Ventral targeted anterior capsulotomy for treatment-resistant depression and obsessive-compulsive disorder: A treatment method with cases.

BACKGROUND: Ablative surgery using bilateral anterior capsulotomy (BAC) is an option for treatment resistant depression (TRD) and obsessive-compulsive disorder (TROCD). The location and extent of the lesion within anterior limb of the internal capsule (ALIC) remains uncertain. Accumulating evidence has suggested that the lesion should be located ventrally while limiting the dorsal extent. Our center is now targeting specific fiber tracts within the lower half of the ALIC. METHOD: Presurgical diffusion tensor Magnetic Resonance Imaging (MRI) was used to identify individual fibre tracts within the ventral aspect of the ALIC in the last two patients who underwent BAC at our center. One patient had TRD and the other had both TROCD and TRD. Radiofrequency-induced thermal lesions were created in the identified targets with lesion volumes between 20 and 229 mm3 (average 95 mm3). FINDINGS: Both patients were responders with neither experiencing significant side effects including compromised executive functions. LIMITATIONS: The generalizability of our findings is limited because the outcome is based on two subjects. CONCLUSION: This work suggests that BAC can be individually tailored and more limited to the ventral aspect of the ALIC and is effective and safe for TRD and TROCD. Accumulating data also suggests that to be clinically effective the length of the capsulotomy should be about 10mm. BAC's use may increase with the growing utilization and mastery of magnetic resonance guided focused ultrasound.

Sweet spots of standard and directional leads in patients with refractory essential tremor: white matter pathways associated with maximal tremor improvement.

OBJECTIVE: In patients with essential tremor (ET) treated with standard deep brain stimulation (sDBS) whose ET had progressed and who no longer received optimal benefit from sDBS, directional deep brain stimulation (dDBS) may provide better tremor control. Current steering may provide better coverage of subcortical structures related to tremor control in patients with ET and significant progression without optimal response to sDBS. METHODS: This study included 6 patients with ET initially treated with sDBS whose tremor later progressed and who then underwent reimplantation with dDBS to optimize their tremor control. To investigate the differences in the local effects of sDBS and dDBS, the authors generated the volume of tissue activation (VTA) to calculate the sweet spots associated with the best possible tremor control with no side effects. Then, to investigate the anatomical structures associated with maximal tremor control, the white matter pathways of the posterior subthalamic areas (PSAs) were generated and their involvement with the sDBS and dDBS sweet spots was calculated. RESULTS: Tremor improvement was significantly better with dDBS (68.4%) than with sDBS (48.7%) (p = 0.017). The sDBS sweet spot was located within the ventral intermediate nucleus, whereas the sweet spot of the dDBS was mainly located within the PSA. The sweet spots of both sDBS and dDBS involved a similar portion of the cerebellothalamic pathway. However, the dDBS had greater involvement of the pallidofugal pathways than the sDBS. CONCLUSIONS: In patients with ET treated with sDBS who later had ET progression, dDBS provided better tremor control, which was related to directionality and a more ventral position. The involvement of both the cerebellothalamic and pallidofugal pathways obtained with dDBS is associated with additional improvement over the sDBS.

Constrained-Spherical Deconvolution Tractography in the Evaluation of the Corticospinal Tract in Glioma Surgery.

Introduction: Tractography has demonstrated utility for surgical resection in the setting of primary brain tumors involving eloquent white matter (WM) pathways. Methods: Twelve patients with glioma in or near eloquent motor areas were analyzed. The motor status was recorded before and after surgery. Two different tractography approaches were used to generate the motor corticospinal tract (CST): Constrained spherical deconvolution probabilistic tractography (CSD-Prob) and single tensor deterministic tractography (Tens-DET). To define the degree of disruption of the CST after surgical resection of the tumor, we calculated the percentage of the CST affected by surgical resection, which was then correlated with the postoperative motor status. Moreover, the fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) of the CST generated by the CSD-Prob and the Tens-DET was measured and compared between the ipsilesional and contralesional side. Results: The CST was identified in all patients and its trajectory was displaced by the tumor. Only the CSD-Prob approach showed the CST with the characteristic fan-like projections from the precentral gyrus to the brainstem. Disruption of the CST was identified in 6/6 with postoperative motor deficit by CSD-Prob approach and in 5/6 in the Tens-DET. The degree of disruption was significantly associated with the motor deficit with the CSD-Prob approach (rho = -0.88, p = 0.021). However, with the Tens-DET approach the CST disruption did not show significant association with the motor function (rho = -0.27, p = 0.6). There was a significant decrease in FA (p = 0.006) and a significant increase in MD (p = 0.0004) and RD (p = 0.005) on the ipsilesional CST compared with the contralesional CST only with the CSD-Prob approach. Conclusion: CSD-Prob accurately represented the known anatomy of the CST and provided a meaningful estimate of microstructural changes of the CST affected by the tumor and its macrostructural damage after surgery. Newer surgical planning stations should include advanced models and algorithms of tractography in order to obtain more meaningful reconstructions of the WM pathways during glioma surgery.

