The Value of Intraoperative Ultrasound in Brain Surgery.

Favorable clinical outcomes in adult and pediatric neurosurgical oncology generally depend on the extent of tumor resection (EOR). Maximum safe resection remains the main aim of surgery in most intracranial tumors. Despite the accuracy of intraoperative magnetic resonance imaging (iMRI) in the detection of residual intraoperatively, it is not widely implemented worldwide owing to enormous cost and technical difficulties. Over the past years, intraoperative ultrasound (IOUS) has imposed itself as a valuable and reliable intraoperative tool guiding neurosurgeons to achieve gross total resection (GTR) of intracranial tumors.Being less expensive, feasible, doesn't need a high level of training, doesn't need a special workspace, and being real time with outstanding temporal and spatial resolution; all the aforementioned advantages give a superiority for IOUS in comparison to iMRI during resection of brain tumors.In this chapter, we spot the light on the technical nuances, advanced techniques, outcomes of resection, pearls, and pitfalls of the use of IOUS during the resection of brain tumors.

A multi-center comparison of surgical techniques for corpus Callosotomy in pediatric drug-resistant epilepsy.

OBJECTIVES: Corpus callosotomy (CC) is used to reduce seizures, primarily in patients with generalized drug-resistant epilepsy (DRE). The invasive nature of the procedure contributes to underutilization despite its potential superiority to other palliative procedures. The goal of this study was to use a multi-institutional epilepsy surgery database to characterize the use of CC across participating centers. METHODS: Data were acquired from the Pediatric Epilepsy Research Consortium (PERC) Surgery Database, a prospective observational study collecting data on children 0-18 years referred for surgical evaluation of DRE across 22 U.S. pediatric epilepsy centers. Patient, epilepsy, and surgical characteristics were collected across multiple CC modalities. Outcomes and complications were recorded and analyzed statistically. RESULTS: Eighty-three patients undergoing 85 CC procedures at 14 participating epilepsy centers met inclusion criteria. Mean age at seizure onset was 2.3 years (0-9.4); mean age for Phase I evaluation and surgical intervention were 9.45 (.1-20) and 10.46 (.2-20.6) years, respectively. Generalized seizure types were the most common (59%). Complete CC was performed in 88%. The majority of CC procedures (57%) were via open craniotomy, followed by laser interstitial thermal therapy (LiTT) (20%) and mini-craniotomy/endoscopic (mc/e) (22%). Mean operative times were significantly longer for LiTT, whereas mean estimated blood loss was greater in open cases. Complications occurred in 11 cases (13%) and differed significantly between surgical techniques (p < .001). There was no statistically significant difference in length of postoperative stay across approaches. Mean follow-up was 12.8 months (range 1-39). Favorable Engel outcomes were experienced by 37 (78.7%) of the patients who underwent craniotomy, 10 (58.8%) with LiTT, and 12 (63.2%) with mc/e; these differences were not statistically significant. SIGNIFICANCE: CC is an effective surgical modality for children with DRE. Regardless of surgical modality, complication rates are acceptable and seizure outcomes generally favorable. Newer, less-invasive, surgical approaches may lead to increased adoption of this efficacious therapeutic option for pediatric DRE.

Predicting 30-Day Non-Seizure Outcomes Following Temporal Lobectomy with Personalized Machine Learning Models.

BACKGROUND: Temporal lobe epilepsy is the most common reason behind drug-resistant seizures and temporal lobectomy (TL) is performed after all other efforts have been taken for a Temporal lobe epilepsy. Our study aims to develop multiple machine learning (ML) models capable of predicting postoperative outcomes following TL surgery. METHODS: Data from the American College of Surgeons National Surgical Quality Improvement Program database identified patients who underwent TL surgery. We focused on 3 outcomes: prolonged length of stay (LOS), nonhome discharges, and 30-day readmissions. Six ML algorithms, TabPFN, XGBoost, LightGBM, Support Vector Machine, Random Forest, and Logistic Regression, coupled with the Optuna optimization library for hyperparameter tuning, were tested. Models with the highest area under the receiver operating characteristic (AUROC) values were included in the web application. SHapley Additive exPlanations was used to evaluate importance of predictor variables. RESULTS: Our analysis included 423 patients. Of these patients, 111 (26.2%) experienced prolonged LOS, 33 (7.8%) had nonhome discharges, and 29 (6.9%) encountered 30-day readmissions. The top-performing models for each outcome were those built with the Random Forest algorithm. The Random Forest models yielded AUROCs of 0.868, 0.804, and 0.742 in predicting prolonged LOS, nonhome discharges, and 30-day readmissions, respectively. CONCLUSIONS: Our study uses ML to forecast adverse postoperative outcomes following TL. We developed accessible predictive models that enhance prognosis prediction for TL surgery. Making ML models available for this purpose represents a significant advancement in shifting toward a more patient-centric, data-driven paradigm.

