Mechanisms and therapeutic implications of hypermutation in gliomas.

A high tumour mutational burden (hypermutation) is observed in some gliomas1-5; however, the mechanisms by which hypermutation develops and whether it predicts the response to immunotherapy are poorly understood. Here we comprehensively analyse the molecular determinants of mutational burden and signatures in 10,294 gliomas. We delineate two main pathways to hypermutation: a de novo pathway associated with constitutional defects in DNA polymerase and mismatch repair (MMR) genes, and a more common post-treatment pathway, associated with acquired resistance driven by MMR defects in chemotherapy-sensitive gliomas that recur after treatment with the chemotherapy drug temozolomide. Experimentally, the mutational signature of post-treatment hypermutated gliomas was recapitulated by temozolomide-induced damage in cells with MMR deficiency. MMR-deficient gliomas were characterized by a lack of prominent T cell infiltrates, extensive intratumoral heterogeneity, poor patient survival and a low rate of response to PD-1 blockade. Moreover, although bulk analyses did not detect microsatellite instability in MMR-deficient gliomas, single-cell whole-genome sequencing analysis of post-treatment hypermutated glioma cells identified microsatellite mutations. These results show that chemotherapy can drive the acquisition of hypermutated populations without promoting a response to PD-1 blockade and supports the diagnostic use of mutational burden and signatures in cancer.

Sustained growth of intraosseous hormone-associated meningiomas after cessation of progestin therapy.

Hormone-associated meningiomas tend to stop growing or decrease in size after cessation of certain progestins, mainly cyproterone acetate. We report three observations on the natural history of hormone-associated intraosseous meningiomas, showing in a first patient that those tumors may grow rapidly under nomegestrol. We then demonstrate the sustained growth of intraosseous hormone-associated meningiomas after cessation of promesgestone and nomegestrol, independently of the intracranial portion, which concurrently decreased in size in the second case or was resected at the time of nomegestrol withdrawal in the third case, thus giving new insights into the tumorigenesis mechanisms of hormone-associated intraosseous meningiomas.

Predictive factors of long-term outcomes of surgery for mesial temporal lobe epilepsy associated with hippocampal sclerosis.

OBJECTIVE: The reasons for failure of surgical treatment for mesial temporal lobe epilepsy (MTLE) associated with hippocampal sclerosis (HS) remain unclear. This retrospective study analyzed seizure, cognitive, and psychiatric outcomes, searching for factors associated with seizure relapse or cognitive and psychiatric deterioration after MTLE-HS surgery. METHODS: Seizure, cognitive, and psychiatric outcomes were reviewed after 389 surgeries performed between 1990 and 2015 on patients aged 15-67 years at a tertiary center. Three surgical approaches were used: anterior temporal lobectomy (ATL; n = 209), transcortical selective amygdalohippocampectomy (SAH; n = 144), and transsylvian SAH (n = 36). RESULTS: With an average follow-up of 8.7 years (range = 1.0-25.2), seizure outcome was classified as Engel I in 83.7% and Engel Ia in 57.1% of patients. The histological classification of HS was type 1 for 75.3% of patients, type 2 for 18.7%, and type 3 for 1.2%. Two factors were significantly associated with seizure recurrence: past history of status epilepticus and preoperative intracranial electroencephalographic recording. In contrast, neither HS type, the presence of a dual pathology, nor surgical approach was associated with seizure outcome. Risk of cognitive impairment was 3.12 (95% confidence interval = 1.27-7.70), greater in patients after ATL than in patients after transcortical SAH. A presurgical psychiatric history and postoperative cognitive impairment were associated with poor psychiatric outcome. SIGNIFICANCE: The SAH and ATL approaches have similar beneficial effects on seizure control, whereas transcortical SAH tends to minimize cognitive deterioration after surgery. Variation in postsurgical outcome with the class of HS should be investigated further.

Risk factors for angiographic recurrence after treatment of unruptured intracranial aneurysms: Outcomes from a series of 178 unruptured aneurysms treated by regular coiling or surgery.

