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OBJECTIVE To determine the compensatory mechanisms involved in the recovery of motor function following surgical lesions of the supplementary motor area (SMA) and their relation to the clinical characteristics of recovery. SUBJECTS AND METHODS Twelve patients were referred for surgery of low-grade gliomas located in the SMA, and compared to eight healthy(More)
Studies in non-human primates have shown that medial premotor projections to the striatum are characterized as a set of distinct circuits conveying different type of information. This study assesses the anatomical projections from the supplementary motor area (SMA), pre-SMA and motor cortex (MC) to the human striatum using diffusion tensor imaging (DTI)(More)
In electroencephalographic (EEG) measurements performed during functional Magnetic Resonance Imaging (fMRI), imaging and cardiac artefacts strongly contaminate the EEG signal. Several algorithms have been proposed to suppress these artefacts and most of them have shown important improvements with respect to uncorrected signals. However, the relative(More)
Interictal diffusion imaging studies in patients with medial temporal lobe epilepsy (MTLE) accompanied by hippocampal sclerosis (HS) have shown an increased diffusivity in the epileptogenic hippocampus. In this study, we wanted to explore the whole brain in order to determine if MTLE could have an impact on the organization and the architecture of a large(More)
BACKGROUND Patients undergoing surgical resection of medial frontal lesions may present transient postoperative speech disorders that remain largely unpredictable. OBJECTIVE To relate the occurrence of this speech deficit to the specific surgical lesion of the supplementary motor area (SMA) involved during language tasks using fMRI. METHODS Twelve(More)
Examination of functional interactions through effective connectivity requires the determination of three distinct levels of information: (1) the regions involved in the process and forming the spatial support of the network, (2) the presence or absence of interactions between each pair of regions, and (3) the directionality of the existing interactions.(More)
OBJECTIVE To explore the selectivity of neuronal somatotopic representation in the striatum of patients with unilateral task-specific dystonia of the right arm. MATERIALS AND METHODS The authors used fMRI in 14 right-handed dystonic subjects to examine putaminal organization. Subjects performed flexion/extension of the right and left fingers and toes, and(More)
BACKGROUND AND PURPOSE Comparative studies across populations using functional magnetic resonance imaging (fMRI) rely on a similar relationship between blood oxygen level-dependent (BOLD) signal and neural activity. However, in elderly and patients with cerebrovascular disease, impaired cerebrovascular dynamics and neurovascular coupling may explain(More)
To present the imaging and perfusion data obtained in nine patients with pilocytic astrocytomas (PA) and to discuss the original functional issues of this technique. Nine patients with pathologically proven PA underwent conventional and perfusion MR imaging. Various areas of relative cerebral blood volume (rCBV) within the tumors were obtained. The maximum(More)
Simultaneous electroencephalography and functional magnetic resonance imaging (EEG/fMRI) have been proposed to contribute to the definition of the epileptic seizure onset zone. Following interictal epileptiform discharges, one usually assumes a canonical hemodynamic response function (HRF), which has been derived from fMRI studies in healthy subjects.(More)