J P Chodkiewicz

Centre Hospitalier Sainte Anne, Lutetia Parisorum, Île-de-France, France

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Publications (86)88.99 Total impact

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    ABSTRACT: The value of functional MR Imaging (fMRI) in assessing language lateralization in epileptic patients candidate for surgical treatment is increasingly recognized. However few data are available for left-handed patients. Moreover determining factors for atypical dominance in patients investigated with contemporary imaging have not been reported. We studied 20 patients (14 males, 6 females; 9 right handed, 11 left handed) aged from 9 to 48 years, investigated for intractable partial epilepsy. Epileptic focus location was temporal in 14 cases, extratemporal in 6, and lateralized in the left hemisphere in 11/20. Hemispheric dominance for language was evaluated by both Wada test and fMRI using a silent word generation paradigm in all patients. Furthermore, a postictal speech test was performed in 15 patients. An fMRI language lateralization index was calculated from the number of activated pixels (Student's t test, P < 0.0001) in the right and left hemispheres. The Wada test showed a right hemispheric dominance in 8 patients (6 were left handed and 2 right handed) and a left hemispheric dominance in 12 patients (5 were left handed and 7 right handed). These results were concordant with clinical postictal examination in 11/15 patients (73%). Clinical status did not allow a conclusion about hemispheric dominance for the remaining 4 patients. FMRI was concordant with the Wada test in 19/20 cases. For one left-handed patient, fMRI showed bilateral activation, whereas the Wada test demonstrated a right hemispheric dominance. Right language lateralization was significantly correlated with left lateralized epilepsy (P < 0.05) but was not correlated with age at epilepsy onset, early brain injury (before 6 years), and lobar localization of epileptogenic focus. However the lack of a significant relationship between these factors and atypical language lateralization may be related to the small sample size.
    NeuroImage 02/2003; 18(2):460-7. · 6.25 Impact Factor
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    ABSTRACT: Focal cortical dysplasia (FCD) is an increasingly recognized cause of intractable epilepsy. Surgical data suggest that the dysplastic cortex should be removed to obtain freedom from seizures, but the prognosis remains poor as FCD is difficult to delineate by imaging. We retrospectively analysed a series of 28 patients (aged 5-41 years, median 16.5 years) with FCD who had been investigated by stereoelectroencephalography (SEEG) between 1964 and 1995. Neurophysiological data were correlated with histological findings and surgical outcome. MRI was available for only seven patients. Severe partial epilepsy of early onset, pre-existing neurological deficit (68%) and cognitive impairment were the main clinical features. FCD was distributed equally between all lobes except for the temporal lobe, and was found predominantly on the mesial aspect of the cerebral hemispheres. SEEG findings provided evidence of dysplastic tissue epileptogenicity, as demonstrated by intralesional rhythmic spike discharges, the onset of ictal discharges and a low epileptogenic threshold. The epileptogenic zone corresponded to histologically defined FCD in 82% of the cases. Despite the lack of adequate neuroimaging in most cases, 64% of the patients became seizure-free after surgery. The main predictors of a favourable outcome were complete removal of the epileptogenic zone (P< 0.01) and complete removal of the dysplastic cortex (P< 0.01). These results emphasize the usefulness of neurophysiological data in accurately assessing the extent of the FCD.
