Beyond the aging spine - a systematic review of functional changes in the human brain in cervical spondylotic myelopathy.

Cervical Spondylotic Myelopathy (CSM) is a degenerative condition that leads to loss of cervical spinal cord integrity, typically affecting the aged population. Emerging fMRI-based evidence suggests that the brain is also affected by CSM. This systematic review aimed to understand the usefulness of brain fMRI in CSM. A comprehensive literature search was conducted until March 2023 according to PRISMA guidelines. The inclusion criteria included original research articles in English, primarily studying the human brain's functional changes in CSM using fMRI with at least 5 participants. The extracted data from each study included demographics, disease severity, MRI machine characteristics, affected brain areas, functional changes, and clinical utilities. A total of 30 studies met the inclusion criteria. Among the fMRI methods, resting-state fMRI was the most widely used experimental paradigm, followed by motor tasks. The brain areas associated with motor control were most affected in CSM, followed by the superior frontal gyrus and occipital cortex. Functional changes in the brain were correlated to clinical metrics showing clinical utility. However, the evidence that a specific fMRI metric correlating with a clinical metric was "very low" to "insufficient" due to a low number of studies and negative results. In conclusion, fMRI can potentially facilitate the diagnosis of CSM by quantitatively interrogating the functional changes of the brain, particularly areas of the brain associated with motor control. However, this field is in its early stages, and more studies are needed to establish the usefulness of brain fMRI in CSM.

A parcellation-based connectomic model of hemispatial neglect.

BACKGROUND AND PURPOSE: Hemispatial neglect is characterized by a reduced awareness to stimuli on the contralateral side. Current literature suggesting that damage to the right parietal lobe and attention networks may cause hemispatial neglect is conflicting and can be improved by investigating a connectomic model of the "neglect system" and the anatomical specificity of regions involved in it. METHODS: A meta-analysis of voxel-based morphometry magnetic resonance imaging (MRI) studies of hemispatial neglect was used to identify regions associated with neglect. We applied parcellation schemes to these regions and performed diffusion spectrum imaging (DSI) tractography to determine their connectivity. By overlaying neglect areas and maps of the attention networks, we studied the relationship between them. RESULTS: The meta-analysis generated a list of 13 right hemisphere parcellations. These 13 neglect-related parcellations were predominantly linked by the superior longitudinal fasciculus (SLF) throughout a fronto-parietal-temporal network. We found that the dorsal and ventral attention networks showed partial overlap with the neglect system and included various other higher-order networks. CONCLUSIONS: We provide an anatomically specific connectomic model of the neurobehavioral substrates underlying hemispatial neglect. Our model suggests a fronto-parietal-temporal network linked via the SLF supports the functions impaired in neglect and implicates various higher-order networks which are not limited to the attention networks.

Delayed hemorrhage following deep brain stimulation device placement in a patient with Parkinson's disease and lupus anticoagulant syndrome: illustrative case.

BACKGROUND: Treatment options for Parkinson's disease (PD) include both medical and surgical approaches. Deep brain stimulation (DBS) is a surgical procedure that aims to improve motor symptomatology. OBSERVATIONS: A 66-year-old White male with a 9-year history of PD presented to the neurosurgery clinic for DBS consideration. On the morning of scheduled surgery, preoperative laboratory test results revealed a prolonged prothrombin time of 50 seconds. Surgery was postponed, and further work-up revealed that the patient had a positive test result for lupus anticoagulant (LA). DBS implantation was performed 2 months later. The first stage of surgery was uneventful. The patient returned 1 week later for the second stage. Postoperatively, the patient exhibited a diminished level of consciousness. Computed tomography revealed left frontal intraparenchymal hemorrhage with surrounding edema, trace subarachnoid hemorrhage, intraventricular hemorrhage, and midline shift. LESSONS: The authors suspect that the hemorrhage occurred secondary to venous infarct, because LA is associated with a paradoxically increased risk of thrombosis. Although there is no documented association between LA and acute or delayed hemorrhage, this case demonstrates a possible relationship in a patient following DBS placement. More research is needed to confirm an association with coexisting LA with PD and an increased hemorrhage risk in neurosurgical interventions.

Management of nonoperative cervical spine fractures: An institutional analysis of follow-up duration and image acquisition.