Tractography-Guided Anterior Capsulotomy for Major Depression and Obsessive-Compulsive Disorder: Targeting the Emotion Network.

BACKGROUND: Bilateral anterior capsulotomy (BAC) is an effective surgical option for patients with treatment-resistant major depression (TRMD) and treatment-resistant obsessive-compulsive disorder (TROCD). The size of the lesion and its precise dorsal-ventral location within the anterior limb of the internal capsule (ALIC) remain undefined. OBJECTIVE: To present a method to identify the trajectories of the associative and limbic white matter pathways within the ALIC for targeting in BAC surgery. METHODS: Using high-definition tractography, we prospectively tested the feasibility of this method in 2 patients with TRMD and TROCD to tailor the capsulotomy lesion to their limbic pathway. RESULTS: The trajectories of the associative and limbic pathways were identified in the ALIC of both patients and we targeted the limbic pathways by defining the dorsal limit of the lesion in a way to minimize the damage to the associative pathways. The final lesions were smaller than those that have been previously published. This individualized procedure was associated with long-term benefit in both patients. CONCLUSION: Tractography-guided capsulotomy is feasible and was associated with long-term benefit in patients with TRMD and TROCD.

Tremor and Quality of Life in Patients With Advanced Essential Tremor Before and After Replacing Their Standard Deep Brain Stimulation With a Directional System.

OBJECTIVES: Patients with essential tremor treated with thalamic deep brain stimulation may experience increased tremor with the progression of their disease. Initially, this can be counteracted with increased stimulation. Eventually, this may cause unwanted side-effects as the circumferential stimulation from a standard ring contact spreads into adjacent regions. Directional leads may offer a solution to this clinical problem. We aimed to compare the ability of a standard and a directional system to reduce tremor without side-effects and to improve the quality of life for patients with advanced essential tremor. MATERIALS AND METHODS: Six advanced essential tremor patients with bilateral thalamic deep brain stimulation had their standard system replaced with a directional system. Tremor rating scale scores were prospectively evaluated before and after the replacement surgery. Secondary analyses of quality of life related to tremor, voice, and general health were assessed. RESULTS: There was a significantly greater reduction in tremor without side-effects (p = 0.017) when using the directional system. There were improvements in tremor (p = 0.031) and voice (p = 0.037) related quality of life but not in general health for patients using optimized stimulation settings with the directional system compared to the standard system. CONCLUSIONS: In this cohort of advanced essential tremor patients who no longer had ideal tremor reduction with a standard system, replacing their deep brain stimulation with a directional system significantly improved their tremor and quality of life. Up-front implantation of directional deep brain stimulation leads may provide better tremor control in those patients who progress at a later time point.

Laser thermal therapy in the management of high-grade gliomas.

Laser interstitial thermal therapy (LITT) is a minimally invasive therapy that have been used for brain tumors, epilepsy, chronic pain, and other spine pathologies. This therapy is performed under imaging and stereotactic guidance to precisely direct the probe and ablate the area of interest using real-time magnetic resonance (MR) thermography. LITT has gained popularity as a treatment for glioma because of its minimally invasive nature, small skin incision, repeatability, shorter hospital stay, and the possibility of receiving adjuvant therapy shortly after surgery instead of several weeks as required after open surgical resection. Several reports have demonstrated the usefulness of LITT in the treatment of newly-diagnosed and recurrent gliomas. In this review, we will summarize the recent evidence of this therapy in the field of glioma surgery and the future perspectives of the use of LITT combined with other treatment strategies for this devastating disease.

