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J Philippon

Publications and source records attributed to J Philippon.

At least 37 records · Page 2Linked to original sources
PubMed1997

[Radiosurgery].

Radiosurgery refers to the possibility of the destruction of a small area in the brain with a high dose of radiation, after determination of the target with stereotactic coordinates. Arteriovenous malformations of small size not treatable by direct surgery are obliterated by radiosurgery in nearly 80 p. 100 of the cases. Cerebral metastasis are also effectively treated with a good local control, especially in case of small solitary lesion. In acoustic tumor, of small and medium size, radiosurgery appears to be an alternative to surgery. Other benign tumors (meningioma, pituitary adenoma) have also been treated, but long-term studies are still necessary to evaluate the efficacy of this technic.

Brain Neoplasms↗
PubMed1997

[Strategy of evaluation and surgical results in medial temporal lobe epilepsy].

To analyse the presurgical evaluation process of mediotemporal lobe epilepsy (MTLE) in relation to electroclinical characteristics of the patients, we reviewed the presurgical data (clinical, EEG, neuropsychological, MRI, FDG-PET and sometimes intracranial EEG) and the post-operative results of 53 consecutive cases treated by antero-medial temporal resection for MTLE (without lesion other than mediotemporal sclerosis). Forty one patients (77 p. 100) had a typical and well-lateralised presentation and were operated without invasive procedure. Twelve patients (23 p. 100) presented less pure data: unusual or absent auras, divergent scalp EEG features (bitemporal, widespread or extratemporal) or absence of MRI-based hippocampal sclerosis or FDG-PET hypometabolism. They were explored by invasive monitoring which confirmed the medial temporal origin of seizures. Outcome (follow-up: 30 months) was excellent in 88 p. 100 of the pure cases (Engel's class I) and less favorable in the more difficult ones (50 p. 100 of class I). In conclusion, the diagnosis and surgical treatment of MTLE can be performed without invasive investigations in the majority of cases owing to the strong contribution of brain imaging and video EEG monitoring. Some patients however present a less pure presentation suggesting more complex epileptogenic networks and associated to relatively less favorable postsurgical results.

Adult↗
PubMed1996

[Surgery of brain tumors].

Treatment of brain tumors represents a very important chapter of neurological surgery. In fact, surgery is of primary importance in the management of benign or potentially anaplastic brain tumors. It not only provides histological diagnosis but radical surgical removal, when feasible, is the goal standard treatment of a very large group of these lesions. Surgery is directed specifically against tumoral processes which are widely different and heterogeneous anatomically and histologically. Some of them are benign and their treatment is essentially relaying on surgery. Others are anaplastic or malignant and surgery has to be associated with other treatment modalities [radiotherapy and (or) chemotherapy] but remains crucial for the histological assessment of the lesion even obtained from stereotactical biopsy specimens. Whenever possible surgical resection must be proposed because it improves the patient's clinical and functional state and allows a better efficacy of complementary treatments when indicated. These factors correlates with the quality and length of the postoperative radiological and clinical remission.

Adult↗
PubMed1996

[Iridium 192 brachytherapy of supra-tentorial high grade glioma recurring in irradiated areas: technique and preliminary results of the Pitié-Salpêtrière hospital group].

UNLABELLED: Our aim was to analyse feasibility and preliminary results obtained with iridium 192 re-irradiation of recurrent high grade gliomas. MATERIAL AND METHODS: a technique for implanting rigid plastic tubes afterloaded with iridium 192 wires was developed that utilised a stereotactic Leksell frame. Nineteen glioblastomas and one anaplastic glioma (12 males and 8 females: age: 20-69 years, median: 50) were implanted between January 1993 and December 1994. Previous treatments included surgery (18/20). 55-60 Gy external beam radiotherapy (20/20), and chemotherapy (16/20); interval between initial treatment and retreatment with iridium 192 was 6 to 39 months (median: 10). Maximum diameter of the tumour at the moment of implantation was 2.1-10.1 cm (median: 6.4 cm) and tumour volume 2.122 cm3 (median: 22 cm3). All tumours were supra-tentorial (right hemisphere: 9; left hemisphere: 11). Karnofsky index was 60-100 (median: 80). Implantation was carried out under local anaesthesia; tumour contours were visualised using either a CT-scan (16/20) or a MRI (4/20). Dosimetry was carried out using two orthogonal films and CT-scan images. Total dose on the reference isodose was 40-60 Gy (60 Gy: 9; 50 Gy: 7; 40 Gy: 4); dose-rate was 0.24-0.73 Gy/h (median: 0.38). RESULTS: probability of overall survival is 90% at 6 months, 55% at one year, and 26% at two years. Median survival is 56 weeks. Eleven patients died from local failure, and three from leptomeningeal metastasis. Six patients are alive, 15-30 months after the implantation. Two were reoperated for brain necrosis. Three patients showed evidence of bacterial meningitis, and three others of skin necrosis. CONCLUSION: according to this preliminary analysis, results obtained after reirradiation of high grade gliomas with iridium 192 are encouraging. More patients and longer follow-up are needed to draw definitive conclusions.

