Philippe Decq

Long-term results of the neuroendoscopic management of colloid cysts of the third ventricle: a series of 90 cases.

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.

Accuracy of external ventricular drainage catheter placement.

BackgroundExternal ventricular drainage (EVD) is a freehand neurosurgical procedure performed routinely using the anatomical landmarks.ObjectiveThe aim of this study was to determine the accuracy of EVD catheter freehand placement.Materials and methodsPre-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.ResultsThe EVD was placed on the right (53 cases) or left (13 cases) side. The mean pre-operative lateral ventricular volume was 51xa0cc (10–118xa0cc). The average distance from the burr hole to the midline was 28xa0mm (10–49xa0mm) and to the supra-orbital ridge was 101xa0mm (75–125xa0mm). The mean intracranial catheter length was 60xa0mm (from 39–102xa0mm). 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.ConclusionFreehand 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.

Disruption of cigarette smoking addiction after posterior cingulate damage

The authors describe the case of a 35-year-old woman with a history of an addiction to cigarette smoking who presented with an intracerebral hemorrhage from a ruptured arteriovenous malformation. The patient reported an immediate and complete disruption of her addiction to cigarette smoking following her stroke. Structural MR imaging revealed a lesion of the posterior cingulate cortex. Neuropsychological tests showed intact cognitive functioning. This observation suggests that the posterior cingulate cortex may play a role in the addiction to cigarette smoking.

Long-term consequences of recurrent sports concussion.

BackgroundRecurrent 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).MethodsA 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).ResultsRRPs reported a higher number of RCs than ORSs (pu2009<u20090.001). A higher rate of major depressive disorder (PHQ-9 scoreu2009>9) was observed among RRPs compared to ORSs (9% versus 6%) (pu2009=u20090.04), and the PHQ-9 score increased with the number of RCs regardless of the type of sport (pu2009=u20090.026). A higher rate of mild cognitive disorders (TICS-m scoreu2009≤30) was observed in RRPs compared to ORSs (57% versus 40%, pu2009=u20090.005), but no association was found with the number of RC. The HIT-6 score increased with the number of RCs (pu2009=u20090.019)ConclusionsMore 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.

Imaging of the entire cerebrospinal fluid volume with a multistation 3D SPACE MR sequence: feasibility study in patients with hydrocephalus

AbstractObjectivesTo evaluate the feasibility of imaging the entire cerebrospinal fluid (CSF) volume using the SPACE MR sequence.MethodsThe SPACE sequence encompassing the brain and spine was performed at 1.5xa0T in 12 healthy volunteers and 26 consecutive patients with hydrocephalus. Image contrast was estimated using difference ratios in signal intensity between CSF and its background. Segmentation of CSF was performed using geometrical features and a topological assumption of CSF shapes. Subarachnoid and ventricular CSF space volumes were assessed in volunteers and patients and linear discriminant analysis was performed.ResultsImage contrast was 0.94 between the CSF and the brain and 0.90 between the CSF and the spinal cord. According to the phantom study, the accuracy of CSF volume measurement was 98.5xa0%. A clear distinction between patients and healthy volunteers was obtained using the linear discriminant analysis. Significant linear regression was found in healthy volunteers between ventricular (Vv) and the whole subarachnoid CSF volume (Vs) with Vvu2009=u20090.083xa0Vs.ConclusionsImaging of the entire CSF volume is feasible in healthy volunteers and patients with hydrocephalus. CSF volume can be obtained on a whole-body scale. This approach may be of use for the diagnosis and follow-up of patients with hydrocephalus.Key Points• MRI assessment of CSF volume is feasible in healthy volunteers/hydrocephalus patients.n • CSF volume can be obtained on a whole-body scale.n • The ratio of subarachnoid and ventricular CSF is constant in healthy volunteers.n • CSF linear discriminant analysis can distinguish between patients and healthy volunteers.n • Entire CSF volume imaging is useful for diagnosing and following hydrocephalus.

Cerebrospinal fluid volume analysis for hydrocephalus diagnosis and clinical research

In this paper we analyze volumes of the cerebrospinal fluid spaces for the diagnosis of hydrocephalus, which are served as reference values for future studies. We first present an automatic method to estimate those volumes from a new three-dimensional whole body magnetic resonance imaging sequence. This enables us to statistically analyze the fluid volumes, and to show that the ratio of subarachnoid volume to ventricular one is a proportionality constant for healthy adults (=10.73), while in range [0.63, 4.61] for hydrocephalus patients. This indicates that a robust distinction between pathological and healthy cases can be achieved by using this ratio as an index.

