Contribution of intraoperative electrical stimulations in surgery of low grade gliomas: a comparative study between two series without (1985-96) and with (1996-2003) functional mapping in the same institution.

OBJECTIVES: Despite the growing use of intraoperative functional mapping in supratentorial low grade glioma (LGG) surgery, few studies have compared series of patients operated on without and with direct electrical stimulation (DES) by the same team. The present study compared the rate of LGG surgery performed in eloquent areas, the rate of postoperative sequelae, and the quality of resection during two consecutive periods in the same department-the first without and the second with the use of intraoperative electrophysiology. METHODS: Between 1985 and 1996, 100 patients harbouring a supratentorial LGG underwent surgery with no functional mapping (S1). Between 1996 and 2003, 122 patients were operated on in the same department for a supratentorial LGG using intraoperative cortico-subcortical DES (S2). RESULTS: Comparison between the two series showed that 35% of LGGs were operated on in eloquent areas in S1 versus 62% in S2 (p<0.0001), with 17% severe permanent deficits in S1 versus 6.5% in S2 (p<0.019). On postoperative MRI, 37% of resections were subtotal and 6% total in S1 versus 50.8% and 25.4%, respectively, in S2 (p<0.001). In both groups, survival was significantly related to the quality of resection. CONCLUSIONS: The results of the present study allow, for the first time, quantification of the contribution of intraoperative DES in LGG resection. Indeed, the use of this method leads to the extension of indications of LGG surgery within eloquent areas; to a decrease in the risk of sequelae; and to improvement of the quality of tumour resection, with an impact on survival.

Intra-operative direct electrical stimulations of the central nervous system: the Salpêtrière experience with 60 patients.

Indications of surgical treatment for lesions in the central nervous system depend on the risk of a definitive neurological deficit, related to the benefit of resection. Detection of eloquent areas is then necessary because of major individual variability. Neuro-imaging functional techniques are in development and are beginning to be efficient for cortical sensorymotor mapping, but still lack sensitivity and specificity for language mapping, and remain unable to give real-time data during surgery and to perform sub-cortical mapping. The more precise and reliable method of functional mapping is represented by the intra-operative direct electrical stimulations (DES), which allow identification and preservation of essential pathways for motricity, sensibility and language, at each level of the central nervous system (cortico-subcortical). We report our experience of DES in the surgery of tumours and vascular malformations located in supra-tentorial brain eloquent areas, with a consecutive series of 60 patients operated on under general or local anaesthesia, from November 1996 until May 1999 in our department at La Salpêtrière Hospital. Presenting symptoms in the 60 subjects (39 males, 21 females, mean age: 45 years) were seizures in 37 cases with normal clinical examination, and mild neurological deficit in 29 cases. MRI showed 60 supra-tentorial brain lesions: 30 precentral, 12 postcentral, 14 perisylvian in the dominant hemisphere, 4 deep-seated. All subjects underwent surgical resection using DES, with supratentorial cortico-subcortical mapping under general anaesthesia for motor areas detection in 43 cases and under local anaesthesia for sensori-motor and/or language tasks in 17 cases. The final histological diagnosis was 44 gliomas (31 low-grade and 13 high-grade), 9 metastasis, 3 cavernomas, 4 arteriovenous malformations (AVM). Resection was total or subtotal in 52 cases (87%) and partial in 8 cases (13%). 29 patients had no post-operative deficit, while the other 31 patients were impaired post-operatively, with in all cases, except 3, a complete recovery delayed for 15 days to 3 months (overall morbidity: 5%). The median follow up was 14 months. Intra-operative direct electrical stimulations of the central nervous system constitute a reliable, precise and safe method, allowing the realization of a functional mapping useful for all operations of lesions located in eloquent areas. This technique allows a minimization of definitive post-operative neurological deficit, and concurrently an improvement in the quality of resection.

[Preoperative direct cortical and sub-cortical electric stimulation during cerebral surgery in functional areas]. / Intérêt des stimulations électriques corticales et sous-corticales directes peropératoires dans la chirurgie cérébrale en zone fonctionnelle.

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.

Bone amyloidoma in a diabetic patient with morbid obesity.

Bone localisations of amyloidosis are rare, usually diffuse and associated with myeloma. We report the case of a patient with massive obesity complicated by diabetes, hypertension, sleep apnea and liver steatosis, who complained of rapidly worsening bilateral polyradiculalgia of the lower limbs. After sufficient weight loss made nuclear magnetic resonance imaging feasible, a spinal tumour was visualised on the 5th lumbar vertebra, extending to soft tissues. Total excision was performed, and pathological studies revealed an amyloid bone tumour with no evidence of myeloma.

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.

[Spinal neurenteric cyst revealed by a cauda equina syndrome]. / Kyste neurentérique spinal révélé par un syndrome du cône terminal.

