Malformations of cortical development: New surgical advances.

Epilepsy related to malformations of cortical development is frequently drug resistant or requires heavy medication, therefore surgery is key in their management. The role of stereotactic surgery has recently changed the diagnosis and treatment of focal cortical dysplasias (FCD), hypothalamic hamartomas (HH) and periventricular nodular heterotopias (PNH). In HH, radiosurgery using Gammaknife® leads to 60 % of seizure control and is associated with excellent neuropsychological results without significant endocrine function impairment. The seizure control rate is even higher (more than 80 %) with monopolar multiple stereotactic thermocoagulations and Laser interstitial Thermal Therapy (LiTT). While the first technique is associated with a 2 % complications rate (but with excellent neuropsychological outcomes), the latest has up to 22 % side effects in some series. All three of these techniques have encouraging results, but controlled studies are still lacking to provide evidence-based new therapeutic algorithms. With regard to the PNH, surgical management has long been limited by the depth of the lesions and their close anatomical relations with the functional brain connectome. Stereotactic approaches required to perform a SEEG, to locate the part of the PNH responsible for the seizure onset, are later followed by a stereotactic lesioning procedure, therefore doubling the bleeding risk. That is why SEEG-guided radiofrequency-thermocoagulation (SEEG guided-RF-TC), which makes it possible to perform these two steps in a single procedure, was considered as a promising option. A recent meta-analysis confirmed this intuition and reported 38 % of seizure-free patients and 81 % of responders with only 0.3 % of complications, making this approach the first treatment line, followed by LiTT. Among the multiple advances in the FCD identification by non-invasive investigations, a new modality of per-operative diagnostic procedure, the three-dimensional electrocorticography may lead to simplify the preoperative investigation and enhance the accuracy of FCD delineation. Evidence is nevertheless still insufficient to validate this promising concept. Conventional surgical resection has also been concerned by significant conceptual advances during the past few years, in particular with the development of the hodotopic approach, initially in oncologic surgery. Associated with a better understanding of neuroplasticity in epilepsy and the setting up of functional mapping during SEEG or during awake surgery, the possibility of surgical resections grew up. A short-term perspective in this field, when surgical resection remains impossible, would be to target crucial nodes of the epileptic network, distinct from the core functional connectome.

Functional mapping of the human insula: Data from electrical stimulations.

Electrical stimulations of the insula performed during stereo-electro-encephalography (SEEG) reproduce the ictal symptoms observed during the development of insular seizures and are also a unique opportunity to provide a functional mapping of the insular cortex. We provide here a functional mapping of the insular cortex obtained by electrical stimulation, based on our previous work and a review of literature. The most frequent responses to insula stimulation were somatosensory sensations followed by visceral responses. Then, in decreasing order of frequency, auditory sensations, vestibular illusions, speech impairment, gustato-olfactory sensations and motor reactions were evoked. A bipolar organization could be evidenced with a posterior part assigned to somatosensory functions and notably to pain perception; and an anterior part assigned to visceral functions. Although some degree of spatial segregation could be evidenced, there was a clear spatial overlap between the representations of the different types of responses. These data provide a better understanding of physiological insular functions, insula seizures semiology and a prediction of post-surgical deficits. Insula is the only cortical region where stimulations demonstrate such a multi-modal representation, perhaps supporting its integrative functions of polymodal inputs.

Semiology of insular lobe seizures.

After the early attempts of intra-operative electrocorticography and insulectomy in the 1950s, the notion of insular lobe seizures was largely forgotten for decades. It is only since the late 1990s that the recent technique of stereo-electroencephalography (SEEG) enabled preoperative diagnosis of insular origin seizures and thus gave rise to a renewed interest for this ill-defined electroclinical entity. Owing to the multiple functional roles of insula and its extensive connectivity with adjacent as well as distant brain structures, insular lobe seizures present with a combination or series of diverse subjective and objective symptoms. In this review, we summarize current knowledge on the semiology of insular origin seizures. The following two distinct forms of clinical presentation have been recognized: 1) Seizures with predominant insulo-perisylvian symptoms, most notably paraesthesia and cervico-laryngeal discomfort. The former typically involves a large/bilateral cutaneous territory and can be perceived as cold, hot, or painful sensations. The latter ranges from slight dyspnea to strong sensation of strangulation. Other symptoms include epigastric discomfort/nausea, hypersalivation, auditory, vestibular, gustatory, and aphasic symptoms. 2) Nocturnal hyperkinetic seizures with/without tonic elevation of upper limbs, masquerading as fronto-mesial seizures. Patients are usually not fully aware of their symptoms despite preserved contact and organized behavior to others. Ipsilateral eye blinking can be observed. These two patterns often occur in succession or simultaneously. This characteristic combination and progression of ictal symptoms orients us strongly towards an insular origin of seizure, a better understanding of which is a crucial key to further optimize modern SEEG strategy.

