDRP) separates the intracavernous from the supracavernous paraclinoid internal carotid artery. The purpose of this MRI protocol is to evaluate the position of this plane for the characterization of paraclinoid aneurysms.

METHOD

The protocol uses a T2 weighted sequence in two orthogonal planes (diaphragmatic and carotid planes) and two correlation lines in each plane. These lines pass through anatomo-radiological reference points correlated with the medio-lateral and antero-posterior margins of the DDRP. We use the intersection angle of these lines as the inferior radiological limit of the DDRP curve.

RESULTS

An aneurysm located above this angle is supracavernous; an aneurysm located below this angle is intracavernous; an aneurysm crossing this angle is transitional.

CONCLUSION

In difficult cases, this MRI protocol could help better characterize the exact localization of paraclinoid aneurysms on both sides of the cavernous sinus roof.

Management of delayed intracranial and intraspinal metastases of intradural spinal paragangliomas

The preferential site of extra-adrenal paragangliomas is the head and neck region. However intradural spinal paragangliomas are commonly described and are considered as benign entities. We report the case of a paraganglioma of the cauda equina followed after complete surgical removal by intracranial and intraspinal cerebrospinal fluid metastases. Seven years after the first operation, a cystic cerebellar lesion was successfully treated by surgery. During a long follow-up, four locations in the posterior fossa, a lumbar recurrence and metastatic nodules at T6 and S1-S2 level were also discovered. Radiotherapy stopped the lesions' growth and allowed improvement of the neurological status. Through a review and analysis of the literature, we discuss the management of this unusual evolution.

Endovascular treatment of remnants of intracranial aneurysms following incomplete clipping

We report clinical and angiographic findings in eight patients treated by the endovascular approach for an intracranial aneurysm remnant after incomplete surgical clipping. They were seven women and one man, mean age 38 years (range 14-50 years). In three, the remnant was responsible for a recurrent subarachnoid haemorrhage. All were treated by embolisation of the remnant using Guglielmi detachable coils. In two, a nondetachable balloon was inflated in front of the remnant during coil detachment because of a wide neck. Mean clinical and imaging follow-up was 19 months (range 12-24 months). Immediate angiography showed complete occlusion of the remnant and follow-up clinical examination showed good or excellent recovery in all patients. Imaging follow-up confirmed persistent occlusion of the remnant in all cases.

[Neurosurgical management of spontaneous cerebral hemorrhage]

Intracerebral hemorrhage (ICH) accounts for 10 to 20% of strokes, but carries the highest rate of morbidity and mortality. Until now, there is no proven benefit in the literature for surgical treatment of ICH, and management of ICH varies greatly in neurosurgical centers. Surgery can be performed through standard craniotomy, or with a stereotactic procedure for deep-seated ICH. Conscious patients with minimal neurological deficit and small ICH are nonsurgical candidates. Patients with a Glasgow Coma Score lower than 4, with large deep-seated ICH are also non surgical candidates. In other situations, the following arguments could lead to the decision of surgery: superficial (so-called lobar) ICH, size above 3 cm in diameter, midline shift, secondary neurological worsening, young patient, underlying vascular malformation. Acute hydrocephalus from ventricular hemorrhage may be treated with external ventricular drainage if the associated deep-seated ICH is small in size. Indications of surgery are more frequent for cerebellar ICH, as the risks for brainstem compression and hydrocephalus from ventricular obstruction are important.

Giant aneurysms of the internal carotid artery: endovascular treatment and long-term follow-up

We report the long-term follow-up of 18 patients with giant aneurysms of the internal carotid artery (ICA) referred for endovascular occlusion of the parent vessel. There were 10 aneurysms involving the infra- and/or supraclinoid cavernous segment, six the ophthalmic segment, one the petrous segment and one the bifurcation. One patient who did not tolerate test occlusion was treated medically. Clinical and imaging follow-up were obtained in 16 patients for a mean of 30 months, range 6-80 months. Endovascular treatment led to excellent clinical outcome in 16 patients. One 34-year-old woman, who presented with subarachnoid haemorrhage (SAH), died from bilateral middle cerebral artery infarcts due to severe vasospasm 4 days after treatment. The patient treated medically died from SAH. Long-term imaging follow-up in 16 patients revealed a markedly smaller aneurysm sac in all cases.

[Clinical implications of acoustic neuromas growth rate in volumetric study]

OBJECTIVE

The pattern of neuroma growth is of great importance in choosing the appropriate management. This paper tests the clinical impact of tumor growth rate assessed by volumetry. There is a conviction that some slowly growing tumors could be observed for many years.