BACKGROUND: Long-term stability after intracranial aneurysm exclusion by coiling is still a matter of debate; after surgical clipping little is known. OBJECTIVE: To study outcome after endovascular and surgical treatments for unruptured intracranial aneurysms in terms of short- and long-term angiographic exclusion and risk factors for recanalization. METHODS: From 2004 and 2009, patients treated for unruptured berry intracranial aneurysms by coiling or clipping were reviewed. Aneurysmal exclusion was evaluated using the Roy-Raymond grading scale; immediate clinical outcome was also assessed. Clinical outcome, recanalization, risk factors for recurrence and bleeding during the follow-up period were analyzed by groups; "surgery" and "embolization". RESULTS: From 2004 to 2009, 178 consecutive unruptured aneurysms were treated. The post-procedure angiographic results for "surgery" were: total exclusion 75.6%; residual neck 13.5%; residual aneurysm 10.8%. For "embolization", the results were, respectively: 72%; 20.7%; and 7.2%. Morbidity was 3% for "surgery" and 1.6% for "embolization" (P=0.74); mortality was nil. Mean clinical and angiographic follow-up was 5years. Recurrence rate was of 11.5% for "surgery" vs. 44% for "embolization" with a mean follow-up of 4 and 5.75years, respectively (P=1.10-5). The retreatment rate was 8.4%. Two significant risk factors for recanalization were identified: maximum diameter of the aneurysm sac (P=0.0038) and pericallosal location (P=0.0388). No bleeding event occurred. CONCLUSION: Both techniques are safe. The rate of aneurismal recurrence was significantly higher for embolization, especially for large diameter aneurysms and pericallosal locations. No bleeding event occurred after recanalization.

Evaluation of intra-aortic CT angiography performances for the visualisation of spinal vascular malformations' angioarchitecture.

PURPOSE: To evaluate the performances of the CT-angiography by direct intra-aortic contrast media injection (IA-CTA) for spinal vascular malformations (SVMs)' imaging. MATERIALS AND METHODS: Thirteen patients (8 males, 5 females, mean age: 56 y) with suspected SVM underwent IA-CTAs by direct intra-aortic iodinated contrast media injection (5 cc/s; 100 cc) via an arterial femoral or humeral access. Two independent observers evaluated the angioarchitecture of the SVMs and the visualisation of both the Adamkiewicz artery and the anterior spinal artery. Then a consensus was obtained between the 2 reviewers; the results of the IA-CTA were finally compared with those of the full spinal DSA evaluated in consensus. RESULTS: The IA-CTA was feasible in all cases and depicted the SVM in all except one case (92 %). Interrater agreement was good for the location of the SVMs' level. Intermodality (IA-CTA/DSA) agreement was excellent for the level and side of the shunt point, as well as for the SVM subtype evaluation. In 77 % of the cases, the Adamkiewicz artery was satisfactorily seen at the same time on IA-CTA. CONCLUSION: IA-CTA is a new technique that seems helpful to reach a better understanding of SMVs and may help to tailor more precisely their treatment. KEY POINTS: • IA-CTA is an accurate technique for the SVMs' angioarchitecture analysis • IA-CTA can locate, at the same time, the Adamkiewicz artery (AKA) • IA-CTA may be helpful in elderly patients with troublesome vasculature.

Pallidal activity in myoclonus dystonia correlates with motor signs.

BACKGROUND: Myoclonus-dystonia related to epsilon-sarcoglycan gene mutations is characterized by myoclonic jerks and mild to moderate dystonia. The role of basal ganglia dysfunction in the pathogenesis is unknown. METHODS: Pallidal neuronal activity was recorded in six myoclonus-dystonia and six primary generalized dystonia patients operated on for internal globus pallidus deep brain stimulation. RESULTS: In myoclonus-dystonia patients compared with primary-dystonia patients, internal pallidum neurons showed higher burst frequency, lower mean burst, and pause durations. External pallidum neurons showed higher mean pause frequency. Oscillatory activity was present in 33% and 35% of internal pallidum neurons in myoclonus-dystonia and primary-dystonia patients, respectively, predominantly in the theta frequency band (3-8 Hz). In myoclonus-dystonia patients with more severe myoclonus, internal pallidum neurons exhibited a higher bursting activity with high intraburst frequency and lower oscillatory activity frequency. CONCLUSIONS: Myoclonus-dystonia appears to be related to specific changes in internal pallidum activity, leading to disruption in striato-pallido-thalamo-cortical circuits. © 2015 International Parkinson and Movement Disorder Society.

