Frameless robot-assisted stereotactic biopsies for lesions of the brainstem-a series of 103 consecutive biopsies.

PURPOSE: Targeted treatment for brainstem lesions requires above all a precise histopathological and molecular diagnosis. In the current technological era, robot-assisted stereotactic biopsies represent an accurate and safe procedure for tissue diagnosis. We present our center's experience in frameless robot-assisted biopsies for brainstem lesions. METHODS: We performed a retrospective analysis of all patients benefitting from a frameless robot-guided stereotactic biopsy at our University Hospital, from 2001 to 2017. Patients consented to the use of data and/or images. The NeuroMate® robot (Renishaw™, UK) was used. We report on lesion location, trajectory strategy, histopathological diagnosis and procedure safety. RESULTS: Our series encompasses 96 patients (103 biopsies) treated during a 17 years period. Mean age at biopsy: 34.0 years (range 1-78). Most common location: pons (62.1%). Transcerebellar approach: 61 procedures (59.2%). Most common diagnoses: diffuse glioma (67.0%), metastases (7.8%) and lymphoma (6.8%). Non conclusive diagnosis: 10 cases (9.7%). After second biopsy this decreased to 4 cases (4.1%). Overall biopsy diagnostic yield: 95.8%. Permanent disability was recorded in 3 patients (2.9%, all adults), while transient complications in 17 patients (17.7%). Four cases of intra-tumoral hematoma were recorded (one case with rapid decline and fatal issue). Adjuvant targeted treatment was performed in 72.9% of patients. Mean follow-up (in the Neurosurgery Department): 2.2 years. CONCLUSION: Frameless robot-assisted stereotactic biopsies can provide the initial platform towards a safe and accurate management for brainstem lesions, offering a high diagnostic yield with low permanent morbidity.

Long-Term Efficacy of Occipital Nerve Stimulation for Medically Intractable Cluster Headache.

BACKGROUND: Occipital nerve stimulation (ONS) has been proposed to treat refractory chronic cluster headache (rCCH) but its efficacy has only been showed in small short-term series. OBJECTIVE: To evaluate ONS long-term efficacy in rCCH. METHODS: We studied 105 patients with rCCH, treated by ONS within a multicenter ONS prospective registry. Efficacy was evaluated by frequency, intensity of pain attacks, quality of life (QoL) EuroQol 5 dimensions (EQ5D), functional (Headache Impact Test-6, Migraine Disability Assessment) and emotional (Hospital Anxiety Depression Scale [HAD]) impacts, and medication consumption. RESULTS: At last follow-up (mean 43.8 mo), attack frequency was reduced >50% in 69% of the patients. Mean weekly attack frequency decreased from 22.5 at baseline to 9.9 (P < .001) after ONS. Preventive and abortive medications were significantly decreased. Functional impact, anxiety, and QoL significantly improved after ONS. In excellent responders (59% of the patients), attack frequency decreased by 80% and QoL (EQ5D visual analog scale) dramatically improved from 37.8/100 to 73.2/100. When comparing baseline and 1-yr and last follow-up outcomes, efficacy was sustained over time. In multivariable analysis, low preoperative HAD-depression score was correlated to a higher risk of ONS failure. During the follow-up, 67 patients experienced at least one complication, 29 requiring an additional surgery: infection (6%), lead migration (12%) or fracture (4.5%), hardware dysfunction (8.2%), and local pain (20%). CONCLUSION: Our results showed that long-term efficacy of ONS in CCH was maintained over time. In responders, ONS induced a major reduction of functional and emotional headache-related impacts and a dramatic improvement of QoL. These results obtained in real-life conditions support its use and dissemination in rCCH patients.

How Should we Use Multicolumn Spinal Cord Stimulation to Optimize Back Pain Spatial Neural Targeting? A Prospective, Multicenter, Randomized, Double-Blind, Controlled Trial (ESTIMET Study).