METHOD AND PATIENTS

Volume measurements were performed on T1- weighted MR images (spin echo sequences) after injection of gadolinium using a special dedicated software. The studied group included 17 patients in whom at least two MRI examinations were carried out and tumor growth was confirmed. The intervals between initial and the first follow-up examination were 14.2 months on the average. In 7 cases tumor evolution was observed in 2 periods (3 MRI studies) and in 4 cases in 3 periods (4 MRI studies).

RESULTS

The growth rate depended on tumors volume and clinical stage (P<0.01). Small tumors can be observed more safely than advanced tumors because their increase in mass is lower.

CONCLUSION

The observation with the tumoral volume measurements appears to be a useful and accurate tool to estimate the tumor growth rate. The growth rate is a major factor for choosing the appropriate management.

Symptomatic vasospasm after subarachnoid haemorrhage: assessment of brain damage by diffusion and perfusion-weighted MRI and single-photon emission computed tomography

Our purpose was to assess the usefulness of diffusion- and perfusion-weighted MRI for the detection of ischaemic brain damage in patients with suspected vasospasm after subarachnoid haemorrhage (SAH). We studied 11 patients admitted with a ruptured aneurysm of the anterior circulation and suspected of intracranial vasospasm on clinical examination and transcranial Doppler sonography (TCD). All were investigated by technetium-hexamethyl-propylene amine oxime (Tc-HMPAO) single photon emission computed tomography (SPECT) and diffusion and perfusion-weighted MRI (DWI, PWI) within 2 weeks of their SAH. Trace images and TTP maps were interpreted by two examiners and compared with clinical and imaging follow-up. PWI revealed an area of slowed flow in seven patients, including four with major and three with minor hypoperfusion on SPECT. In two patients, PWI did not demonstrate any abnormality, while SPECT revealed major hypoperfusion in one and a minor deficit hypoperfusion in the other. Two patients with high signal on DWI had a permanent neurological deficit.

[Diagnostic problems in brain abscess: 45 cases]

BACKGROUND AND PURPOSE

We analysed the difficulties encountered in the differential diagnosis between brain abscess and brain tumor and their influence on treatment and outcome.

METHODS

- Forty-five adults with brain abscess operated on between 1993 and 1999 were retrospectively reviewed. We studied preoperative diagnosis, clinical, radiological, bacteriological findings, surgical procedure, primary sources of infection and outcome.

RESULTS

Preoperative diagnosis was right in 55.6% (25/45), wrong in 22.2% (10/45) and doubtful in 22.2% (10/45). Diffusion-weighted MR imaging was successfully used in 4 doubtful cases to make the differential diagnosis between abscess and tumor. When the preoperative diagnosis was right, the surgical procedure was a burr-hole aspiration in 73.3% (22/25) whereas when it was wrong, an excision was performed in 60% (6/10) of the cases. Aspiration was the last diagnostic investigation in 80% (8/10) of doubtful cases. Microbacterial organisms were identified in 75.5% (34/45) of the cases and primary cause of infection in 62.2% (28/45). The outcome depended on clinical status on admission, preoperative diagnosis and surgical procedure. In four cases, diffusion-weighted MRI allowed differential diagnosis between brain abscess and tumor through calculation of the Apparent Diffusion Coefficient which is low in abscess and high in cystic tumor.

CONCLUSION

The diagnosis of brain abscess remains difficult in certain patients. Correct preoperative diagnosis influences the decision on the appropriate surgical procedure and helps improve outcome.

Image-guided endoscopic spine surgery: Part I. A feasibility study

STUDY DESIGN

A feasibility study was performed to determine the efficacy of computer assistance in endoscopic spine surgery.

OBJECTIVES

To assess a new method for computer assistance based on image guidance during thoracoscopic or any endoscopic spine procedure. To evaluate the reproducibility, the sensitivity and the reliability of the technique first in vitro and second in clinical use.

SUMMARY OF BACKGROUND DATA

The computer-based, image-guided surgery is now a routine tool used in open spine surgery. Exposure of the anatomy of the vertebra is needed for registration. This methodology is inapplicable in endoscopic approach. Fluoroscopic-based navigation combines the technology of image-guided surgery and C-arm fluoroscopy. The navigation is based on the fluoroscopic images acquired before surgery. This technology is applicable to endoscopic surgery but the navigation is based on fluoroscopic image. The computed tomography images are not exploited. There are no published data on a technique that allows image-guided surgery based on computed tomography and magnetic resonance imaging.