3D4K exoscope in epilepsy surgery: a seminal experience.

BACKGROUND AND OBJECTIVES: To report the progressive introduction of the exoscope (EX) from surface lesionectomy to antero-mesial temporal lobectomy (AMTL) in an epilepsy surgery practice. METHODS: We describe a population of ten consecutive patients undergoing EX surgery, with a minimum follow-up of 6 months, that was compared to a similar population of patients referred to operative microscopic surgery (OM). RESULTS: All surgeries were performed with the use of EX or OM alone. Transient neurological complications for surgery in eloquent regions were recorded in one patient for each population. Nine and seven patients undergoing, respectively, EX and OM surgery resulted in Engel class Ia (90% vs. 70%). The mean duration of EX and OM surgery resulted in 265.5 and 237.9 min, respectively, with a mean of 308.3 and 253.3 min for AMTL cases, respectively. CONCLUSIONS: This preliminary study revealed that ORBEYE EX can be safe and effective in different types of epilepsy surgeries. The transition from OM to EX is fast, even though it is slower for the more challenging mesial temporal structure removal. Ergonomic and operative team interaction is improved by the use of EX. Our data need to be confirmed by larger studies.

Happy Birthday "One Flew Over the Cuckoo's Nest": A Momentous Tale in the Quest for an Effective and Ethical Approach to Psychosurgery.

The anniversary of the publication of 'One Flew Over the Cuckoo's Nest' by Ken Kesey offers an opportunity for reflection on the use of neurosurgery in psychiatry. We used a narrative, historical and dialectical method to deliver an account of the controversial subject. A balanced representation of the negative and positive aspects, acknowledging some of the questionable ethical practices while describing well-reasoned applications is provided. It includes neurosurgeons, psychiatrists who have embraced these procedures with unwarranted enthusiasm and those who have opposed. Neurosurgical techniques for the treatment of severe mental disorders have evolved from rudimentary procedures which were used to 'correct' unwanted behaviours associated with a wide range of severe mental disorders to more refined and selective approaches used as a last resort to treat specific mental health conditions. In the absence of specific aetiological models to guide ablative surgical targets, non-ablative, stimulatory techniques have more recently been developed to allow reversibility when surgical treatment fails to obtain a sizeable improvement in quality of life. The subject is concretely illustrated by two eloquent clinical images: one on a series of brain computed tomography scans carried out on a Canadian population of subjects, who underwent leukotomy decades ago, and the other more contemporary on an implantation surgery to epidural stimulation. Alongside technical advances in psychosurgery, a regulatory framework has gradually developed to ensure vigilance in the appropriateness of patients' selection. Nevertheless, harmonisation of protocols around the world is necessary to ensure consistency in obtaining and maintaining the highest possible ethical standards for the benefit of patients. If the neurosciences promise today, in their new, better framed, and reversible applications, to provide answers to unmet therapeutic needs, we still must remain attentive to drifts linked the introduction of intrusive technologies for purposes of domination or behaviour modification that would impede our individual freedom.

Lobectomy versus gross total resection for glioblastoma multiforme: A systematic review and individual-participant data meta-analysis.

