Pierre Kehrli

Selection of cerebral aneurysms for treatment using Guglielmi detachable coils: the preliminary University of Illinois at Chicago experience.

OBJECTIVE We present our initial experience with Guglielmi detachable coils (GDCs). The aim of this study was to determine the criteria for aneurysms, ruptured or unruptured, that are suitable for this technique. The importance of aneurysm geometry and its impact on the final results are discussed. METHODS A retrospective analysis of 329 patients with 339 cerebral aneurysms that were treated at the University of Illinois Hospital at Chicago from May 1994 to June 1997 was conducted. One hundred eighty-five patients were treated surgically, and 144 were selected for treatment using GDCs. Of the 144 patients selected for GDC treatment, 55 patients with 55 aneurysms were admitted during the acute phase of subarachnoid hemorrhage and 89 patients with 97 aneurysms had nonruptured aneurysms or were treated after clinical recovery of previously ruptured aneurysms. All procedures were performed with the patients under general anesthesia and with systemic heparinization using live simultaneous biplane roadmapping, with the exception of the first four patients. These patients were treated before the installation of the biplane system. The percentage of aneurysm occlusion was determined at the end of each procedure. Follow-up angiography was scheduled to be performed at 6 months, 1 year, and 2 years after treatment. PATIENT SELECTION For the initial 25 patients (Group 1), selection for coiling was restricted to nonsurgical candidates or patients in whom coiling was thought to be the best treatment choice, based on medical condition and location of the aneurysm. The geometry of the aneurysm was not considered to be an important factor in the selection for coiling. The remaining patients (Group 2) were selected for coiling based on aneurysm geometry, as determined by pretherapeutic angiography. Aneurysms that were considered to be favorable for coiling included those that had a dome-to-neck ratio of at least 2 and an absolute neck diameter less than 5 mm. RESULTS The initial 25 patients (Group 1) were treated from May 1994 to February 1995. There were high morbidity and mortality rates, with 56% of the treated aneurysms occluded at 6 months. The remaining patients (Group 2) consisted of 119 patients with 123 aneurysms. There was no mortality directly related to the coiling procedure, and permanent morbidity was limited to 1.0%. Three patients (2.5%) developed transient neurological deficits secondary to the procedure, and seven patients (5.8%) experienced periprocedural complications that did not result in neurological sequelae. The morphological results were strongly correlated to the geometry of the aneurysms, with a complete occlusion rate of 72% among the acutely ruptured aneurysms and 80% among the nonacute aneurysms, when patients were selected for treatment based on the geometry of the aneurysms and the dome-to-neck ratio was at least 2. The occlusion rate dropped to 53% when selection was not based on aneurysm geometry and the dome-to-neck ratio was less than 2. A summary of the morphological outcomes for the Group 2 patients shows that 86% of the aneurysms that initially underwent coiling using GDCs were completely occluded (78% by coils alone, 3.0% in conjunction with surgery, and 5.0% with parent artery occlusion). Residual small neck remnants were present in 11% of the Group 2 aneurysms (3.0% were scheduled for surgical treatment of residual neck remnant growths not amenable to further endovascular treatment, and 8% were scheduled for initial 6-mo follow-up examinations). Death resulting from unrelated causes before initial follow-up occurred in 3.0% of the patients. CONCLUSION These preliminary results suggest that using GDCs is a safe technique resulting in low morbidity and mortality rates for the treatment of intracranial aneurysms in appropriately selected patients. The percentage of complete aneurysm occlusion is related to the density of coil packing, which is strongly dependent on the geometry of the aneurysm. Optim

Remote Memory in Temporal Lobe Epilepsy

Summary:  Purpose: The present study aims at characterizing remote memory in patients with temporal lobe epilepsy (TLE); it also considers the impact of its most important variables (lateralization of the lesion, duration of epilepsy, age at onset, and seizure frequency) on remote memory.

Retrospective Comparison of Chemoradiotherapy Followed by Adjuvant Chemotherapy, With or Without Prior Gliadel Implantation (Carmustine) After Initial Surgery in Patients With Newly Diagnosed High-Grade Gliomas

