Search

Presents an obituary for neurosurgery professor Bernard Pertuiset, who died at the age of 80, on November 29, 2000.

Forty-four patients (22 males and 22 females) were admitted to our institution for an intracranial epidermoid cyst between 1980 and 2000. Their mean age was 39.9 years. The duration of the disease at admission varied between a few days and 30 years. CT-scan was performed in all cases, MRI in 33 cases with a diffusion sequence in 3. Most of the 26 patients with posterior fossa lesions were treated surgically in the sitting position, with resection of the tonsils in four cases in order to minimize cerebellar retraction. The other supratentorial tumors were operated using a fronto-temporo-pterional approach in 13 cases (with temporo-polar lobectomy in 6 cases), or a parietal transparenchymal approach in the parieto-occipital lesions (2 cases). The resection was total or subtotal (residual capsule) in 79.5% of cases. Post-operative morbidity was 13.6% and mortality 8.9%. The median follow-up was 8 years, with a recurrence rate of 4.5%. Epidermoid cysts are benign, slowly but ineluctably growing tumors which require surgical treatment. Their diagnosis has become easier, especially with the development of MRI diffusion sequences. Morbidity and mortality (morbi-mortality) reported in the literature as well as found in our series seems to be unrelated to classical aseptic meningitis (22.7% in our series) or hydrocephalus (2 cases in our series). For many authors, it may be the consequence of systematic resection of the tumor capsule. This does not seem to be the case in our series in which only 25% of the patients underwent a complete resection. Prolonged cerebral retraction could be one of the responsible factors. One of the technical proposals could be to perform a transparenchymal approach in selected patients.

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.

Sarcoidosis is a multisystemic granulomatosis disease of unknown etiology which commonly involves hilary nodes and lungs. Involvement of the nervous system represents 5 to 15% of the cases. We report on a rare case of cervicothoracic spinal cord sarcoidosis in an African man and review the literature on the subject. His only symptoms were those of a subacute myelopathy. On MR-imaging, coexistence of abnormal signal of cervicothoracic spinal cord with mediastinal lymph nodes was suggestive of sarcoidosis, which was confirmed by bronchial biopsies making unnecessary biopsies of the spinal cord lesion. Under corticotherapy both symptoms and radiological abnormalities rapidly regressed. We emphasize the rarity of sarcoidosis exclusively revealed by a myelopathy. We stress the importance of searching other localizations which are easier and safer to biopsy than the spinal cord lesion itself and illustrate the MR appearances of the lesion which are suggestive, however not specific of the disease.

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.

Spinal neurosarcoidosis is rare (0.43 p. 100 of all sarcoidosis) and can be the initial manifestation of the disease. A 43-year-old right handed African man developed a progressive dorsal neck pain, slowly worsened paresthesia weakness in the legs and a gait disturbance. Magnetic resonance imaging (MRI) scan of the cervical and thoracic spinal cord (sagittal T(1)- weighted image) revealed diffuse enlargement of the cord from C2 to T7 with intense intramedullary enhancement from C2 to T3 after administration of contrast material on sagittal T(1)- weighted image. Cranial MRI scan was normal. Radiographs of the chest revealed bilateral symmetric hilar mediastinal lymphadenopathy with no pulmonary infiltrates. Bronchial biopsy demonstrated non caseating granulomas with langerhans giant cells. The serum angiotensin converting enzyme level was elevated. The patient received corticosteroid with good progressive response. His neurologic symptoms improved markedly and twenty months post-treatment MRI showed no abnormality on enhanced T(1)- weighted images. Two years later he had no relapse. Only 6 to 10 p. 100 of patients with neurosarcoidosis have spinal cord involvement, which may account for the first clinical manifestation of the disease. Most patients with neurosarcoidosis have associated extraneurologic abnormalities. The diagnosis is supported usually by extraneurologic biopsies. Spinal cord biopsy needs to be considered on case-by-case basis.

