Anterior Limb of Internal Capsule and Bed Nucleus of Stria Terminalis Stimulation for Gilles de la Tourette Syndrome with Obsessive-Compulsive Disorder in Adolescence: A Case of Success.

Gilles de la Tourette syndrome (GTS) is a neurobehavioral disorder comprising motor and vocal tics. In most cases it is associated with other disorders such as obsessive-compulsive disorder (OCD). In refractory cases deep brain stimulation (DBS) is a valid treatment option. This paper describes the case of a 15-year-old adolescent with an extremely refractory GTS with associated OCD. The patient developed catatonia associated with OCD, which partially remitted after electroconvulsive therapy. At the peak of the disease the Yale Global Tic Severity Scale (YGTSS) was 100 and the patient required sedation and intubation. All medical treatment options were unsuccessful. Bilateral DBS of the anterior limb of internal capsule (ALIC)/bed nucleus of stria terminalis (BST) region was performed, using a target below the BST and a trajectory through the ALIC, with stimulation of contacts 0 and 3. Two weeks after surgery sedatives were suspended and the patient was successfully extubated. One year after surgery the patient reached a YGTSS of 19, representing an 81% improvement. OCD completely resolved. Adverse events were a superficial infection and weight gain. In conclusion, this ALIC/BST stimulation appears to have been an effective and safe treatment for GTS with OCD in this case. Young age should not be an exclusion criterion for DBS in severe GTS and OCD. Further studies should be pursued for this target.

Deformable MRI-Ultrasound registration using correlation-based attribute matching for brain shift correction: Accuracy and generality in multi-site data.

Intraoperative tissue deformation, known as brain shift, decreases the benefit of using preoperative images to guide neurosurgery. Non-rigid registration of preoperative magnetic resonance (MR) to intraoperative ultrasound (iUS) has been proposed as a means to compensate for brain shift. We focus on the initial registration from MR to predurotomy iUS. We present a method that builds on previous work to address the need for accuracy and generality of MR-iUS registration algorithms in multi-site clinical data. High-dimensional texture attributes were used instead of image intensities for image registration and the standard difference-based attribute matching was replaced with correlation-based attribute matching. A strategy that deals explicitly with the large field-of-view mismatch between MR and iUS images was proposed. Key parameters were optimized across independent MR-iUS brain tumor datasets acquired at 3 institutions, with a total of 43 tumor patients and 758 reference landmarks for evaluating the accuracy of the proposed algorithm. Despite differences in imaging protocols, patient demographics and landmark distributions, the algorithm is able to reduce landmark errors prior to registration in three data sets (5.37±4.27, 4.18±1.97 and 6.18±3.38 mm, respectively) to a consistently low level (2.28±0.71, 2.08±0.37 and 2.24±0.78 mm, respectively). This algorithm was tested against 15 other algorithms and it is competitive with the state-of-the-art on multiple datasets. We show that the algorithm has one of the lowest errors in all datasets (accuracy), and this is achieved while sticking to a fixed set of parameters for multi-site data (generality). In contrast, other algorithms/tools of similar performance need per-dataset parameter tuning (high accuracy but lower generality), and those that stick to fixed parameters have larger errors or inconsistent performance (generality but not the top accuracy). Landmark errors were further characterized according to brain regions and tumor types, a topic so far missing in the literature.

Long-term follow-up of subthalamic nucleus deep brain stimulation in patients with Parkinson's disease: An analysis of survival and disability milestones.

BACKGROUND: Data on the long-term survival and incidence of disability milestones after subthalamic nucleus deep brain stimulation (STN-DBS) in Parkinson's disease (PD) is limited. OBJECTIVES: To estimate mortality and assess the frequency/time-to-development of disability milestones (falls, freezing, hallucinations, dementia, and institutionalization) among PD patients post STN-DBS. METHODS: A longitudinal retrospective study of patients undergoing STN-DBS. For mortality, Cox proportional hazards regression analysis was performed. For disease milestones, competing risk analyses were performed and cumulative incidence functions reported. The strength of association between baselines features and event occurrence was calculated based on adjusted hazard ratios. RESULTS: The overall mortality for the 109 patients was 16 % (62.1 ± 21.3 months after surgery). Falls (73 %) and freezing (47 %) were both the earliest (40.4 ± 25.4 and 39.6 ± 28.4 months, respectively) and most frequent milestones. Dementia (34 %) and hallucinations (32 %) soon followed (56.2 ± 21.2 and mean 60.0 ± 20.7 months after surgery, respectively). Higher ADL scores in the OFF state and higher age at surgery were associated with falls, freezing, dementia and institutionalization. CONCLUSIONS: Long-term mortality rate is low after STN-DBS. Disease milestones occur later during the disease course, with motor milestones appearing first and at a higher frequency than cognitive ones.