PURPOSE Retrospective study of patients treated for high-grade glioma, with or without biodegradable carmustine wafers and according to the Stupp protocol. METHODS AND MATERIALS Between May 2007 and June 2008, 65 patients underwent surgery for high-grade glioma, 28 had implantation of Gliadel and 37 patients did not. Patients received radiotherapy with concomitant temozolomide followed by 5 consecutive days of temozolomide every month for 6 months. RESULTS Overall median follow-up was 17.1 months; the median relapse-free survival (RFS) was 14 months with a RFS of 54% at 12 months, and 38% at 24 months. For patient with and without Gliadel, median and 1-year RFS were 12.9 months and 52% vs. 14 months and 42%, respectively (p = 0.89). According to pathology, Gliadel did not influence RFS of patients with Grade III or glioblastoma. However, for all patients, in multivariate analysis, non-methylated methylguanine methyltransferase (MGMT) was the only unfavorable prognostic factor of RFS (p = 0.017; HR 2.8; CI [1.2-7]). Median overall survival (OS) was 20.8 months; the OS rate at 12 months was 78.5%, and at 24 months 35.4%. For patients treated with and without Gliadel, median and 1-year OS were 20.6 months and 78.6% vs. 20.8 months and 78.4%, respectively. According to pathology, Gliadel did not influence OS of patients with Grade III or glioblastoma. For all patients, in multivariate analysis, unfavorable prognosticators for OS were non-methylated MGMT (p = 0.001; HR: 6.5; CI [2-20]) and irradiation dose <60 Gy (p = 0.02; HR: 6.3; CI [2-20]). With carmustine wafers, before irradiation, median gross tumor volume plus edema was 84 mL (27-229), whereas it was 68 mL (10-362) without carmustine (p = nonsignificant). Four cases of Grade 3 thrombopenia occurred, all in the carmustine wafer group. CONCLUSION In patients with high-grade gliomas, adding Gliadel before performing a Stupp protocol did not improve survival.

Anatomy and embryology of the lateral sellar compartment (cavernous sinus) medial wall

In order to study the microanatomy of the lateral sellar compartment (cavernous sinus) medial wall, serial histological sections of human fetuses and adults, as well as dissections under operative microscope, were performed. The results were compared to high resolution Magnetic Resonance Images in human, to microdissections and to serial histological sections in adult nonhuman primates (Papio Cynocephalus anubis). We were able to show that the sellar compartment and both lateral sellar osteodural compartments are not separated from each other by a dural wall, but by a more or less dense, interrupted, fibrous tissue which derived from the mesenchyme surrounding the hypophysis, carotid artery, cranial nerves and venous channels. In the human fetus, the previous mentioned structures are located in a unique interperiosteodural space. Histoarchitecture of the superior and lateral wall dura-mater was different from the underlying mesenchyme derived connective tissue and was easily distinguished through histological examination. These findings correspond to MRI data. We conclude that there is no medial dural wall limiting the lateral sellar compartment (cavernous sinus), both parasellar and the hypophyseal compartment should be considered as a unique extradural space. The only dense connective tissue surrounding the pituitary gland is its own glandular capsule and the periosteum.

Selective amygdalohippocampectomy versus standard temporal lobectomy in patients with mesial temporal lobe epilepsy and unilateral hippocampal sclerosis.

Several studies have demonstrated the positive effect of resective epilepsy surgery in drug-resistant temporal lobe epilepsy (TLE). However, it is still a matter of debate whether selective amygdalohippocampectomy (SAH) or standard temporal lobectomy (STL) are the most effective approaches concerning seizure outcome, quality of life and memory. In each of the two centers participating in this study either SAH or STL was the neurosurgical standard procedure irrespective of contextual aspects. Thus, with this postoperative assessment of resected patients we sought to avoid any selection bias that usually impaired comparative trials of both surgical approaches. We finally identified and studied 95 adult patients who had undergone either SAH (n=46) or STL (n=49) between 1999 and 2009 and fulfilled the inclusion criteria, namely drug-resistant unilateral mesial TLE with hippocampal sclerosis without any further structural lesions. We assessed the postoperative seizure outcome according to the ILAE criteria and postoperative quality of life by means of standardized questionnaires. Finally, we compared postoperative neuropsychological performance in 60 completely seizure-free patients (n=27 after SAH, n=33 after STL) prior to, one year after surgery and at a long-term follow-up with a mean of seven years. 78.2% of SAH and 85.7% of STL were seizure-free at the last observation. Quality of life had improved in 95.6% of the SAH patients and 89.8% of the STL patients. These differences were not statistically significant. Left-sided TLE patients had a significantly worse verbal memory outcome irrespective of the surgical method. However, SAH patients had a significantly better outcome concerning visual encoding, verbal and visual short-term memory and visual working memory. In this study, seizure outcome and quality of life did not differ depending on the surgical approach. However, a more selective resection led to better neuropsychological performances.

SPM analysis of ictal-interictal SPECT in mesial temporal lobe epilepsy: relationships between ictal semiology and perfusion changes.