    Brain 09/2000; 123 ( Pt 8):1733-51. · 10.23 Impact Factor
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    ABSTRACT: To demonstrate that DNTs include a large morphological spectrum of tumors that cannot be histologically distinguished from conventional categories of gliomas. All tumors from patients who underwent epilepsy surgery in Sainte-Anne hospital (Paris) that histologically resembled gliomas and did not conform to current histological criteria for DNTs or gangliogliomas were entered in the study. According to the WHO histological classification, the 40 tumors resembled: pilocytic astrocytomas (4 cases), astrocytomas (16 cases), anaplastic astrocytoma (1 case), oligodendrogliomas (10 cases), oligo-astrocytomas (8 cases) or anaplastic oligo-astrocytomas (1 case). However foci of cortical dysplasia could be observed in 47% of the cases. Clinical presentation and imaging features were strikingly similar to that observed in typical DNTs. Although surgical removal was incomplete in 28% of the cases and none of the patients underwent chemo or radiotherapy, none of the tumors recurred (mean follow-up: 7 years). Moreover, serial preoperative imaging in 26 patients (mean follow-up: 4.5 years) demonstrated that these lesions were perfectly stable. Whatever the histological appearance of a glial tumor, the diagnosis of DNT must be considered when all the following criteria are associated: (1) partial seizures, with or without secondary generalization, beginning before the age 20 years, (2) no neurological deficit or stable congenital deficit, (3) cortical topography of the lesion as better demonstrated by MRI and (4) no mass effect on imaging.
    Journal of Neuro-Oncology 03/1999; 41(3):267-80. · 3.12 Impact Factor
  • Advances in neurology 01/1999; 81:189-99.
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    ABSTRACT: Therapeutic strategy for the cerebral arteriovenous malformations (cAVM) is mainly based on the assessment of hemorrhage risk. This risk is estimated between 2 and 4% according to various series. However, this is a collective risk projected upon a given population. To improve therapeutic strategy for cAVM, we propose a grading of the individual hemorrhage risk based on 5 angiographic parameters: 4 are increasing risk factors and one is a favorable index. This grading system has been achieved by univariate then multivariate analysis by logistic regression from angiographic data of 250 consecutive patients with cAVM. Thirty angiographic parameters were studied. Grade I has no risk factors and has two subgrades: Ia with venous recruitment (which is the lonely favorable parameter), Ib without venous recruitment. Grade II is the presence of venous stenosis or venous reflux. Grade III is the presence of exclusive deep venous drainage. Grade IV is the presence of intra or juxta-nidal aneurysm. There were 13% of hemorrhage in grade Ia, 38% in grade Ib, 48% in grade II, 90% in grades III and IV. This model can be helpful for the treatment decision making and also contributes to a better understanding of the natural history of cAVM. It must be further confirmed by a prospective study.
    Neurochirurgie 05/1998; 44(2):83-93. · 0.32 Impact Factor
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    ABSTRACT: This second part of our study of 'pure' oligodendrogliomas focuses on survival data analysis. In order to identify potentially useful prognostic factors and to assess the effectiveness of a new grading system, the 79 patients in the previously analyzed series for whom adequate follow-up could be obtained (52%) were entered in the present analysis. Statistical analysis demonstrated that contrast enhancement and endothelial hyperplasia had powerful and similar influence on survival. Median survival with and without contrast enhancement were: 3 versus 11 years, and with or without endothelial hyperplasia were: 3.5 versus 11 years. Conversely, the degree of nuclear atypia and presence or absence of mitosis or necrosis were not correlated with survival. These findings allowed us to devise a simple grading system which discriminates two malignancy grades as follows: absence of endothelial hyperplasia and of contrast enhancement = Grade A, presence of endothelial hyperplasia and/or of contrast enhancement = Grade B. Of the 79 oligodendrogliomas in this study, 59 tumors were categorized as grade A and 20 as grade B. Median survival were: 11 years in grade A and 3.5 years in grade B. Five-year and 8-year survival rates were: 89% and 60% in grade A and: 33% and 15% in grade B. Double blind grading between two independent observers was concordant in 96% of the cases. Application of this simple efficient and reproducible grading scheme should permit reliable comparison of retrospective or prospective therapeutic data emanating from various institutions.
