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.

The role of Gamma Knife radiosurgery in the treatment of pineal parenchymal tumours.

OBJECT: The aim of this study was to document the possible role of Gamma Knife radiosurgery, suitable for the treatment of deep and well limited tumors, in the management of pineal parenchymal tumors (PPT). POPULATION AND METHODS: We reviewed retrospectively a series of 13 patients with PPT treated by Gamma Knife radiosurgery during 16 procedures. Mean age was 31 (range 10 to 74). Eight patients had pineocytomas (61.5%), and 5 had pineoblastomas (38.5%). Radiosurgery was performed alone in 6 cases, after partial microsurgical resection in 3 cases, in association with chemotherapy in 3 cases and following conventional fractionated radiotherapy in 1 case. The marginal dose to these tumors ranged from 11 to 20 Gy (mean 15 Gy). RESULTS: With a mean follow-up of 34 months (range 6 to 88), all tumors responded to treatment and disappeared or ceased growing. Two patients with pineoblastoma had tumor size progression out of the initial target requiring several radiosurgery procedures. At the end of the follow-up period, 10 out of 12 patients were alive. Two patients with pineoblastoma died because of carcinomatous meningitis or tumor size progression. We observed no mortality or major morbidity related to radiosurgery. CONCLUSION: This study confirms that radiosurgery can be an effective and safe primary treatment modality for patients with pineocytomas. It should have a role in multimodality therapy which includes microsurgical resection, fractionated radiotherapy and chemotherapy for the management of malignant pineal tumors.

Temozolomide in combination with BCNU before and after radiotherapy in patients with inoperable newly diagnosed glioblastoma multiforme.

BACKGROUND: The aim of this study was to evaluate the efficacy and safety of carmustine (BCNU) in combination with temozolomide as first-line chemotherapy before and after radiotherapy (RT) in patients with inoperable, newly diagnosed glioblastoma multiforme (GBM). PATIENTS AND METHODS: Forty patients were treated with BCNU (150 mg/m2) on day 1 and temozolomide (110 mg/m2/day) on days 1 through 5 of each 42-day cycle for up to four cycles prior to conventional RT (2 Gy fractions to a total of 60 Gy). After RT, BCNU + temozolomide was administered for four additional cycles or until progression. The primary end point was response rate; secondary end points included progression-free survival (PFS); overall survival (OS) and safety. RESULTS: Sixty per cent of patients completed four cycles of neo-adjuvant BCNU + temozolomide. Objective response rate (intention-to-treat) was 42.5% (95% confidence interval 27% to 58%), including two (5%) complete and 15 (37.5%) partial responses. In the eligible population (n=37) the objective response rate was 46%. Nine (24%) patients had stable disease and 14 (35%) had progressive disease. Median PFS and OS were 7.4 and 12.7 months, respectively. Age was the only significant prognostic factor and tumor location (lobar versus multifocal versus corpus callosum) showed a trend. Grade 3-4 toxicities included thrombocytopenia (n=11) and neutropenia (n=7) for both pre- and post-RT chemotherapy. Four patients required platelet transfusions. No patient discontinued treatment because of toxicity. CONCLUSIONS: The combination of BCNU plus temozolomide as neo-adjuvant therapy in inoperable GBM exhibited promising activity with a good safety profile and warrants further evaluation.

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.

[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.

[Preservation of hearing function in the radiosurgical treatment of unilateral vestibular schwannomas. Preliminary results]. / Préservation de la fonctionnalité auditive dans le traitement radiochirurgical des schwannomes vestibulaires unilatéraux. Résultats préliminaires.