Background: How long do nonoperative cervical fractures have to be followed and with how many imaging studies? Methods: We reviewed 69 adult patients with 122 (31 occiptocervical and 91 sub-axial) cervical fractures; at least one of the cervical fractures was managed nonoperatively. Outcomes were assessed along with the optimal follow-up duration and frequency of various diagnostic studies. Results: An average of four follow-up visits occurred on average 28-, 66-, 94-, and 158-day post hospital discharge. The average time between discharge and orthotic clearance was 70 days (±32.4 days). Radiographic studies were obtained at follow-up visits, respectively, in, 82.6%, 83.6%, 94.7%, and 100% of patients. Conclusion: The trend for managing nonoperative cervical fractures was an unduly prolonged follow-up duration that included obtaining too many imaging studies.

Practice Patterns of Ventriculoperitoneal Shunt Placement in Academic and Community Settings: A National Survey of Practicing Neurosurgeons.

OBJECTIVE: We sought to assess the practice patterns of ventriculoperitoneal shunt (VPS) placement by neurosurgeons at academic, community, and government-based institutions. METHODS: Using the American Association of Neurological Surgeons directory, a total of 3673 practicing neurosurgeons were contacted. The survey received 495 responses (57% academic, 41% community, 3% other/government based). The survey consisted of 9 questions to assess the frequency of general surgery assistance for distal VPS placement and the use of cranial neuronavigation for proximal placement and to assess subjective beliefs of personal practice pattern and the influence on shunt failure rates. RESULTS: Almost half of the respondents reported using general surgery less than half of the time for distal VPS placement. Regardless of personal practice patterns, roughly one third of respondents reported that general surgery assistance is a common or somewhat common practice at their institution. The most common reasons for recruiting general surgery assistance were cases of higher complexity. Although commonly used, almost 40% of respondents believe that general surgery assistance does not decrease shunt failure rates. Cranial neuronavigation is used less than half of the time, and the most common reason was for improved accuracy. Almost half of the respondents believe navigation does decrease shunt failure rates. CONCLUSIONS: General surgery assistance for distal placement and neuronavigation for the proximal placement of VPS catheters are both commonly used by neurosurgeons in academic, community, and other practice locations. This survey provides the first assessment of practice patterns nationally. The results demonstrate that roughly half of the practicing neurosurgeons use general surgery assistance and neuronavigation, particularly for complex or high-risk cases.

Impact of Obesity and Diabetes on Postoperative Outcomes Following Surgical Treatment of Nontraumatic Subarachnoid Hemorrhage: Analysis of the ACS-NSQIP Database.

BACKGROUND: Nontraumatic subarachnoid hemorrhage (SAH) refers to high pressure extravasation of blood into the subarachnoid space that typically occurs spontaneously from rupture of cerebral aneurysm. The purpose of this study was to identify postoperative complications requiring increased surveillance in obese, diabetic, and hypertensive patients. METHODS: Patients who underwent surgical treatment for nontraumatic SAH were queried in the American College of Surgeons National Surgical Quality Improvement Program database from the years 2012-2018. Cases were identified using International Classification of Diseases codes and then classified independently by 3 dichotomous diagnoses: obesity, diabetes, and hypertension. RESULTS: Among 1002 patients meeting inclusion criteria, 311 (31%) were obese (body mass index >30), 86 (9%) had diabetes treated with insulin or noninsulin agents, and 409 (41%) required medication for hypertension. There was a statistically significant association between diabetes and postoperative pneumonia (odds ratio [OR] = 1.694; 95% confidence interval [CI] = 0.995-2.883; P = 0.050), prolonged ventilator dependence (OR = 1.700; 95% CI = 1.087-2.661; P = 0.019), and death (OR = 1.846; 95% CI = 1.071-3.179; P = 0.025). Medication-dependent hypertension was statistically associated with incidence of stroke/cerebrovascular accident (OR = 1.763; 95% CI = 1.056-2.943; P = 0.023). Obesity was not associated with adverse outcomes in this population. CONCLUSIONS: In patients undergoing surgical management of SAH, hypertensive and diabetic patients had poorer outcomes, including prolonged ventilator dependence, pneumonia, stroke/cerebrovascular accident, and death. Surprisingly, preexisting obesity was not associated with poor outcomes. In fact, overweight body mass index, class I obesity, and class II obesity had decreased need for transfusion in the 30-day postoperative period.

Polymorphous low-grade neuroepithelial tumor of the young: Rare tumor and review of the literature.