Adult↗
PubMed1995

Is interictal temporal hypometabolism related to mesial temporal sclerosis? A positron emission tomography/magnetic resonance imaging confrontation.

The mechanism of interictal glucose hypometabolism remains unclear, but this abnormality occurs more frequently in temporal lobe epilepsy (TLE) than in other types of partial epilepsy. Therefore temporal hypometabolism has been suggested to reflect mesial temporal sclerosis (MTS). To investigate this, we selected 22 patients with refractory partial epilepsy of mesial temporal lobe origin (MTLE) who had hippocampal atrophy based on magnetic resonance imaging (MRI) volumetric analysis. We then analyzed the metabolic correlates of unilateral hippocampal atrophy. Thirteen temporal regions of interest (ROI) were defined on MRI scans for each individual and then applied to high-resolution FDG-positron emission tomography (PET) images obtained parallel to the long axis of the hippocampus. The most hypometabolic regions were the temporal pole and the hippocampal region. When we analyzed ensembles of temporal regions grouped into related networks, the temporolimbic network, which included the hippocampal region and the temporal pole, was abnormal in 95% of the patients at a 3-SD threshold. PET hypometabolism was highly correlated with the degree of hippocampal atrophy in this network, but not in other parts of the temporal lobe, which were less frequently hypometabolic. These data indicate that hypometabolism is a consequence of MTS in the temporolimbic region but not necessarily in the other parts of the temporal lobe. Our results also suggest that the combination of PET and MRI may facilitate the noninvasive diagnosis of MTLE.

Adult↗
PubMed1994

Neurosurgical anatomy of the anterior interhemispheric approach for aneurysms of the anterior communicating artery (26.6.92).

The anterior interhemispheric approach for aneurysms of the anterior communicating artery was studied in ten cadavers. This approach presents several advantages over the pterional approach widely used in neurosurgery. It allows direct access to the region of the anterior communicating artery complex with minimal retraction of the brain and preservation of the olfactory tract and the gyrus rectus.

Cerebral Arteries↗
PubMed1994

[Surgery for temporal lobe epilepsy].

Interest in surgery for intractable temporal lobe epilepsy has increased during the last ten years, mainly due to a better identification of the epileptogenic focus by modern imaging techniques (MRI) or functional tools (TEP and SPECT scanning). Depth electrodes recording is not mandatory and can be restricted to patients who do not meet congruent non invasive criteria. Simultaneously, modification of surgical techniques has been proposed: in addition to classical temporal lobectomy, other methods are used in order to minimize the resection of temporal lateral neocortex, and increase that of mesial temporal structures; the latter can be selectively performed through amygdalo-hippocampectomy. Outcome of surgery is generally excellent or good. More than three-fourths of patients are seizure free or show major reduction in seizure frequency. Outcome at the end of the second year is a good indication of long-term prognosis.

Cerebral Cortex↗
PubMed1993

Impairment of consciousness induced by valproate treatment following neurosurgical operation.

Eight patients, who underwent neurosurgery for various supratentorial lesions presented unexplained impairment of consciousness during the first post-operative days. These states ranged from stupor to deep coma, and two patients had an emergency re-exploration. All these patients were receiving the usual dosage (1000 to 1500 mg per day) of Valproic acid (VPA). The treatment had been initiated either several weeks or months previously in 4 cases, and was thus well tolerated, or the day before surgery in the 4 other cases. EEG recordings displayed diffuse abnormalities, delta waves and/or high voltage triphasic complexes, that led to the diagnosis of VPA intolerance and drug withdrawal. Then full clinical recovery and EEG clearing occurred within 1 to 5 days. VPA intolerances are wellknown but remain exceptional, about 1 case per 100.000. In our neurosurgical population, however, the rate was higher, approximately 2%. Wide areas of blood brain barrier destruction may contribute to the higher frequency of this easily reversible cause of post-operative stupor or coma.