    Journal of Neuro-Oncology 09/1997; 34(1):61-78. · 3.12 Impact Factor
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    ABSTRACT: The present study has attempted to demonstrate that the morphological spectrum of oligodendrogliomas includes tumors which are traditionally misinterpreted as 'diffuse fibrillary astrocytoma'. We have shown that these tumors are in fact made of isolated neoplastic oligodendrocytes which are entrapped in a fibrillary background composed of axons and fibrillary reactive gliosis. Analysis in a series of 153 'pure' supratentorial oligodendrogliomas composed of 'classical' or pseudo 'diffuse fibrillary oligodendrogliomas' diagnosed by imaging-based serial stereotactic biopsies showed that 2/3 of the tumors were exclusively made of isolated tumor cells (ITCs) (structure type III) and that only 1/3 of them exhibited both ITCs and solid tumor tissue components (structure type II). The tumor tissue destroys the brain parenchyma and contains new formed microblood vessels whereas ITCs do not destroy the parenchyma and are not associated with microangiogenesis. These fundamentally opposite morphological characteristics were reflected by the following findings: 1) contrast enhancement was observed in 64% of structure type II but was never seen in structure type III oligodendrogliomas. 2) a neurological deficit occurred in 57% of structure type II but in only 8% of structure type III oligodendrogliomas. 3) using the new grading system described in the companion paper to this study, we found that the biological behavior of oligodendrogliomas was also closely related to the patterns of tumor growth. From a synthesis of data gathered in this study it is suggested that emergence of microangiogenesis within a tumor which at first grows slowly with a structure type III pattern is a crucial event toward more aggressive behavior.
    Journal of Neuro-Oncology 09/1997; 34(1):37-59. · 3.12 Impact Factor
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    ABSTRACT: Dysembryoplastic neuroepithelial tumors (DNTs) histologically resemble gliomas but behave as stable lesions. These tumors initially were considered to be located exclusively within the supratentorial cortex. The four reported cases demonstrate that DNTs may also arise in the area of the caudate nuclei. Moreover, the peculiar topography of these lesions, which suggests a derivation from the subependymal plate, is in accordance with the putative origin of DNTs from secondary germinal layers. The patients experienced partial seizures (two patients), generalized seizures (one patient), or headaches (one patient). All patients were young (17-26 yr) at the onset of symptoms, and all had normal results from their neurological examinations. All lesions demonstrated a pseudocystic appearance on computed tomographic scans, were hypointense on T1-weighted magnetic resonance imaging scans, hyperintense on T2-weighted magnetic resonance imaging scans, and did not show contrast enhancement. The four tumors similarly lined the left or right caudate nuclei and expanded within the homolateral ventricle (three patients) or both lateral ventricles (one patient). In one patient, the tumor also involved the adjacent paraolfactory cortex. In all patients, stereotactic biopsies helped to identify a specific glioneuronal element of DNTs. None of the tumors was operated on. Radiotherapy was performed in only one patient. A long pre- and/or postbiopsy imaging follow-up, which was available in two nontreated patients (3 yr and 16 yr), demonstrated the perfect stability of the lesion. The occurrence of DNTs in this peculiar location needs to be considered to avoid misidentification as "ordinary" gliomas and prevent useless aggressive treatment.
    Neurosurgery 06/1997; 40(5):1065-9; discussion 1069-70. · 2.53 Impact Factor
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    ABSTRACT: Out of 57 patients operated for intractable epilepsy of the central region, 8 harbored an indolent glioma (7 dysembryoplastic neuroepithelial tumors, 1 ganglioglioma). Mapping of the sensorimotor area with depth electrodes implanted for stereoelectroencephalographic exploration demonstrated no or abnormal motor responses after low-frequency stimulation, and variable sensory responses to high-frequency stimulation, suggesting reorganization of the sensorimotor cortex representation around the tumor and absence of functional tissue within the neoplastic volume. After lesionectomy (3 cases) or corticectomy including the tumor (5 cases), 6 (75%) patients were seizure-free (class I of Engel) at the time to follow-up. No permanent motor or sensory deficit was observed in 6 cases. In 2, a mild facial (in 1) and arm (in 1) deficit persisted. It is concluded that the resection of intrinsic low-grade tumors associated with long-standing epilepsy and located in the central region can be associated with excellent seizure outcome and no or minimal postoperative deficit because of functional reorganization of the sensorimotor cortex.
