Nicolas Reyns

Exhaustive, one-year follow-up of subthalamic nucleus deep brain stimulation in a large, single-center cohort of parkinsonian patients.

OBJECTIVE To prospectively assess the impact of subthalamic nucleus (STN) deep brain stimulation (DBS) at 12 months after surgery in a series of 100 consecutive patients treated in a single center. The primary objective was to describe the clinical outcome in terms of efficacy and tolerance in STN-DBS patients. A secondary objective was to discuss presurgery clinical characteristics a posteriori as a function of outcome. METHODS One hundred and three consecutive patients with severe Parkinsons disease received bilateral STN-DBS in our clinic between May 1998 and March 2003. Clinical assessment was performed before and 12 months after surgery and was based on the Unified Parkinsons Disease Rating Scale, Parts II, III, and IV A; the Schwab and England Scale; and cognitive evaluation. Patient-rated overall improvement was also evaluated. RESULTS Twelve months after surgery, the Unified Parkinsons Disease Rating Scale Part III score decreased by 43%, the Unified Parkinsons Disease Rating Scale Part II score (activities of daily living) fell by 34%, and the severity of dyskinesia-related disability decreased by 61%. The main surgical complications after STN-DBS were as follows: infection (n = 7), intracerebral hematoma (n = 5), electrode fracture (n = 4), and incorrect lead placement (n = 8). We observed cognitive decline and depression in 7.7 and 18% of the patients, respectively. The mean patient-rated overall improvement score was 70.7%. CONCLUSION The efficacy and safety of STN-DBS in our centers large cohort of Parkinsonian patients are generally similar to the results obtained by other groups, albeit at the lower limit of the range of reported values. In contrast to efficacy, the occurrence of adverse events cannot be predicted. Younger patients with Parkinsons disease (i.e., those younger than 60 yr) often show an excellent response to levodopa. However, in view of our data on overall patient satisfaction and the occurrence of adverse events, we suggest that older patients (but not those older than 70 yr) and less dopa-sensitive patients (but not those with a response <50%) should still be offered the option of STN-DBS.

Intracranial Arteriovenous Malformation : Time-resolved Contrast-enhanced MR Angiography with Combination of Parallel Imaging, Keyhole Acquisition, and k-Space Sampling Techniques at 1,5 T

PURPOSE To prospectively compare the agreement between digital subtraction angiography (DSA) and time-resolved magnetic resonance (MR) angiography with sensitivity encoding (SENSE) in combination with keyhole acquisition and contrast material-enhanced robust-timing angiography (CENTRA) k-space sampling techniques for the characterization of intracranial arteriovenous malformations (AVMs). MATERIALS AND METHODS The institutional review board approved the study; informed consent was obtained from all patients (or their parents). Twenty-eight patients (15 male, 13 female; mean age, 38.6 years; age range, 16-61 years) with 29 previously diagnosed, untreated intracranial AVMs who were referred for stereotactic gamma knife radiosurgery were evaluated. Preinterventional imaging included intraarterial DSA and time-resolved MR angiography. The time-resolved MR angiography sequence included SENSE with a 1.5-T imager and was optimized by applying keyhole acquisition and CENTRA techniques. Time-resolved MR angiograms were reviewed by two independent raters and compared with DSA images with regard to arterial feeders, nidus size, and venous drainage. kappa Statistics were applied to determine interobserver and intermodality agreement. RESULTS MR angiography enabled time-resolved (1.7 seconds per volume) visualization of cerebral vessels from axis to vertex at high spatial resolution (true voxel size, 1 x 1 x 2 mm). All 25 nidi detected at intraarterial DSA were visualized at time-resolved MR angiography. Intermodality agreement was excellent for arterial feeders (kappa = 0.91; 95% confidence interval [CI]: 0.786, 1.000) and venous drainage (kappa = 0.94; 95% CI: 0.814, 1.000) and was good for nidus size (kappa = 0.76; 95% CI: 0.562, 0.950). CONCLUSION The agreement (good to excellent) between time-resolved MR angiographic and DSA findings suggests that time-resolved MR angiography is a reliable tool for the characterization of intracranial AVMs with respect to arterial feeders, nidus size, and venous drainage.

Role of radiosurgery in the management of cerebral arteriovenous malformations in the pediatric age group: data from a 100-patient series.