Resective surgery in tuberous Sclerosis complex, from Penfield to 2018: A critical review.

Medically treated patients suffering from tuberous sclerosis complex (TSC) have less than 30% chance of achieving a sustained remission. Both the international TSC consensus conference in 2012, and the panel of European experts in 2012 and 2018 have concluded that surgery should be considered for medically refractory TSC patients. However, surgery remains currently underutilized in TSC. Case series, meta-analyses and guidelines all agree that a 50 to 60% chance of long-term seizure freedom can be achieved after surgery in TSC patients and a presurgical work-up should be done as early as possible after failure of two appropriate AEDs. The presence of infantile spasms, the second most common seizure type in TSC, had initially been a barrier to surgical planning but is now no longer considered a contraindication for surgery in TSC patients. TSC patients undergoing presurgical evaluation range from those with few tubers and good anatomo-electro-clinical correlations to patients with a significant "tuber burden" in whom the limits of the epileptogenic zone is much more difficult to define. Direct surgery is often possible in patients with a good electro-clinical and MRI correlation. For more complex cases, invasive monitoring is often mandatory and bilateral investigations can be necessary. Multiple non-invasive tools have been shown to be helpful in determining the placement of these invasive electrodes and in planning the resection scheme. Additionally, at an individual level, multimodality imaging can assist in identifying the epileptogenic zone. Increased availability of investigations that can be performed without sedation in young and/or cognitively impaired children such as MEG and HR EEG would most probably be of great benefit in the TSC population. Of those selected for invasive EEG, rates of seizure freedom following surgery are close to cases where invasive monitoring is not required, strengthening the important and efficient role of intracranial investigations in drug-resistant TSC associated epilepsy.

Epileptic networks in patients with bitemporal epilepsy: the role of SEEG for the selection of good surgical candidates.

OBJECTIVE: In this study we investigated the electrical characteristics of seizures recorded by stereo-EEG (SEEG) in a cohort of patients with bitemporal lobe epilepsy (BTLE), in the attempt to verify the presence/absence of different seizure patterns and to identify good surgical candidates. METHODS: We retrospectively reviewed 14 consecutive patients with medically refractory BTLE confirmed by scalp video-EEG (VEEG) recording of bitemporal independent or non-lateralizing seizure onset. All patients had a comprehensive evaluation including history and neurologic examination, MRI, scalp VEEG and SEEG monitoring. Neuropsychological, Wada testing and FDG-PET were performed in most patients. When temporal lobe resection was performed (7 cases), the postoperative follow-up was of at least 1year. RESULTS: Intracranial EEG (SEEG) revealed that only 4/14 (29%) patients were suffering of unilateral TLE. Two groups of patients with distinct SEEG patterns of seizures were identified: a temporo-mesial origin of seizures was the only SEEG pattern observed in 8 patients (Group 1); in 6 patients seizures originated from multiple onset zones in mesial and lateral temporal cortex or from extra-temporal cortex (Group 2). All patients of group 1 (except one who refused surgery) underwent surgery and had a favorable outcome (6 Engel class I; one Engel's class II). The side of surgery was not necessarily the one responsible for the majority of recorded seizures. It was chosen on the basis of MRI findings and consistency of data from presurgical functional investigations, mostly memory assessment and Wada test. SIGNIFICANCE: In patients with suspected BTLE, SEEG proved to be useful in identifying the origin of seizures. Good surgical outcome can be obtained after unilateral resection in patients with bilateral independent seizure onsets or sequential mesial temporal involvement on SEEG if the side of surgery is chosen considering multimodal data.

Morphological imaging of the hippocampus in epilepsy.