A combination of temporo-limbic hyperperfusion and extratemporal hypoperfusion was observed during complex partial seizures (CPS) in temporal lobe epilepsy (TLE). To investigate the clinical correlate of perfusion changes in TLE, we analyzed focal seizures of increasing severity using voxel-based analysis of ictal SPECT. We selected 26 pre-operative pairs of ictal-interictal SPECTs from adult mesial TLE patients, seizure-free after surgery. Ictal SPECTs were classified in three groups: motionless seizures (group ML, n=8), seizures with motor automatisms (MA) without dystonic posturing (DP) (group MA, n=8), and seizures with DP with or without MA (DP, n=10). Patients of group ML had simple partial seizures (SPS), while others had CPS. Groups of ictal-interictal SPECT were compared to a control group using statistical parametric mapping (SPM). In ML group, SPM analysis failed to show significant changes. Hyperperfusion involved the anteromesial temporal region in MA group, and also the insula, posterior putamen and thalamus in DP group. Hypoperfusion was restricted to the posterior cingulate and prefrontal regions in MA group, and involved more widespread associative anterior and posterior regions in DP group. Temporal lobe seizures with DP show the most complex pattern of combined hyper-hypoperfusion, possibly related both to a larger spread and the recruitment of more powerful inhibitory processes.

Supraorbital eyebrow approach to skull base lesions

We report our experience with a supraorbital eyebrow minicraniotomy. This technique is suitable to lesions situated in the region of the anterior fossa, suprasellar cisterns, parasellar region and Sylvian fissure. A 50 mm incision in the eyebrow and a supraorbital minicraniotomy is performed. Sixteem patients harboring different lesions were operated on with good postoperative and cosmetic results. We conclude that this approach is safe and useful in selected cases.

One-Year Postoperative Autobiographical Memory Following Unilateral Temporal Lobectomy for Control of Intractable Epilepsy

Summary:  Purpose: To examine the effects of temporal lobectomy (TL), particularly concerning its lateralization.

Déficit sélectif de la mémoire des faits publics associé à un oubli accéléré chez un patient atteint d’épilepsie du lobe temporal gauche

Resume Introduction La memoire du passe, contrairement a la memoire anterograde, rarement ete examinee dans l’epilepsie du lobe temporal et jamais avant et apres traitement chirurgical. Par ailleurs, les etudes de cas rapportant un deficit de la memoire des faits publics avec une preservation de la memoire autobiographique sont tres rares. Methodes Nous presentons le cas d’un patient atteint d’une epilepsie temporale pharmacoresistante en rapport avec une sclerose hippocampique gauche. Des examens neuropsychologiques complets ont ete realises avant et apres lobectomie temporale, avec un interet particulier pour la memoire du passe, evaluee exhaustivement au moyen de tests standardises, mais egalement d’epreuves adaptees au patient. Resultats Le patient presentait une memoire preservee pour les faits et episodes autobiographiques, mais des scores deficients aux tests de faits publics, dans un contexte de capacites cognitives generales normales. De plus, un oubli accelere pour du materiel verbal et non verbal etait mis en evidence. Conclusion Les resultats suggerent que le trouble de consolidation a long terme pourrait avoir contribue au deficit de la memoire des faits publics. Nous discutons les caracteristiques specifiques du traitement des faits publics en essayant d’expliquer sa plus grande vulnerabilite par rapport a la memoire autobiographique, dans le cas de l’oubli accelere.

Posterior lumbar epidural fat as a functional structure? Histologic specificities

Study Design. A topographic and histologic study was done to describe the location of the lumbar epidural fat and to find potential tissular specificities. Objectives. To search for possible histologic characteristics of posterior lumbar epidural fat, which so far has been described as semifluid tissue, and to determine whether posterior lumbar epidural fat is not a simple incidental tissue. Summary of Background Data. The lumbar epidural fat on two fetuses was studied. In adults, subcutaneous fat and posterior lumbar epidural fat were taken from seven corpses. The authors obtained 13 posterior lumbar epidural fat pads (two at L1-L2, three at L2-L3, six at L3-L4, and two at L4-L5) and four subcutaneous fat pads. Methods. The authors studied abdominal axial histologic sections in two fetuses, histologic multiplanar sections in seven adults, and semithin sections in four adults of posterior lumbar epidural fat and subcutaneous fat. Results. Fetal distribution of epidural fat was circumferential. Adult epidural fat distribution was limited to the posterior part of the vertebral canal and located at the disc level. Fascicles of connective tissue were less numerous and thinner in posterior lumbar epidural fat than in subcutaneous fat. Organized sliding spaces were found in the posterior epidural fat pad. Conclusions. Posterior lumbar epidural fat is not a simple incidental tissue and shows specific histologic features: sliding spaces and rarefaction of connective tissue that could explain semifluid features of the tissue. These characteristics suggest a functional role of posterior epidural fat in the lumbar spinal unit.