OBJECTIVETo assess the safety and efficacy of radiosurgery for the management of arteriovenous malformations (AVMs) in the pediatric age group. METHODSWe reviewed data from 100 children (44 girls and 56 boys) presenting a total of 103 AVMs treated by linear accelerator radiosurgery between December 1988 and May 2002. The median patient age was 12 years (range, 2–16 yr). Sixty-seven AVMs (65%) were in functional locations and 30% were inoperable. The mean AVM volume was 2.8 cm3 (range, 0.9–21.3 cm3). The mean marginal dose was 23 Gy (range, 15–25 Gy) and required between one and four isocenters. Fifty patients received multimodal treatments with embolization and/or surgery before and/or after radiosurgery. Given that 16 patients underwent two sessions of radiosurgery and one patient received three sessions, a total of 119 radiosurgical treatments were delivered. We maintained our clinical and angiographic follow-up for at least 36 months after irradiation or until the complete obliteration of the AVM was confirmed by angiography (our sole end point for judging clinical efficacy). Univariate and multivariate analysis were performed to determine predictive factors for obliteration. RESULTSComplete obliteration was achieved for 72 AVMs (70%). The permanent neurological deficit rate was 5%. One patient died because of rebleeding. None of our patients presented bleeding after an angiographically verified AVM obliteration. The main predictive factors for obliteration were low AVM volume and no previous embolization. Moreover, the younger the patient, the more effective the radiosurgery seemed to be. CONCLUSIONRadiosurgery is a safe and effective treatment for AVMs in the pediatric age group. One criterion for success was the use of a prescription dose similar to that used with adult populations.

Intraventricular Cavernomas: Three Cases and Review of the Literature

OBJECTIVE AND IMPORTANCE Cavernomas occur very rarely in the ventricular system. We report three cases of intraventricular cavernomas and review the literature. CLINICAL PRESENTATION A 16-year-old female patient presented with a sudden distal deficit of the left superior limb. She had a voluminous tumor involving the two lateral ventricles, with radiological evidence of recent hemorrhage. A 30-year-old man presented with generalized seizures and a right hemiplegia related to a 4-cm-diameter cavernoma in the two lateral ventricles involving the interhemispheric scissure through the corpus callosum and left centrum ovale. The radiological appearance was not typical and did not allow the diagnosis. A 42-year-old man had a cavernoma in the third ventricle, which was responsible for his short-term memory loss. This cavernoma had been revealed by computed tomography that was performed after intracerebral hemorrhage related to another cavernoma in the right parietal lobe occurred. INTERVENTION Stereotactic biopsies allowed the diagnosis of intraventricular cavernoma in the first case. Surgical removal via a right transcortical transventricular approach and a transcallosal approach in the first and second cases, respectively, was complete, resulting in good outcomes. Surgical removal via a right transcortical transventricular approach in the third case was partial. CONCLUSION Intraventricular cavernomas are so uncommon that only 42 well-documented cases have been previously reported in the literature. It seems that their radiological diagnosis may be difficult because of their uncommon location in the ventricular system and their voluminous size. A wrong preoperative diagnosis has sometimes been the cause of inefficient therapy, such as radiotherapy, for these surgically curable benign lesions.

La chirurgie de l'épilepsie en France Évaluation de l'activité

We report here the results of the first survey on epilepsy surgery activity in France. Data from a questionnaire sent to 17 centers practicing epilepsy surgery were analyzed. All centers responded; however, all items were not completely documented. Over 50 years, more than 5000 patients have been operated on for drug-resistant epilepsy and more than 3000 patients underwent some invasive monitoring, most often SEEG. Currently, nearly 400 patients (including more than 100 children) are operated on yearly for epilepsy in France. Over a study period varying among centers (from two to 20 years; mean, 9.5 years), results from more than 2000 patients including one-third children were analyzed. Important differences between adults and children, respectively, were observed in terms of location (temporal: 72% versus 4.3%; frontal: 12% versus 28%; central: 2% versus 11%), etiology (hippocampal sclerosis: 41% versus 2%; tumors 20% versus 61%); and procedures (cortectomy: 50% versus 23%; lesionectomy: 8% versus 59%), although overall results were identical (seizure-free rates following temporal lobe surgery: 80.6% versus 79%; following extratemporal surgery: 65.9% versus 65%). In adults, the best results were observed following temporomesial (TM) resection associated with hippocampal sclerosis or other lesions (class I: 83% and 79%, respectively), temporal neocortical (TNC) lesional (82%), while resections for cryptogenic temporal resections were followed by 69% (TM) and 63% (TNC) class I outcome. Extratemporal lesional resections were associated with 71% class I outcome and cryptogenic 43%. In children, the best results were obtained in tumor-associated epilepsy regardless of location (class I: 80%). A surgical complication occurred in 8% after resective surgery - with only 2.5% permanent morbidity - and 4.3% after invasive monitoring (mostly hemorrhagic). Overall results obtained by epilepsy surgery centers were in the higher range of those reported in the literature, along with a low rate of major surgical complications. Growing interest for epilepsy surgery is clearly demonstrated in this survey and supports further development to better satisfy the populations needs, particularly children. Activity should be further evaluated, while existing epilepsy surgery centers as well as healthcare networks should be expanded.