Overall survival (OS)for glioblastoma multiforme (GBM) has a known association with the extent of tumor resection with gross total resection (GTR) typically considered as the upper limit. In certain regions such as the anterior temporal lobe, more extensive resection by means of a lobectomy may be feasible. In our systematic review and meta-analysis, we aimed to compare the outcomes of lobectomy and GTR for GBM. PubMed and Embase were queriedfor studies that compared the outcomes after lobectomy or GTR for GBM. The primary outcomes were OS, progression-free survival (PFS), and Karnofksy Performance Status (KPS) score at the latest follow-up. The secondary outcomes were seizure control at the latest follow-up and complication rates. Meta-analysis for OS and PFS was performed using individual-participant data reconstructed from published Kaplan-Meier curves. Random-effect meta-analysis was performed for KPS. The secondary outcomes were pooled using descriptive statistics. Of the 795 records screened, 6 were included in our study. Meta-analysis revealed that anterior temporal, frontal, or occipital lobectomy was associated with significantly better OS (p < 0.001) and PFS (p < 0.001) than GTR, but not KPS (MD = 6.37; 95% CI=(-13.80, 26.54); p = 0.536). Anterior temporal lobectomy was associated with significantly better seizure control rates than GTR for temporal GBM (OR = 27; 95% CI=(1.4, 515.9); p = 0.002). There was no statistically significant difference in complication rates between anterior temporal, frontal, or occipital lobectomy and GTR. In conclusion, lobectomy was associated with significantly better OS, PFS, and seizure control than GTR for GBM.

Psychiatric changes after stereotactic laser amygdalohippocampotomy for medial temporal lobe epilepsy.

PURPOSE: Stereotactic laser amygdalohippocampotomy (SLAH) is a minimally invasive surgical treatment for drug-resistant temporal lobe epilepsy (TLE) that has comparable rates of seizure freedom to traditional open resective TLE surgery. The objective of this study was to determine psychiatric outcome (i.e., depression and anxiety changes, psychosis) after SLAH, to explore possible contributory factors to these changes, and to determine the prevalence of de novo psychopathology. METHODS: We explored mood and anxiety in 37 adult patients with TLE undergoing SLAH using the Beck psychiatric symptoms scales (i.e., Beck Depression Inventory-II [BDI-II] and Beck Anxiety Inventory [BAI]) preoperatively and 6 months following surgery. Multivariable regression analysis was conducted to identify predictors of worse depression or anxiety symptoms following SLAH. The prevalence of de novo psychopathology following SLAH was also determined. RESULTS: We found a significant decrease in BDI-II (mean decline from 16.3 to 10.9, p = 0.004) and BAI (mean decline from 13.3 to 9.0, p = 0.045) scores following SLAH at the group level. While the rate of resolution of depression (from 62% to 49%) did not achieve statistical significance (p = 0.13, McNemar's), the rate of resolution of anxiety (from 57% to 35%) was statistically significant (p = 0.03, McNemar's). The de novo rate of psychopathology (i.e., new onset depression or anxiety) following SLAH was 1 of 7 (14%). Using a metric of meaningful change rather than complete symptom resolution, 16 of 37 (43%) patients experienced improvement in depression and 6 of 37 (16%) experienced worsening. For anxiety, 14 of 37 (38%) experienced meaningful improvement and 8 of 37 (22%) experienced worsening. Baseline performance on the Beck Scales was the only factor contributing to outcome status. DISCUSSION: In one of the first studies to evaluate psychiatric outcomes after SLAH, we found promising overall trends toward stability or significant improvement in symptom burden at the group level for both depression and anxiety. There was also a significant improvement in clinical anxiety, though the decrease in clinical depression was not significant, likely owing to the limitations of sample size. SLAH may improve overall psychiatric symptoms, similarly to traditional resective TLE surgery, but de novo psychopathology and postoperative psychiatric morbidity remain significant issues, and larger samples are necessary to determine causal contributory factors.

Cognitive outcomes following functional neurosurgery in refractory OCD patients: a systematic review.

Neurosurgery is a therapeutic option for patients with refractory obsessive-compulsive disorder who do not respond to previous treatments. Although its efficacy in reducing clinical symptomatology has been proven, few studies have analyzed its effects at the cognitive level. The aim of this systematic review was to describe the cognitive outcomes of functional neurosurgery in patients that went through capsulotomies or cingulotomies. PubMed, Medline, Scopus, PsycInfo, PsyArticles, and Web of Knowledge were searched for studies reporting cognitive outcomes in refractory obsessive-compulsive patients after capsulotomies and cingulotomies. The risk of bias was assessed with the Assessment Tool for Before-After (Pre-Post) Studies With No Control Group tool; 13 studies met inclusion criteria, including 205 refractory obsessive-compulsive disorder patients for both surgical procedures. Results showed a substantial number of studies that did report significant cognitive improvement after surgery, being this improvement specially related to memory and executive functions. The second-most frequent finding is the maintenance of cognitive performance (nor improvement or worsening). From a neuropsychological point of view, this outcome might be considered a success, given that it is accompanied by amelioration of obsessive-compulsive symptoms. Subtle cognitive adverse effects have also been reported. Neurosurgery procedures appear to be safe from a cognitive point of view. Methodological issues must be improved to draw clearer conclusions, but capsulotomies and cingulotomies constitute an effective alternative treatment for refractory obsessive-compulsive disorder patients.

