[Atypical location of a solitary fibrous tumor in the fourth ventricle].
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Adult↗
Biomedical subjects
J P Sichez
Publications and source records attributed to J P Sichez.
A new device for electrical stimulation mapping of the brainstem and spinal cord.
With the goal to minimize the risk of sequelae in brainstem and spinal cord surgery, methods of intraoperative mapping using direct electrical stimulations were developed in the last decade. However, the current was delivered with a monopolar stimulator with risk of a spreading, or using a bipolar probe or silicone strip with 5 mm of precision. To improve the accuracy and easiness of the mapping, the authors describe in this work a new device with the following characteristics: bipolar probe without current diffusion; reduction of the space tips to 2 mm; building of a bent handle, improving the field of view and ergonomics under the microscope. This device has been used successfully in 6 consecutive patients, 4 harboring a brainstem lesion and 2 with a spinal cord tumor. This new device allows the surgeon to perform repetitive intraoperative brainstem and spinal cord electrical mapping under the microscope in a very simple, quick and accurate way all along the resection. Improvement of such a mapping first minimizes the risk of sequelae, second optimizes the quality of resection, and third may also give a prognostic value concerning the changes of postsurgical recovery in case of a preoperative deficit.
Adult↗
[Surgery of the central nervous system: value of preoperative functional brain mapping by direct electric stimulation].
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Adult↗
Parenchymal pineal tumors: a clinicopathological study of 76 cases.
PURPOSE: The aim of this study was to identify factors that could lead to optimization of the management of pineal parenchymal tumors (PPT) which remains equivocal and controversial. METHODS AND MATERIALS: In order to determine factors that influence PPT prognosis, a series of 76 consecutive patients from 12 European centers with histologically proven tumors was retrospectively reviewed. The clinical records and material for histologic review were available in all cases. Follow-up was achieved in 90% of cases. RESULTS: According to WHO classification, there were 19 pineocytomas, 28 intermediate and mixed PPT, and 29 pineoblastomas. According to a four-grade institutional classification, there were 11 Grade 1, 27 Grade 2, 20 Grade 3, and 18 Grade 4. Surgical resection was attempted in 44 patients, whereas 30 had biopsy only. In one case, diagnosis was made at autopsy and in another on spinal deposits. Forty-four patients were irradiated following surgery, 15 patients received chemotherapy. Forty-one patients were alive (median follow-up: 85 months); 9 patients died perioperatively; 26 patients relapsed. Univariate analysis showed a good outcome correlated with age above 20 years, tumor diameter less than 25 mm, and low-grade histology. Multivariate analysis confirmed histology and tumor volume to be significant independent prognostic factors. The extent of surgery and radiotherapy had no clear influence on survival. CONCLUSIONS: This review highlights the prognostic features of PPT and may help to determine treatment strategies based on radiologic and pathologic characteristics.
Adolescent↗
The insular lobe: physiopathological and surgical considerations.
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.
Adult↗
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↗
Intraoperative unmasking of brain redundant motor sites during resection of a precentral angioma: evidence using direct cortical stimulation.
We report the first observation of real-time intraoperative evidence of a retrocentral redistribution of motor areas with an unmasking of precentral redundant motor sites, before and after, respectively, surgical removal of a precentral arteriovenous malformation using direct electrical stimulation. This study shows large-scale plasticity of the motor function behind the central sulcus as the result of an arteriovenous malformation, the brain's ability to effect short-term unmasking of precentral motor sites after arteriovenous malformation resection, and the existence of redundant precentral and postcentral motor areas for the same movement, suggesting that the central sulcus does not simply divide motor and sensory functions.
Adult↗
Early rebleeding from intracranial dural arteriovenous fistulas: report of 20 cases and review of the literature.
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.
Adult↗
[Preoperative direct cortical and sub-cortical electric stimulation during cerebral surgery in functional areas].
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.
Adult↗
Three-dimensional computerized tomography in the presurgical evaluation of Chiari malformations.
Malformations of the cranio-cervical junction represent a complex entity, comprising neuro-meningeal and bone anomalies. Malformations of the central nervous system are nowadays easily explored using magnetic resonance imaging (MRI), while osseous malformations are classically assessed with standard radiographic techniques, which can give only incomplete information, and are often difficult to realize and analyse. We report a retrospective study of 10 patients with a Chiari malformation operated on in our department at La Salpêtrière hospital, between July 1995 and December 1996 (1 man, 9 women; mean of age: 35 years; postoperative median follow-up: 6 months; 70% of improvement and 20% of stabilisation), and we underline the interest of the systematic pre-operative realization of a 3D CT and angio-CT studies of the cranio-cervical junction. This examination offers advantages of: a precise analysis of the more complex osseous malformations; a study of the relationships between vascular and bony structures; a study of the relationships between neuraxis and spinal and cranial structures; and an optimal planning of the surgical procedure, adapted to the anatomical particularities of the patient.
Adolescent↗
Intraoperative direct electrical stimulation of the lamina quadrigemina in a case of a deep tectal cavernoma.
Despite the recent neuro-imaging and microsurgical advances, a high rate of postoperative morbidity still remains in brain stem surgery. We report an original case of cavernous angioma of the right inferior colliculus without extension to the surface, operated on using brain stem electrical stimulations. Peroperative ocular motor responses were obtained, allowing identification of essential neural structures before dissection of the brain stem surface, and accurate definition of the limits between the lesion and functional tissue in depth. Total removal of cavernoma and surrounding gliosis was then performed, with normal postoperative neurological status. As already reported at the cortical level, peroperative direct brain stem stimulations constitute a safe and easy method of functional mapping. A more intensive use of this neurophysiological technique might permit one to extend the indications for brain stem surgery, with minimisation of postoperative morbidity and maximisation of tumour resection.