Polymorphous low-grade neuroepithelial tumor of the young (PLNTY) is a recently described low-grade neuroepithelial tumor with an infiltrative growth pattern and oligodendrocyte-like cells that are CD34 immunopositive. Correlating histology and results from molecular testing is critical to correctly diagnosing PLNTY, as its histologic appearance is similar to oligodendrogliomas and shares genetic abnormalities common to other low-grade epilepsy associated tumors (LEATs). In this case report, we describe a 31-year-old female with intractable epilepsy found to have a temporal mass and diagnosed with PLNTY after histopathologic and molecular testing. We describe the radiographic, histologic, and genetic features in relation to the epileptic and oncologic outcomes for this patient. Then, we compare these features and outcomes to other cases of PLNTY described in the literature.

A systematic review of amino acid PET in assessing treatment response to temozolomide in glioma.

The response assessment in neuro-oncology (RANO) criteria have been the gold standard for monitoring treatment response in glioblastoma (GBM) and differentiating tumor progression from pseudoprogression. While the RANO criteria have played a key role in detecting early tumor progression, their ability to identify pseudoprogression is limited by post-treatment damage to the blood-brain barrier (BBB), which often leads to contrast enhancement on MRI and correlates poorly to tumor status. Amino acid positron emission tomography (AA PET) is a rapidly growing imaging modality in neuro-oncology. While contrast-enhanced MRI relies on leaky vascularity or a compromised BBB for delivery of contrast agents, amino acid tracers can cross the BBB, making AA PET particularly well-suited for monitoring treatment response and diagnosing pseudoprogression. The authors performed a systematic review of PubMed, MEDLINE, and Embase through December 2021 with the search terms "temozolomide" OR "Temodar," "glioma" OR "glioblastoma," "PET," and "amino acid." There were 19 studies meeting inclusion criteria. Thirteen studies utilized [18F]FET, five utilized [11C]MET, and one utilized both. All studies used static AA PET parameters to evaluate TMZ treatment in glioma patients, with nine using dynamic tracer parameters in addition. Throughout these studies, AA PET demonstrated utility in TMZ treatment monitoring and predicting patient survival.

Functional connectivity of hippocampus in temporal lobe epilepsy depends on hippocampal dominance: a systematic review of the literature.

BACKGROUND: Lateralized alterations in hippocampal function in the resting-state have been demonstrated for patients with temporal lobe epilepsy (TLE). However, resting-state fMRI of the hippocampus has yet to be substantiated as an adjunct to standard pre-operative assessments of the seizure focus. OBJECTIVE: Here we report the results of a systematic review of resting-state fMRI studies investigating laterality of hippocampal network connectivity in TLE patients. METHODS: A search of the PubMed, SCOPUS, Web of Science, and Embase databases for full-length articles written in English was conducted through June 2020 using the following terms: 'resting state fMRI,' 'hippocampus,' 'epilepsy,' and 'laterality.' RESULTS: Our literature search yielded a total of 42 papers. After excluding studies that did not include patients with epilepsy, utilize resting-state fMRI, or explore the relationship between functional connectivity and disease lateralization, 20 publications were selected for inclusion. From these studies, a total of 528 patients, 258 with left TLE and 270 with right TLE, and 447 healthy controls were included. Of the 20 studies included, 18 found that patients with TLE demonstrated decreased hippocampal functional connectivity ipsilateral to the epileptogenic focus and 10 additionally reported increased hippocampal functional connectivity contralateral to the epileptogenic focus. Several studies demonstrated that the duration of disease was correlated with these changes in functional connectivity. This implies that a compensatory mechanism may be present in patients with treatment-refractory TLE. CONCLUSION: The consistency of this hippocampal connectivity pattern across multiple studies suggests resting-state fMRI may be useful as a non-invasive diagnostic tool for preoperative evaluation of TLE patients.

Utility of machine learning algorithms in degenerative cervical and lumbar spine disease: a systematic review.