BACKGROUND: Recent studies have highlighted multicolumn spinal cord stimulation (SCS) efficacy, hypothesizing that optimized spatial neural targeting provided by new-generation SCS lead design or its multicolumn programming abilities could represent an opportunity to better address chronic back pain (BP). OBJECTIVE: To compare multicolumn vs. monocolumn programming on clinical outcomes of refractory postoperative chronic BP patients implanted with SCS using multicolumn surgical lead. MATERIALS AND METHODS: Twelve centers included 115 patients in a multicenter, randomized, double-blind, controlled trial. After randomization, leads were programmed using only one or several columns. The primary outcome was change in BP visual analogic scale (VAS) at six months. All patients were then programmed using the full potential of the lead up until 12-months follow-up. RESULTS: At six months, there was no significant difference in clinical outcomes whether the SCS was programmed using a mono or a multicolumn program. At 12 months, in all patients having been receiving multicolumn SCS for at least six months (n = 97), VAS decreases were significant for global pain (45.1%), leg pain (55.8%), and BP (41.5%) compared with baseline (p < 0.0001). CONCLUSION: The ESTIMET study confirms the significant benefit experienced on chronic BP by patients implanted with multicolumn SCS, independently from multicolumn lead programming. These good clinical outcomes might result from the specific architecture of the multicolumn lead, giving the opportunity to select initially the best column on a multicolumn grid and to optimize neural targeting with low-energy requirements. However, involving more columns than one does not appear necessary, once initial spatial targeting of the "sweet spot" has been achieved. Our findings suggest that this spatial concept could also be transposed to cylindrical leads, which have drastically improved their capability to shape the electrical field, and might be combined with temporal resolution using SCS new modalities.

Radiosurgery for unruptured brain arteriovenous malformations in the pre-ARUBA era: long-term obliteration rate, risk of hemorrhage and functional outcomes.

The management of non-hemorrhagic arteriovenous malformations (AVMs) remains a subject of debate, even more since the ARUBA trial. Here, we report the obliteration rate, the risk of hemorrhage and the functional outcomes after Gamma Knife radiosurgery (GKRS) as first-line treatment for non-hemorrhagic AVMs treated before the ARUBA publication, in a reference university center with multimodal AVM treatments available. We retrospectively analyzed data from a continuous series of 172 patients harboring unruptured AVMs treated by GKRS as first-line treatment in our Lille University Hospital, France, between April 2004 and December 2013. The primary outcome was obliteration rate. Secondary outcomes were the hemorrhage rate, the modified Rankin Scale (mRS), morbidity and epilepsy control at last follow-up. The minimal follow-up period was of 3 years. Median age at presentation was 40 years (IQR 28; 51). Median follow-up was 8.8 years (IQR 6.8; 11.3). Median target volume was 1.9 cm3 (IQR 0.8-3.3 cm3), median Spetzler-Martin grade: 2 (IQR 1-2), median Pollock-Flickinger score: 1.07 (IQR 0.82-2.94), median Virginia score: 1 (IQR 1-2). Median treatment dose was 24 Gy at 50% isodose line. Twenty-three patients underwent a second GKRS after a median time of 58 months after first GKRS. The overall obliteration rate was of 76%, based primarily on cerebral angiography and/or rarely only upon MRI. Hemorrhage during the post-treatment follow-up was reported in 18 (10%) patients (annual risk of 1.1%). Transient post-GKRS morbidity was reported in 14 cases (8%) and persistent neurological deficit in 8 (4.6%) of patients. At last follow-up, 86% of patients had a mRS ≤ 1. Concerning patients with pretherapeutic epilepsy, 84.6% of them were seizure-free at last follow-up. GKRS as first-line therapeutic option for unruptured cerebral AVMs achieves high obliteration rates (76%) while maintaining a high-level patient's autonomy. All hemorrhagic events occurred during the first 4 years after the initial GKRS. In cases with epilepsy, there was 84.6% seizure free at last follow-up. Permanent morbidity was reported in only 4.6%.