The hippocampus is a structure frequently involved in epilepsy, especially in partial drug-resistant forms. In addition, some hippocampal pathologies are associated with specific types of epilepsy presenting specific clinical courses and requiring specific treatments. Considering these major implications for treatment, morphological investigations of the hippocampus are crucial for epileptic patients. Indeed, discovery of hippocampal sclerosis may (depending on the clinical and electrophysiological findings) lead to the diagnosis of mesial temporal lobe epilepsy (MTLE). If the diagnosis of MTLE is retained in a case of drug-resistance, surgery may be proposed without invasive phase II investigations such as stereoelectroencephalograpy. In other instances, hippocampal abnormalities may be associated with epilepsy, but without the same value for localizing the ictal onset zone. Hippocampal dysgenesis is a strong argument for non-temporo-mesial ictal onset ipsilateral to the malformation. We describe here the specific MRI modalities adapted for hippocampal investigations and the radiological signs of hippocampal pathologies associated with epilepsy (especially hippocampal sclerosis and hippocamal dysgenesis). Hippocampus morphological investigations in epilepsy require specific MRI modalities and appropriate knowledge of the specific signs of each pathology. Careful analysis is crucial since the results may have a major impact on the therapeutic management of epileptic patients.

Invasive EEG explorations.

The Wada test was adapted from the procedure described by Wada in 1964. It still has a role in the prognostic evaluation of memory disorders after mesial temporal lobectomy. The test consists of injecting a short-acting anesthetic into one hemisphere, under continuous EEG monitoring and during carotid catheterization, to verify the function of contralateral structures. Intracranial EEG recordings deliver signals with few artifacts, and which are quite specific of the zone explored. Three types of electrodes are in common use: (a) foramen ovale (FO) electrodes: electrodes can be inserted directly, without any stereotactic procedure, to provide easy and comparative EEG recordings of the lower and middle portions of the temporal lobe close to the hippocampus. These allow validation of the temporal lobe origin of seizures using FO electrodes recording coupled with scalp EEG; (b): subdural strip or grip electrodes. This relatively aggressive technique carries infectious and hemorrhagic risks and does not allow the exploration of deep cortical structures. However, it permits precise functional cortical mapping via electrical stimulation because of dense and regular positioning of electrodes over the cortical convexity; (c) stereotactically implanted depth electrodes (stereo-electroencephalography [SEEG]). Electrodes are individually planned and inserted within the brain parenchyma through small burr holes. This technique is less aggressive than subdural grid exploration. However it offers relatively limited spatial sampling that may be less well adapted to precise functional evaluation. It allows recording from deep cortical structures and can be argued to be the gold standard of presurgical EEG exploration.

[French guidelines on electroencephalogram]. / Recommandations françaises sur l'électroencéphalogramme.

Electroencephalography allows the functional analysis of electrical brain cortical activity and is the gold standard for analyzing electrophysiological processes involved in epilepsy but also in several other dysfunctions of the central nervous system. Morphological imaging yields complementary data, yet it cannot replace the essential functional analysis tool that is EEG. Furthermore, EEG has the great advantage of being non-invasive, easy to perform and allows control tests when follow-up is necessary, even at the patient's bedside. Faced with the advances in knowledge, techniques and indications, the Société de Neurophysiologie Clinique de Langue Française (SNCLF) and the Ligue Française Contre l'Épilepsie (LFCE) found it necessary to provide an update on EEG recommendations. This article will review the methodology applied to this work, refine the various topics detailed in the following chapters. It will go over the summary of recommendations for each of these chapters and underline proposals for writing an EEG report. Some questions could not be answered by the review of the literature; in those cases, an expert advice was given by the working and reading groups in addition to the guidelines.

Reliability of a new hip lateral view to quantify alpha angle in femoroacetabular impingement.