Adolescent↗
PubMed1992

Allelic loss on chromosome 22 correlates with histopathological predictors of recurrence of meningiomas.

Meningiomas are common tumors of the nervous system. Although usually benign, they may exhibit variable degrees of aggressiveness. Their probability of recurrence after subtotal resection has been correlated with several histological parameters. Independently, a loss of chromosome 22, as evidenced either by cytogenetics or by somatic loss of alleles, has been observed in about half of the cases studied. In 34 meningiomas we have examined the relationship between loss of chromosome 22 alleles and 6 histological predictors of recurrence. Significant correlations were found for 3 of these, i.e. prominent nucleoli (p less than 0.002), microscope count of mitoses (p less than 0.05) and nuclear pleomorphism (p less than 0.02). Correlation with the other 3, i.e. sheeting of cells, vascularity and micronecrosis, did not reach significance. Total tumor score, defined by the sum of the individual scores for these 6 parameters, was strongly correlated to allelic loss (p less than 0.0001). Thus, the loss of chromosome 22 alleles, which possibly contribute to the inactivation of tumor-suppressor gene(s), might be a potent genetic marker of the aggressiveness of meningiomas.

Aneuploidy↗
PubMed1992

Increase in omega 3 (peripheral-type benzodiazepine) binding site densities in different types of human brain tumours. A quantitative autoradiography study.

The density of omega 3 (peripheral type benzodiazepine) binding sites, a marker of reactive and tumoural cells, has been measured in different types of human brain tumours; omega 3 sites were quantified autoradiographically in sections from biopsy or autopsy specimens labelled with the specific radioligand 3H-PK 11195. Compared to normal brain parenchyma, up to 12-fold increase in omega 3 site densities were found in apparently viable areas of high grade astrocytoma and glioblastoma specimens, whereas more limited increases (2 to 3-fold) in this marker were observed in areas of necrosis. Low grade gliomas (astrocytomas) and meningiomas exhibited only moderate increases (2 to 3-fold) in this autoradiographic marker. Metastases of lung or kidney origin were characterized by greatly elevated (up to 20-fold) omega 3 site densities as compared to normal brain parenchyma. In every case, there was a good spatial correspondence between the histopathological limits of the tumour and the anatomical location of the increase in omega 3 site densities. These results suggest that omega 3 site densities in human brain tumours reflect their proliferative activity and point to a possible future usefulness of positron or gamma-ray emitting omega 3 site ligands for the clinical investigation and detection of human brain proliferative diseases.

Astrocytoma↗
PubMed1991

Value of electroencephalogram in prediction and diagnosis of vasospasm after intracranial aneurysm rupture.

The Electroencephalogram (EEG) of 151 patients whose ruptured aneurysm was confirmed by CT scan and angiography was recorded on the first day (D1) and the fifth day (D5). On D1, EEG had a prognostic value: among 46 patients with normal EEG, 72% presented neither further electrical ischaemic features nor delayed angiographic vasospasm; on the other hand, when bilateral bursts of slow waves, "axial bursts" or slow delta waves were recorded (78 cases), 97% exhibited EEG signs of ischaemia and angiographic vasospasm a few days later. These data were clearly related to the importance of the haemorrhage, specially when thick clots in the subarachnoid cisterns were found on the CT scan. On D5, EEG had a diagnostic value: focal or asymetrical bilateral delta waves occurring at that date seemed to correspond to ischaemia; among 107 patients with these electrical features, an angiographic vasospasm appeared in 96% of cases, and the importance of electrical abnormalities could be related to the degree of arterial narrowing. We conclude that EEG data are very useful in prediction as well in recognition of post-subarachnoid haemorrhage ischaemia due to vasospasm and are sufficiently precise to postpone control angiography and operation, when delayed surgery is programmed.

Adolescent↗
PubMed1990

[Vascular accidents of the cerebellum].

Vascular accidents of the cerebellum include heamorrhages and infarctions. These two pathologies share the same clinical symptoms and the same potential severity due to the sudden creation of an expansive cerebellar process (haematoma or infarct). Owing to acute compression of the brain stem and of CSF channels in the posterior fossa, and to the resulting supratentorial obstructive hydrocephalus, cerebellar vascular accidents are acute neurosurgical emergencies. Although the diagnosis and prognosis of the lesions have been transformed by computerized tomography of the brain, they remain extremely serious. This underlines the need for early detection, especially since, unlike vascular accidents of the brain, their functional sequelae after treatment are moderate.

Cerebellum↗