METHOD

A laboratory study was performed on a thoracic human spine. One vertebra was marked on the right lateral side of the body with five titanium marks. A percutaneous reference frame was specifically designed to be placed in the pedicle of the same marked vertebrae. The reference frame acted as a 3D localizer and a registration tool. The spine model was scanned including the reference frame. A standard Stealth station treatment guidance platform (Medtronic, Sofamor Danek, Memphis, TN) was used for simulation. The registration was obtained using the reference frame. Twenty navigation procedure trials were done and the error was recorded based on the distance between the anatomical point and the corresponding virtual one.

RESULTS

Registration was always possible using the stealth station and a standard spine navigational software (spine 3, Medtronic Sofamor Danek, Memphis, TN). The mean error after registration given by the computer was 0.96 mm. The mean error recorded during the navigation simulation was 1.6 mm.

CONCLUSIONS

This technique allows the possibility of computed tomography and magnetic resonance imaging-based, image-guided endoscopic surgery. It is probable that in the near future, as image fusion technology improves, the fluoronavigation based on fluoroscopic images would enable to navigate on multimodal images. Otherwise the technique described in this article is the only reproducible one that allows computed-tomography-based computer assistance during endoscopic procedures.

Image-guided endoscopic spine surgery: Part II: clinical applications

STUDY DESIGN

Endoscopic spinal procedures were performed under computed-tomography-based, image-guided assistance.

OBJECTIVE

To assess the clinical feasibility of applying a methodology that allows image-guided assistance in endoscopic spinal surgery.

SUMMARY OF BACKGROUND DATA

Endoscopic spinal procedures have become a part of the minimal invasive approaches to the spine. The main disadvantage of these techniques is the long learning curve and the lack of peroperative monitoring. Fluoroscopy does have disadvantages, such as positioning during surgery and the risk for radiation exposure. Fluoroscopy-based navigation has many advantages, however it is still based on preselected fluoroscopic images. There is no method that allows computed-tomography-based navigation in endoscopic conditions.

METHODS

Two patients have been operated on using endoscopic approaches assisted by computed-tomography-based navigational system. One had a thoracoscopic approach for median calcified disc herniation and another one had an endoscopic posterior approach for resection of a sacro-iliac osteophyte. For each patient, a frame of reference had been placed percutaneously and scanned. The computed tomography images were registered to the anatomy using the geometry of the frame as fiducials. Navigation through endoscopic approaches was possible in both cases.

RESULTS

In both cases navigation was reliable and a helpful monitoring to achieve the surgical goals through endoscopic approaches.

CONCLUSIONS

There are some factors that make endoscopic spine surgery a difficult start. Image-guided spine surgery is technically feasible and clinically applicable in endoscopic approaches.

Meningeal inflammatory pseudotumour: a case report

We report the case of a meningeal inflammatory pseudotumour occurring in a 23-year-old male presenting with focal seizures and headaches. Brain imaging techniques showed a 3.5 cm left parietal meningeal tumour. Histology of the surgical specimen showed a dense lymphoid infiltrate permeating the dura mater and leptomeninges, consisting of a predominant polyclonal B cell population as confirmed by immunophenotyping and genotyping. Cultures of serum, CSF, and surgical specimen were negative and there was no serological evidence of a systemic dysimmune disease. The postoperative course was complicated by an episode of brain oedema resolving under steroid therapy. The patient, free from all medication, is asymptomatic at 3 years of follow-up. We discuss previously published cases and the nosology of intracranial inflammatory pseudotumours.

[Video-assisted thoracoscopic surgery]

We describe our experience with video-assisted thoracoscopic surgery (VATS). Twenty-nine patients were operated on with this technique for various anterior thoracic spinal lesions. There were 6 cases of disc herniation with simple resection, 6 with acute thoracic fractures requiring anterior grafting and stabilization, 7 old fractures and malunions treated by corporectomy, grafting and anterior stabilization in 3, 4 with spinal metastases that were resected and stabilized, 3 with a paravertebral spinal tumor (2 schwannomas and 1 chondroblastoma), and 3 osteoid osteomas that were resected with anterior grafting in one case. Indications for these procedures are specified and the technical considerations discussed for each group of pathologies. We had three complications: one conversion to thoracotomy in a case of spinal metastasis, one pleural effusion, and one incomplete resection of a thoracic disc herniation. We emphasize the need for minimally invasive approaches in spinal surgery.

