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Abstract: Objective: The goal of the present study was to better characterize pre- and immediately post-surgical motor and language deficits resulting from the surgery of tumours located in the medial part of the frontal lobe. Patients and methods: Seven patients treated by surgical resection of low-grade gliomas affecting the medial part of the frontal lobe were studied with neuropsychological tasks investigating motor and language abilities before surgery and at three time points after surgery (first, third and seventh day after surgery). The tasks were constructed in a way that allowed the structured comparison between language and motor functions, and controlled the level of external constraint of the production. Results: The main results of this study are: (1) globally the patients were impaired in both language and motor production the day after surgery; (2) the performance improved faster for tasks with strongly constrained production; (3) the verbal and semantic fluency were very sensitive and appropriate tasks for examination of the deficits resulting from the resection; and (4) performances were back to normal seven days after the surgery for most of the tasks. Conclusion: These results confirm that surgery of low-grade gliomas affecting the prefrontal midline areas affects only transiently motor and language functions as tested in this study. They also suggest that verbal and semantic fluency were the most severely affected tests postoperatively. On the basis of these results, the surgical resection of the low-grade gliomas of the prefrontal midline seems a valuable treatment alternative. [Copyright &y& Elsevier]

To evaluate the natural progression and the impact of temozolomide in low‐grade gliomas and to correlate these changes with the profile of genetic alterations.The mean tumor diameter (MTD) of low‐grade gliomas was evaluated on serial magnetic resonance images before (n = 39), during, and after (n = 107) treatment with neoadjuvant temozolomide. MTD growth curves were correlated with chromosomes 1p‐19q loss and p53 overexpression in the tumors.Before temozolomide onset, MTD increased linearly over time, indicating a continuous growth that was significantly slower in 1p‐19q deleted tumors (3.4 vs 5.9mm/year; p = 0.0016) and in tumors that did not overexpress p53 (4.2 vs 6.3mm/year; p = 0.05). During temozolomide treatment, almost all patients (92%) experienced initial decrease of MTD. Subsequently, some tumors started to resume growth despite continuous administration of temozolomide, with a lower rate of relapse in 1p‐19q deleted tumors (16.6 vs 58%; p = 0.0004) and in tumors that did not overexpress p53 (26 vs 68%; p = 0.003). When temozolomide was discontinued in the absence of tumor progression, a majority of tumors resumed their progressive growth within a year.Untreated low‐grade gliomas grow continuously at a rate that is influenced by the genetic alterations of the tumors. Temozolomide reverses this pattern at the onset, but this effect is often brief in patients whose tumors overexpress p53 and do not harbor the 1p‐19q codeletion, suggesting acquired chemoresistance. A majority of tumors will resume their growth when treatment is discontinued, raising the issue of the optimal duration of treatment in continuously responding patients. Ann Neurol 2007;61:484–490 [ABSTRACT FROM AUTHOR]

Although advances in diffusion tensor imaging have enabled us to better study the anatomy of the inferior longitudinal fasciculus (ILF), its function remains poorly understood. Recently, it was suggested that the subcortical network subserving the language semantics could be constituted, in parallel with the inferior occipitofrontal fasciculus, by the left ILF, joining the posterior occipitotemporal regions to the temporal pole, then relayed by the uncinate fasciculus connecting the anterior temporal pole to the frontobasal areas. Nevertheless, this hypothesis was solely based on neurofunctional imaging, allowing a cortical mapping but with no anatomofunctional information regarding the white matter. Here, we report a series of 12 patients operated on under local anaesthesia for a cerebral low-grade glioma located within the left temporal lobe. Before and during resection, we used the method of intraoperative direct electrostimulation, enabling us to perform accurate and reliable anatomofunctional correlations both at cortical and subcortical levels. In order to map the ILF. Using postoperative MRI, we correlated these functional findings with the anatomical locations of the sites where language disturbances were elicited by stimulations, both at cortical and subcortical levels. Our goal was to study the potential existence of parallel and distributed language networks crossing the left dominant temporal lobe, subserved by distinct subcortical pathways—namely the inferior occipitofrontal fasciculus and the ILF. Intraoperative stimulation of the anterior and middle temporal cortex elicited anomia in four patients. At the subcortical level, semantic paraphasia were induced in seven patients during stimulation of the inferior occipitofrontal fasciculus, and phonological paraphasia was generated in seven patients by stimulating the arcuate fasciculus. Interestingly, subcortical stimulation never elicited any language disturbances when performed at the level of the ILF. In addition, following a transient postoperative language deficit, all patients recovered, despite the resection of at least one part of the ILF, as confirmed by control MRI. On the basis of these results, we suggest that the “semantic ventral stream” could be constituted by at least two parallel pathways within the left dominant temporal lobe: (i) a direct pathway, the inferior occipitofrontal fasciculus, that connects the posterior temporal areas and the orbitofrontal region, crucial for language semantic processing, since it elicits semantic paraphasia when stimulated; (ii) and also possibly an indirect pathway subserved by the ILF, not indispensable for language, since it can be compensated both during stimulation and after resection. [ABSTRACT FROM AUTHOR]