BACKGROUND: Radiographic measurement of the alpha angle (AA) in femoroacetabular impingement (FAI) is not well codified and invasive techniques such as MR- or CT-arthrography remain the gold standard. Excessive acetabular coverage described in pincer-type FAI can be seen on plain radiographs but has never been quantified and anterior center edge (ACE) angle, described on the false-profile view (FP) to measure anterior acetabular coverage has never been evaluated in FAI. HYPOTHESIS: In this study we wanted to determine if a plain radiograph could efficiently measure AA compared to CT-arthrography and if ACE could quantify the acetabular coverage in FAI. MATERIALS AND METHODS: We developed a hip view combining a lateral view and a FP, called profile view in impingement position (PIP). Twenty-six patients operated for FAI had CT-arthrography, PIP and FP. Nineteen control subjects had the PIP. AA were measured twice by three raters and ACE once. We compared AA measured on patients between CT and PIP, on PIP between patients and controls, ACE measured on patients between PIP and FP, and did a reproducibility analysis. Means were compared by paired or unpaired t-tests; reproducibility was measured by intraclass correlation coefficient (ICC). RESULTS: Mean AA was 65.8° (range, 48-85°) on CT-arthrography and 63.9° (range, 50-87°) on PIP (P>0.05). ICC for PIP measures were 0.8-0.9 for intra-rater and 0.6-0.9 for inter-rater reliability. Mean AA on PIP in patients was 63.3° (range, 52-87°) and 44.9° (range, 34-67°) in controls (P<0.001). Mean ACE was 26.8° (range, 14-41°) on PIP and 32.8° (range, 18-56°) on the FP (P=0.015). DISCUSSION: The PIP is a reliable view to measure the AA in FAI as measures on PIP and CT-arthrography were not significantly different with a good reproducibility. All of the painful hips and 2 controls had an AA>50°. PIP was not efficient to measure ACE. LEVEL OF EVIDENCE: Level III, case-control study.

Insular and insulo-opercular epilepsy in childhood: an SEEG study.

PURPOSE: In recent years, there have been series analysing the electro-clinical correlations of insular epilepsy in adult populations. In contrast, the ictal semiology in children with insular epilepsy is poorly described. Considering that early and successful surgery may greatly improve the cognitive outcome and quality of life, it is worthwhile to deepen our knowledge of insular epilepsy in children. METHODS: We retrospectively evaluated ten children with drug-resistant focal insular epilepsy who had been consecutively explored with stereoelectroencephalography (SEEG), followed by individually tailored resective surgery that included part of the insula in all cases. A detailed anatomo-electro-clinical analysis of non-invasive EEG and SEEG data was performed. At least one of the electrodes explored the insular cortex. SEEG analysis confirmed that the insular cortex was included in the ictal onset zone. RESULTS: Epilepsy onset was mostly during the first year of life, characterized by subtle seizures as well as spasms and myoclonic seizures. Later on, neurovegetative signs and asymmetric tonic and hypermotor seizures (HMS) dominated the ictal semiology. The epileptogenic zone was frequently wider than insular with frontal and central predominance. In eight patients, the tailored resection included a lesion. In seven patients, an Engel class 1 outcome as well as neuropsychological and behavioural improvement was obtained. CONCLUSIONS: SEEG is feasible and useful in children with drug-resistant insular epilepsy which is often characterized by autonomic symptoms as the initial symptoms and should be suspected in cases with HMS, asymmetric tonic seizures and even asymmetric spasms. Early propagation is mostly frontal and central. Analysis of a larger population is required to refine these findings.

SEEG-guided RF-thermocoagulation of epileptic foci: a therapeutic alternative for drug-resistant non-operable partial epilepsies.