An Open-Label, Analgesic Efficacy and Safety of Pituitary Radiosurgery for Patients With Opioid-Refractory Pain: Study Protocol for a Randomized Controlled Trial.

BACKGROUND: Hypophysectomy performed by craniotomy or percutaneous techniques leads to complete pain relief in more than 70% to 80% of cases for opioid refractory cancer pain. Radiosurgery could be an interesting alternative approach to reduce complications. OBJECTIVE: To assess the analgesic efficacy compared with standard of care is the primary goal. The secondary objectives are to assess ophthalmic and endocrine tolerance, drug consumption, quality of life, and mechanisms of analgesic action. METHODS: The trial is multicenter, randomized, prospective, and open-label with 2 parallel groups. This concerns patients in palliative care suffering from nociceptive or mixed cancer pain, refractory to standard opioid therapy. Participants will be randomly assigned to the control group receiving standards of care for pain according to recommendations, or to the experimental group receiving a pituitary GammaKnife (Elekta, Stockholm, Sweden) radiosurgery (160 Gy delivered in pituitary gland) associated with standards of care. Evaluation assessments will be taken at baseline, day0, day4, day7, day14, day28, day45, month3, and month6. EXPECTED OUTCOMES: We could expect pain improvement in 70% to 90% of cases at day4. In addition we will assess the safety of pituitary radiosurgery in a vulnerable population. The secondary endpoints could show decay of opioid consumption, good patient satisfaction, and improvement of the quality of life. DISCUSSION: The design of this study is potentially the most appropriate to demonstrate the efficacy and safety of radiosurgery for this new indication. New recommendations could be obtained in order to improve pain relief and quality of life.

Glossopharyngeal neuralgia treated by Gamma Knife radiosurgery: safety and efficacy through long-term follow-up.

OBJECTIVE Glossopharyngeal neuralgia (GPN) is a rare and disabling condition. Just as for trigeminal neuralgia, Gamma Knife radiosurgery (GKRS) is increasingly proposed as a therapeutic option for GPN. The purpose of this study was to assess long-term safety and efficacy of GKRS for this indication. METHODS From 2007 to 2015, 9 patients (4 male and 5 female) underwent a total of 10 GKRS procedures. All of the patients presented with GPN that was refractory to all medical treatment, and all had a long history of pain. One patient had previously undergone surgical microvascular decompression. In 5 cases, a neurovascular conflict had been identified on MRI. For the GKRS procedure, the glossopharyngeal nerve was localized on MRI and CT under stereotactic conditions. The target was located at the glossopharyngeal meatus of the jugular foramen. The dose administered to the nerve was 80 Gy in 3 procedures and 90 Gy in the others. Follow-up was planned for 3, 6, and 12 months after the procedure and annually thereafter. RESULTS Eight patients experienced an improvement in their pain. The median length of time from GKRS to symptom improvement in this group was 7 weeks (range 2-12 months). At the first follow-up, 6 patients were pain-free (pain intensity scores of I-III, based on an adaptation of the Barrow Neurological Institute scoring system for trigeminal neuralgia), including 4 patients who were also medication-free (I). One patient had partial improvement (IV) and 2 patients had no change. The mean duration of follow-up was 46 months (range 10-90 months). At the last follow-up 6 patients remained pain-free (pain scores of I-III), including 4 patients who were pain free with no medication (I). No side effect was observed. CONCLUSIONS Because of its safety and efficacy, GKRS appears to be a useful tool for treatment of GPN, including first-line treatment.

Occipital nerve stimulation improves the quality of life in medically-intractable chronic cluster headache: Results of an observational prospective study.