Patterns of relapse and growth kinetics of surgery- and radiation-refractory meningiomas.

Patients with surgery- and radiation-refractory meningiomas have a poor outcome. Due to our lack of knowledge concerning multi-recurrent meningioma natural history, their clinical course is poorly defined. This retrospective study aims at defining patterns of relapse in order to help in the definition of response criteria in future clinical trials. We performed a retrospective review of surgery- and radiotherapy-refractory meningioma cases with interpretable radiological follow-up treated in our department. Tumor volumes were measured on 3D T1 Gadolinium volumetric sequences using a semi-automated algorithm for tumor segmentation. Twenty nine patients with multi-treated meningioma (11 WHO Grade II, 5 de novo WHO Grade III and 13 transformed WHO Grade III), were evaluated. Median PFS was 16 months for patients with Grade II meningiomas. In patients with Grade III meningiomas, the de novo subgroup had a median PFS of 4 months compared with 7 months in patients with malignant transformation. Volumetric analysis of tumor growth concerned 95 tumor nodules in 50 relapses. The mean growth rate of tumor nodules was 10.4 cm(3)/year (95% CI 7.3-14.8 cm(3)/year). Three patterns of tumor growth were described: "classical" for 9 (31%) patients, "local multi-nodular" for 6 (21%) patients and "multi-nodular metastatic" for the last 14 (48%) patients. Considering all tumor nodules, median time to tumor progression (TTP) was 3.7 months. Progressing tumors represent the most frequent histological subgroup of surgery and radiation-refractory meningiomas while tumors with multi-nodular metastatic dissemination are the prominent radiological pattern of progression.

Anatomical features of skull base and oral cavity: a pilot study to determine the accessibility of the sella by transoral robotic-assisted surgery.

The role of transoral robotic surgery (TORS) in the skull base emerges and represents the natural progression toward miniinvasive resections in confined spaces. The accessibility of the sella via TORS has been recently described on fresh human cadavers. An anatomic study is mandatory to know if this approach would be feasible in the majority of patients regardless of their oral morphological features. From 30 skull base CT scans from patients who were asked to open their mouth as wide as they can, we measured specific dimensions of the oral cavity and the skull base, such as length of the palate, mouth opening and distance from the sella to the palate. All data were acquired on a sagittal midline plane and on a 25° rotation plane, which simulated the axis of the robotic instruments. Looking at the projection of the dental palatine line on the sella, we studied possible predictive factors of sellar accessibility and tried to bring objective data for surgical feasibility. We also proposed an angle α to study the working angle at the skull base. We observed that the maximal mouth opening was a good predictive factor of sellar accessibility by TORS (p < 0.05). The mouth aperture threshold value for a good sensitivity, over 80 %, was comparable to the mean value of mouth opening in our series, 38.9 and 39.4 mm respectively. Moreover, we showed a statistically significant increase of the working angle α at the skull base comparing the lateral access to the midline one (p < 0.05). This seemed to quantitatively demonstrate that the robotic arms placed at the labial commissure of the mouth can reach the sella. From these anatomical features and previous cadaveric dissections, we assume that TORS may be feasible on a majority of patients to remove pituitary adenomas.

Neuronal activity correlated with checking behaviour in the subthalamic nucleus of patients with obsessive-compulsive disorder.

Doubt, and its behavioural correlate, checking, is a normal phenomenon of human cognition that is dramatically exacerbated in obsessive-compulsive disorder. We recently showed that deep brain stimulation in the associative-limbic area of the subthalamic nucleus, a central core of the basal ganglia, improved obsessive-compulsive disorder. To understand the physiological bases of symptoms in such patients, we recorded the activity of individual neurons in the therapeutic target during surgery while subjects performed a cognitive task that gave them the possibility of unrestricted repetitive checking after they had made a choice. We postulated that the activity of neurons in this region could be influenced by doubt and checking behaviour. Among the 63/87 task-related neurons recorded in 10 patients, 60% responded to various combinations of instructions, delay, movement or feedback, thus highlighting their role in the integration of different types of information. In addition, task-related activity directed towards decision-making increased during trials with checking in comparison with those without checking. These results suggest that the associative-limbic subthalamic nucleus plays a role in doubt-related repetitive thoughts. Overall, our results not only provide new insight into the role of the subthalamic nucleus in human cognition but also support the fact that subthalamic nucleus modulation by deep brain stimulation reduced compulsive behaviour in patients with obsessive-compulsive disorder.