BACKGROUND: Previous literature includes numerous reports of acute stereotactic ablation for epilepsy. Most reports focus on amygdalotomies or amygdalohippocampotomies, some others focus on various extra-limbic targets. These stereotactic techniques proved to have a less favourable outcome than that of standard surgery, so that their rather disappointing benefit/risk ratio explains why they have been largely abandoned. However, depth electrode recordings may be required in some cases of epilepsy surgery to delineate the best region of cortical resection. We usually implant depth electrodes according to Talairach's stereo electroencephalography (SEEG) methodology. Using these chronically implanted depth electrodes, we are able to perform radiofrequency (RF)-thermolesions of the epileptic foci. This paper reports the technical data required to perform such multiple cortical thermolesions, as well as the results in terms of seizure outcome in a group of 41 patients. TECHNICAL DATA: Lesions are placed in the cortex areas showing either a low amplitude fast pattern or spike-wave discharges at the onset of the seizures. Interictal paroxysmal activities are not considered for planning thermocoagulation sites. All targets are first functionally evaluated using electrical stimulation. Only those showing no clinical response to stimulation are selected for thermolesion, including sites located inside or near primary functional area. Lesions are performed using 120mA bipolar current (50 V), applied for 10-30 sec. Each thermocoagulation produces a 5-7mm diameter cortical lesion. A total of 2-31 lesions were performed in each of the 41 patients. Lesions are placed without anaesthesia. RESULTS: 20 patients (48.7%) experienced a seizure frequency decrease of at least 50% that was more than 80% in eight of them. One patient was seizure free after RF thermocoagulation. In 21 patients, no significant reduction of the seizure frequency was observed. Amongst the characteristics of the disease (age and sex of the patient, lobar localization of the EZ) and the characteristics of the thermocoagulations (topography, lateralization, number, morphology of the lesions on MRI) no factor was significantly linked to the outcome. However, the best results were clearly observed in epilepsies symptomatic of a cortical development malformation (CDM), with 67% of responders in this group of 20 patients (p = 0.052). Three transient post-procedure side-effects, consisting of paraesthetic sensations in the mouth (2 cases), and mild apraxia of the hand, were observed. CONCLUSION: SEEG-guided-RF-thermolesioning is a safe technique. Our results indicate that such lesions can lead to a significant reduction of seizure frequency. Our experience suggests that SEEG-guided RF thermocoagulation should be dedicated to drug-resistant epileptic patients for whom conventional resection surgery is risky or contra-indicated on the basis of invasive pre-surgical evaluation, particularly those suffering from epilepsy symptomatic of cortical development malformation.

[Insular epilepsy: A model of cryptic epilepsy. The Lyon experience]. / L'épilepsie insulaire : un modèle d'épilepsie cryptique. L'expérience lyonnaise.

The role of the insular lobe in temporal lobe epilepsy (TLE) has often been suggested but never directly demonstrated. In this article, we review data from recent literature and from our own stereo-electroencephalographic (SEEG) recordings in patients referred for temporal lobe epilepsy surgery. Our description of the clinical features of insular lobe seizures is based on data from video and SEEG ictal recordings and direct electric cortical stimulation in a population of 50 consecutive patients whose seizures, on the basis of scalp video EEG recordings, were suspected to originate from, or to rapidly propagate to, the perisylvian cortex. One hundred and forty-four intrainsular electrodes have been implanted in this series of patients. In six patients a stereotyped sequence of ictal symptoms could be identified on the basis of electroclinical correlations. The clinical presentation of insular lobe seizures is that of simple partial seizures occurring in full consciousness, beginning with a sensation of laryngeal constriction followed by paresthesiae that were often unpleasant and affected large cutaneous territories. These initial symptoms were eventually followed by dysarthric speech and/or elementary auditory hallucinations, and seizures often ended with focal dystonic postures. The insular origin of these symptoms was supported by the data from functional cortical mapping of the insula using direct cortical stimulations from a total of 472 intrainsular electrodes in 164 consecutive patients. We were able to reproduce several of the spontaneous ictal symptoms in the six patients with insular seizures. Moreover, from the whole set of insular stimulations that we performed it could be concluded that the insular cortex is involved in somatic, vegetative and visceral functions to which spontaneous ictal insular symptoms are related. The observation of the insular symptoms sequence at the onset of seizures in patients who are candidates for TLE surgery strongly suggests that the epileptic focus is located in the insular lobe. It entails the risk of unsuccessful temporal lobectomy and should lead to reconsider the indication of temporal lobectomy and to explore directly the ictal activity of both mesiotemporal and insular cortices before making any decision regarding epilepsy surgery.

Somatotopic organization of pain responses to direct electrical stimulation of the human insular cortex.

