Biomedical subjects

Hugues Duffau

Publications and source records attributed to Hugues Duffau.

40 records · Page 3Linked to original sources

PubMed2002

Intraoperative mapping of the subcortical language pathways using direct stimulations. An anatomo-functional study.

Functional neuroimaging has improved pre-planning of surgery in eloquent cortical areas, but remains unable to map white matter. Thus, tumour resection in functional subcortical regions still presents a high risk of sequelae. The authors successfully used intraoperative electrical stimulations to perform subcortical language pathway mapping in order to avoid postoperative definitive deficit, and correlated these functional findings with the anatomical location of the eloquent bundles detected using postoperative MRI. At the same time, this also improved knowledge of fibre connectivity. Thirty patients harbouring a cortico-subcortical low-grade glioma in the left dominant hemisphere were operated on whilst awake using intraoperative electrical functional mapping during surgical resection. Language cortical sites and subcortical pathways were clearly identified and preserved in the 30 cases. The anatomo-functional correlations between data obtained using intraoperative subcortical mapping and postoperative MRI revealed the existence in all patients of common pathways which seem essential to language. This was shown by inducing reproducible speech disturbances during stimulations as follows: the subcallosal fasciculus (initiation disorders), the periventricular white matter (dysarthria), the arcuate fasciculus and the insular connections (anomia). Clinically, all patients except three presented a transient postoperative dysphasia, which resolved within 3 months. On control MRI, 14 resections were total and 16 subtotal due to infiltration of functional bundles described above. It is recommended that the combination of the techniques as described could prove ideal for future non-invasive reliable subcortical mapping both in healthy volunteers and in patients harbouring a (cortico)subcortical lesion in order to optimize surgical pre-planning.

Adult↗

PubMed2002

Somatotopy of the supplementary motor area: evidence from correlation of the extent of surgical resection with the clinical patterns of deficit.

OBJECTIVE: This study, which aimed to confirm or invalidate the somatotopic organization of the supplementary motor area (SMA), correlates the pattern of clinical symptoms observed after SMA removal with the extent of resection. METHODS: Eleven patients with medial precentral glioma underwent partial or complete tumoral resection of the SMA. Seven patients underwent preoperative functional magnetic resonance imaging that incorporated speech and motor tasks. During the operation, the primary motor and speech areas and pathways (in the dominant side) were identified by use of intraoperative direct cortical or subcortical stimulation, and these areas were respected. RESULTS: SMA resection resulted in motor deficits, language deficits, or both; the deficits were always regressive, and they corresponded to the SMA syndrome. The topography and severity of these deficits were correlated to the extent of the SMA resection. The location of the deficit corresponded to SMA somatotopy: the representations of the lower limb, the upper limb, the face, and language (in the left-dominant SMA) were located from posterior to anterior. This somatotopy was also observed with functional magnetic resonance imaging. CONCLUSION: Correlation between clinical patterns of deficit and the extent of SMA resection, guided by means of pre- and intraoperative functional methods, provides strong arguments in favor of somatotopy in this area. This knowledge should allow clinicians to base preoperative predictions of the pattern of postsurgical deficit and recovery on the planned resection, thus allowing them to inform patients accurately before the procedure.

Adult↗

PubMed2002

Absence of movement disorders after surgical resection of glioma invading the right striatum.

OBJECT: Despite the high frequency of striatal lesions, the rate of movement disorders reported in the literature is lower than expected (< 10%). To maximize the extent of resection in low-grade gliomas invading the right striatum, the authors performed a striatal resection in a series of 14 patients, observed the lack of movement disorders following these procedures, and discuss herein the mechanisms likely to explain these findings. METHODS: Fourteen patients harboring a low-grade glioma that was infiltrating the right nondominant striatum, and in whom the results of neurological examination were normal, underwent surgery in which intraoperative electrical mapping was used, allowing the identification of pyramidal pathways. The striatum was resected in all procedures, and corticospinal tracts were systematically detected and preserved. Ten patients presented with a transient postoperative motor deficit, and nine with a loss of interest and affect. These symptoms all resolved within 3 months, except for one case of persistent hemiparesis. No postoperative movement disorder was noted, even transitorily. All resections were categorized as either total or subtotal on control magnetic resonance images. CONCLUSIONS: These findings show that the nondominant striatum can be removed in cases of glioma invasion without inducing even transitory movement disorders. This phenomenon could be explained by the combined resection of the two classes of striatal neurons, an associated pallidal and thalamocortical resection, or a compensatory recruitment of parallel networks. Thus, these results may allow the surgeon to maximize the extent of removal of low-grade gliomas involving basal ganglia. Striatal resection may induce transient hemiparesis and "athymhormic syndrome," however, necessitating that the patient be clearly informed before surgery.

Adult↗

PubMed2002

Analysis of loss of chromosome 10q, DMBT1 homozygous deletions, and PTEN mutations in oligodendrogliomas.

OBJECT: Chromosomal deletions of 10q and candidate genes such as PTEN and DMBT1 have been thoroughly investigated in glioblastomas but few data specifically address oligodendrogliomas. METHODS: In this study, 39 pure oligodendrogliomas were investigated for loss of heterozygosity (LOH) on 10q, PTEN mutations, and DMBT1 homozygous deletions. The LOH on 10q was found in 19 (48%) of 39 oligodendrogliomas and was closely related to anaplasia (p = 0.02), shorter time to progression (p = 0.0005), and poorer survival (p = 0.035). The DMBT1 homozygous deletions were found in 10 (26%) of 39 oligodendrogliomas but only one PTEN mutation was detected. The LOH on 10q is a strong predictor of survival and could be a valuable prognostic marker in oligodendrogliomas. CONCLUSIONS: Frequent inactivation of DMBT1 contrasting with rare mutations of PTEN may indicate that DMBT1 is preferentially involved in oligodendrogliomas. Nevertheless, the absence of a correlation with survival makes the role of DMBT1 in tumorigenesis still questionable and warrants further investigation.

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