Brain ventricular wall movement assessed by a gated cine MR trueFISP sequence in patients treated with endoscopic third ventriculostomy

The purpose of this study was to investigate the value of brain ventricular wall movement assessment with a gated cine trueFISP MR sequence for the diagnosis of endoscopic third ventriculostomy (ETV) patency. Sixteen healthy volunteers and ten consecutive patients with noncommunicating hydrocephalus were explored with a MR scanner (Siemens, Avanto 1.5 T) before, 1 week and 3 months after ETV. TrueFISP was evaluated qualitatively (ventricular wall movement and CSF flow through ETV) and quantitatively [distance moved (DMLT) during a cardiac cycle by the lamina terminalis]. The third ventricle volume (TVV) was assessed. Statistical analysis was performed using nonparametric tests. There was no motion of the lamina terminalis (LT) detected on preoperative data. A pulsatile motion of the LT was found for patients with a patent ETV and for controls. DMLT and TVV were correlated (ru2009=u20090.79, Pu2009=u20090.006). A transient dysfunction of ETV was successfully diagnosed on the trueFISP sequence with no motion of the LT or CSF flow observed. The trueFISP sequence appears reliable for the diagnosis of ETV patency and provides non-invasive assessment of the movement of the ventricular wall related to CSF pressure changes.

New method for 3D reconstruction of the human cranial vault from CT-scan data

This study presents a new method for the 3D reconstruction of the human cranial vault from routine Computed Tomography (CT) data. The reconstruction method was based on the conceptualization of the shape of the cranial vault with a parametric description. An initialization was first realized with the identification of anatomical landmarks and contours on Digitally Reconstructed Radiographs (DRR) in order to obtain a pre-personalized reconstruction. Then an optimization of the reconstruction was performed to segment the internal and external surfaces of the cranial vault for thickness computation. The method was validated by comparing final reconstructions issued from our approach and from a manual slice-by-slice segmentation method on ten CT-scans. Errors were comparable to the CT image resolution, and less than 2 min were dedicated to the operator-dependent marking step. The reconstruction of internal and external surfaces of the cranial vault allows quantifying and visualizing of thickness throughout the cranial vault. This thickness mapping is useful for clinical purposes as additional pre-surgical information. Moreover, this study constitutes a first step in the personalized characterization of skull resistance directly from routine exams.

Intracranial cerebrospinal fluid spaces imaging using a pulse-triggered three-dimensional turbo spin echo MR sequence with variable flip-angle distribution

ObjectiveTo assess the three-dimensional turbo spin echo with variable flip-angle distribution magnetic resonance sequence (SPACE: Sampling Perfection with Application optimised Contrast using different flip-angle Evolution) for the imaging of intracranial cerebrospinal fluid (CSF) spaces.MethodsWe prospectively investigated 18 healthy volunteers and 25 patients, 20 with communicating hydrocephalus (CH), five with non-communicating hydrocephalus (NCH), using the SPACE sequence at 1.5T. Volume rendering views of both intracranial and ventricular CSF were obtained for all patients and volunteers. The subarachnoid CSF distribution was qualitatively evaluated on volume rendering views using a four-point scale. The CSF volumes within total, ventricular and subarachnoid spaces were calculated as well as the ratio between ventricular and subarachnoid CSF volumes.ResultsThree different patterns of subarachnoid CSF distribution were observed. In healthy volunteers we found narrowed CSF spaces within the occipital aera. A diffuse narrowing of the subarachnoid CSF spaces was observed in patients with NCH whereas patients with CH exhibited narrowed CSF spaces within the high midline convexity. The ratios between ventricular and subarachnoid CSF volumes were significantly different among the volunteers, patients with CH and patients with NCH.ConclusionThe assessment of CSF spaces volume and distribution may help to characterise hydrocephalus.

3D mapping of cerebrospinal fluid local volume changes in patients with hydrocephalus treated by surgery: preliminary study

AbstractObjectiveTo develop automated deformation modelling for the assessment of cerebrospinal fluid (CSF) local volume changes in patients with hydrocephalus treated by surgery.MethodsVentricular and subarachnoid CSF volume changes were mapped by calculating the Jacobian determinant of the deformation fields obtained after non-linear registration of pre- and postoperative images. A total of 31 consecutive patients, 15 with communicating hydrocephalus (CH) and 16 with non-communicating hydrocephalus (NCH), were investigated before and after surgery using a 3D SPACE (sampling perfection with application optimised contrast using different flip-angle evolution) sequence. Two readers assessed CSF volume changes using 3D colour-encoded maps. The Evans index and postoperative volume changes of the lateral ventricles and sylvian fissures were quantified and statistically compared.ResultsBefore surgery, sylvian fissure and brain ventricle volume differed significantly between CH and NCH (Pu2009=u20090.001 and Pu2009=u20090.025, respectively). After surgery, 3D colour-encoded maps allowed for the visual recognition of the CSF volume changes in all patients. The amounts of ventricle volume loss of CH and NCH patients were not significantly different (Pu2009=u20090.30), whereas readjustment of the sylvian fissure volume was conflicting in CH and NCH patients (Pu2009<u20090.001). The Evans index correlated with ventricle volume in NCH patients.Conclusion3D mapping of CSF volume changes is feasible providing a quantitative follow-up of patients with hydrocephalus.Key Points• MRI can provide helpful information about cerebrospinal fluid volumes.n • 3D CSF mapping allows quantitative follow-up in communicating and non-communicating hydrocephalus.n • Following intervention, fissures and cisterns readjust in both forms of hydrocephalus.n • These findings support the hypothesis of suprasylvian block in communicating hydrocephalus.n • 3D mapping may improve shunt dysfunction detection and guide valve pressure settings.