Background Occipital nerve stimulation (ONS) has been proposed to treat chronic medically-intractable cluster headache (iCCH) in small series of cases without evaluation of its functional and emotional impacts. Methods We report the multidimensional outcome of a large observational study of iCCH patients, treated by ONS within a nationwide multidisciplinary network ( https://clinicaltrials.gov NCT01842763), with a one-year follow-up. Prospective evaluation was performed before surgery, then three and 12 months after. Results One year after ONS, the attack frequency per week was decreased >30% in 64% and >50% in 59% of the 44 patients. Mean (Standard Deviation) weekly attack frequency decreased from 21.5 (16.3) to 10.7 (13.8) ( p = 0.0002). About 70% of the patients responded to ONS, 47.8% being excellent responders. Prophylactic treatments could be decreased in 40% of patients. Functional (HIT-6 and MIDAS scales) and emotional (HAD scale) impacts were significantly improved, as well as the health-related quality of life (EQ-5D). The mean (SD) EQ-5D visual analogic scale score increased from 35.2 (23.6) to 51.9 (25.7) ( p = 0.0037). Surgical minor complications were observed in 33% of the patients. Conclusion ONS significantly reduced the attack frequency per week, as well as the functional and emotional headache impacts in iCCH patients, and dramatically improved the health-related quality of life of responders.

Gamma Knife Radiosurgery of Brainstem Cavernous Malformations.

BACKGROUND/AIMS: Our study aimed to evaluate the efficiency and morbidity of Gamma Knife radiosurgery (GKS) in the treatment of hemorrhagic brainstem cavernous malformations (CMs). METHODS: We included in this study all patients who underwent GKS for the treatment of a hemorrhagic brainstem CM(s) in our institution between January 2007 and December 2012. The GKS was privileged when the surgical procedure was evaluated as very risky. The mean dose of radiation was 14.8 Gy, and the mean target volume was 0.282 cm3. All patients participated in a scheduled clinical follow-up. The posttreatment MRI was performed after 6 months and after 1 year, and then all patients had an annual MRI follow-up. RESULTS: There were 19 patients with a mean age of 36.7 years. The mean follow-up period was 51.2 months. The annual hemorrhage rate (AHR) was 27.31% before GKS, 2.46% during the first 2 years following the GKS, and 2.46% after the first 2 years following the GKS. The decrease in AHR after GKS was significant (p < 0.001). CONCLUSION: GKS should be suggested when the surgical procedure harbors a high risk of neurological morbidity in patients with brainstem CM. Compared to prior literature results, a lower dose than applied in this study could be discussed.

Effects of tibial nerve neurotomy on posture and gait in stroke patients: A focus on patient-perceived benefits in daily life.

OBJECTIVE: To evaluate the objective and subjective functional effectiveness of tibial nerve neurotomy (TNN) in post-stroke spastic equinovarus foot (SEF). METHODS: In an open study, 23 hemiplegic patients were assessed immediately before TNN and then 5months after TNN. The main outcome measure was the Lower Limb Function Assessment Scale (LL-FAS), which provided an ecologic assessment of impairments in standing and walking (i.e. kinematic abnormalities) and their impacts on activities of daily living. Patients were also assessed for global clinical impression of change, fear of falling, neuromotor impairments, spatiotemporal and video gait parameters and walking capacities. RESULTS: TNN had a very marked effect on the level of spasticity and the range of motion in dorsiflexion (p<10(-3)). These changes resulted in better foot positioning when standing and walking (particularly in stance), which was perceived very favorably by the patients. There was a clear, patient-perceived improvement in activities performed when standing and walking (LL-FAS (p<0.01)), the global clinical impression of change (p<10(-3)) and the fear of falling (p=0.022) that was not revealed by conventional, objective measurements (New Functional Ambulation Classification, Rivermead Mobility Index). CONCLUSION: TNN is an effective treatment for post-stroke SEF; it is associated with a patient-reported improvement in standing and walking abilities during activities of daily living. Further research must now assess the long-term subjective efficacy of TNN.

Endoscopic Versus Stereotactic Procedure for Pineal Tumor Biopsies: Focus on Overall Efficacy Rate.