Concurrent Glossopharyngeal Neuralgia and Hemi-Laryngopharyngeal Spasm (HeLPS): A Case Report and a Review of the Literature.

BACKGROUND AND IMPORTANCE: Hemi-laryngopharyngeal spasm (HeLPS) has been recently described but is not yet widely recognized. Patients describe intermittent coughing and choking and can be cured following microvascular decompression of their Xth cranial nerve. This case report and literature review highlight that HeLPS can co-occur with glossopharyngeal neuralgia (GN) and has been previously described (but not recognized) in the neurosurgical literature. CLINICAL PRESENTATION: A patient with GN and additional symptoms compatible with HeLPS is presented. The patient reported left-sided, intermittent, swallow-induced, severe electrical pain radiating from her ear to her throat (GN). She also reported intermittent severe coughing, throat contractions causing a sense of suffocation, and dysphonia (HeLPS). All her symptoms resolved following a left microvascular decompression of a loop of the posterior inferior cerebellar artery that was pulsating against both the IXth and Xth cranial nerves. A review of the senior author's database revealed another patient with this combination of symptoms. An international literature review found 27 patients have been previously described with symptoms of GN and the additional (but not recognized at the time) symptoms of HeLPS. CONCLUSION: This review highlights that patients with symptoms compatible with HeLPS have been reported since 1926 in at least 4 languages. This additional evidence supports the growing recognition that HeLPS is another neurovascular compression syndrome. Patients with HeLPS continue to be misdiagnosed as conversion disorder. The increased recognition of this new medical condition will require neurosurgical treatment and should alleviate the suffering of these patients.

An Analysis of Clinical Outcome and Tractography following Bilateral Anterior Capsulotomy for Depression.

INTRODUCTION: Bilateral anterior capsulotomy (BAC) is an effective surgical procedure for patients with treatment-resistant major depression (TRMD). In this work, we analyze the connectivity of the BAC lesions to identify connectivity "fingerprints" associated with clinical outcomes in patients with TRMD. METHODS: We performed a retrospective study of ten patients following BAC surgery. These patients were divided into "responders" and "non-responders" based on the relative change in the Beck depression inventory (BDI) score after surgery. We generated the dorsolateral prefrontal associative (DLPFC) pathways and the ventromedial prefrontal limbic (vmPFC) pathways going through the anterior limb of the internal capsule and analyzed if the overlap of the BAC lesions with these pathways was associated with either outcome. Finally, we used the BAC lesions of our patients to generate group-averaged connectivity "fingerprints" associated with either outcome. RESULTS: Six patients were responders (≥50% improvement in BDI), four patients were non-responders (<50% improvement). No significant impairments were found in most neuropsychological tests after surgery. The overlap analysis showed that in the responder group, there was less involvement of the DLPFC pathways than the vmPFC pathways (p = 0.001). Conversely, in the non-responder group, there was no significant difference between the involvement of both pathways (p = 0.157). The responder and non-responder connectivity fingerprint showed significant connections with the vmPFC limbic areas. However, the non-responder connectivity fingerprint also showed stronger connectivity to associative areas including the DLPFC and lateral orbitofrontal cortices. CONCLUSIONS: The optimum outcome following BAC surgery in this cohort was associated with interruption of vmPFC pathways and the relative preservation of DLPFC pathways.

Implantation of Depth Electrodes in Children Using VarioGuide® Frameless Navigation System: Technical Note.