INTRODUCTION: Preservation of functional hearing can be now attempted during the surgical treatment of a vestibular schwannomas. The probability of functional hearing preservation for each of the neurosurgical approaches is currently under evaluation. We report here a preliminary evaluation of our radiosurgical experience. MATERIAL AND METHOD: In Marseilles, we performed 800 gamma-knife procedures for cochleovestibular schwannomas by between July 1992 and December 2000. These patients were evaluated systematically according to a prospective methodology. We report here the study of the population of 211 patients with unilateral schwannoma and a functional preoperative hearing (Gardner and Robertson 1 or 2) treated as first intention, with a follow-up longer than two years. RESULTS: Hearing was improved with the radiosurgery in 3% of cases with a average gain of 10 decibels. Average loss in decibel on the four main frequencies (500, 1,000, 2,000, 4,000 Hz) was 17 dB. The probability of functional hearing preservation with radio surgery was high: 73%. However, this probability depended on numerous factors related to the patient and to the "operative technique". The main parameters of predictability were limited preoperative tonal loss, Gardner and Robertson stage 1 (versus 2), multiisocentric planning, peripheral dose lower than 13 Gy. So a Gardner and Robertson stage 1 intracanalicular tumor treated in accordance with "the state of the art" with a gamma-knife and a marginal dose inferior to 13 Gy has a probability of functional conservation at 2 years greater than 95%. CONCLUSION: Our results are preliminary and they require the confirmation of a more extensive and more prolonged follow-up. However, the large size of this population and the systematic methodology should help us in determining more precisely the place of radiosurgery and especially to better inform the patients of their chances of hearing preservation according to their individual risk profile.

[Gamma-knife radiosurgery for brainstem arteriovenous malformations. Preliminary results]. / Traitement radiochirurgical gamma-knife des malformations artério-veineuses du tronc cérébral. Résultats préliminaires.

BACKGROUND AND PURPOSE: Microsurgical resection have the advantage to be immediately effective according to bleeding risk and is the reference treatment for cerebral arteriovenous malformations. For cerebral arteriovenous malformations located in the brainstem gamma-knife radiosurgery due to its low invasivity is classically a first line treatment. We reviewed the Marseilles experience to assess the efficacy and safety of gamma-knife radiosurgery for brain stem arteriovenous malformations. METHODS: We analyzed retrospectively data of 45 patients with an arteriovenous malformation located in the brain stem treated in Marseilles by gamma-knife radiosurgery by between 07/92 and 12/99. Mean age was 42 years, there were 5 children. Arteriovenous malformations were located in the pons or midbrain for the majority of the patients. Intraaxial lesion was found in 82% of patients. Hemorrhage prior to radiosurgery occurred in 75% of the patients. Gamma-knife procedure was the first treatment of the arteriovenous malformations for 29 patients (65%); previous surgery was performed in 34 patients (15%). Mean nidus volume was 550 mm(3) (32-14 196 mm(3)). Mean margin dose was of 23 Gy (range 15-30 Gy). Follow up was available for 25 patients (mean 18 months). RESULTS: One patient presented a transient worsening of his neurological status, and 2 patients developed a fixed deficit. Two patients underwent rebleeding at an interval of 12 to 36 months after the gamma-knife procedure. At last angiographic follow-up (13 patients), the obliteration rate was 82% of the arteriovenous malformations. A second procedure was proposed to a patient with only partial occlusion at 3 years. CONCLUSIONS: Gamma-knife radiosurgery can achieve good obliteration rate of brain stem arteriovenous malformations with low morbidity and may be a valuable first-choice therapy for such arteriovenous malformations. A larger population and longer follow up are mandatory in order to confirm these preliminary results.

[Surgical removal of radio-induced lesions after radiosurgery of cerebral arteriovenous malformations]. / La chirurgie des lésions radio-induites après irradiation des malformations artErio-veineuses cérébrales.

Radioinduced lesions after radiosurgery of cerebral arteriovenous malformations may be associated with an increased signal on T2-weighted and gadolinium enhancement on T1-weighted MR images. They do not have necessarily a poor prognosis. These lesions are mostly asymptomatic. But in a few cases they can be associated with severe clinical symptoms which can become corticodependant or corticoresistant. We present the 5 cases of such cerebral arteriovenous malformations treated by radiosurgery, out of our series of 705 patients. The removal was easier than that of untreated cerebral arteriovenous malformations, and led to a complete recovery of symptoms and progressive decrease of imaging abnormalities. Such surgery should be proposed in case of symptomatic radioinduced lesions which fail to respond to steroids.

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.

[Neurofibromatosis type 2. Preliminary results of gamma knife radiosurgery of vestibular schwannomas]. / Neurofibromatose de type 2. Résultats préliminaires de la radiochirurgie gamma knife des schwannomes vestibulaires.