Correlation between Ki-67 index and some clinical aspects of acoustic neuromas (vestibular schwannomas)

Evaluation of the proliferation activity of neuromas has a practical meaning when there are doubts about the complete resection of the tumor. Evaluation of the clinical aspects connected with increased proliferation activity may have a much broader application. The aim of this study was to correlate selected clinical and radiologic aspects of vestibular schwannomas with the results of the Ki-67 index. The studied group included 23 males and 20 females. Unilateral neuromas were stated in 38 cases (mean age, 52.2 years) and bilateral tumors in 5 cases (mean age, 44.2 years). The immunohistochemical tests (Ki-67) were performed on the specimens preserved in formalin and stored in paraffin. The Ki-67 index was estimated in a semiquantitative study. The mean value of Ki-67 index was 1.86%. In case of unilateral neuromas (n = 38), the average Ki-67 index was 1.74%. In 5 cases of bilateral tumors, the index amounted to 2.79% (P = 0.278). No significant correlation was found by comparing the value of the Ki-67 index with the age of patients (P = 0.410: r = 0.128). Significant differences in the value of the Ki-67 index were noted in the sub-groups of tumors that were evaluated radiologically as growing and stable. The mean value of Ki-67 index was 3.17% in the first subgroup; in stable neuromas, it was significantly lower, amounting to 1.11% (P = 0.020). Such results may confirm that the growth rate of vestibular schwannomas varies and may explain the difficulties in estimating the growth of neuromas on the basis of clinical aspects only.

[Introduction and history of surgery of the third ventricle]

In this annual report of the Société de Neurochirurgie de Langue Française, the authors reviewed in a retrospective study 262 cases of tumors exclusively located in the third ventricle (thalamic, chiasmatic and pineal tumors were excluded). Modern neuroradiology easily discloses these lesions, and therapeutic management represents the main challenge : most of the patients present with few symptoms, and even in some cases the lesions are diagnosed fortuitously. Neuropsychological assessment appears necessary to evaluate the long-term outcome of the patients : unfortunately few cases in this series were informative for these data. Walter Dandy described the operative approach of these tumors in 1922, and he also reported the benefits of endoscopy. Almost 80 years later, technical advances such as CSF shunts, stereotaxis, neuronavigation have improved the results of the neurosurgical treatment of these deep-seated lesions.

[Tumors of the third ventricle in children: review of 46 cases]

In the national series, 46 patients out of 262 (17.5%) were children under 15 years of age. Most of them presented with gliomas (50 %), choroid plexus tumors were recorded in 8 cases (17%). Intracranial hypertension revealed the tumor in 80% of children, endocrine disorders were recorded in 8 patients. A stereotactic procedure was performed in 7 patients, 1 had ventriculoscopy, and a direct surgical approach to the third ventricle was performed in 37 patients, in one case after the failure of the endoscopic procedure. Two patients with a radiological appearance of hamartoma received no treatment. Most of patients were operated on via a transcortical approach (27 cases). The overall mortality in this series is 9%. The death was directly correlated to the surgical procedure (1 case), or to recurrence of the tumor (3 cases). The final outcome analysis recorded neurological impairment in 50% of cases, neuropsychological deficit in 58 % of patients, and residual endocrine disorders in 41%. Social independence was recovered by 82% of the children, and 68% returned to normal school attendance.

[Surgical anatomy and surgical approaches of the third ventricle]

Careful analysis of MRI images is mandatory before any surgical procedure in the third ventricle. This analysis should take in account the relationship of the tumor itself, but also the grade of hydrocephalus and the main anatomical landmarks along the surgical approach. The first step is the access to the lateral ventricle, which may be achieved via transcortical or anterior transcallosal routes : these two operative procedures are detailed. The transforaminal entry to the third ventricle may be easy if hydrocephalus has widened the foramen of Monro. In other cases, a subchoroidal (or interthalamo-trigonal) approach is necessary, and the division of the thalamostriate vein is sometimes required. In this series, the transcortical route has been favoured by neurosurgeons. The advantages and drawbacks of both transcortical and anterior transcallosal routes are discussed. The anterior interhemispheric and pterional approaches are briefly evoked, as they were used in very few cases of this series. The management of hydrocephalus is discussed.