The question whether pain encoding in the human insula shows some somatotopic organization is still pending. We studied 142 patients undergoing depth stereotactic EEG (SEEG) exploration of the insular cortex for pre-surgical evaluation of epilepsy. 472 insular electrical stimulations were delivered, of which only 49 (10.5%) elicited a painful sensation in 38 patients (27%). Most sites where low intensity electric stimulation produced pain, without after-discharge or concomitant visually detectable change in EEG activity outside the insula, were located in the posterior two thirds of the insula. Pain was located in a body area restricted to face, upper limb or lower limb for 27 stimulations (55%) and affected more than one of these regions for all others. The insular cortex being oriented parallel to the medial sagittal plane we found no significant difference between body segment representations in the medio-lateral axis. Conversely a somatotopic organization of sites where stimulation produced pain was observed along the rostro-caudal and vertical axis of the insula, showing a face representation rostral to those of upper and lower limbs, with an upper limb representation located above that of the lower limb. These data suggest that, in spite of large and often bilateral receptive fields, pain representation shows some degree of somatotopic organization in the human insula.

[Coronary CTA evaluation of the relationship between mitral valve annulus and coronary circulation: implications for percutaneous mitral annuloplasty]. / Etude de la relation entre l'anneau mitral et la circulation coronaire dans l'insuffisance mitrale par scanner cardiaque: implications dans l'annuloplastie mitrale percutanée.

PURPOSE: To evaluate anatomical relationships between mitral annulus (MA), coronary arteries and coronary sinus (CS) in two groups of patients with and without moderate mitral insufficiency on coronary CTA to identify candidates to percutaneous mitral valve annuloplasty via the coronary sinus without risk of coronary artery occlusion. MATERIALS AND METHODS. Fifty-one ECG-gated coronary CTA examinations, obtained during injection of iodinated contrast material on a 16 MDCT were retrospectively reviewed. The mitral valve annulus diameter, anatomical relationships between CS and coronary arteries and MA-CS distance were compared between both patient groups. RESULTS: The group with mitral insufficiency included 16 patients and the control group included 35 patients. The AP diameter of the MA was 45,7+/-5,2 mm in the group with mitral insufficiency, significantly larger (p=0.0009) compared to the control group (39,3+/-5,9 mm). In 70.4% of cases, the CS was located next to a coronary artery in an overlapping configuration. The unfavorable anatomical configuration with regards to annuloplasty appeared related to mitral insufficiency (p=0.0539). The distance between MA and CS was greatly variable with the CS routinely extending over the left atrial surface: the distance was significantly (p=0.0002) greater for all patients along the posterior surface (8,1+/-3,8 mm) compared to the lateral surface (5,2+/-4,6 mm) with this différence persisting within both groups: p=0.004 for patients with mitral insufficiency and p=0.0001 for control patients. CONCLUSION: Our results demonstrate the value of coronary CTA in selecting candidates to percutaneous mitral annuloplasty. In 70.4% of cases, the CS overlaps a coronary artery with risk of compression at the time of annuloplasty.

SEEG-guided thermocoagulations: a palliative treatment of nonoperable partial epilepsies.

OBJECTIVE: Intracranial stereotactic EEG recordings (SEEG) in presurgical epilepsy assessment are currently carried out in our department. The SEEG method generally used for exploration can also be used to perform radiofrequency thermocoagulations (RFTC) of the epileptic foci. To assess the indications of the RFTC procedure in the therapeutic arsenal of drug-resistant epilepsies, we report the results obtained in 41 patients to whom RFTC was proposed as a first therapeutic step before surgery or as a palliative treatment when surgery was not possible. METHODS: RFTC were produced by applying a 50-volt, 110 mA current, during 10-30 seconds within the epileptogenic zone, as identified by the SEEG investigation. Two to 31 RFTC (mean, 12) were performed per patient. The median follow-up was 19 months (range: 4 to 72). RESULTS: Twenty patients (48.7%) experienced a seizure frequency decrease of at least 50%, which was over 80% in eight of them. One patient was seizure-free. The tolerance was excellent. A total of 67% of the 21 patients presenting a cortical development malformation benefited from RFTC (p = 0.052). In the group of noneligible patients for resective surgery (n = 13), six were responders to SEEG-guided RFTC and one of them was seizure-free. CONCLUSIONS: This study suggests that stereotactic EEG-guided radiofrequency thermocoagulations can be proposed only as a palliative procedure, able to bring a substantial improvement of seizure frequency, to drug-resistant patients with epilepsy for whom conventional resection surgery is risky or contraindicated on the basis of invasive presurgical evaluation.

[Epilepsy and insula]. / Epilepsie et insula.

