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Obsessive-compulsive disorder is a chronic and severe psychiatric disorder with a high prevalence (2-3%) worldwide, of which 30% will be refractory to conventional treatment. Surgical treatment with deep brain stimulation, approved by the U.S. Food and Drug Administration in 2009, seems to be effective in symptomatic control, with response rates exceeding 50% in severely affected patients. However, despite the efficacy indicated in the different studies, surgical treatments for psychiatric disorders are still controversial, and deep brain stimulation for obsessivecompulsive disorder is not yet considered a standard therapy. Since 2009, a wide variety of targets have been suggested for the treatment of obsessive-compulsive disorder; however, to date, there is still no consensus on which target might be optimal for the treatment of obsessivecompulsive disorder. On one hand, authors are trying to find the best target based on each patient and the variability of their symptoms, in an attempt to personalize the treatment. In parallel, there has been a shift in the paradigm of functional neurosurgery from the belief in stimulation focusing on a single target to the modulation of brain circuits or connectomes. With this in mind, it may be possible that many of the targets used in obsessive-compulsive disorder could modulate the same brain network and thus produce an improvement in patients' symptomatology. This study aims to review the evolution of this treatment up to the present time; as well as to make a comparison between these two lines of thought, thus exposing the current state of deep brain stimulation for obsessive-compulsive disorder. [ABSTRACT FROM AUTHOR]

Introduction: A subgroup of patients with autism spectrum disorder (ASD) show self or heteroaggression, dyscontrol episodes, and others are of obsessive-compulsive disorder (OCD) profile; some of them are resistant to medical and behavioural treatment. We describe the long-term outcome in a group of these patients, treated with radiofrequency brain lesions or combined stereotactic surgery and Gamma Knife (GK) radiosurgery. Methods: We reviewed the medical records of 10 ASD patients with pathological aggressiveness and OCD, who had undergone radiofrequency lesions and/or radiosurgery with GK in our institution. Results: The 10 patients had a significant reduction of their symptoms (PCQ 39.9 and 33, OAS 11.8 and 5, CYBOCS-ASD 30.4 and 20), preoperatively and in the last follow-up, respectively; p < 0.005 (in all cases), although all but 2 needed more than 1 treatment to maintain this improvement. Conclusions: We observed a marked improvement in behaviour, quality of life, and relationship with the environment in all our 10 patients after the lesioning treatments, without long-lasting side effects. [ABSTRACT FROM AUTHOR]

Study Design. A case report and literature review. Objective. We present the fourth case of a spinal epidural capillary hemangioma with a dumbbell-shaped appearance in the magnetic resonance image reported in the literature and the second presented as a lung mass. Summary of Background Data. Hemangiomas are congenital vascular malformations that pathologists frequently consider to be hamartomatous malformations. Hemangiomas of the spine are usually lesions of the vertebral bodies, but they can sit in other locations such as the intramedullary or epidural space. Purely epidural hemangiomas are rare and most of them are of cavernous type. Methods. We present a 67-year-old female with a thoracic dumbbell-shaped capillary hemangioma with both foraminal and intrathoracic extensions, whose presentation was pleural effusion associated with mediastinal mass suggestive of pulmonary neoplasia. Surgical treatment consisted of total removal en bloc of the lesion. Results. Microscopic evaluation showed a fibrofatty tissue with a proliferation of vascular structures that were generally of a small size, with areas of myxoid appearance. To date, there have been 8 epidural capillary hemangiomas of the thoracic and lumbar spine reported in the literature, and only 3 of them were dumbbell-shaped with extraforaminal extension. Conclusion. It is important to consider the diagnosis of hemangiomas in the differential diagnosis of epidural lesions with dumbbell-shaped appearance in the magnetic resonance image, especially at the thoracic level. It is a benign and potentially curable disease and the most appropriate surgical treatment is en bloc resection of the entire lesion. They are usually presented as a progressive myelopathy, so early treatment may prevent permanent neurological deficits. [ABSTRACT FROM AUTHOR]