    Stereotactic and Functional Neurosurgery 02/1997; 69(1-4 Pt 2):229-38. · 1.46 Impact Factor
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    ABSTRACT: The overall haemorrhagic risk of a cerebral arteriovenous malformation (cAVM) is 2-4% per year. However, the individual risk of haemorrhage has never been determined. This study was undertaken to assess the haemorrhage risk of an individual cAVM. Neuroangiographic findings of 160 cAVM were analysed retrospectively, looking at 30 angiographic features. A statistical model was established by logistic regression to evaluate the risk of an individual cAVM. We statistically correlated 15 parameters with the haemorrhage risk. The statistical model includes five independent parameters. Four are unfavourable: exclusively deep drainage, venous stenoses, venous reflux and the radio of afferent to efferent systems; one is favourable: venous recruitment. This model quantifies the individual risk of haemorrhage. When this model is applied to the population studied, the error rate is 5%. This model can contribute to therapeutic strategy, and to a better understanding of the natural history of cAVM.
    Neuroradiology 02/1997; 39(1):52-8. · 2.70 Impact Factor
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    ABSTRACT: Radiosurgery of cerebral arteriovenous malformations (cAVM) can induce parenchymal changes seen on MRI. The purpose of this study was to classify these changes and to correlate them to clinical outcome and obliteration of the cAVM. 142 patients with cAVM underwent radiosurgery with a linear accelerator between 1994 and 1995. 60 clinical records, MR images, and postradiation angiograms were reviewed. Signal abnormalities and contrast enhancements were correlated with clinical deterioration and size decrease of the AVM. The Spearman nonparametric test was used for statistical correlation. MR findings allowed to differentiate between four grades: grade 1 = no parenchymal changes; grade 2 = hypersignal on T2-weighted sequences, grade 3 = grade 2 + contrast enhancement on T1-weighted sequences; grade 4 = grade 3 + central hyposignal (necrosis-like) + peripheral hyposignal surrounding the AVM on T1-weighted sequences. Grade 4 was significantly related (p < 0.001) to clinical deterioration (deficit, seizures, increased intracranial pressure). All grade 4 patients, and only them, had clinical symptoms. Most of these symptoms regressed with corticoid treatment. Grade 4 was also related to the proportion of obliteration of the cAVM at 1 year after radiotherapy: mean proportion of obliteration was 12.5&percnt; for grade 2, 25&percnt; for grade 3 and 82.2&percnt; for grade 4 (p < 0.01). The size of T2-weighted MR images was related to clinical symptom appearance (p < 0.001). Finally, contrast enhancement was not predictive of the occurrence of the clinical symptoms. This proposed classification allows one to differentiate between the various MR images, and seems to predict clinical complications and response to radiotherapy of the cAVM.
    Stereotactic and Functional Neurosurgery - STEREOTACT FUNCT NEUROSURG. 01/1997; 69:143-146.
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    ABSTRACT: Radiosurgery of cerebral arteriovenous malformations (cAVM) can induce parenchymal changes seen on MRI. The purpose of this study was to classify these changes and to correlate them to clinical outcome and obliteration of the cAVM. 142 patients with cAVM underwent radiosurgery with a linear accelerator between 1994 and 1995. 60 clinical records, MR images, and postradiation angiograms were reviewed. Signal abnormalities and contrast enhancements were correlated with clinical deterioration and size decrease of the AVM. The Spearman nonparametric test was used for statistical correlation. MR findings allowed to differentiate between four grades: grade 1 = no parenchymal changes; grade 2 = hypersignal on T2-weighted sequences, grade 3 = grade 2 + contrast enhancement on T1-weighted sequences; grade 4 = grade 3 + central hyposignal (necrosis-like) + peripheral hyposignal surrounding the AVM on T1-weighted sequences. Grade 4 was significantly related (p < 0.001) to clinical deterioration (deficit, seizures, increased intracranial pressure). All grade 4 patients, and only them, had clinical symptoms. Most of these symptoms regressed with corticoid treatment. Grade 4 was also related to the proportion of obliteration of the cAVM at 1 year after radiotherapy: mean proportion of obliteration was 12.5% for grade 2, 25% for grade 3 and 82.2% for grade 4 (p < 0.01). The size of T2-weighted MR images was related to clinical symptom appearance (p < 0.001). Finally, contrast enhancement was not predictive of the occurrence of the clinical symptoms. This proposed classification allows one to differentiate between the various MR images, and seems to predict clinical complications and response to radiotherapy of the cAVM.