Transoral robotic-assisted skull base surgery to approach the sella turcica: cadaveric study.

Transoral robotic surgery (TORS) offers new possibilities that have not been experimented in the field of minimally invasive skull base neurosurgery. We propose to evaluate the feasibility of transoral approach to the sella turcica with the da Vinci system on cadavers. We performed four robot-assisted dissections on human fresh cadavers in order to reach the pituitary fossa by the oral cavity. Cavum mucosa dissection was performed by the head and neck surgeon at the console and then the sphenoid was drilled by the neurosurgeon at the bedside, with intraoperative fluoroscopy and a "double surgeon" control. Mucosa closure was attempted with robotic arms. We succeeded in performing a sellar opening in all cadavers with a minimally invasive approach, as the hard palate was never drilled. The video endoscope offered a large view inside the sphenoidal sinus, as observed in transnasal endoscopy, but with 3D visualization. The camera arm could be inserted into the sphenoidal sinus, and instrument arms in the pituitary fossa. Operative time to reach the pituitary fossa was approximately 60 min in all procedures: 20 min of initial setup, 10 min of mucosal dissection, and 30 min of sphenoid surgery. New anatomical landmarks were defined. Advantages and pitfalls of such an unpublished technique were discussed. This is the first cadaveric study reported da Vinci robotic transoral approach to the sella turcica with a minimally invasive procedure. This innovative technique may modify the usual pituitary adenoma removal as the sella is approached infero-superiorly.

Recovery from oculomotor nerve palsy due to posterior communicating artery aneurysms: results after clipping versus coiling in a single-center series.

BACKGROUND: Oculomotor nerve palsy (ONP) is a common clinical manifestation of ruptured or unruptured posterior communicating artery (PcomA) aneurysms. Although microsurgical clip ligation has been proven a safe and durable treatment, endovascular management is emerging as an increasingly popular alternative. The aim of our study is to compare the recovery rate from ONP and assess the safety and long-term durability of both techniques. METHODS: We have reviewed the retrospective data concerning twenty-two patients treated at our institution between 2004 and 2012 for PcomA aneurysms with ONP. Seven patients were operated on via a standard pterional approach, and fourteen were treated by endovascular occlusion with coils. One patient was managed conservatively. Pre-treatment and post-treatment severity of ONP was recorded, as well as the duration of symptoms before admission and treatment-related complications. RESULTS: All seven patients who underwent surgery improved, with six total recoveries and one partial recovery. Among the fourteen patients treated by embolization, thirteen initially recovered, but long-term follow-up revealed three cases of exacerbation of ONP after refilling of the aneurysms. Two of them were clipped, and one embolized. Also, one partially resolved patient underwent a second embolization. No severe complications occurred in either group. CONCLUSIONS: Despite the small number of patients, our study suggests that both surgical clipping and embolization are safe and effective methods in regards to functional recovery (complete ONP recovery in about 85 % of the cases). However, coiling may lead to delayed recurrence of third cranial nerve (CN) palsy at long-term follow-up, requiring additional treatment.

Risks of presurgical embolization of feeding arteries in 137 intracranial meningeal tumors.