Future directions in psychiatric neurosurgery: Proceedings of the 2022 American Society for Stereotactic and Functional Neurosurgery meeting on surgical neuromodulation for psychiatric disorders.

OBJECTIVE: Despite advances in the treatment of psychiatric diseases, currently available therapies do not provide sufficient and durable relief for as many as 30-40% of patients. Neuromodulation, including deep brain stimulation (DBS), has emerged as a potential therapy for persistent disabling disease, however it has not yet gained widespread adoption. In 2016, the American Society for Stereotactic and Functional Neurosurgery (ASSFN) convened a meeting with leaders in the field to discuss a roadmap for the path forward. A follow-up meeting in 2022 aimed to review the current state of the field and to identify critical barriers and milestones for progress. DESIGN: The ASSFN convened a meeting on June 3, 2022 in Atlanta, Georgia and included leaders from the fields of neurology, neurosurgery, and psychiatry along with colleagues from industry, government, ethics, and law. The goal was to review the current state of the field, assess for advances or setbacks in the interim six years, and suggest a future path forward. The participants focused on five areas of interest: interdisciplinary engagement, regulatory pathways and trial design, disease biomarkers, ethics of psychiatric surgery, and resource allocation/prioritization. The proceedings are summarized here. CONCLUSION: The field of surgical psychiatry has made significant progress since our last expert meeting. Although weakness and threats to the development of novel surgical therapies exist, the identified strengths and opportunities promise to move the field through methodically rigorous and biologically-based approaches. The experts agree that ethics, law, patient engagement, and multidisciplinary teams will be critical to any potential growth in this area.

Effects of ultrasound-guided erector spinae plane block on postoperative acute pain and chronic post-surgical pain in patients underwent video-assisted thoracoscopic lobectomy: a prospective randomized, controlled trial.

OBJECTIVE: To investigate the effects of ultrasound-guided erector spinae plane block (ESPB) on acute and chronic post-surgical pain in patients underwent video-assisted thoracoscopic lobectomy. METHODS: A total of 94 patients, who underwent elective unilateral video-assisted thoracoscopic lobotomy from August 2021 to December 2021 were randomly divided into general anesthesia group (group A, n = 46) and ESPB combined with general anesthesia group (group B, n = 48) by computer. Patient controlled intravenous analgesia(PCIA) was performed in both groups after operation. The numerical rating scale(NRS) of rest and cough pain at post anesthesia care unit(PACU), 2 h, 6 h, 12 h, 24 and 48 h after operation, frequency of PCIA in 24 h after operation, frequency of rescue analgesia, patient satisfaction, adverse reactions and complications were recorded in the two groups. Incidence of chronic pain at 3 months and 6 months after operation, the effect of daily life and rating of chronic pain management measures were recorded in the two groups. RESULTS: Compared with group A, rest and cough NRS score at 2 h, 6 h, 12 h, 24 and 48 h after surgery, frequency of PCIA use at 24 h after surgery, frequency of rescue analgesia were significantly decreased in group B (P < 0.05). There was no significant difference in NRS scores of rest and cough at PACU after operation between 2 groups after surgery at post anesthesia care unit (P > 0.05). There were no significant differences in the incidence of postoperative chronic pain between the 2 groups(P > 0.05);The effect of postoperative chronic pain on daily life and pain management measures in group B were significantly lower than those in group A(P < 0.05). Compared with group A, patients in group B had higher satisfaction degree, lower incidence of postoperative nausea and vomiting(PONV), and lower incidence of agitation during anesthesia recovery (P < 0.05). There were no pneumothorax, hematoma and toxicity of local anesthetic in the 2 groups. CONCLUSION: Ultrasound-guided erector spinae plane block can significantly reduce acute post-surgical pain, can not reduce the incidence of chronic post-surgical pain, but can significantly reduce the severity of chronic pain in patients underwent video-assisted thoracoscopic lobectomy. TRIAL REGISTRATION: ChiCTR2100050313,date of registration:26/08/2021.