BACKGROUND: Electrode placement in epilepsy surgery seeks to locate the sites of ictal onset and early propagation. An invasive diagnostic procedure, stereoelectroencephalography (SEEG) is usually implemented with frame-based methods that can be especially problematic in young children. OBJECTIVE: To evaluate the feasibility and accuracy of a new technique for frameless SEEG in children using the VarioGuide® system (Brainlab AG, München, Germany). METHODS: A frameless stereotactic navigation system was used to implant depth electrodes with percutaneous drilling and bolt insertion in pediatric patients with medically refractory epilepsy. Data on general demographic information of electrode implantation, duration, number, and complications were retrospectively collected. To determine the placement accuracy of the VarioGuide® frameless system, the mean Euclidean distances were calculated by comparing the preoperatively planned trajectories with the final electrode position observed on postoperative computed tomography scans. RESULTS: From May 2011 to December 2015, 15 patients (8 males, 7 females; mean age: 8 yr, range: 3-16 yr) underwent SEEG depth electrode implantation of a total of 111 electrodes. The mean error measured by the Euclidean distance from the center of the entry point to the intended entry point was 3.64 ± 1.78 mm (range: 0.58-7.59 mm) and the tip of the electrode to the intended target was 2.96 ± 1.49 mm (range: 0.58-7.82 mm). There were no significant complications. CONCLUSION: Depth electrodes can be placed safely and accurately in children using the VarioGuide® frameless stereotactic navigation system.

[Erdheim-Chester disease, an incredible simulator. Cases reports and review of literature]. / Enfermedad de Erdheim-Chester, una gran imitadora. Presentación de casos y revisión de la literatura.

Erdheim-Chester disease is a non-Langerhans histiocytosis. Until 2014 at least 550 cases have been reported. According to European Rare Disease Organization and National Organization for Rare Disorders it is a rare disease. The most common symptom is bone pain in the lower extremities and it usually appears between the 5th and 7th decades of life. The diagnostic is based on immunohistochemical results: S100(+/-), CD68(+), and CD1a(-), the latter 2 are mandatory. The best treatment nowadays is alpha-interferon or pegylated alpha-2. The overall survival is 96% at one year and 68% at 5 years. Central nervous system involvement is associated with a worse outcome. Two cases are presentedwith central nervous system lesions in the absence of lesions in other organs on their onset. Very few cases have been reported with this kind of presentation. We also noted that these patients had recurrences or new lesions at 8 months. A follow-up is proposed with brain MRI and thoraco-abdominal PET every 3-4 months.

Tractographical model of the cortico-basal ganglia and corticothalamic connections: Improving Our Understanding of Deep Brain Stimulation.

The cortico-basal ganglia and corticothalamic projections have been extensively studied in the context of neurological and psychiatric disorders. Deep brain stimulation (DBS) is known to modulate many of these pathways to produce the desired clinical effect. The aim of this work is to describe the anatomy of the main circuits of the basal ganglia using tractography in a surgical planning station. We used imaging studies of 20 patients who underwent DBS for movement and psychiatric disorders. We segmented the putamen, caudate nucleus (CN), thalamus, and subthalamic nucleus (STN), and we also segmented the cortical areas connected with these subcortical areas. We used tractography to define the subdivisions of the basal ganglia and thalamus through the generation of fibers from the cortical areas to the subcortical structures. We were able to generate the corticostriatal and corticothalamic connections involved in the motor, associative and limbic circuits. Furthermore, we were able to reconstruct the hyperdirect pathway through the corticosubthalamic connections and we found subregions in the STN. Finally, we reconstructed the cortico-subcortical connections of the ventral intermediate nucleus, the nucleus accumbens and the CN. We identified a feasible delineation of the basal ganglia and thalamus connections using tractography. These results could be potentially useful in DBS if the parcellations are used as targets during surgery.

Neuroendoscopic Intraventricular Biopsy in Children with Small Ventricles Using Frameless VarioGuide System.

Endoscopic biopsy for intraventricular tumors in pediatric patients with small ventricles is a challenging procedure because of the risk of morbidity during the intraventricular approach. We describe the use of the VarioGuide system for intraventricular endoscopic biopsy in 9 consecutive pediatric patients with intraventricular lesions and small ventricular size. All patients had lesions in the anterior part of the third ventricle with a median frontal and occipital horn ratio of 0.33. Patients presented with growth failure (n = 4), visual disturbances (n = 4), and seizures (n = 1). The VarioGuide system consists of an ergonomic arm with 3 joints for gross adjustment. The 3 rotational joints on the distal side of the system are adjusted according to the angles of the planned trajectory. The endoscope is adjusted to the distal side of the VarioGuide and inserted through the ring, previously set for the diameter of the endoscope and for the planned trajectory. The accuracy of the trajectory and correct ventricular cannulation are confirmed under endoscopic guidance. The biopsy is carried out according to the standard technique. In all cases, the biopsy sample provided the definitive diagnosis. Diagnoses included germinomas in 4 patients, hamartoma in 1 patient, hypothalamic astrocytoma in 2 patients, and craniopharyngioma in 2 patients. The use of the VarioGuide system for intraventricular endoscopic biopsy is highly recommended for pediatric patients with small ventricle size. This technique may help minimize the risk of unnecessary brain damage during the entrance to small ventricles.