Objective: Surgery of the insula represents a technical challenge, because of the proximity of the internal capsule to the lenticulostriate arteries and the lack of certainty concerning its functionality. Using intraoperative direct cerebral stimulation, combined with neuronavigation, the authors operated on 12 insular gliomas. On the basis of this experience, the physiopathological and surgical implications are discussed., Methods: A low-grade insular glioma, revealed by seizures, was diagnosed in 12 right-handed patients with a normal neurological status. Preoperative magnetic resonance imaging showed that, according to Yasargil's classification system, three patients harbored Type 3 lesions and nine patients had Type 5 lesions (10 tumors on the right side and 2 on the left dominant side). All patients underwent surgery using direct cerebral stimulation, under general anesthesia in nine patients (motor mapping) and under local anesthesia in three patients (sensorimotor and language mapping). Ultrasonography and/or neuronavigation was used in all cases. Preoperative angio-computed tomographic scanning showed the lenticulostriate arteries in two patients., Results: The internal capsule was systematically detected, and the language areas were identified within the left insula in the awake patients. The lenticulostriate arteries were seen in two patients. Seven patients presented an immediate postoperative deficit; six of them recovered completely within 3 months. Four resections were total, six were subtotal, and two were partial (left insula)., Conclusion: The use of intraoperative direct cerebral stimulation and neuronavigation allows surgery of the insula with minimization of the risk of sequelae, but its use is still limited with regard to the dominant hemisphere, owing to the essential role of this structure in language.

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.

A case of recurrent bleeding from a probable left thalamic cavernoma in a 26 year old woman taking hormonal treatment is reported. Four episodes of bleeding were clinically and radiologically documented, prior to her referral to our institution. Interestingly, each episode occurred three weeks after starting hormonal treatment, dydrogesterone, desogestrel ethinylestradiol, chlormadin, nomegestrel acetate). The patient was not operated because of the deep situation of the cavernoma which was remote from the thalamic surface within the third ventricle. There was no recurrent bleeding after the onset hormonal treatment was discontinued. Although no similar case has been found in the literature, we believe that this case gives further argumentation in favor of a role of hormonal factors influencing the biological behavior of cavernous angiomas which has been previously suggested in pregnant females with bleeding cavernous angiomas.

Indications of surgical treatment for lesions in functional cerebral areas depend on the ratio between the definitive neurological deficit and the beneficial effect of resection. Detection of eloquent cortex is difficult because of important individual variability. Peroperative direct cortical and subcortical electrical stimulations (DCS) provide the most precise and reliable method currently available allowing identification and preservation of neurons essential for motricity, sensitivity++ and language. We report our preliminary experience with DCS in surgery of intracerebral infiltrative tumors with a consecutive series of 15 patients operated from November 96 through September 97 in our institution. Presenting symptoms in the 15 patients (8 males, 7 females, mean age 43 years) were seizures in 11 cases (73%) and neurological deficit in 4 cases (27%). Clinical examination was normal in 11 patients and revealed hemiparesia in 4. Magnetic resonance imaging (MRI) with three-dimensional reconstruction showed a precentral tumor in 10 cases, central lesion in one patient, postcentral lesion in two cases, right insular tumor (non-dominant hemisphere) in one case. All patients underwent surgical resection using DCS with detection in 13 cases of motor cortex and subcortical pathways under genera anesthesia, in one case of somatosensory area under local anesthesia, and in one case of language areas also under local anesthesia. The tumor was recurrent in two patients had been operated earlier but without DCS. Resection, verified by postoperative MRI, was total in 12 cases (80%) and estimated at 80% in 3 patients. Histological examination revealed an infiltrative glioma in 12 cases (8 low grade astrocytomas, 3 low grade oligodendrogliomas, and one anaplastic oligodendroglioma), and metastases in 3 cases. Eight patients had no postoperative deficit, while the other 7 patients were impaired, with, in all cases except one, complete recovery in 15 days to 2 months. Direct cortical and subcortical electrical stimulations offer a reliable, precise and safe method, allowing functional mapping especially useful in case of infiltrative cerebral tumors in eloquent areas. This technique allows improvement in the quality of tumoral resection and concurrently a minimization of the risk of definitive postoperative neurological deficit.

Local control of brain metastases is better with first treatment by stereotactic radiosurgery than with radiosurgery for recurrence. We reported a retrospective analysis of the influence of clinical and technical factors on local control and survival after radiosurgery realised in first intention. From January 1994 to December 1997, 26 patients presenting with 43 metastases underwent radiosurgery. The median age was 61 years and the median Karnofsky index 70. Primary sites included: lung (12 patients), kidney (7 patients), breast (2 patients), colon (1 patient), melanoma (2 patients), osteosarcoma (1 patient), it was unknown for one patient. Seven patients had extracranial metastases. Twenty-one sessions of radiosurgery have been realized for one metastase, and 9 for two, three or four lesions. The median diameter was 21 mm and the median volume 1.8 cm3. The median peripheral dose to the lesion was 14 Gy, and the median dose at the isocenter 20 Gy. Forty-two metastases were evaluable for response analysis. The overall local control rate was 90.5% and the 1-year, 2- and 3-year actuarial rates were 85% and 75%. In univariate analysis, theorical radioresistance was significantly associated with better local control (100% versus 77%, p < 0.05). All patients were evaluable for survival. The median survival rate was 15 months. Four patients had a symptomatic oedema (RTOG grade II). Two lesions have required a surgical excision. In conclusion, low dose radiosurgery (14 Gy delivered at the periphery of metastasis) can be proposed in first intention for brain metastases, in particularly for theorical radioresistant lesions.