BACKGROUND: Embolization of extra-axial tumors has shown its effectiveness in reducing perisurgical blood loss. However, the complication rate of this procedure is poorly reported. We aimed to evaluate the rate of procedure-related complications and their risk factors. METHODS: From 1998 to 2011, 193 consecutive patients (141 females, 52 males; mean age = 52.9 years) were referred to our institution for presurgical embolization of an extra-axial tumor (meningiomas: n = 178; solitary fibrous tumors: n = 3; other: n = 12). Of 193 patients, 137 (71 %) underwent 141 embolizations (by microparticles: n = 133; by glue: n = 8). The remaining 56 patients (29 %) were not embolized due to unstable catheterization or dangerous anastomosis. Occurrence of neurological deficit was systematically assessed during and after embolization. The risk factors of procedure-related neurological complications were evaluated. RESULTS: Neither intratumoral hemorrhage nor procedure-related death was reported. Two of the 137 patients (1.5 %) had ischemic events with permanent neurological deficit after microparticles embolization. One patient had cortical blindness and one had hemiparesis. Both complications involved the vertebrobasilar system. The first patient had direct intratumoral anastomosis between the middle and the posterior meningeal arteries (PMA); the second one had reflux in the vertebral artery during particles injection in the PMA. Occurrence of ischemic complication was not related to the size of the microparticles. CONCLUSIONS: Though embolization of meningeal tumors is considered as a safe technique, serious neurological complications may occur. Opening of dangerous anastomosis or uncontrolled reflux caused two neurological complications (1.5 %). The size of the microparticles was not associated with the occurrence of neurological event.

Surgery for glioblastomas in the elderly: an Association des Neuro-oncologues d'Expression Française (ANOCEF) trial.

OBJECTIVE: The role of surgery in the treatment of malignant gliomas in the elderly is not settled. The authors conducted a randomized trial that compared tumor resection with biopsy only-both followed by standard therapy-in such patients. METHODS: Patients ≥ 70 years of age with a Karnofsky Performance Scale (KPS) score ≥ 50 and presenting with a radiological suspicion of operable glioblastoma (GBM) were randomly assigned between tumor resection and biopsy groups. Subsequently, they underwent standard radiotherapy during the first years of the trial (2008-2017), with the addition of adjunct therapy with temozolomide when this regimen became standard (2017-2019). The primary endpoint was survival, and secondary endpoints were progression-free survival (PFS), cognitive status (Mini-Mental State Examination), autonomy (KPS), quality of life (European Organisation for Research and Treatment of Cancer [EORTC] QLQ-C30 and QLQ-BN20), and perioperative morbidity and mortality. RESULTS: Between 2008 and 2019, 107 patients from 9 centers were enrolled in the study; 101 were evaluable for analysis because a GBM was histologically confirmed (50 in the surgery arm and 51 in the biopsy arm). There was no statistically significant difference in median survival between the surgery (9.37 months) and the biopsy (8.96 months, p = 0.36) arms (adjusted HR 0.79, 95% CI 0.52-1.21, p = 0.28). However, the surgery group had an increased PFS (5.06 vs 4.02 months; p = 0.034) (adjusted HR 0.50, 95% CI 0.32-0.78, p = 0.002). Less deterioration of quality of life and KPS score evolution than in the biopsy group was observed. Surgery was not associated with increased mortality or morbidity. CONCLUSIONS: This study suggests that debulking surgery is safe, and-compared to biopsy-is associated with a less severe deterioration of quality of life and autonomy, as well as a significant although modest improvement of PFS in elderly patients suffering from newly diagnosed malignant glioma. Although resection does not provide a significant survival benefit in the elderly, the authors believe that the risk/benefit analysis favors an attempt at optimal tumor resection in this population, provided there is careful preoperative geriatric evaluation. Clinical trial registration no.: NCT02892708 (ClinicalTrials.gov).

Surgical treatment of brain arteriovenous malformations: clinical outcomes of patients included in the registry of a pragmatic randomized trial.