Brain Mapping↗
Ganglioglioma of the pineal region: case report and review of the literature.
BACKGROUND: Ganglioglioma is a lesion rarely encountered in the pineal region. Only six cases have been published to our knowledge. METHODS AND RESULTS: We present the case of a 38-year-old male suffering from a pineal ganglioglioma that was totally removed by surgery. Histological diagnosis was made by light microscopy using immunostaining for synaptophysin. We review the few radiological and pathological data available in the literature concerning this very rare lesion for which surgery alone provides excellent results. CONCLUSION: The possibility of long term remission obtained by surgery alone and the lack of specificity of clinical and radiological features of ganglioglioma are additional reasons for an aggressive surgical management of pineal tumors when tumor markers and cytopathological examination of the cerebrospinal fluid are not contributive.
Adult↗
Early radiologically proven rebleeding from intracranial cavernous angiomas: report of 6 cases and review of the literature.
Although intracranial cavernomas are known to cause haemorrhage, data concerning the frequency, severity and delay of recurrent bleedings are controversial. We report a series of 6 patients with histologically proven cavernoma, presenting with early clinical signs and radiological proof of rebleeding, that is occurring in the first month after initial overt haemorrhage. These 6 cases have been selected from a series of 142 patients seen between 1980 and 1995 in our department with cavernous angiomas or so-called AOVMs, of whom 93 presented with clinical symptoms of haemorrhage (34 patients presented symptoms of one or more rebleeding, but only 6 had radiological proof). All patients suffered neurological worsening due to the rebleeding, with an increase of the size of the haematoma on the CT scan. Five MRIs were performed at the acute stage: 3 showed evidence of cavernoma (60%). All patients underwent surgery at the acute stage of the rebleeding, with 5 improvements and 1 stabilization. A cavernous angioma was found in 5 cases at first surgery, but a further operation was necessary in the last patient to find and remove the cavernoma, after a second rebleeding following the first intervention. Our series reveals a high frequency of rebleeding after a first intracranial haemorrhage from a cavernous angioma, and highlights the precocity of such rebleedings. Therefore, we advocate early aggressive surgical management: in cases of cavernoma revealed by a first clinical overt haemorrhage, when there is strong radiological suspicion at the acute stage; and in all cases of rebleeding, even without radiological evidence of malformation, in the absence of vascular risk factors. Surgical indication must be discussed in particular cases of cavernomas of the brain stem when neither the haematoma nor the cavernoma reach the surface, and in deep supratentorial cavernomas, when the neurological status is good, because of the therapeutic risk.
Adolescent↗
MRI evaluation of sacral cysts.
Sacral cysts or intrasacral sacral meningeal cysts constitute a well-defined entity. Their clinical presentation is protean. Few cases have been reported concerning their MR aspects. From a series of six patients, the authors present the MR images. MRI is the examination of choice to demonstrate their liquid content. MRI provides a good evaluation of the lesion, and sagittal images show the intrasacral development. MRI scan appears to be superior to CT scan.
Adult↗
Thoracic disc herniation and spinal cord compression. MRI and gadolinium-enhancement.
The authors present a study of 6 patients aimed at assessing the role of Magnetic Resonance Imaging with gadolinium-enhancement in the diagnosis of thoracic disc herniation. The results of MRI were compared with the findings of computed tomography, myelography and surgery. In two patients, the signal from the herniated disc was so low on all sequences that thoracic disc herniation was diagnosed only on the mass effect on the cord. The anterior longitudinal epidural venous plexus (AEVP) is displaced posteriorly and thickened in case of thoracic disc herniation. Gadolinium-enhancement of AEVP was marked in these conditions, giving a "tent-like" round configuration, or "lifted band" appearance. The exact volume and mass effect of the thoracic disc herniation were assessed by T1-enhanced images on the sagittal and axial planes.
Adult↗
[Severe multiple injuries. Strategy and results. Experience at the Hôpital de la Pitié in 1988 and 1989].
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)
Emergencies↗
[Unruptured intracranial saccular aneurysms less than 20 mm in diameter in adults. Radical surgery in 89 cases].
Between 1972 and 1989, 131 unruptured intracranial saccular aneurysms were clipped in the Neurosurgical Department of La Pitié Hospital, Paris. Only 89 of these are considered here, the remaining 42 aneurysms having been discovered and clipped during surgery for a ruptured aneurysm. All isolated unruptured aneurysms were detected by angiography, computerized tomography or magnetic resonance imaging. Twenty out of the 89 aneurysms were asymptomatic ("incidental") while 69 were accompanied by clinical symptoms indicating radiological examination. It is generally accepted that in ruptured aneurysms the mortality rate during 3 days following the rupture is about 50 percent, and for this reason many neurosurgeons are in favour of unruptured aneurysms being treated either by open surgery with clipping of the aneurysmal neck or by inserting a balloon into the aneurysmal sac. The results obtained in 377 published cases, including ours, justify this approach: no recurrent bleeding was observed after open surgery and the mortality rate was nil when the contra-indications of surgery were respected. There was a permanent morbidity of less than 2 per cent directly related to the surgeon's experience.
Adult↗
Haemostatic clips and clamps used in surgical neurology with special reference to non ferro magnetic Phynox spring clips by Aesculap.
This paper concerns the historical developments and technical properties of haemostatic devices used in neurosurgery with the exception of coagulation. Therefore there are described haemostatic clips designed for the scalp, clips used on arteries and veins, a clamp for the reduction of the carotid diameter in the neck, and a clamp for closing the venous dural sinuses. Special reference will be made regarding non ferro magnetic Phynox clips by Aesculap.
Hemostasis, Surgical↗