BACKGROUND AND PURPOSE: The aim of this study was to assess tolerance and efficacy of gamma knife radiosurgery on vestibular schwannomas for patients affected with neurofibromatosis type 2. METHODS: Between July 1992 and December 1997, a gamma knife procedure was performed on 35 vestibular schwannomas affecting 27 patients (12 females and 15 males, mean age=27 years-old, range: 14-65). Fifteen of the patients were included in the Wishart subtype (severe form) and 12 patients in the Gardner subtype (mild form). This group of 27 patients represented 8,2% of the total group of vestibular schwannomas radiosurgically treated by our team. The mean tumor volume was 4,000 mm(3) (range: 400-14,400 mm(3)) and staging according to Koos classification was 9 stage 2 tumors (extension in the cerebellopontine angle), 19 stage 3 tumors (in contact with the brain stem or cerebellum) and 7 stage 4 tumors (compression of axial structures). The delivered mean marginal dose (50% isodose) was 13 Gy (range: 10-18 Gy). After the treatment, the mean clinical and radiological follow-up was 32 months (range: 6-70). RESULTS: Twenty six (74%) of the treated tumors were controlled by the treatment (15 stabilizations and 11 regressions of the tumor volume) at last follow-up. One microsurgical removal was required in a growing stage 4 tumor and in 2 cases of growing stage 3 tumors. Three post-radiosurgical facial nerve deficits (9%) were observed, 2 of them were transient. According to the Gardner and Robertson classification, classes I (good) and II (serviceable) hearing were preserved at last follow-up in 57% of the patients having the same hearing level prior to the gamma knife. CONCLUSIONS: Our experience confirms that tolerance of gamma knife radiosurgery compares favorably with microsurgery of bilateral vestibular schwannomas. This treatment should be restricted to small and medium growing tumors. Treatment strategy of neurofibromatosis type 2 patients should be planned by multidisciplinary experienced teams disposing of the whole armamentarium. A longer follow-up study is required to confirm the current results regarding the tumor control rate.

[Synovial cyst of cervical spine]. / Kyste synovial du rachis cervical.

The synovial cyst is a rare cause of cervical medullar compression. We report on one case of a 74-year-old man hospitalized for electric discharge in the limbs at neck extension. The MRI and CT-scan revealed a posterior extradural cystic lesion at the level of C5-C6. The surgical excision of the lesion resulted in completed recovery. The histological examination confirmed the diagnosis of a synovial cyst. Through this case and the review of the 9 reported cases in the literature, we discuss the etiopathogenesis, diagnosis and treatment of the lower cervical synovial cyst.

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.

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.

Gamma knife surgery for mesial temporal lobe epilepsy.

PURPOSE: Gamma knife radiosurgery (GK) allows precise and complete destruction of chosen target structures containing healthy and/or pathologic cells, without significant concomitant or late radiation damage to adjacent tissues. All the well-documented radiosurgery of epilepsy cases are epilepsies associated with tumors or arteriovenous malformations (AVMs). Results prompted the idea to test radiosurgery as a new way of treating epilepsy without space-occupying lesions. METHODS: To evaluate this new method, we selected seven patients with drug-resistant "mesial temporal lobe epilepsy" (MTLE). The preoperative evaluation program was the one we usually perform for patients selected for microsurgery of TLE [video-EEG analysis of seizures, foramen ovale electrode recording, magnetic resonance imaging (MRI) positron emission tomography (PET) scan, neuropsychological testing]. In lieu of microsurgery, the amygdalohippocampectomy was performed by using GK radiosurgery. RESULTS: Morphologic (MRI) signs of destruction of the target took place at 9 months after GK surgery. Since the treatment day, the first patient has been seizure free. Seizure improvement came more gradually for the following patients, and complete cessation of seizures occurred around the tenth month (range, 8-15 months). MRI shows that the amygdaloentorhinohippocampal target was selectively injured. No significant side effect (except one case of homologous quadrantanopia) or morbidity and no mortality was observed. The current follow-up is 24-61 months, and all (but one) patients are seizure free. CONCLUSIONS: This initial experience proves clearly the short-to middle-term efficiency and safety of GK for MTLE surgery. These results need further confirmation of long-term efficiency, but the introduction of GK surgery into epilepsy surgery can reduce dramatically its invasiveness and morbidity.

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.