Contemporary Role of Stereotactic Radiosurgery for Psychiatric Disorders.

Psychiatric disorders are the hidden pandemic of the current century. Despite major advances in medical management, the options for treatment are still limited. Neurosurgical intervention is effective for certain refractory psychiatric illnesses and the options range from stimulation surgeries to precise disconnection procedures influencing the neuronal network. Literature regarding stereotactic radiosurgery (SRS) is now enriched with successful treatment of obsessive compulsive disorder, major depression disorder, and anorexia nervosa. These procedures by reducing compulsions, obsessions, depression, and anxiety, improve substantially the quality of life for patients with a good safety profile. It is a valid treatment alternative for a selected group of patients who otherwise have no therapeutic options for whom the neurosurgical intervention is the only hope. It is also cost effective and highly reproducible among specialists. These procedures are adjuvant to the medical and behavioural treatment of psychiatric disorders. In this study the Contemporary role of Stereotactic radiosurgery is reviewed starting with relevant history of psychosurgery followed by individual psychiatric disorders.

Behavioral Improvements following Lesion Resection for Pediatric Epilepsy: Pediatric Psychosurgery?

INTRODUCTION: Resection of brain lesions associated with refractory epilepsy to achieve seizure control is well accepted. However, concurrent behavioral effects of these lesions such as changes in mood, personality, and cognition and the effects of surgery on behavior have not been well characterized. We describe 5 such children with epileptogenic lesions and significant behavioral abnormalities which improved after surgery. CASE DESCRIPTIONS: Five children (ages 3-14 years) with major behavioral abnormalities and lesional epilepsy were identified and treated at our center. Behavioral problems included academic impairment, impulsivity, self-injurious behavior, and decreased social interaction with diagnoses of ADHD, oppositional defiant disorder, and autism. Pre-operative neuropsychiatric testing was performed in 4/5 patients and revealed low-average cognitive and intellectual abilities for their age, attentional difficulties, and poor memory. Lesions were located in the temporal (2 gangliogliomas, 1 JPA, 1 cavernoma) and parietal (1 DNET) lobes. Gross total resection was achieved in all cases. At mean 1-year follow-up, seizure freedom (Engel 1a in 3 patients, Engel 1c in 2 patients) and significant behavioral improvements (academic performance, attention, socialization, and aggression) were achieved in all. Two patients manifested violence pre-operatively; one had extreme behavior with violence toward teachers and peers despite low seizure burden. Since surgery, his behavior has normalized. CONCLUSION: We identified 5 patients with severe behavioral disorders in the setting of lesional epilepsy, all of whom demonstrated improvement after surgery. The degree of behavioral abnormality was disproportionate to epilepsy severity, suggesting a more complicated mechanism by which lesional epilepsy impacts behavior. We propose a novel paradigm in which lesionectomy may offer behavioral benefit even when seizures are not refractory. Thus, behavioral improvement may be an important novel goal for neurosurgical resection in children with epileptic brain lesions.

Effects of thoracic paravertebral nerve block on postoperative pain and postoperative delirium in elderly patients undergoing thoracoscopic lobectomy.