    Stereotactic and Functional Neurosurgery 01/1997; 69(1-4 Pt 2):143-6. · 1.46 Impact Factor
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    ABSTRACT: We wished to evaluate adjunctive therapy for partial-onset seizures with topiramate (TPM) for efficacy and safety in a double-blind, placebo-controlled, randomized, parallel-group study. Sixty outpatients with epilepsy (47 men and 13 women, mean age 32.9 years) were studied. All had a documented history of partial-onset seizures with or without secondarily generalized seizures. After an 8-week baseline during which patients had at least one seizure per week, 30 patients each were randomized to TPM 300 mg twice daily (b.i.d.) or placebo for 12 weeks. TPM was significantly superior to placebo, as indicated by all efficacy assessments: greater median percent reduction from baseline in the average monthly seizure rate (46 vs. -12%, p = 0.004); greater number of treatment responders (patients with > or = 50% reduction in seizure rate) (47 vs. 10%, p = 0.001), and better investigator (p = 0.002) and patient (p = 0.010) global assessments of treatment. Among TPM-treated patients, the most commonly reported adverse events (AE) were headache, somnolence, fatigue, dizziness, and abnormal thinking. Most AE were mild or moderate in severity. The results of the present trial indicate that TPM 600 mg/day is effective in the treatment of refractory partial-onset seizures with or without secondarily generalized seizures.
    Epilepsia 08/1996; 37(8):763-8. · 3.91 Impact Factor
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    ABSTRACT: The identification of the central region--i.e. the central sulcus, the pre- and post-central gyri, the paracentral lobule--on MRI and angiographic images may be necessary prior to stereotactic procedures such as biopsies or resection of centrally located tumors, depth electrode recordings for presurgical evaluation of drug-resistant epilepsies, or radiosurgery of arteriovenous malformations. Stereotactic methods, such as the Talairach's proportional grid based on the bicommissural system, demonstrated the statistical position of the central sulcus according to the Ac-Pc, Vac and Vpc baselines. However, the course and the spatial position of this sulcus have remarkable individual differences that sometimes make the sulcus difficult to identify on serial sagittal MRI or lateral angiographic images. In order to facilitate this identification, the authors propose a new oblique baseline, the rolandic (R) line. The stereotactic MRI and angiography of 22 patients were reviewed for this study. Eleven of these patients had stereotactic biopsies for a low-grade tumor located in the central region, while eleven others had multiple intracerebral electrodes implantation and depth EEG recording (SEEG: stereoelectroencephalography) in the presurgical evaluation of drug-resistant partial epilepsy, prior to epileptogenic cortex resection. The Ac-Pc, Vac, Vpc baselines and segments of the central sulcus were drawn from the mid-sagittal and lateral T1-weighted MRI images and reported on an individual graph. Surface and deep margins as well as axis of the central sulcus were also reported along with corpus callosum baselines as defined by Olivier et al.: horizontal plane, anterior and posterior callosal planes. The rolandic line was then traced from the graph:it joined the intersection point between the anterior callosal plane and an orthogonal line passing through the floor of the temporal fossa, and the intersection point between posterior callosal plane and an orthogonal line passing through the top of the hemisphere. The rolandic line was then superimposed on any sagittal MRI image or lateral stereotactic angiographic film. Finally, the spatial position of electrode contracts through which electrical stimulations elicited motor and/or sensory responses, either from central electrode implanted for motor fibers identification prior to stereotactic biopsies or from SEEG electrodes implanted for epileptogenic zone identification and cortical mapping, was reported on the individual