Background: Angiolipomas are considered to be rare. They are benign mesenchymal tumors generally located in the subcutaneous tissue of trunk and limbs., Methods: The authors report a thoracic epidural angiolipoma mimicking a vertebro-epidural metastasis. The patient suffered from medullary compression related to an extradural mass in T6., Results: Pathological ex-, amination was obtained from tumoral samples. They consisted of mature adipose tissue with numerous sections of abnormal vascular channels., Conclusions: Reviewing literature particular attention is paid to some questions raised in connection with different kinds of vertebro-epidural tumors. The authors give importance to relationships between angiolipomas and angiomyolipomas using MRI as a tool in differential diagnosis. Pathogenesis is evokated especially regarding the role of corticotherapy, the case herein reported lying within this therapeutical context.

Object: In this study the authors sought to estimate the frequency, seriousness, and delay of rebleeding in a homogeneous series of 20 patients whom they treated between May 1987 and May 1997 for arteriovenous fistulas (AVFs) that were revealed by intracranial hemorrhage (ICH). The natural history of intracranial dural AVFs remains obscure. In many studies attempts have been made to evaluate the risk of spontaneous hemorrhage, especially as a function of the pattern of venous drainage: a higher occurrence of bleeding was reported in AVFs with retrograde cortical venous drainage, with an overall estimated rate of 1.8% per year in the largest series in the literature. However, very few studies have been designed to establish the risk of rebleeding, an omission that the authors seek to remedy., Methods: Presenting symptoms in the 20 patients (17 men and three women, mean age 54 years) were acute headache in 12 patients (60%), acute neurological deficit in eight (40%), loss of consciousness in five (25%), and generalized seizures in one (5%). Results of the clinical examination were normal in five patients and demonstrated a neurological deficit in 12 and coma in three. Computerized tomography scanning revealed intracranial bleeding in all cases (15 intraparenchymal hematomas, three subarachnoid hemorrhages, and two subdural hematomas). A diagnosis of AVF was made with the aid of angiographic studies in 19 patients, whereas it was a perioperative discovery in the remaining patient. There were 12 Type III and eight Type IV AVFs according to the revised classification of Djindjian and Merland, which meant that all AVFs in this study had retrograde cortical venous drainage. The mean duration between the first hemorrhage and treatment was 20 days. Seven patients (35%) presented with acute worsening during this delay due to radiologically proven early rebleeding. Treatment consisted of surgery alone in 10 patients, combined embolization and surgery in eight, embolization only in one, and stereotactic radiosurgery in one. Three patients died, one worsened, and in 16 (80%) neurological status improved, with 15 of 16 AVFs totally occluded on repeated angiographic studies (median follow up 10 months)., Conclusions: The authors found that AVFs with retrograde cortical venous drainage present a high risk of early rebleeding (35% within 2 weeks after the first hemorrhage), with graver consequences than the first hemorrhage. They therefore advocate complete and early treatment in all cases of AVF with cortical venous drainage revealed by an ICH.

