Controlled general anaesthesia for subthalamic nucleus stimulation in Parkinson's disease.

OBJECTIVE: To report the short-term (1 year) and long-term (5 years) outcome of patients with Parkinson's disease (PD) with subthalamic nucleus (STN) stimulation operated upon under controlled general anaesthesia (GA). METHODS: 213 consecutive patients with PD were included between January 2000 and March 2009 and operated upon under a particular type of GA with close control of the level of sedation allowing intraoperative recordings. 188 patients were assessed 1 year postoperatively. 65 patients also completed the long-term observation period and were evaluated 5 years postoperatively. RESULTS: The Unified PD Rating Scale III score in the 'Off drug--On stim' condition was improved at 1 year and 5 years by 61% and 37%, respectively, (p<0.001). Motor complications decreased at short-term and long-term by 68% and 65%, respectively, for dyskinesia and by 52% and 48%, respectively, for fluctuations, (p<0.001). Dopaminergic treatment could also be reduced at short-term and long-term by 46% and 49%, respectively (p<0.001). There was no significant modification of mood and cognition assessments (Mattis scale and Beck depression inventory) at 1 year and 5 years. Concerning the main adverse events related to the surgery, we report four haematomas (1.9%) with two deaths (0.9%), eight cases of transient confusion (3.7%) and no epileptic seizure. CONCLUSIONS: Our results confirm that STN stimulation performed under controlled GA is efficient and has similar short-term and long-term motor effects than intervention under local anaesthesia. Furthermore, this specific procedure is not associated with more adverse events. The success of such an intervention requires strict anaesthetic monitoring and accurate STN identification.

[Measurement of intra-oral pressure as a contributor for the understanding of pneumophonic coordination impairment in Parkinsonian dysarthria]. / Contribution de la mesure de la pression intra-orale pour la compréhension des troubles de la coordination pneumophonique dans la dysarthrie parkinsonienne.

INTRODUCTION: Parkinsonian dysarthria can alter oral communication of the patients in the long-term. Subthalamic nucleus (STN) stimulation represents an interesting therapeutic option, although it does not seem to improve axial signs, of which dysarthric speech. The objective of our study was to contribute to the evaluation of STN stimulation effects on speech impairment and in particular on pneumophonic coordination: this latter parameter can be assessed indirectly by evaluating the temporal progression of the intraoral pressure (IOP) during the expiratory phase; thus, IOP represents the transient expression of subglottal pressure (SGP). PATIENTS AND METHOD: Using a dedicated system (EVA2), 20 parkinsonian patients were recorded in ON and OFF STN stimulation conditions in order to evaluate IOP on three measurement points (2nd, 4th and 6th consonants P) during realization of the sentence "Papa ne m'a pas parlé de beau-papa" ("Daddy did not speak to me about daddy-in-law") which corresponds to a breath group. Eleven control subjects were recorded in parallel in order to define reference measurements. RESULTS: STN stimulation improved significantly IOP at the level of the initial measurement points (2nd P and 4th P), with an effect of convergence at the level of the third point (6th P) where the difference between OFF and ON STIM conditions was not significant any more. In addition, the performance of the patients ON STIM remained much lower than that of the control subjects. CONCLUSION: Our results raise the significant concept that IOP measurement can be regarded as a relevant indicator for dysarthria in Parkinson's disease. They also show that the improvement of pneumophonic coordination by STN stimulation is restricted to the initial period of the expiratory phase, confirming again the mitigated and controversial effect of STN stimulation on axial signs.

[Radiosurgery in trigeminal neuralgia: long-term results and influence of operative nuances]. / La radiochirurgie dans le traitement de la névralgie trigéminale : résultats à long terme et influence des nuances techniques.