OBJECTIVE: The management of pineal region tumors depends on the histologic subtypes. Two minimally invasive techniques are available: endoscopic intraventricular biopsies and stereotactic biopsies. The recent Southampton and Lille series are the largest endoscopic and stereotactic series of pineal region tumors reporting both diagnosis rate and accuracy rate, respectively; we elaborated on these results in the light of other recent studies. METHODS: We compared the Southampton endoscopic series with the Lille series, reflecting our 25-year experience of stereotactic biopsies, and the metadata of the literature for both approaches, as reported in the 2013 Report of the French-Speaking Society of Neurosurgery on tumors of the pineal region. RESULTS: The results of the Southampton series match the endoscopic literature, in particular regarding the diagnosis rate (81.2%) and the perioperative morbidity (25.0%), and provide a rarely reported accuracy rate (78.6%), giving access to the overall efficacy rate (63.8%). The results of the Lille series match the stereotactic literature and show better results than endoscopic biopsies concerning the diagnosis rate (98.9%), accuracy rate (100%), resulting overall efficacy rate (98.9%), and perioperative morbidity (6.4%). CONCLUSIONS: The Southampton and Lille series provide a unique opportunity to compare the overall efficacy rates of endoscopic and stereotactic biopsies, respectively. The stereotactic approach is safer and more effective for biopsies of pineal region tumors. To improve the safety and reliability of endoscopic biopsies, various methods have to be evaluated: alternative burr-hole strategies, use of neuronavigation, and a combination of flexible and rigid endoscopes.

Grade 2 meningioma and radiosurgery.

OBJECT: World Health Organization Grade 2 meningiomas are aggressive tumors associated with a high recurrence rate leading to repeated surgical procedures, which can seriously worsen a patient's neurological status. Although radiosurgery is an increasingly popular technique, its role in the management of Grade 2 meningiomas has yet to be defined. In this study the authors aimed to evaluate radiosurgery in achieving control of proven tumor progression occurring after resection of Grade 2 meningioma. METHODS: This retrospective study included consecutive patients who, between 2000 and 2012, had undergone radiosurgery for radiologically proven progression of a previously surgically treated Grade 2 meningioma. RESULTS: Twenty-seven patients were eligible for analysis. There were 9 men and 18 women with a mean age of 59 years. The mean radiation dose was 15.2 Gy (range 12-21 Gy), and the mean target volume was 5.4 cm(3) (range 0.194-14.2 cm(3)). Thirty-four radiosurgical procedures were performed in the 27 patients. The mean progression-free survival after radiosurgery was 32.4 months among those with progression in a target irradiated volume and 26.4 months among those with progression in any intracranial meninges. With a mean follow-up of 56.4 months (range 12-108 months), the 12-, 24-, and 36-month actuarial local control rates for all patients were 75%, 52%, and 40%, respectively, and the regional control rates were 75%, 48%, and 33%. A single case of transient hemiparesis completely resolved without sequelae. CONCLUSIONS: Radiosurgery appears to be a safe and effective treatment for the local control of delayed progression after resection of a Grade 2 meningioma. Higher radiation doses similar to those applied for malignant tumors should be recommended when possible.

[The stem cell niche in glioblastoma: from fundamental aspects to targeted therapies]. / La niche des cellules souches tumorales dans le glioblastome : des aspects fondamentaux au ciblage thérapeutique.

The concept of cancer stem cell (CSC) was established from models of leukemogenesis explaining tumor repopulation by the clonogenic properties of this specific population of tumoral cells. Among solid tumors, glioblastoma are currently the most documented models. Cancer stem cells reside in specific locations within tumors called niches. Anatomically, two complementary niches have been described in glioblastoma. The first one is a perivascular niche composed of vessels (endothelial cells, pericytes) and their microenvironment (integrins, interleukins) constitutive the nest of "normal" neural stem cells and cancer stem cells. The second one is a hypoxic niche found in regions with low oxygen tension such as the core of the tumor. In these niches, mutual interactions between CSC and their microenvironment involving the activation of multiple signaling pathways promote stemness maintenance and tumor propagation. The median overall survival of glioblastoma does not exceed 15 months despite an aggressive multimodal treatment, thus the therapeutic targeting of these niches, by systemic agents or radiotherapy, in order to inhibit the signaling pathways involved in the maintenance of the CSC niches, represents a major challenge. The combination of these two strategies appears promising and many clinical trials are underway.