Purpose: Retrospective analysis of the influence of clinical and technical factors on local control and survival after radiosurgery for brain metastasis., Patients and Methods: From January 1994 to December 1996, 42 patients presenting with 71 metastases underwent radiosurgery for brain metastasis. The median age was 56 years and the median Karnofsky index 80. Primary sites included: lung (20 patients), kidney (seven), breast (five), colon (two), melanoma (three), osteosarcoma (one) and it was unknown for three patients. Seventeen patients had extracranial metastasis. Twenty-four patients were treated at recurrence which occurred after whole brain irradiation (12 patients), surgical excision (four) or after both treatments (eight). Thirty-six sessions of radiosurgery have been realized for one metastasis and 13 for two, three or four lesions. The median metastasis diameter was 21 mm and the median volume 1.7 cm3. The median peripheral dose to the lesion was 14 Gy, and the median dose at the isocenter 20 Gy., Results: Sixty-five metastases were evaluable for response analysis. The overall local control rate was 82% and the 1-year actuarial rate was 72%. In univariate analysis, theoretical radioresistance (P = 0.001), diameter less than 3 cm (P = 0.039) and initial treatment with radiosurgery (P = 0.041) were significantly associated with increased local control. Only the first two factors remained significant in multivariate analysis. No prognostic factor of overall survival was identified. The median survival was 12 months. Six patients had a symptomatic oedema (RTOG grade 2), only one of which requiring a surgical excision., Conclusion: In conclusion, 14 Gy delivered at the periphery of metastasis seems to be a sufficient dose to control most brain metastases, with a minimal toxicity. Better results were obtained for lesions initially treated with radiosurgery, theoretically radioresistant and with a diameter less than 3 cm.

Objective: Epidermal growth factor receptor (EGFR) is an operationally specific antigen in malignant gliomas; it is overexpressed in > 60% of these tumors, whereas its expression is very low in normal brain. This study aimed to evaluate whether an adequate amount of an anti-EGFR monoclonal antibody (MAb) could reach a tumor after a single intravenous administration., Methods: This study was open, nonrandomized, and uncontrolled. Single doses (20, 40, 100, 200, or 400 mg) of the murine MAb EMD55900 (MAb 425) were administered intravenously before surgery to 30 patients with malignant brain tumors. Serum samples were taken at defined time intervals during infusion, to determine EMD55900 concentrations, and 10, 21, and/or 42 days after infusion, to evaluate the development of human anti-mouse antibodies. Tumor samples were investigated for EGFR and EMD55900 contents., Results: Tolerance to EMD55900 was good. Increased liver transaminase levels were noted for three patients with Grade 1 toxicity. Twenty patients developed significant human anti-mouse antibody titers, without correlation with the administered dose. The median half-life of EMD55900 in serum ranged from 6 hours for 20 mg to 24 hours for 400 mg. In the membrane fractions of the tumors, EGFR saturation by EMD55900 varied with the injected dose of MAb. No binding was detected after a 20-mg dose. After doses of 40, 100, 200, and 400 mg, the mean saturation levels were 33, 73, 89, and 71%, respectively., Conclusion: This study indicates that a single intravenous administration of EMD55900 is well tolerated and produces substantial in vivo tumor binding with doses > 100 mg.

This paper presents 6 patients with catatonia and subthalamic mesencephalic tumors with hydrocephalus involving the third and the lateral ventricles. This anatomic and psychiatric anomaly is investigated on the basis of personal observations and a review of the literature. These cases allow an interesting parallel to be traced between neurological clinical signs and psychiatric signs. Various anatomic and physiological models are discussed which emphasize specialized neuronal circuits (somewhat similar to those involved in Parkinson's disease) and certain specific neurotransmitters such as dopamine, together with the reactivity of these circuits to intracranial pressure variations. Once more, clinical and laboratory data on schizophrenia concur to suggest that organic etiology is the causal factor in a known psychiatric pathology.

A large paraganglioma invaded the neck and skull, with extension into the right supratentorial cerebral hemisphere through the calvarium. Immunohistological markers were found useful for the diagnosis. The patient died rapidly. Despite no evidence of metastasis, the usually benign paraganglioma can have a malignant course.

In our series of 97 patients with multiple in juries observed in 2 consecutive years (1988-1989), we have selected only the most severe injuries, of which the patients died within 48 hours, and those that required a long stay in the intensive care department. On admission, we recorded 49 cases of stage II or more severe coma, and 67% of patients under respiratory assistance with an instable hemodynamic state. Out of the 44 deaths recorded, 30 subjects were comatose from the beginning. The justifies the confrontation of 3 specialist teams in 2/3 of cases. The specific recruitment of the hospital and the selection of the most severe cases of these "people under a death sentence" for the study shows a heavy toll of mortality (45,4%), including 60% on the first day. The main cause of death is head injuries (81%). The multivisceral and infectious consequences of long-lasting, heavy intensive care and pulmonary or myocardial contusions account fort secondary deaths in 25% of the patients who had survived. Emergent neurosurgical operations are exceptional, but a neurosurgeon's opinion is always essential. Orthopedic surgical issues are not specific, but the frequency of spinal lesions must be emphasized (27,2%). In this series, 85% of the patients with multiple trauma presented with a lesion of the locomotive apparatus and underwent emergent surgery in every second case in satisfactory conditions. Severe thoracic and maxillofacial lesions requiring surgery are rare. Abdominal lesions are more frequent (17%) and must be dealt with in priority, but they rarely cause death. On the contrary, lesions to the major blood vessels and retroperitoneal compound lesions have a very poor prognosis.(ABSTRACT TRUNCATED AT 250 WORDS)