graph. Angular and linear measurements were taken from the graph, between the rolandic line, the central sulcus axis, the Ac-Pc and callosal baselines, and the central sulcus limits (top, bottom, anterior and posterior margins). Graph measurements indicated that the rolandic line was significantly closer to the inferior part of the central sulcus than to its superior part (average distance between the line and the inferior point of the sulcus: 1.86 +/- 1.87 mm; average distance between the line and the superior point of the sulcus: 4.5 +/- 2.3 mm; p < 0.001-t test); similarly, the rolandic line was closer to the deep margin of the sulcus rather than to its superficial border (average distance between the line and the most anterior point of the sulcus: 11.43 +/- 3.16 mm; average distance between the line and the most posterior point of the sulcus: 7.95 +/- 4.14 mm; p < 0.01-t test). In 90% of the cases, the rolandic line followed the deep or middle part of the sulcus, with an average angle of 4.18 degrees +/- 2.53 degrees between the line and the sulcus axis. The spatial position of the electrode contacts that elicited motor/or sensory responses to stimulations correlated topographically well in all cases with the position of the motor and sensory fibers defined according to the central sulcus, baselines and reference to stereotactic atlases. (ABSTRACT TRUNCATED)
    Journal of Neuroradiology 06/1996; 23(1):6-18. · 1.24 Impact Factor
  • Epilepsy research. Supplement 02/1996; 12:293-300.
  • Advances in neurology 02/1995; 66:115-25; discussion 125-6.
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    ABSTRACT: In the rat brain, the presynaptic 5-hydroxytryptamine (5-HT) autoreceptors located on 5-HT terminals correspond to the 5-HT1B subtype. The presence of a 5-HT receptor probably located on 5-HT nerve endings and modulating transmitter release in the human neocortex has been reported, but its detailed pharmacological characterization is not yet available. On the other hand, receptor binding and autoradiographic results indicate that the 5-HT1B receptor subtype is not present in the human brain. We, therefore, studied the modulation of the electrically evoked release of [3H]5-HT by various 5-HT receptor agonists and antagonists in preloaded slices of human neocortex obtained from 18 patients undergoing neurosurgery. The nonselective 5-HT1A/1B/1D receptor agonist 5-carboxamidotryptamine produced a potent inhibition (70% at 0.03 microM) of the electrically evoked release of [3H]5-HT which was blocked by 5-HT receptor antagonists with the following relative order of potency: methiothepin greater than metergoline = methysergide greater than propranolol. The selective 5-HT1A receptor agonist 8-hydroxy-2-(di-n-propylamino)tetralin at 0.1 microM did not modify the electrically evoked release of [3H]5-HT. The 5-HT1A/1B receptor agonist RU 24969 was 10 times more potent at inhibiting [3H]5-HT overflow in the rat frontal cortex than in the human neocortex. The potent 5-HT1B receptor antagonist cyanopinodolol did not modify the 5-carboxamidotryptamine-induced inhibition of the electrically evoked release of [3H]5-HT in slices of the human neocortex, but produced by itself a small inhibition of [3H]5-HT overflow.(ABSTRACT TRUNCATED AT 250 WORDS)
    Journal of Neurochemistry 11/1992; 59(4):1293-301. · 3.97 Impact Factor
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    ABSTRACT: : In the rat brain, the presynaptic 5-hydroxytrypt-amine (5-HT) autoreceptors located on 5-HT terminals correspond to the 5-HT1B subtype. The presence of a 5-HT receptor probably located on 5-HT nerve endings and modulating transmitter release in the human neocortex has been reported, but its detailed pharmacological characterization is not yet available. On the other hand, receptor binding and autoradiographic results indicate that the 5-HT1B receptor subtype is not present in the human brain. We, therefore, studied the modulation of the electrically evoked release of [3H]5-HT by various 5-HT receptor agonists and antagonists in preloaded slices of human neocortex obtained