Stereotactic radiosurgery is an alternative to conventional surgery for the treatment of trigeminal neuralgia. To better define the safety of radiosurgery and optimal technical choices, we reviewed our patient records and the literature. A total of 334 patients presenting with trigeminal neuralgia were treated between December 1992 and September 2005. A minimum of 1 year of follow-up was available for 262 patients. The mean age was 68 years (range: 30-90); 128 patients were male and 134 female. A neurovascular conflict was clearly visualized on MRI in 167 patients. Twenty-one had a past history of multiple sclerosis and 110 had already received conventional surgical treatment for trigeminal neuralgia. The intervention consisted of gamma knife radiosurgery (GKS) to the retrogasserian cisternal portion of the Vth cranial nerve. The median maximal dose used was 85Gy (range: 70-90). Actuarial curves show a plateau at 5 years for both the risk of hypoesthesia and recurrence. At 5 years, 58% of the patients remain pain-free and 83% have no trigeminal nerve disturbance. The median delay for pain cessation was 15 days. The initial pain-relief rate was 89%. None of the complications reported for the other techniques were observed. Patient selection (typical versus atypical, age, past surgery, multiple sclerosis) and details of operative technique (maximum dose, volume of nerve treated, target location, etc.) had a major influence on the probability of pain relief and toxicity risk. The details of operative technique are turning out to have a major influence on the clinical results. In our experience, high-dose (80-90Gy) retrogasserian (7-8mm from the brainstem) GKS provides the patient with a better chance of long-term pain relief and a lower risk of trigeminal nerve functional disturbance. GKS applied to the cisternal anterior trigeminal nerve using high doses provided safe and effective treatment for trigeminal neuralgia over the long term.

[Radiosurgery for drug-resistant epilepsies: state of the art, results and perspectives]. / Rôle de la radiochirugie Gamma Knife dans le traitement des épilepsies pharmacorésistantes: situation actuelle, résultats et perspectives.

BACKGROUND: There is growing interest in the use of radiosurgery in epilepsy. We analyzed our experience in this field in an attempt to define the potential of radiosurgery in epileptology. MATERIAL AND METHODS: [corrected] Our local clinical experience (134 patients), accumulated over the last 15 years, mainly includes treatment of temporal lobe epilepsy without space-occupying lesions (59 patients), including 53 with pure MTLE, 61 cases of hypothalamic hamartoma, two cases of callosotomy, and 12 other types of epilepsy. RESULTS: The analysis of our material, as well as other clinical and experimental data, suggest that the use of radiosurgery is beneficial only to patients in whom a strict preoperative definition of the extent of the epileptogenic zone (or network) has been achieved and strict rules of dose planning have been applied. As soon as these principles are not observed, the risk of treatment failure and/or side effects increases dramatically. Long-term outcome data are now available and published for MTLE but not yet for other types of epilepsy. Long-term safety and efficacy in MTLE are comparable to surgical resection but radiosurgery has the advantage of sparing verbal memory in patients operated by Gamma Knife (GK) on the dominant side. In small hamartomas, the efficacy is comparable to microsurgery but with a dramatic reduction in risk. CONCLUSION: The vast amount of clinical materiel and long-term evaluation now support the use of GK surgery in small hypothalamic hamartomas and MTLE when the patient is at risk of verbal memory loss.

Adenosine and neuropathic pain.

Recent studies have reported the possibilities of relieving neuropathic pain by administering adenosine or its analogs. In order to determine if there exists a metabolic anomaly of this nucleoside in patients with neuropathic pain, circulating adenosine levels were compared in three patient groups. The first was composed of individuals suffering from neuropathic pain, the second of patients with nervous system lesions in the absence of pain, and the third was composed of patients suffering from pain resulting from excessive nociception. The adenosine blood levels of these patients were compared to those of a control group. Finally, adenosine in the cerebrospinal fluid (CSF) of some patients was also assayed. The results show that there are reduced levels of blood and CSF adenosine in patients with neuropathic pain. This adenosine deficiency could explain the potential therapeutic effects of administering adenosine or its analogs.

Atypical inflammatory histiocytic tumor of the cerebellum. A histological, immunohistochemical, and ultrastructural study.

We report a primary histiocytic tumor involving the cerebellum. Microscopically, the tumor was composed of nests of pleomorphic cells surrounded by thin vascular septa invaded by lymphocytes. Immunocytochemistry and electron microscopy confirmed the histiocytic origin of the tumor. Although we considered several diagnoses, we ultimately concluded that "atypical inflammatory histiocytic tumor of the cerebellum" best characterized the lesion. This case represents another example of the diversity of histiocytic tumors and shows that they can occur in the central nervous system.

Early and delayed MR and PET changes after selective temporomesial radiosurgery in mesial temporal lobe epilepsy.