Background: It has been generally accepted that deep brain stimulation (DBS) not only acts in the nucleus where it is being applied, as initially thought, but that chronic stimulation activates axons located in its scope, and that this activation can exert its effects in distant areas. Considering this, DBS target identification should be made based on techniques that identify white matter tracts, such as tractography, rather than only by identifying specific nuclei on conventional magnetic resonance imaging. Methods: In this study, we performed a review of the literature on the use of tractography in DBS surgery and provide an overview of the main results. Results: Tractography has been used in the field of DBS to help clarify relevant aspects in the selection of targets and in evaluating its therapeutic effects in movement disorders, psychiatric diseases and pain. Conclusions: Studies are scarce so far, but they have provided data that, if confirmed, may optimize DBS surgery. Tractography might become a routine tool for DBS surgery in the near future. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Any search effort for gravitationalwaves (GWs) using interferometric detectors like LIGO needs to be able to identify if and when noise couples into the detector's output signal. The critical coupling likelihood (CCL) method has been developed to characterize potential noise coupling and in the future aid GW search efforts. By testing two hypotheses about pairs of channels, CCL is able to identify undesirable coupled instrumental noise from potential GW candidates. Our preliminary results show that CCL can associate up to ∼80% of observed artifacts with SNR > 8 with local noise sources, while reducing the duty cycle of the instrument by < 15%. An approach like CCL will become increasingly important as GW research moves into the advanced LIGO era, going from the first GW detection to GW astronomy. [ABSTRACT FROM AUTHOR]

Deep brain stimulation (DBS) requires precise localization, which is especially difficult at the thalamus, and even more difficult in anesthetized patients. We aimed to characterize the neurophysiological properties of the ventral intermediate (V.im), ventral caudal (V.c), and centromedian parvo (Ce.pc) and the magnocellular (Ce.mc) thalamic nuclei. We obtained microelectrode recordings from five patients with refractory epilepsy under general anesthesia. Somatosensory evoked potentials recorded by microelectrodes were used to identify the V.c nucleus. Trajectories were reconstructed off-line to identify the nucleus recorded, and the amplitude of the action potential (AP) and the tonic (i.e., mean frequency, density, probability of interspike interval) and phasic (i.e., burst index, pause index, and pause ratio) properties of the pattern discharges were analyzed. The Mahalanobis metric was used to evaluate the similarity of the patterns. The mean AP amplitude was higher for the V.im nucleus (172.7 ± 7.6 µV) than for the other nuclei, and the mean frequency was lower for the Ce.pc nucleus (7.2 ± 0.8 Hz) and higher for the V.c nucleus (11.9 ± 0.8 Hz) than for the other nuclei. The phasic properties showed a bursting pattern for the V.c nucleus and a tonic pattern for the centromedian and V.im nuclei. The Mahalanobis distance was the shortest for the V.im/V.c and Ce.mp/Ce.pc pairs. Therefore, the different properties of the thalamic nuclei, even for patients under general anesthesia, can be used to positively define the recorded structure, improving the exactness of electrode placement in DBS. [ABSTRACT FROM AUTHOR]