OBJECTIVE: The Treatment of Brain Arteriovenous Malformations Study (TOBAS) is a pragmatic study that includes 2 randomized trials and registries of treated or conservatively managed patients. The authors report the results of the surgical registry. METHODS: TOBAS patients are managed according to an algorithm that combines clinical judgment and randomized allocation. For patients considered for curative treatment, clinicians selected from surgery, endovascular therapy, or radiation therapy as the primary curative method, and whether observation was a reasonable alternative. When surgery was selected and observation was deemed unreasonable, the patient was not included in the randomized controlled trial but placed in the surgical registry. The primary outcome of the trial was mRS score > 2 at 10 years (at last follow-up for the current report). Secondary outcomes include angiographic results, perioperative serious adverse events, and permanent treatment-related complications leading to mRS score > 2. RESULTS: From June 2014 to May 2021, 1010 patients were recruited at 30 TOBAS centers. Surgery was selected for 229/512 patients (44%) considered for curative treatment; 77 (34%) were included in the surgery versus observation randomized trial and 152 (66%) were placed in the surgical registry. Surgical registry patients had 124/152 (82%) ruptured and 28/152 (18%) unruptured arteriovenous malformations (AVMs), with the majority categorized as low-grade Spetzler-Martin grade I-II AVM (118/152 [78%]). Thirteen patients were excluded, leaving 139 patients for analysis. Embolization was performed prior to surgery in 78/139 (56%) patients. Surgical angiographic cure was obtained in 123/139 all-grade (89%, 95% CI 82%-93%) and 105/110 low-grade (95%, 95% CI 90%-98%) AVM patients. At the mean follow-up of 18.1 months, 16 patients (12%, 95% CI 7%-18%) had reached the primary safety outcome of mRS score > 2, including 11/16 who had a baseline mRS score ≥ 3 due to previous AVM rupture. Serious adverse events occurred in 29 patients (21%, 95% CI 15%-28%). Permanent treatment-related complications leading to mRS score > 2 occurred in 6/139 patients (4%, 95% CI 2%-9%), 5 (83%) of whom had complications due to preoperative embolization. CONCLUSIONS: The surgical treatment of brain AVMs in the TOBAS registry was curative in 88% of patients. The participation of more patients, surgeons, and centers in randomized trials is needed to definitively establish the role of surgery in the treatment of unruptured brain AVMs. Clinical trial registration no.: NCT02098252 (ClinicalTrials.gov).

Endovascular treatment of brain arteriovenous malformations: clinical outcomes of patients included in the registry of a pragmatic randomized trial.

OBJECTIVE: The role of endovascular treatment in the management of patients with brain arteriovenous malformations (AVMs) remains uncertain. AVM embolization can be offered as stand-alone curative therapy or prior to surgery or stereotactic radiosurgery (SRS) (pre-embolization). The Treatment of Brain AVMs Study (TOBAS) is an all-inclusive pragmatic study that comprises two randomized trials and multiple registries. METHODS: Results from the TOBAS curative and pre-embolization registries are reported. The primary outcome for this report is death or dependency (modified Rankin Scale [mRS] score > 2) at last follow-up. Secondary outcomes include angiographic results, perioperative serious adverse events (SAEs), and permanent treatment-related complications leading to an mRS score > 2. RESULTS: From June 2014 to May 2021, 1010 patients were recruited in TOBAS. Embolization was chosen as the primary curative treatment for 116 patients and pre-embolization prior to surgery or SRS for 92 patients. Clinical and angiographic outcomes were available in 106 (91%) of 116 and 77 (84%) of 92 patients, respectively. In the curative embolization registry, 70% of AVMs were ruptured, and 62% were low-grade AVMs (Spetzler-Martin grade I or II), while the pre-embolization registry had 70% ruptured AVMs and 58% low-grade AVMs. The primary outcome of death or disability (mRS score > 2) occurred in 15 (14%, 95% CI 8%-22%) of the 106 patients in the curative embolization registry (4 [12%, 95% CI 5%-28%] of 32 unruptured AVMs and 11 [15%, 95% CI 8%-25%] of 74 ruptured AVMs) and 9 (12%, 95% CI 6%-21%) of the 77 patients in the pre-embolization registry (4 [17%, 95% CI 7%-37%] of 23 unruptured AVMs and 5 [9%, 95% CI 4%-20%] of 54 ruptured AVMs) at 2 years. Embolization alone was confirmed to occlude the AVM in 32 (30%, 95% CI 21%-40%) of the 106 curative attempts and in 9 (12%, 95% CI 6%-21%) of 77 patients in the pre-embolization registry. SAEs occurred in 28 of the 106 attempted curative patients (26%, 95% CI 18%-35%, including 21 new symptomatic hemorrhages [20%, 95% CI 13%-29%]). Five of the new hemorrhages were in previously unruptured AVMs (n = 32; 16%, 95% CI 5%-33%). Of the 77 pre-embolization patients, 18 had SAEs (23%, 95% CI 15%-34%), including 12 new symptomatic hemorrhages [16%, 95% CI 9%-26%]). Three of the hemorrhages were in previously unruptured AVMs (3/23; 13%, 95% CI 3%-34%). CONCLUSIONS: Embolization as a curative treatment for brain AVMs was often incomplete. Hemorrhagic complications were frequent, even when the specified intent was pre-embolization before surgery or SRS. Because the role of endovascular treatment remains uncertain, it should preferably, when possible, be offered in the context of a randomized trial.