The insula is the only cortical part of the brain that is not visible on the surface of the hemisphere, because it is totally covered by the frontoparietal and temporal opercula. The insula is triangular in shape and is separated from the opercula by the anterior, superior, and inferior peri-insular sulci. It is morphologically divided into two parts by the central insular sulcus. The anterior part of the insula bears three short gyri, and its posterior part contains two long gyri. The vascular supply of the insula is mainly provided by the M2 segment of the middle cerebral artery, a substantial obstacle to any open or stereotactic procedure aiming at the insular region. The insula is functionally involved in cardiac rhythm and arterial blood pressure control, as well as in visceromotor control and in viscerosensitive functions. There is substantial evidence that the insula is involved as a somesthetic area, including a major role in the processing of nociceptive input. The role of the insula in some epilepsies was recently investigated by means of depth electrode recordings made following Talairach's stereoelectroencephalography (SEEG) methodology. It appears that ictal signs associated with an insular discharge are very similar to those usually attributed to mesial temporal lobe seizures. Ictal symptoms associated with insular discharges are mainly made up of respiratory, viscerosensitive (chest or abdominal constriction), or oroalimentary (chewing or swallowing) manifestations. Unpleasant somatosensory manifestations, always opposite the discharging side, are also frequent. Ictal signs arising from the insula occur in full consciousness; these are always simple partial seizures. Seizures arising from the temporal lobe always invade the insular region, but in approximately 10% of cases, the seizures originate in the insular cortex itself. These data explain that there has been a rebirth of interest in the insula from a surgical perspective over the past few years. The literature contains no reports of cases of resection of insular cortex alone; most insular resections are performed in the context of temporal resection, when there is some evidence of seizures originating in the insula itself. Such procedures are risky and their efficacy, in terms of postoperative surgical outcome, has not yet been clearly assessed. In this context, less invasive procedures, such as SEEG-guided radiofrequency thermolesions of the insular cortex, are under investigation.

[Multiple SEEG-guided RF-thermolesions of epileptogenic foci]. / La thermocoagulation multiple de foyers épileptogènes guidée par la SEEG (thermo-SEEG).

In many patients with drug-resistant partial epilepsy, depth electrode recordings may be required to delineate the best region for cortical resection. We usually implant depth electrodes according to Talairach's stereoelectroencephalography (SEEG) methodology. Using these chronically-implanted depth electrodes, it is possible to generate radiofrequency (RF) thermolesions of the epileptic foci and networks. The advantages of this type of technique are supported by several lines of evidence, in particular, the high number of implanted electrodes makes it possible to generate several thermolesions, whereas the bleeding risk is null, since no additional electrode trajectory is required. Lesions are generated using 100- to 120-mA bipolar current (50V), applied for 10-40s within the epileptogenic zone, as identified by the SEEG recordings. No general or neurological complication occurred during the procedures. Forty-three patients investigated with video-SEEG recordings for presurgical assessment of drug-resistant partial epilepsy were treated using SEEG-guided RF-thermolesions of the epileptic foci between 2001 and 2006, with a follow-up ranging from 12 to 66 months. Three patients were seizure-free and 52% of the patients had a decrease in their seizure frequency of at least 50%. Of the patients presenting a malformation of cortical development etiology (i.e. dysplasia or heterotopia), 70% were classified as responders (at least a 50% decrease in seizure frequency) (p=0.052), whereas the results were less favorable in patients with a cryptogenic and hippocampal sclerosis etiology. Twenty patients underwent conventional cortectomy in a second step, 18 of whom are in Engel class I. In conclusion, SEEG-guided RF-thermolesions of the epileptic foci and networks proved to be a safe therapeutic procedure capable of providing an immediate benefit in terms of seizure control, especially in patients with epilepsy symptomatic of cortical development malformation. Such thermolesions do not preclude subsequent conventional surgery in case of failure, which can be proposed as an alternative procedure if no resective surgery is possible.

Indications and limits of intraoperative cortico-subcortical mapping in brain tumor surgery: an analysis of 101 consecutive cases.