[Tumors of the third ventricle: review of 262 cases]

The data from 262 cases of third ventricle (V3) tumors treated in 21 Departments of Neurosurgery in France between 1980 and 1995 were collected in this series. These tumors were frequent in young adults, and 17.5% of the patients were children. Colloid cysts (55%) and gliomas (19%) were the most frequent lesions. Other tumors were rare, or exceptional.

CLINICAL PRESENTATION

The duration of symptoms was short in time, despite these lesions were usually benign. Most of cases were revealed by intracranial hypertension (63%), sometimes with a paroxystic or positional evolution. Neuropsychological signs (48 %) were undoubtedly under-estimated, revealing the disease in only 10% of cases. Ophthalmologic signs and endocrine disorders were infrequent. This feature is related to the selection of patients in this series, as tumors arising from the floor of the third ventricle or from the optic chiasm were excluded. Endocrine disorders were frequent with gliomas (30 %).

THERAPEUTIC MANAGEMENT

In half of the patients, hydrocephalus was absent or mild and was ruled out after the treatment of the ventricular lesion. However, 12% of patients required a shunt procedure after the treatment of the ventricular lesion. A stereotactic procedure was performed in 63 patients, 12 had ventriculoscopy, and a direct surgical approach to the V3 was performed in 200 patients, sometimes after the failure of stereotactic or endoscopic procedures. Thirty six patients received no treatment. The patients were operated on via a transcortical approach (159 cases), or via the anterior transcallosal route (35 patients). Postoperative course was uneventful in 67% of the patients, complications were recorded in 24% of patients.

MORTALITY AND MORBIDITY

The overall mortality in the national series is 13.7 % (36/262 died). The death occurred before any treatment (4 patients), or was directly correlated to the surgical procedure (13 cases), to long-term complications of hydrocephalus (2 patients), to general complications (7 patients), or to recurrence of the tumor (10 cases). The final outcome analysis recorded neurological impairment in 29% of cases, neuropsychological deficit in 50% of patients, and residual endocrine disorders in 19%. Social independence was recovered by 86% of patients, 76% of them returned to work, 72% of students returned to normal school attendance. The long-term neurological outcome was better with the transcallosal approach. No conclusion was possible concerning neuropsychological outcome, as postoperative neuropsychological assessment was not available for most of the patients operated on with the transcortical approach.

PROGNOSIS

The results of treatment were evaluated only for the most frequent lesions (colloid cysts and gliomas). The outcome was worse for gliomas when compared to colloid cysts, considering mortality (13% vs 8%), neurological impairment (36% vs 21%), residual endocrine disorders (34% vs 0%), and ability to return to work (83% vs 56%).

Cochlear fossa enhancement at MR evaluation of vestibular Schwannoma: correlation with success at hearing-preservation surgery

PURPOSE

To describe a sign in magnetic resonance (MR) imaging that could reflect the state of the cochlear nerve before hearing-preservation surgery in small vestibular schwannomas.

MATERIALS AND METHODS

Thirty-one patients with serviceable hearing underwent 1.5-T MR imaging before hearing-preservation surgery. The presence of cochlear fossa enhancement on T1-weighted spin-echo images obtained after the administration of contrast material was compared with the results of hearing-preservation surgery.

RESULTS

Cochlear fossa enhancement was present in 13 patients, and all of them had total hearing loss after surgery. There was no cochlear fossa enhancement in 18 patients; 15 maintained serviceable hearing after surgery, and three had postoperative hearing loss with no serviceable hearing (sensitivity, 81%; specificity, 100%).

CONCLUSION

Cochlear fossa enhancement on T1-weighted spin-echo images seems to be a reliable sign for analyzing the state of the cochlear nerve. The absence of cochlear fossa enhancement could become an additional criterion for selecting the surgical approach in vestibular schwannomas.

[Suprasellar arachnoid cyst associated with syringomyelia. Case report]

We present a case of suprasellar arachnoid cyst which was revealed by visual impairement and hypopituitarism. Neuroradiological imaging showed the peculiar association of the suprasellar cyst with cerebellar tonsillar herniation and a large asymptomatic cervical syringomyelic cavity. Surgical treatment of the suprasellar cyst allowed the reduction of both the cyst and the syrinx. A common pathophysiological mechanism of these lesions is discussed. We suggest the possibility that an initial obstruction of the basal cisterns caused the suprasellar cyst formation which led to medullar cavity formation.