Objectives: The large number of infected patients requiring mechanical ventilation has led to the postponement of scheduled neurosurgical procedures during the first wave of the COVID-19 pandemic. The aims of this study were to investigate the factors that influence the decision to postpone scheduled neurosurgical procedures and to evaluate the effect of the restriction in scheduled surgery adopted to deal with the first outbreak of the COVID-19 pandemic in Spain on the outcome of patients awaiting surgery., Design: This was an observational retrospective study., Settings: A tertiary-level multicentre study of neurosurgery activity between 1 March and 30 June 2020., Participants: A total of 680 patients awaiting any scheduled neurosurgical procedure were enrolled. 470 patients (69.1%) were awaiting surgery because of spine degenerative disease, 86 patients (12.6%) due to functional disorders, 58 patients (8.5%) due to brain or spine tumours, 25 patients (3.7%) due to cerebrospinal fluid (CSF) disorders and 17 patients (2.5%) due to cerebrovascular disease., Primary and Secondary Outcome Measures: The primary outcome was mortality due to any reason and any deterioration of the specific neurosurgical condition. Second, we analysed the rate of confirmed SARS-CoV-2 infection., Results: More than one-quarter of patients experienced clinical or radiological deterioration. The rate of worsening was higher among patients with functional (39.5%) or CSF disorders (40%). Two patients died (0.4%) during the waiting period, both because of a concurrent disease. We performed a multivariate logistic regression analysis to determine independent covariates associated with maintaining the surgical indication. We found that community SARS-CoV-2 incidence (OR=1.011, p<0.001), degenerative spine (OR=0.296, p=0.027) and expedited indications (OR=6.095, p<0.001) were independent factors for being operated on during the pandemic., Conclusions: Patients awaiting neurosurgery experienced significant collateral damage even when they were considered for scheduled procedures., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective: Individuals with autism spectrum disorder (ASD) may display extreme behaviors such as self-injury or aggression that often become refractory to psychopharmacology or behavioral intervention. Deep brain stimulation (DBS) is a surgical alternative that modulates brain circuits that have yet to be clearly elucidated. In the current study the authors performed a connectomic analysis to identify brain circuitry engaged by DBS for extreme behaviors associated with ASD., Methods: A systematic review was performed to identify prior reports of DBS as a treatment for extreme behaviors in patients with ASD. Individual patients' perioperative imaging was collected from corresponding authors. DBS electrode localization and volume of tissue activated modeling were performed. Volumes of tissue activated were used as seed points in high-resolution normative functional and structural imaging templates. The resulting individual functional and structural connectivity maps were pooled to identify networks and pathways that are commonly engaged by all targets., Results: Nine patients with ASD who were receiving DBS for symptoms of aggression or self-injurious behavior were identified. All patients had some clinical improvement with DBS. Connectomic analysis of 8 patients (from the systematic review and unpublished clinical data) demonstrated a common anatomical area of shared circuitry within the anterior limb of the internal capsule. Functional analysis of 4 patients identified a common network of distant brain areas including the amygdala, insula, and anterior cingulate engaged by DBS., Conclusions: This study presents a comprehensive synopsis of the evidence for DBS in the treatment of extreme behaviors associated with ASD. Using network mapping, the authors identified key circuitry common to DBS targets.

Objective: To assess the effect of the first wave of the SARS-CoV-2 pandemic on the outcome of neurosurgical patients in Spain., Settings: The initial flood of COVID-19 patients overwhelmed an unprepared healthcare system. Different measures were taken to deal with this overburden. The effect of these measures on neurosurgical patients, as well as the effect of COVID-19 itself, has not been thoroughly studied., Participants: This was a multicentre, nationwide, observational retrospective study of patients who underwent any neurosurgical operation from March to July 2020., Interventions: An exploratory factorial analysis was performed to select the most relevant variables of the sample., Primary and Secondary Outcome Measures: Univariate and multivariate analyses were performed to identify independent predictors of mortality and postoperative SARS-CoV-2 infection., Results: Sixteen hospitals registered 1677 operated patients. The overall mortality was 6.4%, and 2.9% (44 patients) suffered a perioperative SARS-CoV-2 infection. Of those infections, 24 were diagnosed postoperatively. Age (OR 1.05), perioperative SARS-CoV-2 infection (OR 4.7), community COVID-19 incidence (cases/10 5 people/week) (OR 1.006), postoperative neurological worsening (OR 5.9), postoperative need for airway support (OR 5.38), ASA grade ≥3 (OR 2.5) and preoperative GCS 3-8 (OR 2.82) were independently associated with mortality. For SARS-CoV-2 postoperative infection, screening swab test <72 hours preoperatively (OR 0.76), community COVID-19 incidence (cases/10 5 people/week) (OR 1.011), preoperative cognitive impairment (OR 2.784), postoperative sepsis (OR 3.807) and an absence of postoperative complications (OR 0.188) were independently associated., Conclusions: Perioperative SARS-CoV-2 infection in neurosurgical patients was associated with an increase in mortality by almost fivefold. Community COVID-19 incidence (cases/10 5 people/week) was a statistically independent predictor of mortality., Trial Registration Number: CEIM 20/217., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background and Importance: Deep brain stimulation of the posteromedial hypothalamus (PMH DBS) appears to be an effective treatment for drug-resistant aggressiveness. Weaver syndrome (WS) is a rare genetic disorder in which patients develop some degree of intellectual disability and rarely severe behavioral alterations that may benefit from this procedure., Clinical Presentation: We present the case of a 26-yr-old man diagnosed with WS presenting with uncontrollable self and heteroaggressiveness and disruptive behavior refractory to pharmacological treatment and under severe physical and mechanical restraining measures. The patient was successfully treated with bilateral PMH DBS resulting in affective improvement, greater tolerance for signs of affection, regularization in his sleep pattern and appetite disturbances at 12-mo follow-up. A detailed description and video of the procedure are presented, and a review of the clinical characteristics of WS and the utility and benefits of PMH DBS for refractory aggressiveness are reviewed., Conclusion: To our knowledge, this is the first case of refractory aggressiveness described in WS as well as the first patient with WS successfully treated with PMH DBS., (© Congress of Neurological Surgeons 2021.)