Position and Orientation Errors in a Neuronavigation Procedure: A Stepwise Protocol Using a Cranial Phantom.

OBJECTIVE: Neuronavigation procedures demand high precision and accuracy. Despite this need, there are still few studies analyzing errors in such procedures. The aim of this study was to use a custom-built cranial phantom to measure target position and orientation errors in different phases of a simulated neuronavigation procedure. METHODS: A cranial phantom with 10 target sites was designed and imaged with computed tomography and magnetic resonance. A segmentation of a cloud of points of the phantom (ground truth) was obtained using an optical tracking system and compared with the images (imaging phase). Targets and trajectories were then planned with neuronavigation software and compared with the ground truth (planning phase). The same plan was used to identify the points in real space after image-to-phantom registration and calculate the final error of the procedure by comparison with the ground truth (registration and execution phase). RESULTS: The mean errors after the imaging phase were 1.11 ± 0.42 mm and 3.23° ± 1.69° for position and orientation, respectively. After planning the mean errors were 1.10 ± 0.39 mm and 5.55° ± 2.91°. The global errors after the registration and mechanical execution were 3.93 ± 1.70 mm and 3.65° ± 1.29°. CONCLUSIONS: After a stepwise analysis, registration and mechanical execution were the main contributors to the global position error.

Non-rigid registration of 3D ultrasound for neurosurgery using automatic feature detection and matching.

PURPOSE: The brain undergoes significant structural change over the course of neurosurgery, including highly nonlinear deformation and resection. It can be informative to recover the spatial mapping between structures identified in preoperative surgical planning and the intraoperative state of the brain. We present a novel feature-based method for achieving robust, fully automatic deformable registration of intraoperative neurosurgical ultrasound images. METHODS: A sparse set of local image feature correspondences is first estimated between ultrasound image pairs, after which rigid, affine and thin-plate spline models are used to estimate dense mappings throughout the image. Correspondences are derived from 3D features, distinctive generic image patterns that are automatically extracted from 3D ultrasound images and characterized in terms of their geometry (i.e., location, scale, and orientation) and a descriptor of local image appearance. Feature correspondences between ultrasound images are achieved based on a nearest-neighbor descriptor matching and probabilistic voting model similar to the Hough transform. RESULTS: Experiments demonstrate our method on intraoperative ultrasound images acquired before and after opening of the dura mater, during resection and after resection in nine clinical cases. A total of 1620 automatically extracted 3D feature correspondences were manually validated by eleven experts and used to guide the registration. Then, using manually labeled corresponding landmarks in the pre- and post-resection ultrasound images, we show that our feature-based registration reduces the mean target registration error from an initial value of 3.3 to 1.5 mm. CONCLUSIONS: This result demonstrates that the 3D features promise to offer a robust and accurate solution for 3D ultrasound registration and to correct for brain shift in image-guided neurosurgery.

Disability in Activities of Daily Living and Severity of Dyskinesias Determine the Handicap of Parkinson's Disease Patients in Advanced Stage Selected to DBS.

BACKGROUND: There is scarce data on the level of handicap in Parkinson's disease (PD) and none in advanced stage PD. OBJECTIVE: To assess the handicap in advanced stage PD patients with disabling levodopa-induced motor complications selected to deep brain stimulation (DBS). METHODS: Data was prospectively recorded during routine evaluation for DBS. Handicap was measured using London Handicap Scale (LHS) (0 = maximal handicap; 1 = no handicap). Disease severity was evaluated using the Hoehn & Yahr scale and the UPDRS/MDS-UPDRS, during off and on after a supra-maximal dose of levodopa. Schwab and England Scale (S&E) was scored in off and on. Dyskinesias were scored using the modified Abnormal Involuntary Movement Scale (mAIMS). Results concern cross-sectional assessment before DBS. RESULTS: 100 PD patients (mean age 61 (±7.6); mean disease duration 12.20 (±4.6) years) were included. Median score of motor MDS-UPDRS was 54 in off and 25 in on. Mean total LHS score was 0.56 (±0.14). Patients were handicapped in several domains with a wide range of severity. Physical Independence and Social Integration were the most affected domains. Determinants of total LHS score were MDS-UPDRS part II off (ß= -0.271; p = 0.020), S&E on (ß= 0.264; p = 0.005) and off (ß= 0.226; p = 0.020), and mAIMS on (ß= -0.183; p = 0.042) scores (R2  = 29.6%). CONCLUSIONS: We were able to use handicap to measure overall health condition in advanced stage PD. Patients were moderately to highly handicapped and this was strongly determined by disability in ADL and dyskinesias. Change in handicap may be a good patient-centred outcome to assess efficiency of DBS.