MR-guided laser-induced thermal therapy (LITT) for recurrent glioblastomas.

BACKGROUND AND OBJECTIVE: Laser-induced thermal therapy (LITT), coupled with magnetic resonance thermal imaging (MRTI) guidance, provides a minimally invasive and safe approach to treat brain tumors, especially metastases. We report here our experience using this treatment for recurrent glioblastomas. MATERIALS AND METHODS: Four patients, from 40 to 58 years old, were diagnosed with glioblastoma. After total resection, chemotherapy and radiation therapy, recurrence occurred. As each was ineligible for a second surgery, LITT was proposed as salvage therapy. Under stereotactic guidance, a fiberoptic applicator was inserted within the tumor LITT was performed under continuous MRTI. Real-time feedback control based on MRTI was employed to assess the quality of local tissue destruction and to prevent unwanted damage to nearby structures. RESULTS: The procedure was well tolerated with no peroperative neurological deterioration. In the short-term follow-up, one transient supplementary motor area syndrome, one epileptic seizure, and one cerebrospinal fluid leakage occurred. All were successfully managed. Post-procedure MRI showed no complication, satisfying treatment volume, and a decrease in size of the treated tumor. For all patients, recurrence was observed with a mean/median progression free survival of 37/30 days. Mean/median overall survival after LITT was 10.5/10 months. CONCLUSION: Focal tumor control was performed safely using minimally invasive LITT with real-time MRTI control. LITT could be considered as salvage therapy for high-grade recurrent gliomas if a 1-day treatment is considered useful for a few weeks gain in survival. Larger experience will be required to define indications for such infiltrative disease and accurately determine a potentially significant survival gain in good neurological condition associated with this 1-day procedure.

Subthalamic nucleus stimulation in severe obsessive-compulsive disorder.

BACKGROUND: Severe, refractory obsessive-compulsive disorder (OCD) is a disabling condition. Stimulation of the subthalamic nucleus, a procedure that is already validated for the treatment of movement disorders, has been proposed as a therapeutic option. METHODS: In this 10-month, crossover, double-blind, multicenter study assessing the efficacy and safety of stimulation of the subthalamic nucleus, we randomly assigned eight patients with highly refractory OCD to undergo active stimulation of the subthalamic nucleus followed by sham stimulation and eight to undergo sham stimulation followed by active stimulation. The primary outcome measure was the severity of OCD, as assessed by the Yale-Brown Obsessive Compulsive Scale (Y-BOCS), at the end of two 3-month periods. General psychopathologic findings, functioning, and tolerance were assessed with the use of standardized psychiatric scales, the Global Assessment of Functioning (GAF) scale, and neuropsychological tests. RESULTS: After active stimulation of the subthalamic nucleus, the Y-BOCS score (on a scale from 0 to 40, with lower scores indicating less severe symptoms) was significantly lower than the score after sham stimulation (mean [+/-SD], 19+/-8 vs. 28+/-7; P=0.01), and the GAF score (on a scale from 1 to 90, with higher scores indicating higher levels of functioning) was significantly higher (56+/-14 vs. 43+/-8, P=0.005). The ratings of neuropsychological measures, depression, and anxiety were not modified by stimulation. There were 15 serious adverse events overall, including 1 intracerebral hemorrhage and 2 infections; there were also 23 nonserious adverse events. CONCLUSIONS: These preliminary findings suggest that stimulation of the subthalamic nucleus may reduce the symptoms of severe forms of OCD but is associated with a substantial risk of serious adverse events. (ClinicalTrials.gov number, NCT00169377.)