from 18 patients undergoing neurosurgery. The nonselective 5-HT1A/1B/1D receptor agonist 5-carboxamidotryptamine produced a potent inhibition (70% at 0.03 μM) of the electrically evoked release of [3H]5-HT which was blocked by 5-HT receptor antagonists with the following relative order of potency: methiothepin > metergoline = methysergide > propranolol. The selective 5-HT1A receptor agonist 8-hydroxy-2–(di-n-propylamino)tetralin at 0.1 μM did not modify the electrically evoked release of [3H]5-HT. The 5-MT1A/1B receptor agonist RU 24969 was 10 times more potent at inhibiting [3H]5-HT overflow in the rat frontal cortex than in the human neocortex. The potent 5-HT1B receptor antagonist cyanopindolol did not modify the 5-carboxamidotryptamine-induced inhibition of the electrically evoked release of [3H]5-HT in slices of the human neocortex, but produced by itself a small inhibition of [3H]5-HT overflow. The α2-adrenoceptor antagonist yohimbine, which possesses affinity for the 5-HT1D receptor subtype, decreased the release of [3H]5-HT, but only in the presence of the selective α2-adrenoceptor antagonist idazoxan, which by itself increased significantly [3H]5-HT overflow. Taken together, these results support the view that the 5-HT receptor modulating the electrically evoked release of [3H]5-HT in slices of the human neocortex could be of the 5-HT1D subtype. Moreover, preliminary results obtained with idazoxan confirm the existence of a presynaptic α2-adrenoceptor modulating the release of [3H]5-HT in the human neocortex. These α2-heteroreceptors could exert a tonic inhibitory modulation on 5-HT neurotransmission in the human neocortex.
    Journal of Neurochemistry 01/1992; 59(4):1293-1301. · 3.97 Impact Factor
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    ABSTRACT: Considering that the 1.32-microns Nd-YAG laser should have physicothermal properties close to those of the CO2 laser, a series of experiments were conducted on rat cortex (N = 51). Three laser wavelengths were compared: CO2 laser (10.6 microns), 1.06-microns Nd-YAG, and 1.32-microns Nd-YAG lasers. For each shot, temperature measurements were recorded with an infrared thermographic videocamera. The digitized signals were figured as thermal profiles and temperature developments. Ninety-five shots were correctly studied and analyzed: CO2, N = 29; 1.06-microns Nd-YAG, N = 20; 1.32-microns Nd-YAG, N = 46. The histological lesions produced by these three lasers were compared on animals killed 24 hours (N = 20), 8 days (N = 20), and 30 days (N = 5) after the laser impacts. For equivalent densities of energy, the depth of cortical necrosis was comparable for the CO2 laser (200-250 microns) and the 1.32-microns Nd-YAG laser (210-260 microns) whatever the date of death; the 1.06-microns Nd-YAG laser shots were responsible for much more important damage (400-550 microns). Because of its important absorption in water and nervous tissue, the authors consider the 1.32-microns Nd-YAG laser most suitable for neurosurgery, particularly because it is conducted through optic fibers, and therefore is easy to handle during neurosurgical procedures.
    Surgical Neurology 01/1991; 34(6):402-7. · 1.67 Impact Factor
  • F X Roux, B Devaux, S Mordon, S Nguyen, J P Chodkiewicz
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    ABSTRACT: The authors present their experience with the 1.32 mum Nd:YAG laser in neurosurgical procedures. In a first step, they conducted experiments on rat cortex. The thermic data and histologic results confirmed that the 1.32 Nd:YAG laser has physical properties quite close to the CO2 laser. Furthermore, the fact that the 1.32 mum wavelength can be conducted through optic fibers makes it well adapted to neurosurgery. The authors present experimental data (50 rats) and comment on their surgical experience with such a wavelength (70 patients). In the future, this laser should see its indications broadened in conventional neurosurgical procedures as well as in endoscopic and stereotactic neurosurgery.
    Journal of Clinical Laser Medicine & Surgery 09/1990; 8(4):55-61.