OBJECTIVES: To evaluate the effects of ultrasound-guided thoracic paravertebral nerve block on perioperative pain and postoperative delirium in elderly patients undergoing thoracoscopic lobotomy. METHODS: Patients aged 60 to 80 years who underwent the surgery of thoracoscopic lobectomy were selected; ASA grades I to III and New York Heart Association (NYHA) grades I to II. Patients were randomly divided into two groups: group C (group Compaired) and group T (group Thoracic Paravertebral Nerve Block TPVB). Patients in group T received ultrason-guided TPVB while those in group C didn't received TPVB. Postoperative patient-controlled intravenous analgesia was administered to all the patients. The consumption of intraoperative opioids, cases of hipoxemia, operative time, and extubation time was also recorded. Pain scores (static and dynamic) were assessed at 2, 4, 6, 24, 48, 72, 96, and 120 hours point after the operation. Pain scores, occurrence of postoperative delirium occurrence, postoperative complications, total amount of analgesic drugs, length of hospital stay, rescue analgesic requirement, and side effects were recorded within 5 days. RESULTS: Intraoperative dosages of sufentanil and remifentanil were significantly lower in group T (Table 1). The postoperative recovery time in group T was significantly shortened (Table 1). The VAS pain scores of group T at 2, 4, 6, and 24 hours after surgery were much lower. The consumption of intraoperative opioids, number of rescue analgesic requirements, and the occurrence of postoperative delirium incidence in group T was significantly reduced (Table 2). There were no differences in hipoxemia events, postoperative nausea, vomiting and pulmonary complications between the two groups (Table 2). CONCLUSION: Preoperative ultrasound-guided thoracic paravertebral nerve block (TPVB) can obviously decrease the intraoperative and postoperative opioids consumption, shorten the recovery time, reduce the number of rescue analgesia and the incidence of postoperative delirium in elderly patients undergoing thoracoscopic lobotomy.

Balloon-Assisted Corpus Callosotomy. Reducing the Impact of Transcallosal Approaches.

BACKGROUND: The interhemispheric transcallosal approach is widely used to remove intraventricular lesions. Corpus callosotomy gives immediate access to the ventricular chambers but is invasive in nature. Loss of callosal fibers, although normally tolerate, may cause disturbances ranging from a classical disconnection syndrome up to minor neuropsychological changes. OBJECTIVE: To open an operative window in the corpus callosum through separation rather than disconnection of the white matter fibers. METHODS: In 7 patients undergoing the interhemispheric transcallosal approach for intraventricular lesions, lying around or below the foramen of Monro, a stoma was created within the corpus callosum by using a 4F Fogarty catheter. The series included 3 colloid of the third ventricle, 2 thalamic cavernomas, 1 subependymoma, and 1 ependymoma of the foramen of Monro. We illustrate the technique and the clinico-radiological outcome, focusing on the size of callosotomy as seen on postoperative MRI. RESULTS: The balloon-assisted corpus callosotomy provided a circular, smooth-walled access to the ventricular chambers, which allowed uncomplicated removal of the lesions. On postoperative MRI, the size of the callosotomy shrinked compared with surgery (2.8-6.4 mm at follow-up vs 6-9 mm as measured intraoperatively). No signs of disconnection syndrome or new permanent deficits were observed in this series. CONCLUSION: The balloon-assisted technique produces a small callosotomy, without clinical consequences, showing a self-closing trend on postoperative MRI. This technique is a rewarding tool to reduce the impact of callosotomy while keeping the advantages of microsurgical interhemispheric approaches.

William Macewen and the first documented successful resection of a brain tumor.

William Macewen was a visionary fearless Scottish surgeon who performed the first documented successful resection of a brain tumor on July 27, 1879. The pioneering operation received little attention at the time, and even today Macewen is under-recognized for his historic accomplishment. In this vignette, the author discusses details of Macewen's landmark procedure and describes two other groundbreaking brain tumor operations, one performed by Rickman Godlee 5 years later and another performed by Zanobi Pecchioli almost half a century earlier.

Corpus Callosotomy for Non-Localizing Drug Resistant Epilepsy with Drop Attacks.

BACKGROUND: Corpus callosotomy (CC) is a surgical palliative procedure done for a selected group of patients with drug resistant epilepsy (DRE) to stop drop attacks and prevent falls. METHODS: We performed a retrospective chart review of consecutive patients who underwent CC for DRE with drop attacks at our center between 2015 and 2019. Clinical, imaging details and surgical findings were noted. Clinical outcomes and functional status were evaluated. RESULTS: During the study period, 17 patients underwent corpus callosotomy (Male: Female 14:3). The mean age at surgery was 10.3 years (standard deviation - 5.85, interquartile range [IQR] = 6.5). The mean age at onset of seizure was 2.23 years (standard deviation - 3.42, IQR = 1.5). Preoperative seizure frequency ranged from 2 to 60 attacks per day (median: 20, IQR= 36). All patients had atonic seizures/drop attacks. One patient underwent anterior CC and 16 underwent complete CC. Three patients had complications in the postoperative period. The median follow-up was 26 months. All patients had cessation of drop attacks immediately following surgery. One patient with anterior CC had a recurrence of drop attacks for which she underwent completion CC. Another patient had recurrent drop attacks 3 years later and was found to have a residual callosal connection. Three patients had complete seizure freedom and 4 patients had a <50% reduction in seizure frequency. CONCLUSIONS: Our study lends additional support to the efficacy of CC in patients with DRE, with the cessation of drop attacks. It also provided a reasonable reduction in seizure frequency. Complete CC led to better control of drop attacks.