Clinical outcomes after Gamma Knife surgery for idiopathic trigeminal neuralgia: review of 76 consecutive cases

OBJECT Stereotactic radiosurgery is an increasingly used, and the least invasive, surgical option for patients with trigeminal neuralgia (TN). In this study, the authors performed a retrospective evaluation of the safety and efficacy of this method for idiopathic TN. METHODS The authors reviewed data from 76 patients with idiopathic TN who underwent Gamma Knife surgery (GKS). The mean age of the patients was 64 years (range 27-83 years). All patients had typical features of TN. Thirty patients (39.5%) had previously undergone surgery. The intervention consisted of GKS on the retrogasserian cisternal portion of the fifth cranial nerve. The mean maximum GKS dose used was 85.1 Gy (range 75-90 Gy). RESULTS Patients were followed-up from 6 to 42 months (mean 20.3 months) after GKS. Complete pain relief was achieved in 83.1% of the patients within 1 year, 70.9% within 2 years, and 62.5% within 3 years. Patients who underwent previous surgery demonstrated a lower rate of pain relief (p < 0.05). Twenty patients (26.3%) reported pain recurrence between 6 and 42 months after treatment. New or worsened persistent trigeminal dysfunction developed after GKS in 16 patients (21%); 8 of these patients described some facial numbness/not bothersome, and 8 reported some facial numbness/somewhat bothersome. None of the patients developed troublesome dysesthesia or anesthesia dolorosa. CONCLUSIONS Gamma Knife surgery for idiopathic TN proved to be safe and effective and was associated with a particularly low rate of complications.

Predictors of functional outcomes and recurrence of chronic subdural hematomas

We aimed to evaluate the functional outcome and risk factors of recurrence in patients operated on for a chronic subdural hematoma (CSH), and discuss systematic early postoperative CT scans. CSH is a very common disease in neurosurgical practice, especially in elderly patients who are treated with anticoagulation. The challenge is to rapidly restore the independence of these patients. We retrospectively analyzed data from 164 consecutive surgical procedures performed on 140 CSH patients, including recurrent surgery, at our institution from June 2011 to June 2012. Pre- and postoperative CT scans, and medical records, were systematically reviewed using the institutional computing database. A poor functional outcome was defined by a modified Rankin scale (mRS) score>2 at 3 months. Among the 140 patients (mean age 76 years; 64% men), a single burr hole craniostomy was performed in 122 patients, and a craniotomy in 18. A poor functional outcome was recorded in 39 patients (28%; 95% confidence interval [CI] 20-35%). In multivariate analyses, an increased risk of poor functional outcome was associated with age >75 years (odds ratio [OR] 5.88; 95% CI 1.96-17.63), residual hematoma thickness >14 mm (OR 3.79; 95% CI 1.47-9.77), and GCS<15 (OR, 2.96; 95% CI, 1.18-7.40). Recurrences occurred in 24 patients (17%; 95% CI 11-23%), with a median delay to reintervention of 13 days. The independent predictors of CSH recurrence were preoperative anticoagulant therapy (OR 3.68; 95% CI 1.13-12.00), and persistence of mass effect on the postoperative CT scan (OR 5.61; 95% CI 1.52-20.66). Three months after surgical treatment, more than one quarter of the CSH patients had a mRS⩾3. The loss of independence was associated with older age, initial GCS<15, and residual hematoma thickness postoperatively. Anticoagulant therapy and persistence of postoperative mass effect heightened the risk of recurrence.