Objective: Language lateralization is a major concern in some patients with pharmacoresistant epilepsy who will face surgery; in these patients, hemispheric dominance testing is essential to avoid further complications. The Wada test is considered the gold standard examination for language localization, but is invasive and requires many human and material resources. Functional MRI and tractography with diffusion tensor imaging (DTI) have demonstrated that they could be useful for locating language in epilepsy surgery, but there is no evidence of the correlation between the Wada test and DTI MRI in language dominance., Methods: The authors performed a retrospective review of patients who underwent a Wada test before epilepsy surgery at their institution from 2012 to 2017. The authors retrospectively analyzed fractional anisotropy (FA), number and length of fibers, and volume of the arcuate fasciculus and uncinate fasciculus, comparing dominant and nondominant hemispheres., Results: Ten patients with temporal lobe epilepsy were reviewed. Statistical analysis showed that the mean FA of the arcuate fasciculus in the dominant hemisphere was higher than in the nondominant hemisphere (0.369 vs 0.329, p = 0.049). Also, the number of fibers in the arcuate fasciculus was greater in the dominant hemisphere (881.5 vs 305.4, p = 0.003). However, no differences were found in the FA of the uncinate fasciculus or number of fibers between hemispheres. The length of fibers of the uncinate fasciculus was longer in the dominant side (74.4 vs 50.1 mm, p = 0.05). Volume in both bundles was more prominent in the dominant hemisphere (12.12 vs 6.48 cm3, p = 0.004, in the arcuate fasciculus, and 8.41 vs 4.16 cm3, p = 0.018, in the uncinate fasciculus). Finally, these parameters were compared in patients in whom the seizure focus was situated in the dominant hemisphere: FA (0.37 vs 0.30, p = 0.05), number of fibers (114.4 vs 315.6, p = 0.014), and volume (12.58 vs 5.88 cm3, p = 0.035) in the arcuate fasciculus were found to be statistically significantly higher in the dominant hemispheres. Linear discriminant analysis of FA, number of fibers, and volume of the arcuate fasciculus showed a correct discrimination in 80% of patients (p = 0.024)., Conclusions: The analysis of the arcuate fasciculus and other tract bundles by DTI could be a useful tool for language location testing in the preoperative study of patients with refractory epilepsy.