Thalamic stimulation for tremor: can target determination be improved?

High frequency stimulation of the ventral intermedius nucleus (Vim) of the thalamus is successfully used for the treatment of postural tremor. Target coordinates are most commonly calculated using a statistical method. Here, we compare a statistical and an individual targeting method, using an histology-based three-dimensional deformable brain atlas which allows localization of the Vim on individual patient's MR images by adaptation of the atlas onto the patient's brain. Twenty-nine consecutive patients had electrodes implanted in the Vim uni-or bilaterally for severe essential tremor. Thirty-five targets were determined by calculating the statistical target and then using the deformable atlas to compute the individual target. Pythagorean distance between these targets was calculated. Statistical and individual targets were compared by double blind evaluation of perioperative stimulation effects. For most cases (n = 24), the Pythagorean distance was higher than 1.5 mm. In 79% of these cases, the definitive electrode was implanted using the position of the individual target. For the remaining cases (n = 11, distance < 1.5 mm), the definitive electrode was implanted according to the statistical target location in 73% of the cases. As a whole, when individual target was used, it was located at least 2 mm more medial than the statistical one in 86% cases. These results suggest that Vim target determination based on a statistical method might be inaccurate. In particular, laterality might be overestimated, leading to nonoptimal clinical results. In clinical practice, this means that microelectrode exploration during Vim surgery should include at least one trajectory more medial than the statistical target.

Direct puncture of the superficial temporal artery for ethylene vinyl alcohol embolization of a type 3 arteriovenous fistula with a dual lumen balloon.

Intracranial dural arteriovenous fistulas (dAVFs) may be difficult to treat by endovascular means, especially when the arterial feeders to the fistula are tortuous. 1 The usual main feeder to intracranial dAVFs is the middle meningeal artery, which may present very tight loops that are often difficult to cross with a microcatheter. 2 Direct puncture of a subcutaneous artery feeding the fistula indirectly via transosseous branches may be a valuable strategic option to overcome this limitation. 3 4 We report here the successful embolization of a Cognard type 3 parietal dAVF by direct puncture of the superficial temporal artery under roadmap guidance. The dAVF was subsequently embolized with ethylene vinyl alcohol via a dual lumen balloon, under balloon inflation. We highlight in this technical video 1 the potential difficulties and risks of direct puncture of the superficial temporal artery. We also stress the risk of delayed scalp necrosis using this technique. neurintsurg;13/5/493/V1F1V1Video 1.

Long-term results of a multicenter study on subthalamic and pallidal stimulation in Parkinson's disease.

We report the 5 to 6 year follow-up of a multicenter study of bilateral subthalamic nucleus (STN) and globus pallidus internus (GPi) deep brain stimulation (DBS) in advanced Parkinson's disease (PD) patients. Thirty-five STN patients and 16 GPi patients were assessed at 5 to 6 years after DBS surgery. Primary outcome measure was the stimulation effect on the motor Unified Parkinson's Disease Rating Scale (UPDRS) assessed with a prospective cross-over double-blind assessment without medications (stimulation was randomly switched on or off). Secondary outcomes were motor UPDRS changes with unblinded assessments in off- and on-medication states with and without stimulation, activities of daily living (ADL), anti-PD medications, and dyskinesias. In double-blind assessment, both STN and GPi DBS were significantly effective in improving the motor UPDRS scores (STN, P < 0.0001, 45.4%; GPi, P = 0.008, 20.0%) compared with off-stimulation, regardless of the sequence of stimulation. In open assessment, both STN- and GPi-DBS significantly improved the off-medication motor UPDRS when compared with before surgery (STN, P < 0.001, 50.5%; GPi, P = 0.002, 35.6%). Dyskinesias and ADL were significantly improved in both groups. Anti-PD medications were significantly reduced only in the STN group. Adverse events were more frequent in the STN group. These results confirm the long-term efficacy of STN and GPi DBS in advanced PD. Although the surgical targets were not randomized, there was a trend to a better outcome of motor signs in the STN-DBS patients and fewer adverse events in the GPi-DBS group.