We report a patient with medically refractory mesial temporal lobe epilepsy treated by gamma knife radiosurgery. In lieu of a microsurgical procedure, an entorhinoamygdalohippocampectomy was performed with a gamma knife and low marginal doses (25 Gy). The clinical and imaging studies, including CT, MR imaging, 18F-fluorodeoxyglucose positron emission tomography (FDG-PET), and long-term follow-up MR examinations, are reported. The patient has been seizure-free since the day of treatment, with no clinical complications. MR studies accurately depicted the effect on the target structures and the transient secondary changes around them. FDG-PET scans showed decreased metabolism after gamma knife surgery throughout the anteromesial part of the epileptogenic temporal lobe. This metabolic decrease was reversible in the lateral temporal cortex. Our case suggests that gamma knife surgery is a promising tool for use as a minimally invasive approach to the treatment of epilepsy.

Cavernous angiomas and arteriovenous malformations of the spinal epidural space: report of 11 cases.

We have retrospectively studied 11 cases of solitary cavernous and arteriovenous malformations of the spinal epidural space. The acute or subacute onset of symptoms was found in all cases, with a neurological deficit in five cases. A plain x-ray study revealed abnormal calcification in one case. Hyperdensity with no iodine enhancement was found on computed tomographic scans in all cases. Magnetic resonance imaging studies showed ovoid or round lesions with isosignal and gadolinium enhancement on T1-weighted images and hypersignal on T2-weighted images, except in one case with hypersignal on T1 and T2 before the administration of a contrast medium. Four lumbar cases were localized in the posterior vertebral ligament; all the thoracic cases were posterior with foraminal extension. The other cases were anterolateral. The surgical findings revealed a dark vascularized epidural lesion associated in two cases with a localized epidural hematoma. A pathological examination revealed seven cavernous angiomas and four arteriovenous malformations. These arteriovenous malformations were all lumbar, and two of four localized within the posterior ligament. The pathophysiology of these vascular malformations is discussed. In light of the good postoperative prognosis of these lesions, surgical removal is recommended for all the symptomatic cases.

Perioperative lumbar injection of Ringer's lactate solution in chronic subdural hematomas: a series of 100 cases.

A series of 100 patients underwent surgical treatment for chronic subdural hematomas between 1979 and 1987. The procedure consisted of craniectomy with a 30-mm trephine, irrigation and drainage of the hematoma, laceration of the outer and inner membranes, and lumbar intrathecal injection of Ringer's lactate solution for immediate cerebral reexpansion (average injection, 130 ml). This technique gave the following results: 2% mortality, 2% moderate morbidity, and 96% recovery. The recovery of the patients was rapid, and good outcome was achieved in Grade 3 and Grade 4 cases (Markwalder's classification).

Anterior discectomy without fusion for treatment of cervical lateral soft disc extrusion: a follow-up of 120 cases.

One hundred and twenty patients with soft lateral disc herniation underwent surgery by anterior microsurgical discectomy and routine ablation of the posterior longitudinal ligament between 1976 and 1986. The study excluded patients with hard discs and soft disc extrusion with medullary symptoms. In our series 76.6% of patients were men. In 64% of the patients no causative factor was found. All of the patients presented with cervicobrachialgia; 53% also had a motor deficit. In 91.7% a single disc was involved. The last 40 cases were evaluated by computed tomography alone. In 51.5% an extruded disc was found. No permanent postoperative complication was encountered. All patients returned to their previous activities. Fifty patients underwent follow-up radiological evaluation at 1 and 5 years after the intervention and vertebral fusion was observed in 70% of these.

Pineal region tumors and the role of stereotactic biopsy: review of the mortality, morbidity, and diagnostic rates in 370 cases.

OBJECTIVE: It is classically considered that the morbidity and mortality rates are greater for stereotactic biopsies of pineal region tumors, compared with tumors in other regions. However, to date, the number of cases studied in the literature has been insufficient to evaluate these parameters and compare them with the morbidity and mortality rates for stereotactic biopsies of tumors located elsewhere. METHODS: With the aim of evaluating these parameters, we reviewed 370 stereotactic biopsies of pineal region tumors, from 15 French neurosurgical centers. We statistically verified the absence of heterogeneity of the different French centers with regard to diagnostic, mortality, and morbidity rates. In contrast, statistical heterogeneity was clearly seen for the large stereotactic biopsy series (for all tumor locations) in the literature. RESULTS: The mortality rate was 1.3% (5 patients of 370), and 3 patients suffered severe neurological complications. This study is the first to clearly demonstrate that the mortality, morbidity, and diagnostic rates for stereotactic biopsies are not different in the pineal region. CONCLUSION: Our conclusion is that stereotactic biopsy must remain a main diagnostic modality for tumors of the pineal region.

Gamma knife surgery for mesial temporal lobe epilepsy.

