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C A Valery

Publications and source records attributed to C A Valery.

6 recordsLinked to original sources
PubMed2001

Role of the supplementary motor area in motor deficit following medial frontal lobe surgery.

OBJECTIVE: Patients undergoing surgical resection of medial frontal lesions may present a transient postoperative deficit that remains largely unpredictable. The authors studied the role of the supplementary motor area (SMA) in the occurrence of this deficit using fMRI. METHODS: Twenty-three patients underwent a preoperative fMRI before resection of medial frontal lesions. Tasks included self-paced flexion/extension of the left and right hand, successively. Preoperative fMRI data were compared with postoperative MRI data and with neurologic outcome. RESULTS: Following surgery, 11 patients had a motor deficit from which all patients recovered within a few weeks or months. The deficit was similar across patients, consisting of a global reduction in spontaneous movements contralateral to the operated side with variable severity. SMA activation was observed in all patients. The deficit was observed when the area activated in the posterior part of the SMA (SMA proper) was resected. CONCLUSIONS: fMRI is able to identify the area at risk in the SMA proper whose resection is highly related to the occurrence of the motor deficit. The clinical characteristics of this deficit support the role of the SMA proper in the initiation and execution of the movement.

Adult↗
PubMed2001

Radiosurgery for re-irradiation of brain metastasis: results in 54 patients.

PURPOSE: To evaluate in terms of probabilities of local-regional control and survival, as well as of treatment-related toxicity, results of radiosurgery for brain metastasis arising in previously irradiated territory. PATIENTS AND METHODS: Between January 1994 and March 2000, 54 consecutive patients presenting with 97 metastases relapsing after whole brain radiotherapy (WBRT) were treated with stereotactic radiotherapy. Median interval between the end of WBRT and radiosurgery was 9 months (range 2-70). Median age was 53 years (24-80), and median Karnofski performance status (KPS) 70 (60-100). Forty-seven patients had one radiosurgery, five had two and two had three. Median metastasis diameter and volume were 21 mm (6-59) and 1.2 cc (0.1-95.2), respectively. A Leksell stereotactic head frame (Leksell Model G, Elektra, Instrument, Tucker, GA) was applied under local anesthesia. Irradiation was delivered by a gantry mounted linear accelerator (linacs) (Saturne, General Electric). Median minimal dose delivered to the gross disease was 16.2 Gy (11.8-23), and median maximal dose 21.2 Gy (14- 42). RESULTS: Median follow-up was 9 months (1-57). Five metastases recurred. One- and 2-year metastasis local control rates were 91.3 and 84% and 1- and 2-year brain control rates were 65 and 57%, respectively. Six patients died of brain metastasis evolution, and three of leptomeningeal carcinomatosis. One- and 2-year overall survival rates were 31 and 28%, respectively. According to univariate analysis, KPS, RPA class, SIR score and interval between WBRT and radiosurgery were prognostic factors of overall survival and brain free-disease survival. According to multivariate analysis, RPA was an independent factor of overall survival and brain free-disease survival, and the interval between WBRT and radiosurgery longer than 14 months was associated with longer brain free-disease survival. Side effects were minimal, with only two cases of headaches and two of grade 2 alopecia. CONCLUSION: Salvage radiosurgery of metastasis recurring after whole brain irradiation is an effective and accurate treatment which could be proposed to patients with a KPS>70 and a primary tumour controlled or indolent. We recommend that a dose not exceeding 14 Gy should be delivered to an isodose representing 70% of the maximal dose since local control observed rate was similar to that previously published in literature with upper dose and side effects were minimal.

Adult↗
PubMed2000

Correspondence between functional magnetic resonance imaging somatotopy and individual brain anatomy of the central region: comparison with intraoperative stimulation in patients with brain tumors.

OBJECT: The goal of this study was to determine the somatotopical structure-function relationships of the primary motor cortex in individual patients by using functional magnetic resonance (fMR) imaging. This was done to assess whether there is a displacement of functional areas compared with anatomical landmarks in patients harboring brain tumors close to the central region, and to validate these findings with intraoperative cortical stimulation. METHODS: One hundred twenty hemispheres in 60 patients were studied by obtaining blood oxygen level-dependent fMR images in patients while they performed movements of the foot, hand, and face on both sides. There was a good correspondence between anatomical landmarks in the deep portion of the central sulcus on axial slices and the somatotopical organization of primary motor areas. Pixels activated during hand movements were centered on a small characteristic digitation; those activated during movements in the face and foot areas were located in the lower portion of the central sulcus (lateral to the hand area) and around the termination of the central sulcus, respectively. In diseased hemispheres, signal-intensity changes were still observed in the projection of the expected anatomical area. The fMR imaging data mapped intraoperative electrical stimulation in 92% of positive sites. CONCLUSIONS: There was a high correspondence between the somatotopical anatomy and function in the central sulcus, which was similar in normal and diseased hemispheres. The fMR imaging and electrical stimulation data were highly concordant. These findings may enable the neurosurgeon to locate primary motor areas more easily during surgery.

Adult↗
PubMed1996

Tumorigenicity of cerebellar primitive neuro-ectodermal tumors in athymic mice correlates with poor prognosis in children.

The histogenesis of medulloblastoma, also described as a cerebellar primitive neuro-ectodermal tumor (PNET), remains controversial and unresolved. In addition, genetic markers which characterize cerebellar PNETs with poor prognosis in children have not been identified. Since xenografts can be valuable tools for better understanding the genetic events involved in cerebellar PNETs, small fragments of tumor samples from 17 children with newly diagnosed cerebellar PNETs were transplanted s.c. into female athymic Swiss mice. Eleven were non-metastatic and 6 were metastatic PNETs. Eight tumors (47%) were tumorigenic. Histological analysis showed 6 typical medulloblastomas, 1 PNET with melanin pigment and 1 PNET with a rhabdoid phenotype. Wide heterogeneity was observed in tumor growth, with a doubling time ranging from 8 to 81 days after the first passage. Tumorigenicity was correlated with the metastatic phenotype of the tumor (p < 0.001). All the patients but one with a tumorigenic tumor relapsed and died. The survival of patients with a non-tumorigenic PNET (67%) was significantly higher than that of patients with a tumorigenic PNET (13%) (p < 0.02). None of the xenografts or tumors from patients exhibited N-myc-gene alteration. Only one xenograft showed c-myc amplification, with an abnormal 15-kilobase fragment. None of the 17 tumors from patients showed amplification or c-myc-gene rearrangement. In conclusion, tumorigenicity of cerebellar PNETs strongly correlates both with the metastatic phenotype of the tumors and with the disease-free survival of the patients. In addition, genetic events other than c-myc-gene amplification might be involved in cerebellar PNETs with poor prognosis.

Animals↗