Intra-operative mapping of cortical areas involved in reading in mono- and bilingual patients.

In order to identify the cortical areas involved in the reading process and to spare them during surgery, we systematically studied cortical areas by direct cortical stimulation in patients operated on for brain tumours. Seventy-six cortical stimulation mapping studies for language were performed in 35 monolingual and 19 bi- or multilingual patients over a 5-year period. We systematically searched for reading interference areas in addition to standard naming areas using an 'awake surgery' technique for brain mapping. A 'reading aloud' task (translated into different languages in multilingual patients) was used. Brain mapping was performed in left (44 patients) and right (10 patients) hemispheres. Cortical areas involved in reading were identified according to the type of interference, location and distinctness from naming areas. Stimulation of several major hemispheric regions resulted in significant interference with reading aloud: (i) the lower part of the pre- and postcentral gyri (P < 0.00001); (ii) the dominant supramarginal, angular and the posterior part of the superior temporal gyri (P < 0.00001); (iii) in the dominant inferior and middle frontal gyri (P < 0.001); and (iv) in the posterior part of the dominant middle temporal gyrus (P < 0.05). Interferences in reading were generally found in small cortical areas, with intervening areas evoking no reading interferences. Only partial overlap between reading and naming sites was found. Reading-specific sites were preferentially found when stimulating dominant inferior parietal or posterior temporal areas. Different types of reading interferences were noted. While 'articulatory' interferences were found in pre- and postcentral gyri bilaterally, and ocular-induced movements in bilateral middle frontal gyri, paraphasias were found mainly in the dominant supramarginal and posterior superior temporal gyri. Reading arrest sites were found in many regions. Reading interference sites were also occasionally found in the non-dominant hemisphere. In bilingual patients, if common cortical areas could be found, language- and reading-specific areas were sometimes detected, lending support to the concept that bilinguals can have relatively distinct cortical representation of their language skills. Finally, in this series, the location of reading interference sites and their relative specialization showed considerable individual variability.

Organization of language areas in bilingual patients: a cortical stimulation study.

OBJECT: In an attempt to gain a better understanding of how multiple languages are represented in the human brain, the authors studied bilingual patients who underwent surgery for brain tumors, during which the authors mapped cortical language sites by using electrostimulation. METHODS: Reading, counting, and word retrieval tasks were studied in 12 right-handed bilingual patients with no language deficit. All bilingual patients were native to France. One patient spoke four languages. The patients constituted a nonhomogeneous group in terms of language proficiency or age of acquisition. Languages were evaluated and classified into three major groups, depending on proficiency and date of acquisition. Strict conditions of language site validation were applied, separating typical anomia sites from speech arrest or other language sites (such as hesitation sites). A total of 30 speech arrest sites, 16 anomia sites, and three sites of language difficulties (not typically classified as speech arrest) were found throughout the 26 language studies performed. Strict overlapping of language areas (for all language tasks) was found in five patients, whereas the remaining seven had at least one area that was language-specific and sometimes task-specific. Specific areas for a particular language were found for word retrieval tasks (anomia) in eight sites (50%) but also in six (20%) of the reading or counting sites (speech arrest), either in frontal (three patients) or in temporoparietal (four patients) regions. Among the four early bilingual patients tested (languages acquired before the age of 7 years), three had language-specific cortical areas. Interestingly, six patients in this series who had a discrepancy between two languages did not have more cortical areas devoted to the less proficient language (with acknowledgment of the limit in cortical exposure available for testing by the craniotomy). CONCLUSIONS: In this series, the authors found that bilingual patients could have common but also different cortical areas for both languages in temporoparietal areas and in frontal areas. In some cases, the authors found that language tasks such as counting, reading, or word retrieval in different languages can be sustained by language- and task-specific cortical areas. In bilingual patients, cortical mapping should ideally be performed using different language tasks in all languages in which the patient is fluent.

Writing, calculating, and finger recognition in the region of the angular gyrus: a cortical stimulation study of Gerstmann syndrome.