Relevance of gamma knife radiosurgery alone for the treatment of non-small cell lung cancer brain metastases.

BACKGROUND AND PURPOSE: Stereotactic radiosurgery (SRS) followed by close follow-up is becoming a popular strategy for the management of brain metastases as cancer patients live longer and late adverse effects of whole brain radiotherapy (WBRT) are increasingly reported. The authors report their experience in consecutively treated patients with limited brain metastases from non-small cell lung cancer (NSCLC), who underwent SRS alone followed by a close follow-up. METHODS: This study is the retrospective analysis of prospectively collected data. We included of 89 consecutive patients (80 men; mean age 59.7 years) with a KPS score of 60 or greater, who underwent Gamma Knife SRS for 1-4 metastases, at Lille University Hospital between January 2004 and December 2010. The mean radiation dose was 23.41Gy (range 18-26Gy) and the mean tumour volume was 2.47cm(3) (range 0.3-6.7cm(3)). After treatment, clinical and radiological (MRI) monitoring was scheduled at 2, 4, 8 and 12 months in the first year and at 4-month intervals thereafter. RESULTS: Overall survival was 70.8% at 1 year and 50% at 2 years. The actuarial local control rate was 91.5% at 1 year and 85.5% at 2 years. Ten of 89 patients experienced a local failure, which required a salvage treatment. The distant brain control rate was 79.2% at 1 year, and 67.1% at 2 years. A total of 25 patients developed new metastases, 10 patients were treated with a new radiosurgical procedure, 12 patients underwent a WBRT while 3 patients developed a leptomeningeal disease. We reported an overall complication rate of 10.1% per patient and 7.8% per treated tumour; all complications were classified grade 1 or 2. CONCLUSION: In patients with limited brain metastases from NSCLC, SRS is an effective treatment associated with high local control rate with low morbidity. When performed in isolation, close follow-up is mandatory and radiosurgery can be renewed as salvage treatment for distant brain progression, limiting the use of WBRT.

Surgery followed by radiosurgery: a deliberate valuable strategy in the treatment of intracranial meningioma.

OBJECTIVE: The aim of our study is to show that surgery followed by Gamma Knife Radiosurgery is an effective and safe combined treatment for the control of intracranial meningiomas located close to critical structures. MATERIALS AND METHODS: This retrospective study followed 31 patients with intracranial meningioma between 2005 and 2010. We included patients when initial therapeutic decision was deliberate subtotal surgical resection preparing a target for early postoperative GKR. Early MRI was performed to evaluate the tumor residual volume after surgical procedure. Annual MRI was performed to detect any tumor progression. RESULTS: The mean follow-up was 4.5 years. The mean margin dose was 14.5 Gy and the mean target volume was 2.4 cm3. The mean progression free survival after combined treatment was 4.4 years in the irradiated target volume and 3.9 years on the limit or remotely of irradiated target volume. Of all patients, we recorded 5 tumor progressions after combined treatment, in-field in 1 case and out-of-field in 4 cases. All tumor progressions were high-grade meningiomas. CONCLUSION: Surgery followed by radiosurgery is a safe and effective combined treatment for intracranial meningiomas. We recommend it in case of meningioma located close to critical structures for which it is safer to leave in place a tumor remnant to reduce morbidity.

Predictive factors for improvement of gait by low-frequency stimulation in Parkinson's disease.