OBJECT: Gamma knife radiosurgery (GKS) allows precise and complete destruction of chosen target structures containing healthy and/or pathological cells, without causing significant radiation damage to adjacent tissues. Almost all the well-documented cases of radiosurgery for epilepsy are for epilepsies associated with space-occupying lesions. These results prompted the authors to investigate the use of radiosurgery as a new way of treating epilepsy not associated with space-occupying lesions. METHODS: To evaluate this new method, 25 patients who presented with drug-resistant mesial temporal lobe epilepsy (MTLE) were selected. A follow up of more than 24 months is now available for 16 patients. The preoperative evaluation was performed as it usually is in patients selected for microsurgery for MTLE. In lieu of microsurgery, the treatment of amygdalohippocampal structures was performed using GKS. Thirteen (81%) of these 16 patients are seizure free, and two are improved. The median latent interval from GKS to seizure cessation was 10.5 months (range 6-21 months). Two patients were immediately seizure free. The median latency in aura cessation was 15.5 months (range 9-22 months). Morphological changes on magnetic resonance imaging were visible at 11 months (median) after GKS (range 7-22 months). During the onset period of these radiological changes, three patients experienced headache associated, in two cases, with nausea and vomiting. In these three patients the signs resolved immediately after prescription of low doses of steroids. No cases of permanent neurological deficit (except three cases of nonsymptomatic visual field deficit), or morbidity, or mortality were observed. CONCLUSIONS: This initial experience indicates that there is short- to middle-term efficiency and safety when using GKS to treat MTLE. Further long-term follow up is required. It seems that the introduction of GKS into epilepsy treatment can reduce the invasiveness and morbidity.

Gamma knife radiosurgery in the management of cavernous sinus meningiomas.

OBJECT: The authors sought to assess the functional tolerance and tumor control rate of cavernous sinus meningiomas treated by gamma knife radiosurgery (GKS). METHODS: Between July 1992 and October 1998, 92 patients harboring benign cavernous sinus meningiomas underwent GKS. The present study is concerned with the first 80 consecutive patients (63 women and 17 men). Gamma knife radiosurgery was performed as an alternative to surgical removal in 50 cases and as an adjuvant to microsurgery in 30 cases. The mean patient age was 49 years (range 6-71 years). The mean tumor volume was 5.8 cm3 (range 0.9-18.6 cm3). On magnetic resonance (MR) imaging the tumor was confined in 66 cases and extensive in 14 cases. The mean prescription dose was 28 Gy (range 12-50 Gy), delivered with an average of eight isocenters (range two-18). The median peripheral isodose was 50% (range 30-70%). Patients were evaluated at 6 months, and at 1, 2, 3, 5, and 7 years after GKS. The median follow-up period was 30.5 months (range 12-79 months). Tumor stabilization after GKS was noted in 51 patients, tumor shrinkage in 25 patients, and enlargement in four patients requiring surgical removal in two cases. The 5-year actuarial progression-free survival was 92.8%. No new oculomotor deficit was observed. Among the 54 patients with oculomotor nerve deficits, 15 improved, eight recovered, and one worsened. Among the 13 patients with trigeminal neuralgia, one worsened (contemporary of tumor growing), five remained unchanged, four improved, and three recovered. In a patient with a remnant surrounding the optic nerve and preoperative low vision (3/10) the decision was to treat the lesion and deliberately sacrifice the residual visual acuity. Only one transient unexpected optic neuropathy has been observed. One case of delayed intracavernous carotid artery occlusion occurred 3 months after GKS, without permanent deficit. Another patient presented with partial complex seizures 18 months after GKS. All cases of tumor growth and neurological deficits observed after GKS occurred before the use of GammaPlan. Since the initiation of systematic use of stereotactic MR imaging and computer-assisted modern dose planning, no more side effects or cases of tumor growth have occurred. CONCLUSIONS: Gamma knife radiosurgery was found to be an effective low morbidity-related tool for the treatment of cavernous sinus meningioma. In a significant number of patients, oculomotor functional restoration was observed. The treatment appears to be an alternative to surgical removal of confined enclosed cavernous sinus meningioma and should be proposed as an adjuvant to surgery in case of extensive meningiomas.

Long-term outcome after gamma knife surgery for secondary trigeminal neuralgia.

