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Bertrand Devaux

Publications and source records attributed to Bertrand Devaux.

3 recordsLinked to original sources

Diffusion tensor imaging of partial intractable epilepsy.

Our aim was to assess the value of diffusion tensor imaging (DTI) in patients with partial intractable epilepsy. We used DTI (25 non-collinear directions) in 15 patients with a cortical lesion on conventional MRI. Fractional anisotropy (FA) was measured in the internal capsule, and in the normal-appearing white matter (WM), adjacent to the lesion, and away from the lesion, at a set distance of 2-3 cm. In each patient, increased or decreased FA measurements were those that varied from mirror values using an arbitrary 10% threshold. Over the whole population, ipsi- and contralateral FA measurements were also compared using a Wilcoxon test (p<0.05). Over the whole population, FA was significantly reduced in the WM adjacent to and away from the lesion, whilst being normal in the internal capsule. FA was reduced by more than 10% in the WM adjacent to and distant from the lesion in 13 and 12 patients respectively. For nine of the ten patients for whom the surgical resection encompassed the limits of the lesion on conventional MRI, histological data showed WM alterations (gliosis, axonal loss, abnormal cells). DTI often reveals WM abnormalities that are undetected on conventional MRI in patients with partial intractable epilepsy.

Adolescent↗

Metabolic changes and electro-clinical patterns in mesio-temporal lobe epilepsy: a correlative study.

Interictal hypometabolism is commonly found in mesio-temporal lobe epilepsy (MTLE), but its pathophysiology remains incompletely understood. We hypothesized that metabolic changes reflect the preferential networks involved by ictal discharges. We analysed the topography of interictal hypometabolism according to electro-clinical patterns in 50 patients with unilateral hippocampal sclerosis (HS) and consistent features of MTLE. Based on electro-clinical correlations, we identified four groups: (i) mesial group (13 cases) characterized by mesial seizure onset without evidence of early spread beyond the temporal lobe; (ii) anterior mesio-lateral group (AML; 18 cases) with early anterior spread involving the anterior lateral temporal cortex and insulo-fronto-opercular areas; (iii) widespread mesio-lateral group (WML; 15 cases) with wide spread (involving both anterior and posterior lateral temporal and perisylvian areas); and (iv) bitemporal (BT) group (four cases) with early contralateral temporal spread. Results of [18F]fluorodeoxyglucose-PET imaging in each group were compared with those of 10 control subjects using statistical parametric mapping software (SPM99). MRI data and surgical outcome in each group were compared with metabolic findings. Hypometabolism was limited to hippocampal gyrus, temporal pole and insula in the mesial group. Gradual involvement of lateral temporal cortex, insula and perisylvian areas was observed in the AML and WML groups. The BT group differed from the others with mild bitemporal involvement, bilateral insular hypometabolism and longer epilepsy duration. MRI structural abnormalities outside of the mesial formations were detected in 65% of the cases. Neither the severity of HS nor temporal atrophy appeared related to the topography of hypometabolism. However, temporal hypometabolism was more extended when temporo-polar signal changes were detected. Among operated patients (n = 43), seizure-free outcome was obtained in 82%. Surgical outcome appeared more favourable in the mesial group. However, the difference between the four groups was not significant. Our results suggest that hypometabolism in MTLE may be related to ictal discharge generation and spread pathways, even if structural changes and epilepsy duration may also play a role.

Adolescent↗