In a 63-year old male patient coccygodynia, initially isolated then complicated by incomplete cauda equina syndrome, could be attributed to large perineurel meningeal cysts on the sacral nerve roots. The diagnosis was suspected at computerized tomography and nuclear magnetic resonance and confirmed by sacculoradiculography. Intradural injections of corticosteroids provided lasting pain relief. Arachnoid cysts are often asymptomatic, by they may be responsible for coccygodynia and/or incomplete cauda equina syndrome. Their presence is suggested by the characteristics of the symptoms which are paroxysmal, exacerbated in standing position, relieved in dorsal position and revived by percussing the sacrum. Treatment is medical in most cases. The decision to operate depends on the persistence and intensity of pain and on whether signs of neurological defecit are present.

A series of 162 arteriovenous malformations (A.V.M.) surgically removed is reported. All patients had a post operative control angiogram showing that the lesion had been totally excised. Supra and infra tentorial A.V.M. are included in the series as well as conscious and comatous patients. The overall mortality has been 11.1% and the mortality in conscious patients has been 6.9%. Mortality is higher when the volume of A.V.M. is over 60 cm3 and when a rupture has occurred. The influence of the operation on epileptic seizures, motor, speech or visual fields deficits has been reviewed in 109 patients who answered to the survey. Morbidity has been higher in patients with a cerebral heamorrhage, therefore the authors advise to operate these patients before the rupture when, for instance, seizures represents the only clinical picture. C.A.T. scan in these epileptic patients is a remarkable investigation to track down A.V.M.

A prolactin-secreting pituitary adenoma was removed trans-sphenoidally from a 37 years old man with gigantism (218 cm). Serum levels of prolactin (PRL) were elevated pre-operatively and decreased after administration of L-Dopa with no increase after TRH as is usually observed in PRL-secreting adenomas. Growth hormone (GH) and somatomedin serum levels were normal with no modification of GH after insulin hypoglycemia, oral glucose loading or L-Dopa. Morphological examination of the tumour demonstrated the presence of lactotrophs by light and electron microscopy and by immunofluorescense staining. No somatotrophs were found. In this unique case, the relationship between a PRL-secreting adenoma and gigantism is discussed.

Cytosolic and/or nuclear 3H-R 5020 binding sites were detected in 6/6 samples of normal leptomeninges obtained at the time of operation in human adults. The levels of binding sites were higher in leptomeninges samples (range of values: 140-1780 fmol/gT) than in the corresponding intracranial tumors (one meningioma, two neurinomas, one metastasis) in 3 out of the 4 cases that were simultaneously studied. The 3H-R 5020 binding systems were characterized in 2 groups, A and B, of pooled samples representing respectively 4 and 17 samples of normal leptomeninges. The study of A (cytosolic and nuclear binding sites) and B (cytosolic binding sites) groups showed that binding systems had a limited capacity and a high affinity (Kd were respectively 2 X 10(-9) and 5.3 10(-10) M) as previously noted for the progestin receptor in human meningioma. Biochemical data and ultrastructural pictures obtained in the present study as well as in previous works, allow to consider the presence of the progestin receptor in normal leptomeninges.

Stereotaxic biopsy of cerebral tumors has been considerably facilitated by the use of CT scanner. A new method is described using the CT section in the horizontal or oblique plan of biopsy. When this has been determined, it is possible to define a trajectory, calculated by the CT scan computer, with external landmarks marked on the skin. This method is possible with any kind of CT apparatus; the surgical biopsy is performed in the operating room with a simple stereotaxic frame square-shaped and fixed in the plan of the CT section. The biopsy needle may be oriented in an antero-posterior or medio-lateral direction. This method has been used in 33 patients, leading to as precise histological diagnosis in 30 cases. No complications have been noted, except for transient neurological deterioration in two cases, due to local edema. Hemorrhage have not been observed. The topographical precision of the method was verified by the injection of lcc of air followed by a post-biopsy CT scan. This technique seems particularly valuable for the diagnosis of deep or wide spread hemispheric tumors, non indicated for open surgery.