AIM: Here we report our recent experience in supratentorial cortico-subcortical stimulation mapping during surgery for cerebral lesions closely related to sensorimotor and language areas. METHODS: We retrospectively analyzed clinical data of 101 consecutive patients operated on with the aid of electrical stimulation mapping (ESM). Patients harbored a mass lesion situated in or near language (Group A, 30 patients) and sensorimotor (Group B, 71 patients) areas. RESULTS: A macroscopically complete removal of the tumor was carried out in 22 cases out of 28 of group A and in 57 out of 73 of group B. In the first group there was one postoperative death due to a pulmonary embolism. At a mean follow-up of 24.3 months, 15 patients are still alive, 12 out of them are recurrence free and hold a useful language function, while the other 12 patients had a mean survival time of 19.3 months, with a mean high quality survival period (KPS?70) of 17.8 months. In the second group there was no postoperative death. At a mean follow-up of 24.8 months, 55 patients are alive and 47 maintain a useful motor function. Eighteen patients died for tumor progression, with a mean survival time of 18.7 months. Their median high-quality survival period (KPS ? 70), with preservation of a useful motor function, was 16.5 months. CONCLUSION: When properly indicated and correctly carried out, ESM for language and motor functions allows to enhance resection of lesions in eloquent areas with a surgical permanent morbidity comparable to that for lesion in non eloquent areas.

[Heart and heart-lung transplants thorax complications: major radiologic forms]. / Complications thoraciques des greffes pulmonaires et cardiopulmonaires: principaux aspects radiologiques.

Bipulmonary and cardiopulmonary transplantations are among the most difficult to perform, with a 10-year survival rate estimated at 33%. This low rate can be attributed to thoracic complications that can be classified into three distinct groups: 1) early complications, occurring in the first 30 days after transplantation (hemothorax, diaphragmatic paralysis, reperfusion edema, hydric overloading, acute rejection); 2) late complications that occur beyond the first month (bronchiolitis obliterans syndrome, bronchic stenosis, sirolimus-induced lung disorders, initial disease recurrence); and 3) infections classed separately because of their high morbidity and mortality (thoracic wall abscess, bacterial and viral pneumonia, CMV, pneumocystosis, Aspergillus necrotizing bronchitis). Imaging is essential in screening and diagnosing these complications as part of the clinician's monitoring throughout the rest of the transplant recipient's life. In diagnosis, combined with clinical and biological data, imaging has its place in delaying the onset of these diseases.

[Long-term efficiency of vagus nerve stimulation (VNS) in non-surgical refractory epilepsies in adolescents and adults]. / Efficacité de la stimulation intermittente du nerf vague dans les épilepsies pharmaco-résistantes non chirurgicales de l'adolescent et de l'adulte.

Vagus Nerve Stimulation (VNS) is recognized as an efficient procedure for controlling seizures in patients with drug-refractory epilepsies. It is used as a palliative procedure as a complement to conventional treatment by antiepileptic (AE) drugs and, according to literature, 40 to 50p.cent of patients report a decrease in seizures frequency >or=50p.cent, which is usually accepted to classify patients as responders in add on AE drug trials. The objectives of this study based on retrospective analysis of 50 consecutive patients with partial (39) or generalized (11) refractory epilepsy non eligible for surgery were; firstly to evaluate the global long term VNS efficacy and secondly to identify potential predictors of the VNS effects on seizure frequency. No patient has been seizure free at any moment of the follow up (2.8+/-1.8 years, max: 6 years) and the AE has been maintained in all. During follow up 44, 66, 61 and 58p.cent of patients were classified as responders at 6 months, 1, 2 and 3 years, respectively. Logistic regression analysis showed that: the percentage of responders at 6 months of follow up and later was significantly higher than that before 6 months (p=0.002); generalized epilepsy was predictive of a better outcome as compared to partial epilepsy (p=0.03); there was a trend for a better outcome in partial epilepsies symptomatic of a focal lesion than in those with normal brain MRI (p=0.06). These results are in line with previously published data in terms of global efficiency and confirm that seizures control does not reach its maximal level before at least one year of VNS. In severe generalized epilepsies (either secondary or cryptogenic) manifesting by frequent falls due to atonic or tonic-clonic generalized seizures VNS is a useful palliative procedure, which entails much les of surgical risk than callosotomy. The better VNS effects in patients with partial epilepsy possibly reflect the high incidence in our series of Malformations of Cortical Development, which have been identified as one the few variables possibly predictive of a response over 50p.cent of seizures frequency reduction.