Epilepsy surgery in France

We report here the results of the first survey on epilepsy surgery activity in France. Data from a questionnaire sent to 17 centers practicing epilepsy surgery were analyzed. All centers responded; however, all items were not completely documented. Over 50 years, more than 5000 patients have been operated on for drug-resistant epilepsy and more than 3000 patients underwent some invasive monitoring, most often SEEG. Currently, nearly 400 patients (including more than 100 children) are operated on yearly for epilepsy in France. Over a study period varying among centers (from two to 20 years; mean, 9.5 years), results from more than 2000 patients including one-third children were analyzed. Important differences between adults and children, respectively, were observed in terms of location (temporal: 72% versus 4.3%; frontal: 12% versus 28%; central: 2% versus 11%), etiology (hippocampal sclerosis: 41% versus 2%; tumors 20% versus 61%); and procedures (cortectomy: 50% versus 23%; lesionectomy: 8% versus 59%), although overall results were identical (seizure-free rates following temporal lobe surgery: 80.6% versus 79%; following extratemporal surgery: 65.9% versus 65%). In adults, the best results were observed following temporomesial (TM) resection associated with hippocampal sclerosis or other lesions (class I: 83% and 79%, respectively), temporal neocortical (TNC) lesional (82%), while resections for cryptogenic temporal resections were followed by 69% (TM) and 63% (TNC) class I outcome. Extratemporal lesional resections were associated with 71% class I outcome and cryptogenic 43%. In children, the best results were obtained in tumor-associated epilepsy regardless of location (class I: 80%). A surgical complication occurred in 8% after resective surgery - with only 2.5% permanent morbidity - and 4.3% after invasive monitoring (mostly hemorrhagic). Overall results obtained by epilepsy surgery centers were in the higher range of those reported in the literature, along with a low rate of major surgical complications. Growing interest for epilepsy surgery is clearly demonstrated in this survey and supports further development to better satisfy the populations needs, particularly children. Activity should be further evaluated, while existing epilepsy surgery centers as well as healthcare networks should be expanded.

Post-movement beta synchronization in subjects presenting with sensory deafferentation

OBJECTIVE We studied the time course and location of post-movement beta synchronization (PMBS) in patients presenting with sensory deafferentation, in order to assess the hypothetical relationship between the PMBS and the cortical processing of movement-related somatosensory afferent inputs. METHODS We used the event-related synchronization (ERS) method. EEG activity was recorded (via a 128-electrode system) during brisk, unilateral right and left index finger extension by 10 patients presenting with neuropathic pain related to sensory deafferentation. Intra- and post-movement changes in beta source power were calculated relative to pre-movement baseline activity. We compared the PMBS results for the painful and non-painful body sides. Furthermore, PMBS patterns in patients were compared with those in nine healthy volunteers. RESULTS PMBS pattern related to the painful side had a spatial distribution, with an ipsilateral preponderance, significantly more restricted than PMBS pattern on the non-painful side and in the control group. There were no significant differences between patient PMBS patterns on the non-painful side and those in the control group. CONCLUSIONS Sensory deafferentation disrupts normal PMBS patterns. SIGNIFICANCE This work provides additional arguments to the hypothesis supporting that the PMBS is influenced by movement-related somatosensory input processing.

Image-Guided Endoscopic Spine Surgery : Part II : Clinical Applications

Study Design. Endoscopic spinal procedures were performed under computed–tomography-based, image-guided assistance. Objective. To assess the clinical feasibility of applying a methodology that allows image-guided assistance in endoscopic spinal surgery. Summary of Background Data. Endoscopic spinal procedures have become a part of the minimal invasive approaches to the spine. The main disadvantage of these techniques is the long learning curve and the lack of peroperative monitoring. Fluoroscopy does have disadvantages, such as positioning during surgery and the risk for radiation exposure. Fluoroscopy-based navigation has many advantages, however it is still based on preselected fluoroscopic images. There is no method that allows computed–tomography-based navigation in endoscopic conditions. Methods. Two patients have been operated on using endoscopic approaches assisted by computed–tomography-based navigational system. One had a thoracoscopic approach for median calcified disc herniation and another one had an endoscopic posterior approach for resection of a sacro-iliac osteophyte. For each patient, a frame of reference had been placed percutaneously and scanned. The computed tomography images were registered to the anatomy using the geometry of the frame as fiducials. Navigation through endoscopic approaches was possible in both cases. Results. In both cases navigation was reliable and a helpful monitoring to achieve the surgical goals through endoscopic approaches. Conclusions. There are some factors that make endoscopic spine surgery a difficult start. Image-guided spine surgery is technically feasible and clinically applicable in endoscopic approaches.