OBJECT: This study was directed to evaluate the potential role of gamma knife surgery (GKS) in the treatment of secondary trigeminal neuralgia (TN). The authors have identified three anatomicoclinical types of secondary TN requiring different radiosurgical approaches. METHODS: Pain control was retrospectively analyzed in a population of patients harboring tumors of the middle or posterior fossa that involved the trigeminal nerve pathway. This series included 53 patients (39 women and 14 men) treated using GKS between July 1992 and June 1997. The median follow-up period was 55 months. Treatment strategies differed according to lesion type, topography, and size, as well as visibility of the fifth cranial nerve in the prepontine cistern. Three different treatment groups were established. When the primary goal was treatment of the lesion (Group IV, 46 patients) we obtained pain cessation in 79.5% of cases. In some patients in whom GKS was not indicated for treatment of the lesion, TN was treated by targeting the fifth nerve directly in the prepontine cistern if visible (Group II, three patients) or in the part of the lesion including this nerve if the nerve root could not be identified (Group III, four patients). No deaths and no radiosurgically induced adverse effects were observed, but in two cases there was slight hypesthesia (Group IV). The neuropathic component of the facial pain appeared to be poorly sensitive to radiosurgery. At the last follow-up examination, six patients (13.3%) exhibited recurrent pain, which was complete in four cases (8.8%) and partial in two (4.4%). CONCLUSIONS: The results of GKS regarding facial pain control are very similar to those achieved by microsurgery according to series published in the literature. Nevertheless, the low rate of morbidity and the greater comfort afforded the patient render GKS safer and thus more attractive.

Stereotactic radiosurgery for trigeminal neuralgia: a multiinstitutional study using the gamma unit.

A multiinstitutional study was conducted to evaluate the technique, dose-selection parameters, and results of gamma knife stereotactic radiosurgery in the management of trigeminal neuralgia. Fifty patients at five centers underwent radio-surgery performed with a single 4-mm isocenter targeted at the nerve root entry zone. Thirty-two patients had undergone prior surgery, and the mean number of procedures that had been performed was 2.8 (range 1-7). The target dose of the radiosurgery used in the current study varied from 60 to 90 Gy. The median follow-up period after radiosurgery was 18 months (range 11-36 months). Twenty-nine patients (58%) responded with excellent control (pain free), 18 (36%) obtained good control (50%-90% relief), and three (6%) experienced treatment failure. The median time to pain relief was 1 month (range 1 day-6.7 months). Responses remained consistent for up to 3 years postradiosurgery in all cases except three (6%) in which the patients had pain recurrence at 5, 7, and 10 months. At 2 years, 54% of patients were pain free and 88% had 50% to 100% relief. A maximum radiosurgical dose of 70 Gy or greater was associated with a significantly greater chance of complete pain relief (72% vs. 9%, p = 0.0003). Three patients (6%) developed increased facial paresthesia after radiosurgery, which resolved totally in one case and improved in another. No patient developed other deficits or deafferentation pain. The proximal trigeminal nerve and root entry zone, which is well defined on magnetic resonance imaging, is an appropriate anatomical target for radiosurgery. Radiosurgery using the gamma unit is an additional effective surgical approach for the management of medically or surgically refractory trigeminal neuralgia. A longer-term follow-up review is warranted.

Small conductance calcium-activated K+ channels, SkCa, but not voltage-gated K+ (Kv) channels, are implicated in the antinociception induced by CGS21680, a A2A adenosine receptor agonist.

It has been shown that A2A adenosine receptors are implicated in pain modulation. The precise mechanism by which activation of A2A receptors produces analgesic effects, however, remains unclear. The aim of this study was to investigate the possible involvement of apamin-sensitive calcium-activated potassium channels (SKCa) and voltage-gated potassium (Kv) channels in A2A receptor activation-induced analgesic effects. Using mice, we evaluated the influence of apamin, a non specific blocker of SKCa channels, Lei-Dab7 (an analog of scorpion Leiurotoxin), a selective blocker of SKCa2 channels, and kaliotoxin (KTX) a Kv channel blocker, on the CGS 21680 (A2A adenosine receptor agonist)-induced increases in hot plate and tail pinch latencies. All drugs were injected in mice via the intracerebroventricular route. We found that apamin and Lei-Dab7, but not KTX, reduced antinociception produced by CGS21680 on the hot plate and tail pinch tests in a dose dependent manner. Lei-Dab 7 was more potent than apamin in this regard. We conclude that SKCa but not Kv channels are implicated in CGS 21680-induced antinociception.

Radiosurgery for trigeminal neuralgia and epilepsy.