[Clinical aspects and treatment of dural-spinal arteriovenous fistulas with perimedullary venous drainage. 10 cases]

BACKGROUND AND PURPOSE

Spinal dural arteriovenous fistulas (SDAVF) are rare but represent the most frequent spinal arteriovenous malformation. Their clinical manifestations are well known, but their management can still be discussed between surgery and endovascular treatment. The purpose of this study is to emphasize the pre-eminence of surgical management for posterior and postero-lateral fistulas, which are the most common location of the malformation.

METHODS

We report a consecutive series of 10 patients with SDAVF treated between July, 1995 and July, 1997. Results are compared with other series of the literature.

RESULTS

Clinical manifestations were not specific and the diagnosis was established in most cases only one year after the onset of symptoms, as a progressive myelopathy. Low back pain was present in 4 patients, with pseudo-radicular pain in the lower limbs suggesting spinal degenerative disease in 3 cases. At the time of diagnosis, 8 patients had permanent motor weakness of the lower limbs, usually associated with hypesthesia and sphincterial dysfunction (7 cases). In all cases, the diagnosis was established using MRI. In most cases, the intradural draining spinal veins were also visible on MRI images. The location of the SDAVF was always precised by angiography, and was located between T5 and L1 in our series. Seven patients were successfully operated on, with surgical interruption of the intradural draining vein. Three patients underwent an endovascular treatment, but two of them were operated on later, as control angiography showed recurrence of the SDAVF. The clinical status of patients always improved after treatment, but recovery was incomplete in patients with severe and long lasting neurological deficit.

CONCLUSIONS

Surgical interruption of the intradural draining vein is a safe and effective method of treatment of SDAVF, especially for posterior and postero-lateral fistulas. Endovascular treatment is recommended for anterior locations of SDAVF.

[Chronic subdural hematoma in patients over 80 years of age]

Eighty cases of chronic subdural haematomas (SDH) in elderly patients (over 80 year-old) are reported retrospectively. The estimated incidence of the disease is 17 cases per 10(5) per year. The main presenting symptoms were confusion and impaired mentation. Surgical treatment was performed in all patients. Biological disorders deserved particular attention in the elderly SDH population. Complications occurred in 10% of patients, and recurrence of SDH was noted in 5% of patients. After their hospital discharge, 85% of patients returned to their previous neurological status. In this study, the age of patients did not appear to be a poor prognostic factor.

Endovascular treatment of ruptured intracranial aneurysms

The Guglielmi detachable coil (GDC) is an important tool for the treatment of ruptured intracranial aneuryms by an endovascular approach. This new device may be introduced under fluoroscopy into the aneurysmal sac through a microcatheter. When the coil is judged well positioned, it can be detached with accuracy by electrolytic breakdown. The procedure is completed when a dense coil packing is obtained. When vasospasm is present, papaverin infusion or angioplasty may be used by the endovascular approach as well. Best results are achieved in cases of small aneurysm with small neck. The morbidity and mortality rates in the first 200 patients treated by GDC for a ruptured intracranial aneurysm were 4% and 1.5%, respectively. Complications are generally related to rupture of the malformation by the endovascular device or to thromboembolic events. Despite these promising results, further studies using larger numbers of patients are required to determine the exact role of these procedures in patient care.

The growth of acoustic neuromas in volumetric radiologic assessment

OBJECTIVE

The volumetric assessments of neuroma were applied for radiologic observation of tumor growth. The hypothesis that most of neuromas are stable or show only slight growth was tested.

STUDY DESIGN

This was an observational study.

SETTING

The study was performed in the university centers.

PATIENTS

The study group included 27 patients with 15 unilateral tumors and 12 bilateral tumors. All patients had at least 2 magnetic resonance imaging (MRI) examinations, and the average interval between initial and control examinations was 11.4 months.

MAIN OUTCOME MEASURE

Volume measurements were performed on T1- weighted MRI spin echo sequences after injection of gadolinium using special software. Growth of the tumors was estimated by comparison of the results of three measurements from the initial and control MRI examinations.

RESULTS

The growth was confirmed in 17 of 27 tumors (63%). Growth was found in 10 of 12 neuromas of neurofibromatosis type 2 (83.7%). In 15 unilateral neuromas, growth was found in 7 (43%). Unilateral neuromas were observed for a shorter period of time (6.3 months) than bilateral tumors (14.7 months). The correlation between a neuroma volume gain and the follow-up period was statistically significant (p = 0.003, r = 0.544).

CONCLUSIONS

The growth of tumors can be confirmed despite a short follow-up period.