OBJECT: In an attempt to gain a better understanding of the cerebral functions represented in the angular gyrus and to spare them during surgery, the authors studied patients with brain tumors located close to the angular gyrus and mapped cortical sites by using electrostimulation. METHODS: Before undergoing tumor removal, six right-handed patients (five with left and one with right hemisphere tumors) were studied using cortical mapping with the aid of calculating, writing, finger-recognition, and color-naming tasks in addition to standard reading and object-naming tasks (for a total of 36 brain mapping studies). Strict conditions of functional site validation were applied to include only those cortical sites that produced repetitive interferences in the function tested. Preoperatively, four of the patients exhibited discrete symptoms related to Gerstmann syndrome while performing very specific tasks, whereas the other two patients presented with no symptoms of the syndrome. No patient had significant language or apraxic deficits. Distinct or shared cortical sites producing interferences in calculating, finger recognition, and writing were repeatedly found in the angular gyrus. Object- or color-naming sites and reading-interference sites were also found in or close to the angular gyrus; although frequently demonstrated, these latter results were variable and unpredictable in the group of patients studied. Finger agnosia and acalculia sites were also found elsewhere, such as in the supramarginal gyrus or close to the intraparietal sulcus. Mechanisms involved in acalculia, agraphia, or finger agnosia (either complete interferences or hesitations) during stimulation were various, from an aphasia-like form (for instance, the patient did not understand the numbers or words given for calculating or writing tasks) to an apparently pure interference in the function tested (patients understood the numbers, but were unable to perform a simple addition). CONCLUSIONS: Symptoms of Gerstmann syndrome can be found during direct brain mapping in the angular gyrus region. In this series of patients, sites producing interferences in writing, calculating, and finger recognition were demonstrated in the angular gyrus, which may or may not have been associated with object-naming, color-naming, or reading sites.

Neurotological complications after radiosurgery versus conservative management in acoustic neuromas: a systematic review-based study.

OBJECTIVE: Treatment modalities for acoustic neuroma (AN) include surgery, observation and gamma-knife surgery. The aim of this study was to compare neurotological complications resulting from two treatment alternatives to microsurgery: radiosurgery and observation. MATERIAL AND METHODS: We conducted a systematic review of the literature dealing with radiosurgery for AN and compared the rate of neurotological complications in this population with that in a cohort of patients managed conservatively. RESULTS: We found that neurotological complications, namely facial hypoesthesia (p = 0.002), hearing loss (p < 0.05) and hydrocephalus (p = 0.02), were more frequently encountered after radiosurgery than with conservative management. In contrast, we found that the risk of growth of AN is significantly higher with conservative management and that the rate of stability of the tumor did not differ significantly between the two treatments. CONCLUSION: We prefer a conservative management regimen for patients who cannot be operated on for their AN. However, there are some difficulties inherent in this conservative management policy, namely non-compliance and difficulties in establishing the evolution of the tumor.

Evaluation of O-(2-[18F]-Fluoroethyl)-L-Tyrosine in the Diagnosis of Glioblastoma.

OBJECTIVE: To assess the feasibility of synthesis of O-(2-[(18)F]-fluoroethyl)-l-tyrosine (FET), a new positron emission tomographic (PET) tracer described in several studies but not yet considered standard in management of glioma, in routine practice and to determine FET uptake in a homogeneous group of patients with suspected high-grade glioma. DESIGN: Prospective nonrandomized trial. PATIENTS: Twelve patients with suspicion of high-grade glioma. RESULTS: The mean (SD) FET uptake ratio was 3.15 (0.72) for the 12 patients and 3.16 (0.75) for the 11 patients with glioblastoma. CONCLUSION: The initial results are promising and indicate that FET PET is a valuable and applicable tool for the imaging of high-grade glioma.

Initial primary endovascular treatment in the management of ruptured intracranial aneurysms: a prospective consecutive series.

INTRODUCTION: From January 1998 to December 2002, endovascular treatment (EVT) was used as first intention in all patients with ruptured aneurysms. The objective of this study was to analyze the results of this therapeutic strategy. METHODS: Among 401 patients admitted with a subarachnoid hemorrhage (SAH), 73 (18%) had a nonaneurysmal perimesencephalic SAH, 28 were not explored by angiography due to very poor clinical status, and 28 with aneurysmal SAH were not treated due to poor clinical status. Thus, of the 300 patients with a proven aneurysmal SAH, 272 (83%) were treated. EVT was attempted in 230 patients and was successful in 222 (82%), and clipping was performed in 50 (18%). RESULTS: Finally, EVT was successful in 234 aneurysms (96.7%) in 222 patients out of 242 aneurysms in 230 patients (some of the patients were treated for more than one aneurysm in the same procedure). EVT-related morbidity occurred in ten patients (4.5%) and mortality in eight (3.6%). Rate of dependency or death (modified Rankin scale 3-5) was 24.5% at 26 months. Initially, complete aneurysm occlusion was obtained in 81%, a dog ear in 3.4%, a neck remnant in 8% and incomplete occlusion in 8.1% of the patients. At follow-up (mean 26 months), the occlusion rate remained stable at 75%. CONCLUSION: This consecutive prospective series shows that EVT can be performed routinely as first-intention treatment in most aneurysmal SAH. Using this therapeutic strategy, EVT was performed in 82% of patients with long-term clinical results similar to those of the ISAT study.