The role of Gamma Knife surgery in the field of functional surgery recently has evolved dramatically. For treatment of trigeminal neuralgia, Gamma Knife surgery is the least invasive procedure, with a low rate of hypesthesia. If a rate of complete relief similar to that of other surgical techniques could be achieved, this approach will become one of the main techniques used to treat the disease initially. The authors present their experience with a group of 16 patients with mesial temporal lobe epilepsy who have been treated successfully (15 completely seizure-free and 1 with rare, nondisabling seizures) without significant complication. After additional follow-up to demonstrate the absence of long-term consequences, this fascinating new approach could change epilepsy surgery practice dramatically.

The role of gamma knife surgery in the treatment of severe epilepsies.

There is a strong rationale for investigation of the role of gamma knife radiosurgery in the treatment of medically intractable epilepsy. To explore this potential application, the current outcome and morbidity associated with established microsurgical treatment, as well as the associated advantages and disadvantages of open surgery, are reviewed. The preliminary evidence in support of radiosurgical treatment and the recent experience with gamma knife treatment for epilepsy associated with mesial temporal sclerosis, cavernous angioma, and hypothalamic hamartoma or other lesions are presented. The strengths and limitations of this application are discussed, and the challenges facing both microsurgical and radiosurgical approaches are considered. Gamma knife surgery can be a main approach among others in the armamentarium of epilepsy surgery. Although the benefits of comfort and reduced invasivity can be clearly perceived, larger series and long-term follow up are still required in order to evaluate the future of this particular surgical approach.

[Radiosurgery of brain metastasis]. / Radiochirurgie des métastases cérébrales.

Radiosurgery has recently provided an alternative to conventional therapy for the treatment of brain metastases. This non-invasive technique delivers a single large fraction of ionizing radiation to a well-defined small intracranial target as brain metastases. After a computerized tomography (CT) with stereotactic frame in place for tumor localization, a dosimetric study was performed. The sharp dose gradient of radiation reduces the dose to the surrounding normal structures at a minimal level (> 10%). The prescribed dose at the periphery of the lesion varies from 8 to 27 Gy with a combined whole brain irradiation and from 20 to 35 Gy without any irradiation. Radiosurgery has been reported to be highly efficacious with a local control rate of 86% (not increased size without local recurrence). Brain metastases from melanoma and renal carcinoma are usually resistant to conventional irradiation and are highly sensitive with this technique. The morbidity is very low with a symptomatic edema rate of 5-10% at 2 years, resolved with corticosteroids. A radiation necrosis has been reported in less than 5% of cases. The patients with a good performance status, without any extracranial metastasis and with a solitary brain metastases have presented the best survival rate. New brain metastases have occurred in 20 to 30% of the cases during the follow-up. Eleven to 25% of patients died from their intracranial disease and the others from the extracranial evolution of the cancer. The median survival was still poor, ranging from 8 to 12 months. Radiosurgery is a good choice for surgically inaccessible and recurrent tumors. It represents an alternative to the neurosurgery with or without whole brain irradiation, taking into account different prognostic factors and morbidity rate. The local control and the survival rates without neurologic symptom should be considered the major endpoints of different ongoing randomized studies for evaluating the role of the radiosurgery.

[Gamma knife radiosurgery for the treatment of severe epilepsy]. / Rôle de la radiochirurgie Gamma Knife dans le traitement des épilepsies sévères.

The Gamma Knife radiosurgery is a neurosurgical approach having now demonstrated well its efficiency, its low morbidity and its comfort in the treatment of numerous neurosurgical disorders. These advantages of this type of intervention make it a method of great interest in functional neurosurgery and quite particularly in surgery of epilepsy. French experience is a pionner one in this domain. If for several years the positive evolution of the epilepsy associated to brain lesions had been noticed after the Gamma Knife radiosurgical treatment, the use of this approach in surgery of the epilepsy is systematically estimated since 1993. Data are today available concerning the surgical treatment of the epilepsies originating in temporomesiale area without occupying process, epilepsies associated to hypothalamic hamartomas and epilepsies associated to cavernous angiomas or to low grade gliomas. The quality of the epileptological result obtained in these various indications associated to a very reduced morbidity lets suppose that the Gamma Knife radiosurgery could indeed have tomorrow a place within the sample group of surgical approaches dedicated to the treatment of severe epilepsies. However, a larger number of treated patients and a more prolonged follow-up remains necessary to estimate in a more definitive way this approach.