Intraventricular cavernomas: three cases and review of the literature

OBJECTIVE AND IMPORTANCE

Cavernomas occur very rarely in the ventricular system. We report three cases of intraventricular cavernomas and review the literature.

CLINICAL PRESENTATION

A 16-year-old female patient presented with a sudden distal deficit of the left superior limb. She had a voluminous tumor involving the two lateral ventricles, with radiological evidence of recent hemorrhage. A 30-year-old man presented with generalized seizures and a right hemiplegia related to a 4-cm-diameter cavernoma in the two lateral ventricles involving the interhemispheric scissure through the corpus callosum and left centrum ovale. The radiological appearance was not typical and did not allow the diagnosis. A 42-year-old man had a cavernoma in the third ventricle, which was responsible for his short-term memory loss. This cavernoma had been revealed by computed tomography that was performed after intracerebral hemorrhage related to another cavernoma in the right parietal lobe occurred.

INTERVENTION

Stereotactic biopsies allowed the diagnosis of intraventricular cavernoma in the first case. Surgical removal via a right transcortical transventricular approach and a transcallosal approach in the first and second cases, respectively, was complete, resulting in good outcomes. Surgical removal via a right transcortical transventricular approach in the third case was partial.

CONCLUSION

Intraventricular cavernomas are so uncommon that only 42 well-documented cases have been previously reported in the literature. It seems that their radiological diagnosis may be difficult because of their uncommon location in the ventricular system and their voluminous size. A wrong preoperative diagnosis has sometimes been the cause of inefficient therapy, such as radiotherapy, for these surgically curable benign lesions.

[Familial intracranial aneurysms. Review of the literature]

The pathogenesis of intracranial aneurysms is multifactorial, with acquired factors probably associated with genetic factors. Intracranial aneurysms may be associated with heritable connective tissue disorders, mainly polycystic kidney disease, Ehlers-Danlos syndrome, Marfan's syndrome, and pseudoxhantoma elasticum. In the recent literature, familial intracranial aneurysms have been documented by large epidemiological studies in Sweden and Finland, with a frequency as high as 6.7 to 10%. Familial intracranial aneurysms have special characteristics concerning the age of the patient at the time of rupture, the location of the aneurysm, the size of the aneurysm at the time of rupture. The frequency of familial intracranial aneurysms is an argument for systematic screening, especially for patients aged between 30 and 65, when a familial occurrence of the disease has been clearly established. Magnetic resonance angiography is the most convenient method of screening, before intra-arterial arteriography is performed when an aneurysm is suspected.

Anatomic basis for auditory brainstem implant

Profound bilateral retrocochlear deafness cannot respond to a cochlear implant. For such patients only electrical stimulation of the cochlear nucleus complex can achieve, at best, a partial restoration of hearing. Based on the experience of the W.F. House group at the House Ear Institute in Los Angeles, we have developed an implantable device with many surface electrodes. A personal study has enabled us to establish the main relationships of the nucleus with the aim of inserting the device in contact with it, and to verify its effectiveness in the region. Histological study of anatomic specimens has shown the presence of spheroid neurone, considered to be the secondary neurone of the auditory pathway, at the level of the area of implantation.

Strategy of craniofacial reconstruction after resection of spheno-orbital "en plaque" meningiomas

Surgical resection of spheno-orbital "en plaque" meningiomas should be as complete as possible to prevent tumor recurrence and therefore requires a bone reconstruction. We report a series of 20 patients operated on for spheno-orbital "en plaque" meningioma between 1981 and 1993. The surgical treatment included a resection of the involved dura and a wide resection of tumoral bone using a fronto-temporal craniotomy extended to the orbitozygomaticomalar bone ridge. The craniofacial reconstruction was performed in the same operative procedure using iliac bone autograft in 11 patients, internal cortical bone from the bone flap in 8 patients, and a coral graft in 1 patient. The cosmetic result was scored according to the following criteria: superior frontal paralysis, appearance of the orbitomalar bone ridge, shape of the external temporal fossa, and projection of the eyeballs. The cosmetic result was scored as excellent or good in 17 patients, average in 2 patients, and poor in 1 patient. The iliac bone autograft appeared to be the best material for craniofacial reconstruction because it could be modeled easily to the desired shape. However, the reconstruction technique was modified as necessary according to the extent of tumor removal, clinical presentation, and age of the patient.