BACKGROUND: Intraspinal neurenteric cysts are exceptional formations which develop from incomplete separation of the neural tube and the endodermis during the third week of gestation. Symptoms generally appear before the age of 40 years and are associated with spinal malformations. Most neurenteric cysts lie in an extra-spinal position in the lower cervical and upper dorsal spine. We report a case involving the cauda equina with no associated spinal lesion. CASE REPORT: A 63-year-old woman was admitted for low back pain and right L3 radiculalgia triggered by exertion. Urinary disorders had developed over the preceding year. Physical examination found a spinal syndrome with hypoesthesia of the right para-anal area, an atonic anal sphincter and a globular bladder. Plain films showed a widened interpedicular space between L1 and L2 interpreted as the consequence of an expansive intraspinal lesion. Saccoradiculography led to the diagnosis of an intradural lesion involving L1 and L2. At magnetic resonance imaging, the lesion's signal intensity was similar to cerebrospinal fluid on T1 and T2 sequences, deforming the cauda equina and displacing the nerve roots. Surgical resection of the cyst was incomplete due to adherences to several roots and was followed by persistent radiculalgia and sphincter disorders. DISCUSSION: This case demonstrates an exceptional cause of cauda equina syndrome. Fissuration or rupture of the cyst might explain symptom exacerbation following trauma. Magnetic resonance imagining can confirm the cystic nature of the intradural lesion and help guide surgery. Resection is often incomplete with the risk of long-term recurrence.

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.

[Unruptured intracranial saccular aneurysms less than 20 mm in diameter in adults. Radical surgery in 89 cases]. / Les anévrysmes artériels sacculaires intracrâniens non rompus de l'adulte d'un diamètre inférieur à 20 mm. Chirurgie radicale dans 89 cas.

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.

Clipping of the anterior communicating artery to eliminate the contralateral blood supply in supratentorial large AVM of the carotid system. A report of 22 cases.

Large supratentorial arteriovenous malformations (AVMs) of the carotid system are vascularized by the ipsilateral internal carotid artery (ICA) and often, in addition, by the contralateral ICA via the anterior communicating artery (ACoA). In these AVMs we have previously advocated (1981) multiple staged operations with the progressive reduction of the blood stream passing through the AVM. In twenty-two cases, starting in 1983, the reduction of the blood stream into the shunt has been performed as a first operation by placing a clip on the middle of the ACoA through a pterional approach on the opposite side of the AVM before radical open surgery. Results were excellent when considering the control angiogram and the measurement of the blood velocity in the ICA opposite to the AVM side. There were no neurological complications and no mortality.

Classification of supratentorial arteriovenous malformations. A score system for evaluation of operability and surgical strategy based on an analysis of 66 cases.

A classification of arteriovenous malformations (AVM) is proposed, which is based on a retrospective analysis of the records and results of radical operation in 57 patients between 1983 and 1990. It represents the new developments and more recent technical facilities which influence operability of supratentorial AVMs. Predictability of outcome has been settled upon three groups of factors: anatomical, haemodynamical, and clinical. Anatomical factors are localisation and sectorisation of AVM, determination, caliber and straightening of feeding arteries. Haemodynamical factors are volume of AVM and vascular autoregulation, circulatory velocity of red blood cells in the main arteries of the neck and brain tissue cellular steal. Clinical factors are age, previous rupture of AVM, associated diseases and malformations of vital organs. Each of these factor groups has been divided into parameters to which a code number from 0 to 5 according to the severity of the considered parameter has been attributed. When a contraindication for radical surgery was clearly obvious, as, for example, an AVM with extension to the upper brain stem, number 10 was given. This grading has been done by a team of four persons (3 neurosurgeons including the senior author, and one biophysicist). By adding up all code numbers an Operability Score for a given patient is defined by the number of points, with a minimum of 3 and a maximum of 69. In cases with a score higher than 30 surgery is not advisable. A score between 21 and 30 indicates that always several staged operations are required, whilst only some of the patients with a score between 11 and 20 may require two stage operative treatment. The AVM in patients with a score under 10 can always be radically excised in a single stage operation. We have been able to demonstrate that the Operability Score allows a reliable prediction of outcome, thus giving indications and contraindications for surgery, and also for the surgical strategy. Moreover, we have explained why surgery had been refused in 9 additional cases during the same period. The causes of 8 fatalities out of 57 surgical cases are analyzed. These 57 cases represent a systematically explored series of the senior author; his experience is based upon 295 personal AVM cases (1958-1990).

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.

A new haemodynamic factor in cerebral AVM. Aspiration from the venous system demonstrated in two cases of pedonculo-Galen AVM successfully cured by occlusion of the superior longitudinal sinus.

Using a Doppler Mark 500 of ATL we measured the systolic and diastolic velocity of the red cells into the main arteries of the neck (diastolic rate cm/sec) thus approaching the flow in two cases of upper brain stem AVM with a unique drainage into the superior longitudinal sinus through an enlarged vein of Galen and a falcine sinus. Because of the desperate clinical condition of the children it was decided to stop the high blood flow by closing the aspiration coming from the low pressure of the venous system above and below the site of union between the malformation and the superior longitudinal sinus. An intra-operative and post-operative measurement of the diastolic rate showed a radical effect of the closure of the superior longitudinal sinus. The demonstration of this aspirative factor has allowed us to classify an AVM as a haemodynamic push-pull malformation.

Examination of epidural tumors of the spinal canal. Comparative study with magnetic resonance imaging, computed tomography and tomo-myelography.

To delimit the vertical extension of epidural tumors of the spinal canal, tomo-myelography and magnetic resonance imaging (MRI) are the most accurate examinations, MRI appearing to us to be even superior to tomo-myelography. To evaluate precisely the bone extension of tumor growth as compared with the epidural lesions, computed tomography (CT) is more accurate than the other methods mentioned. The choice between these three techniques is of great importance as an aid in selection the best therapeutic method in each particular case.