Cavernous sinus lesions biopsy with neuronavigation and tip-cut needle.

BACKGROUND: Transoval biopsy of cavernous sinus (CS) lesions is the last non-invasive diagnostic option in those 15% of patients in whom etiology remains unclear in spite of extensive neuroradiological imaging, clinical assessment, and laboratory evaluation. However, there are no guidelines defining indications and the most appropriate technique for this procedure. CASE DESCRIPTION: We present four patients in whom we performed X-ray and neuronavigation-assisted transoval CS biopsies using tip-cut needles. CONCLUSION: The technique described allows the operator to determine the optimal angle for entering the CS, avoiding the complications due to distorted anatomy, and facilitating orientation once inside the CS. It reduces both radiation exposure as well as general anesthesia duration.

STN-DBS does not change emotion recognition in advanced Parkinson's disease.

UNLABELLED: Deep brain stimulation of the subthalamic nuclei (STN-DBS) for the treatment of levodopa-induced motor complications in advanced Parkinson's disease (APD) has been associated with neuropsychiatric disorders. It has been suggested that a postoperative decline in visual emotion recognition is responsible for those adverse events, although there is also evidence that emotional processing deficits can be present before surgery. The aim of the present study is to compare the ability to recognize emotions before and one year after surgery in APD. METHODS: Consecutively operated APD patients were tested pre-operatively and one year after STN-DBS by the Comprehensive Affect Testing System (CATS), which evaluates visual recognition of 7 basic emotions (happiness, sadness, anger, fear, surprise, disgust and neutral) on facial expressions and 4 emotions on prosody (happiness, sadness, anger and fear). RESULTS: In a sample of 30 patients 6 had depression or apathy at baseline that significantly increased to 14 post-surgery. There were no significant changes in the tests of identity discrimination, discrimination of emotional faces, naming of emotional faces, recognition of emotional prosody, and naming of emotional prosody after STN-DBS. The results of emotion tests could not predict the development of the neuropsychiatric symptoms. DISCUSSION: This study does not support the hypothesis of an acquired change in emotion recognition, either in faces or in prosody, after STN-DBS in APD patients. Neuropsychiatric symptoms appearing after STN-DBS should not be attributed to new deficits in emotional recognition.

A 22-year-old man with intracraneal hypertension and impaired sensation over the perineum and left foot.

Primary leptomeningeal tumors are rare and can have multiple origins. This young man presented an intracranial hypertension syndrome and brain MRI features of diffuse leptomeningeal enhancement over cerebral and cerebellar hemispheres. A second cerebellar biopsy allowed the diagnosis of a primary diffuse leptomeningeal Primitive Neuroectodermal Tumor (PNET). Besides the paucity of reports of primary leptomeningeal PNET, its differentiation from primary leptomeningeal medulloblastomas is not always clear-cut and is discussed.

Rosette-forming glioneuronal tumor: pathology case report.

OBJECTIVE: Rosette-forming glioneuronal tumor is a newly described mixed glial and neuronal tumor. We describe two cases and review the literature to better characterize this entity. METHODS: Patients were surgically treated, and tumors were diagnosed by light microscopy and immunohistochemistry using the avidin-biotin complex method. PubMed was searched for previously reported cases. RESULTS: Patient 1 was a 38-year-old woman who presented with headaches and no neurological abnormality. Magnetic resonance imaging showed a solid mass in the fourth ventricle. Subtotal excision of the mass caused transient gait ataxia. Patient 2 was a 51-year-old woman with dizziness who fell and sustained head trauma. Magnetic resonance imaging revealed a right paramedian cerebellar cystic and nodular mass and a separate nodule in the vermis, which were excised gross totally with no morbidity. Microscopic examination showed neuroepithelial tumors composed of neurocytic cells focally forming well-defined rosettes that were immunopositive for neuronal markers and of elongated, glial fibrillary acidic protein-immunoreactive astrocytes. No histological anaplasia was present. Both patients were well 18 and 8 months after surgery, respectively. Eighteen rosette-forming glioneuronal tumors were identified with the literature search. CONCLUSION: These are tumors of young adulthood (range, 12-59 yr) usually in or close to the fourth ventricle. Histologically, they are low-grade, although multiple foci or local extension may prevent total excision and account for some recurrences. On imaging, they are cystic, solid, or both, with minimal perilesional edema or mass effect. They are composed of neurocytic and glial elements, probably arising from a common progenitor in the subependymal plate, and need to be differentiated from a variety of glioneuronal tumors.