[Results of hearing preservation in surgery of vestibular schwannoma. Value of combined retrosigmoid and middle fossa approaches]

We report our experience of hearing preservation in acoustic neurinoma surgery, using combined retrosigmoid and middle fossa approaches. Fifty neurinomas operated on between 1987 and 1994 were included in this retrospective study. Hearing preservation surgery was performed for patients with grade II or grade III tumors (mean average tumor diameter: 14.4 mm), presenting with normal or serviceable pre-operative hearing (pure tonal average decrease less than 50 dB, speech discrimination score better than 50%). Isolated middle fossa approach was used in 3 cases, isolated retrosigmoid approach in 2 cases. The 45 other cases were operated on using both routes during the same procedure. Total removal of the tumor with anatomic facial preservation was performed in all cases. No death occurred. The facial function assessed 3 months after surgery was good in 84% of cases (House-Brackmann grades I or II). The mean follow-up was 42 months. Post-operative hearing was measurable in 48% of cases and serviceable in 30% of cases. The size of the tumor and the level of preoperative hearing appear to be the most important predictive criteria for successful hearing preservation.

Preoperative percutaneous injection of methyl methacrylate and N-butyl cyanoacrylate in vertebral hemangiomas

PURPOSE

To investigate the usefulness of preoperative percutaneous injections in vertebral hemangiomas.

METHODS

Four patients presented with complicated vertebral hemangioma (spinal cord compression in three cases, intermittent spinal claudiction in one case). A three-part treatment was performed: initially, arterial embolization in three cases; 1 day later, percutaneous injections of methyl methacrylate into the vertebral body to strengthen it and of N-butyl cyanoacrylate into the posterior arch to optimize hemostasis during surgery; finally, the day after percutaneous injections, decompressive laminectomy and epidural hemangioma excision (when present).

RESULTS

Laminectomy was performed with minimal blood loss. The epidural component present in three cases was excised without any difficulty. The follow-up (average, 20 months) showed no evidence of vertebral collapse.

CONCLUSION

Percutaneous injections of methyl methacrylate and N-butyl cyanoacrylate might be useful before surgery for vertebral hemangiomas.

Isoelectric point differentiates PHF-tau from biopsy-derived human brain tau proteins

In the present study, Tau proteins were detected by two monoclonal antibodies AD2 and Tau-1 raised against PHF-tau and normal Tau proteins respectively using single- and two-dimensional immunoblotting. We demonstrate here the presence of a Tau triplet in brain homogenates from patients with Alzheimer's disease (AD) processed human brain biopsies from controls. However PHF-tau proteins have a slight but significantly higher mol. wt and a much more acidic isoelectric point. Therefore, Tau proteins are more phosphorylated in AD.

Vertebrobasilar insufficiency resulting from traumatic atlantoaxial instability: case report

Vertebrobasilar ischemia revealed atlantoaxial instability in a patient who had cervical spine trauma 2 years previously. Vertigo was elicited by rotation of the head to the right; angiography demonstrated the occlusion of the left vertebral artery in the same position. The patient recovered totally after surgical fusion of the atlantoaxial joint.

Intradural epidermoid cysts of the cerebellopontine angle: diagnosis and surgery

We report on our recent experience with epidermoid cysts in the cerebellopontine angle. We operated on nine patients since 1985, seven of which were investigated with magnetic resonance imaging. Since the arrival of modern neuroimaging, large lesions can be found with only discrete symptoms, such as isolated tinnitus or unspecific headache. With computed tomography and magnetic resonance imaging, preoperative diagnosis was achieved for most patients; sometimes, however, epidermoid cysts may be very similar to arachnoid cysts. Surgery is the only possible treatment. The decision to operate should be carefully discussed for each patient, particularly if the patient is asymptomatic. The extent of the lesion at the anterior aspect of the brain stem, and sometimes above the tentorium cerebelli, fragile cortex, and vessels, and hazards of postoperative chemical meningitis often make such surgery difficult. The surgeon should not attempt total removal of the cyst membrane. Most patients who undergo surgery, however, recover well, with no or few sequelae. With a mean 3-year follow-up, no recurrence occurred, despite partial removal, as a result of the peculiarly slow growth of these lesions.

Carcinomatous meningitis in a case of anaplastic meningioma

Malignant meningiomas are associated with a high rate of local recurrence, but seldom give remote metastases. Here, we report a case with carcinomatous meningitis occurring 13 months after treatment of the initial tumor. MRI showed no significant abnormalities. CSF contained abnormal cells, and electronic microscopy after cytocentrifugation confirmed their identity with the initial tumor.