Objective: Initial studies applying deep brain stimulation (DBS) of the posteromedial hypothalamus (PMH) to patients with pathological aggressiveness have yielded encouraging results. However, the anatomical structures involved in its therapeutic effect have not been precisely identified. The authors' objective was to describe the long-term outcome in their 7-patient series, and the tractography analysis of the volumes of tissue activated in 2 of the responders., Methods: This was a retrospective study of 7 subjects with pathological aggressiveness. The findings on MRI with diffusion tensor imaging (DTI) in 2 of the responders were analyzed. The authors generated volumes of tissue activated according to the parameters used, and selected those volumes as regions of interest to delineate the tracts affected by stimulation., Results: The series consisted of 5 men and 2 women. Of the 7 patients, 5 significantly improved with stimulation. The PMH, ventral tegmental area, dorsal longitudinal fasciculus, and medial forebrain bundle seem to be involved in the stimulation field., Conclusions: In this series, 5 of 7 medication-resistant patients with severe aggressiveness who were treated with bilateral PMH DBS showed a significant long-lasting improvement. The PMH, ventral tegmental area, dorsal longitudinal fasciculus, and medial forebrain bundle seem to be in the stimulation field and might be responsible for the therapeutic effect of DBS.

Approximately 30% of epilepsy patients are refractory to antiepileptic drugs. In these cases, surgery is the only alternative to eliminate/control seizures. However, a significant minority of patients continues to exhibit post-operative seizures, even in those cases in which the suspected source of seizures has been correctly localized and resected. The protocol presented here combines a clinical procedure routinely employed during the pre-operative evaluation of temporal lobe epilepsy (TLE) patients with a novel technique for network analysis. The method allows for the evaluation of the temporal evolution of mesial network parameters. The bilateral insertion of foramen ovale electrodes (FOE) into the ambient cistern simultaneously records electrocortical activity at several mesial areas in the temporal lobe. Furthermore, network methodology applied to the recorded time series tracks the temporal evolution of the mesial networks both interictally and during the seizures. In this way, the presented protocol offers a unique way to visualize and quantify measures that considers the relationships between several mesial areas instead of a single area.

Introduction: Intracranial angioleiomyomas are extremely rare lesions. Only 22 intracranial angioleiomyomas have been described in the literature and only three were infratentorial., Case Report: We report a case of an infratentorial angioleiomyoma in a 43 year-old-man, who underwent a brain computer tomography because of hearing loss. The MRI showed a 1.4 cm tumor, initially described as a meningioma, with progressive enhancement after gadolinium injection, an augmented apparent diffusion coefficient and a generalized metabolite decreased in the spectroscopy. The lesion was surgically removed through a suboccipital approach with a good evolution and without postoperative complications. In the immunohistological study, the lesion was mainly composed of multiple vessels and the immunohistochemistry was positive for actin and caldesmon. Two years after surgery, no recurrence has been found in the MRI., Conclusion: Angioleiomyomas diagnostic may be complex, but some radiological features could help in the differential diagnostic. Angioleiomyomas are benign tumors associated with favorable outcomes after total resection, that in our case, did not show a significant bleeding risk.

Object: Hemispherectomy is an established neurosurgical procedure for medication-resistant epilepsy in children. Despite the effectiveness of this technique, there are patients who do not achieve an optimum outcome after surgery; possible causes of suboptimal results include the presence of bilateral independent epileptogenic foci. Magnetoencephalography (MEG) is an emerging tool that has been found to be useful in the management of lesional and nonlesional epilepsy. The authors analyzed the relative contribution of MEG in patient selection for hemispherectomy., Methods: The medical records of children undergoing hemispherectomy at the Hospital for Sick Children were reviewed. Those patients who underwent MEG as part of the presurgical evaluation were selected., Results: Thirteen patients were included in the study. Nine patients were boys. The mean age at the time of surgery was 66 months (range 10-149 months). Seizure etiology was Rasmussen encephalitis in 6 patients, hemimegalencephaly in 2 patients, and cortical dysplasia in 4 patients. In 8 patients, video-EEG and MEG results were consistent to localize the primary epileptogenic hemisphere. In 2 patients, video-EEG lateralized the ictal onset, but MEG showed bilateral spikes. Two patients had bilateral video-EEG and MEG spikes. Engel Class I, II, and IV outcomes were seen in 10, 2, and 1 patients, respectively. In 2 of the patients who had an outcome other than Engel Class I, the MEG clusters were concentrated in the disconnected hemisphere. The third patient had bilateral clusters and potentially independent epileptogenic foci from bilateral cortical dysplasia., Conclusions: The presence of unilateral MEG spike waves correlated with good outcomes following hemispherectomy. In some cases, MEG provides information that differs from that obtained from video-EEG and conventional MR imaging studies. Further studies with a greater number of patients are needed to assess the role of MEG in the preoperative assessment of candidates for hemispherectomy.