Ablation Surgeries for Treatment-Resistant Depression: A Meta-Analysis and Systematic Review of Reported Case Series.

BACKGROUND AND OBJECTIVES: Ablative lesion procedures remain as the last option in treatment of refractory depression. Contemporary ablative psychosurgeries involve producing lesions in the anterior limb of the internal capsule (bilateral anterior capsulotomy - BAC), the supragenual anterior cingulate gyrus and cingulum (bilateral anterior cingulotomy - BACING), and subgenual anterior cingulate gyrus and subcortical orbitofrontal white matter (bilateral subcaudate tractotomy - BST). A combination of BACING and BST is known as limbic leukotomy (bilateral limbic leukotomy - BLL). All procedures claim some success, but cohorts are small, depression assessment instruments differ, and inclusion and outcome criteria and follow-up duration vary. In some cohorts, more than one type of surgery was performed in several patients, further confounding interpreting the available data. Current evidence is equivocal on which surgical target works best. Method and Aim: This systematic review and meta-analysis using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) standard on published cohorts was conducted to review and identify which is the best standalone ablative procedure for treatment-resistant depression (TRD) based on response rate (event rate) and adverse-effect profile using the Comprehensive Meta-Analysis software. RESULTS AND CONCLUSION: As a standalone neurosurgical procedure, we found that BAC appears to be the most effective and safest of all the ablative targets for TRD. A major limitation of this conclusion is the paucity of published case series where sample sizes are small and all are open label.

Serendipity and Observations in Functional Neurosurgery: From James Parkinson's Stroke to Hamani's & Lozano's Flashbacks.

BACKGROUND: Serendipity and observations have a noble tradition in medicine, including neurology, and are responsible for many medical treatments (carbamazepine for tic douloureux, amantadine for Parkinson's disease, gabapentin for restless legs…). We aimed at examining the contribution of serendipity and observations to functional neurosurgery. Scholarly publications relevant to the history of functional neurosurgery for movement and psychiatric disorders were reviewed, starting from the pre-stereotactic era. The documents were scrutinized with respect to indications for surgery, surgical methods, and brain targets, in view of determining whether serendipitous discoveries and other observations contributed to various functional neurosurgical procedures. SUMMARY: James Parkinson's observation that tremors disappeared in the arm of a person with shaking palsy after a hemiparetic stroke encouraged neurosurgeons in the first half of the 20th century to perform ablative procedures on central motor pathways. Following a lobotomy performed by Browder that extended too far medially in a psychiatric patient with coexisting Parkinson's disease (PD), it was noted that the Parkinsonian signs improved. This encouraged Russel Meyers to carry out open surgery on the caudate nucleus and basal ganglia in PD. Cooper introduced ligation of the anterior choroidal artery as a treatment for PD following a surgical accident during a pedunculotomy. Cooper later started to perform stereotactic surgery on the ventrolateral thalamus following the pathological finding that an intended pallidal lesion had in fact targeted the thalamus. Leksell discovered the ideal location of a pallidal lesion being in the posteroventral area empirically, long before the advent of the basal ganglia model of PD. Modern Deep Brain Stimulation (DBS) that started in the thalamus for tremor was the result of an observation by Benabid that intraoperative high-frequency stimulation during a thalamotomy reduced tremor. Both the discoveries of the anterior limbic subthalamic nucleus as a DBS target for OCD and the medial forebrain bundle as a DBS target for depression occurred by chance. Hamani and Lozano observed memory flashbacks in a patient who was undergoing DBS for obesity, which led to the discovery of the fornix as a potential DBS target for Alzheimer's disease. KEY MESSAGES: In the history of functional neurosurgery, serendipity and observations have resulted in discoveries of several procedures, brain targets for lesioning or DBS as well as new clinical surgical indications. In this era of neuromodulation, this technology should be exquisite in allowing potential serendipitous discoveries, provided that clinicians remain both observant and prepared.