BACKGROUND: After several years duration of Parkinson's disease, with or without deep brain stimulation, axial signs (such as postural instability, freezing of gait) may worsen. High-voltage, low-frequency stimulation has been shown to improve severe gait disorders in some patients. OBJECTIVE: To identify predictive factors for the efficacy of low-frequency stimulation. METHODS: We assessed the respective effects of low- and high-frequency stimulation using an acute stand-walk- sit test, and on motor performance in 22 patients with longstanding, bilateral sub-thalamic nucleus stimulation. We calculated the difference in the number of steps (delta steps) between high and low -frequency stimulation during the stand-walk-sit test. Our aim was to establish a profile for low-frequency responders, which was defined by a positive value for delta steps. RESULTS: Low frequency responders presented higher age, a severe axial phenotype five years after surgery and a lower L-dopa responsiveness of (i) the Unified Parkinson's Disease Rating Scale part III score and its akinesia subscore before surgery and (ii) the axial subscore one year after surgery. CONCLUSION: Here we defined a specific and severe axial profile of minority of patients who could benefit from low frequency stimulation parameters. Our findings challenge the conventional treatment approach (i.e. high-frequency stimulation) in patients who develop gait disorders after several years of stimulation.

Motor cortex stimulation modulates defective central beta rhythms in patients with neuropathic pain.

OBJECTIVE: Motor cortex stimulation therapy (MCS) is increasingly used to control refractory neuropathic pain. Post-movement beta synchronization (PMBS) is defined as a sharp increase in beta-frequency electroencephalographic power following movement offset and may reflect sensorimotor cortex inhibition induced, at least in part, by cortical processing of movement-related sensory afferent inputs. PMBS pattern is then often altered in case of neuropathic pain. The main objective of the present study was to test the hypothesis that implanted MCS modulates PMBS in patients presenting with neuropathic pain. METHODS: Using a high-resolution, 128-electrode electroencephalographic system, we recorded and compared, before and during MCS, PMBS patterns during brisk, unilateral right and left index finger extension in 8 patients presenting with neuropathic pain. RESULTS: The pre-operative PMBS patterns were altered in all cases. MCS increased the spatial distribution and amplitude of PMBS in most of cases and restored maximum-intensity of PMBS contralateral to the painful body side. These modifications appeared significantly correlated with the analgesic effect of MCS. CONCLUSION: This study provides evidence of central beta rhythms neuromodulation induced by MCS. SIGNIFICANCE: The restoration by MCS of defective cortical inhibition in patients with neuropathic pain is evoked.

Diffuse brainstem glioma: prognostic factors.

OBJECT: Brainstem gliomas were regarded as a single entity prior to the advent of MRI; however, several studies investigating MRI have recognized that these lesions are a heterogeneous group, and certain subgroups have a better prognosis for long-term survival. The aim of this study was to conduct a retrospective analysis of prognostic factors of patients with brainstem gliomas confirmed by histopathological diagnosis, particularly regarding assessment of whether histological grade, age, and MRI findings are prognostic factors for patient survival. METHODS: The study evaluated 100 patients diagnosed with brainstem glioma. There were 63 adults (40 men and 23 women; age range 18-75 years, mean 41 years) and 37 children (19 boys and 18 girls; age range 2-12 years, mean 6.9 years). RESULTS: The mean overall survival of this population, measured from the date of biopsy, was 57 months for diffuse low-grade glioma and 13.8 months for diffuse high-grade glioma (p < 0.001). The mean survival among patients with nonenhancing contrast lesions on MRI was 54.2 months, whereas for patients with enhancing lesions, it was 21.7 months (p < 0.001). Comparisons between the Kaplan-Meier survival curves of adults and children revealed similar median survival periods of 25 and 16 months, respectively (p > 0.05). The multivariate analysis (Cox proportional hazards regression) revealed that only histological grade was a significant prognostic factor (p < 0.001). CONCLUSIONS: The study revealed that histological grade and MRI features were significant prognostic factors for survival in these patients, but in multivariate analysis, only histological grade remained a significant factor.