Bilateral deep brain stimulation of the globus pallidus pars interna (GPi) is the favored neuromodulation procedure in cases of cervical dystonia. The authors report on a case of unilateral GPi implantation that resulted in sustained benefit with marked improvement in pain and dystonia.

Background: Tremor is an important cause of disability in patients with multiple sclerosis (MS). Deep brain stimulation (DBS) in the ventral intermediate nucleus (VIM) of the thalamus is said to be beneficial for MS tremor., Objective: To assess the long-term efficacy of VIM DBS for MS disabling tumor., Methods: We treated 10 patients (4 men and 6 women) with advanced MS-related medication-resistant tremor with DBS at the VIM thalamic nucleus. DBS was unilateral in 9 patients and bilateral in 1 patient in 2 stages. Contralateral arm tremor was assessed with the Fahn-Tolosa-Marin tremor rating scale., Results: At 1 year, 5 of 10 patients (5 of 11 hemispheres) had a reduction in tremor scores with stimulation compared with baseline; in 3 patients, the reduction was > 50%. After 36 months, 3 patients continued benefiting from stimulation, 2 having > 50% improvement. Of the 6 symptomatic sides that did not benefit at 1 year, 3 failed to have even initial benefit, and 3 had a transient improvement lasting < 1 year. One patient stopped using stimulation because of a lack of improvement at 5 months after surgery and was lost to follow-up., Conclusion: Approximately one-half of the patients derived some benefit from VIM DBS 1 year after surgery, but this benefit reached a > 50% reduction in only 30% of the patients. This level of improvement may be related to the variability of the demyelinating lesions and the superimposition of ataxia in the MS patients. Developing better treatments for MS tremor continues to be a challenge.

Stereological methods were employed to estimate the volume and neuron numbers of the rat dorsal column nuclei (DCN). These methods were applied to Nissl-stained sections from control animals and cases that received injections of horseradish peroxidase in the thalamus, the cerebellum, or the spinal cord. Additional cases received combinations of fluorescent tracers in the same structures, to examine whether some of the retrogradely labeled neurons sent collaterals to different targets. The mean volume of the DCN is 0.81 mm(3) (range 0.65-1.10 mm(3)), of which 3%, 39%, and 59% correspond, respectively, to the nucleus of Bischoff (Bi), the gracile (Gr), and the cuneate (Cu) nuclei. Within Cu, the middle division (CuM) is the largest (42%), followed by the rostral (CuR; 36%) and caudal (CuC; 22%) divisions. The mean total number of neurons in the DCN is 16,000 (range 12,400-19,500), of which 2.4%, 34.0% and 63.6% correspond, respectively, to Bi, Gr, and Cu. Within Cu, CuM contains 48% of all neurons, and 27% correspond to CuR and 25% to CuC. Interanimal variability is moderate for the whole DCN and Cu but increases when individual nuclei are considered. About 80% of DCN neurons project to the thalamus, 3% to the spinal cord, and 7% to the cerebellum. Thalamic-projecting cells are more numerous in CuM and Gr (83%), and relatively less common in Bi and CuC (72-74%). Most of the DCN neurons projecting to the spinal cord appear in CuC and CuM. Two-thirds of the neurons projecting to the cerebellum are located in CuR, 20% in CuM, and 15% in Gr. A small fraction of neurons projects simultaneously to spinal cord and thalamus., (Copyright 2003 Wiley-Liss, Inc.)