Multiple spinal arteriovenous fistulas: A case-based review.

The occurrence of multiple spinal dural arteriovenous fistulas (AVFs) is rare. The majority of cases reported are synchronous and the lesions are mainly found at different spinal levels. Metachronous AVFs have been defined as lesions that manifest in a temporal sequence after treatment of a first AVF. In this report, we present two distinct cases of multiple spinal AVFs. Also, we review the main features of the cases previously reported, with emphasis on the proposed theories for the origin of multiple AVFs. In patients with failure to improve after treatment of a spinal DAVF, a whole-spine angiographic examination is mandatory, not only to ascertain the complete closure of the treated fistula, but also to look for a possible second lesion at a different spinal level.

Assessment of a method to determine deep brain stimulation targets using deterministic tractography in a navigation system.

Recent advances in imaging permit radiologic identification of target structures for deep brain stimulation (DBS) for movement disorders. However, these methods cannot detect the internal subdivision and thus cannot determine the appropriate DBS target located within those subdivisions. The aim of this study is to provide a straightforward method to obtain an optimized target (OT) within DBS target nuclei using a widely available navigation system. We used T1- and T2-weighted images, fluid-attenuated inversion recovery (FLAIR) sequence, and diffusion tensor imaging (DTI) of nine patients operated for DBS in our center. Using the StealthViz® software, we segmented the targeted deep structures (subcortical targets) and the anatomically identifiable areas to which these target nuclei were connected (projection areas). We generated fiber tracts from the projection areas. By identifying their intersections with the subcortical targets, we obtained an OT within the DBS target nuclei. We computed the distances from the clinically effective electrode contacts (CEEC) to the OT obtained by our method and the targets provided by the atlas. These distances were compared using a Wilcoxon signed-rank test, with p < 0.05 considered statistically significant. We were able to identify OT coincident with the motor part of the subthalamic nucleus and the ventral intermediate nucleus. We clinically tested the results and found that the CEEC were significantly more closely related to the OT than with the targets obtained by the atlas. Our present results show that this novel method permits optimization of the stimulation site within the internal subdivisions of target nuclei for DBS.

Scalp Metastases of Recurrent Meningiomas: Aggressive Behavior or Surgical Seeding?

OBJECTIVE: Scalp metastases of meningiomas seldom have been reported. Here, we report a series of 4 cases of this rare event and discuss the relevant potential risk factors. METHODS: We performed a retrospective review of patients treated for scalp metastases of meningiomas at our institution. A literature review was performed for the terms "scalp meningioma," "cutaneous meningioma," "skin meningioma," "extracranial meningioma," and "subcutaneous meningioma." RESULTS: Four patients showed scalp metastases of recurrent meningiomas with the following associated clinical features: multiple reoperations (n = 4), immunosuppression (n = 2), radiation therapy (n = 3), surgical wound complications with cerebrospinal fluid fistula (n = 2), and histologic grade progression (n = 2). The timescale for development of scalp metastasis was between 5 months and 13 years after intracranial meningioma surgery. In all cases, the metastases were located close to the surgical scalp incision for the craniotomy. Previously, 11 cases of meningioma with scalp metastasis, with similar features to those described here, were reported in the literature. CONCLUSIONS: Spreading of meningioma cells during surgery is a possible mechanism for scalp metastases of recurrent meningiomas. Factors associated with scalp metastases include reoperations, immunosuppression, radiation therapy, torpid course of the surgical wound with cerebrospinal fluid fistula, and histologic progression. Awareness of these features is advisable for neurosurgeons involved in the care of patients with similar profiles.