Machine learning is a rapidly evolving field that offers physicians an innovative and comprehensive mechanism to examine various aspects of patient data. Cervical and lumbar degenerative spine disorders are commonly age-related disease processes that can utilize machine learning to improve patient outcomes with careful patient selection and intervention. The aim of this study is to examine the current applications of machine learning in cervical and lumbar degenerative spine disease. A systematic review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A search of PubMed, Embase, Medline, and Cochrane was conducted through May 31st, 2020, using the following terms: "artificial intelligence" OR "machine learning" AND "neurosurgery" AND "spine." Studies were included if original research on machine learning was utilized in patient care for degenerative spine disease, including radiographic machine learning applications. Studies focusing on robotic applications in neurosurgery, navigation, or stereotactic radiosurgery were excluded. The literature search identified 296 papers, with 35 articles meeting inclusion criteria. There were nine studies involving cervical degenerative spine disease and 26 studies on lumbar degenerative spine disease. The majority of studies for both cervical and lumbar spines utilized machine learning for the prediction of postoperative outcomes, with 5 (55.6%) and 15 (61.5%) studies, respectively. Machine learning applications focusing on degenerative lumbar spine greatly outnumber the current volume of cervical spine studies. The current research in lumbar spine also demonstrates more advanced clinical applications of radiographic, diagnostic, and predictive machine learning models.

Patient Outcomes in Disorders of Consciousness Following Transcranial Magnetic Stimulation: A Systematic Review and Meta-Analysis of Individual Patient Data.

Background: There are few treatments with limited efficacy for patients with disorders of consciousness (DoC), such as minimally conscious and persistent vegetative state (MCS and PVS). Objective: In this meta-analysis of individual patient data (IPD), we examine studies utilizing transcranial magnetic stimulation (TMS) as a treatment in DoC to determine patient and protocol-specific factors associated with improved outcomes. Methods: We conducted a systematic review of PubMed, Ovid Medline, and Clinicaltrials.gov through April 2020 using the following terms: "minimally conscious state," or "persistent vegetative state," or "unresponsive wakefulness syndrome," or "disorders of consciousness" and "transcranial magnetic stimulation." Studies utilizing TMS as an intervention and reporting individual pre- and post-TMS Coma Recovery Scale-Revised (CRS-R) scores and subscores were included. Studies utilizing diagnostic TMS were excluded. We performed a meta-analysis at two time points to generate a pooled estimate for absolute change in CRS-R Index, and performed a second meta-analysis to determine the treatment effect of TMS using data from sham-controlled crossover studies. A linear regression model was also created using significant predictors of absolute CRS-R index change. Results: The search yielded 118 papers, of which 10 papers with 90 patients were included. Patients demonstrated a mean pooled absolute change in CRS-R Index of 2.74 (95% CI, 0.62-4.85) after one session of TMS and 5.88 (95% CI, 3.68-8.07) at last post-TMS CRS-R assessment. The standardized mean difference between real rTMS and sham was 2.82 (95% CI, -1.50 to 7.14), favoring rTMS. The linear regression model showed that patients had significantly greater CRS-R index changes if they were in MCS, had an etiology of stroke or intracranial hemorrhage, received 10 or more sessions of TMS, or if TMS was initiated within 3 months from injury. Conclusions: TMS may improve outcomes in MCS and PVS. Further evaluation with randomized, clinical trials is necessary to determine its efficacy in this patient population.

A systematic review of the utility of amino acid PET in assessing treatment response to bevacizumab in recurrent high-grade glioma.

BACKGROUND: Currently, bevacizumab (BEV), an antiangiogenic agent, is used as an adjunctive therapy to re-irradiation and surgery in patients with recurrent high-grade gliomas (rHGG). BEV has shown to decrease enhancement on MRI, but it is often unclear if these changes are due to tumor response to BEV or treatment-induced changes in the blood brain barrier. Preliminary studies show that amino acid PET can aid in distinguishing these changes on MRI. METHODS: The authors performed a systematic review of PubMed and Embase through July 2020 with the search terms 'bevacizumab' or 'Avastin' and 'recurrent glioma' and 'PET,' yielding 38 papers, with 14 meeting inclusion criteria. RESULTS: Thirteen out of fourteen studies included in this review used static PET and three studies used dynamic PET to evaluate the use of BEV in rHGG. Six studies used the amino acid tracer [18F]FET, four studies used [11C]MET, and four studies used [18F]FDOPA. CONCLUSION: [18F]FET, [11C]MET, and [18F]FDOPA PET in combination with MRI have shown promising results for improving accuracy in diagnosing tumor recurrence, detecting early treatment failure, and distinguishing between tumor progression and treatment-induced changes in patients with rHGG treated with BEV.

Reported incidence and treatment modalities of giant cerebral aneurysms in the pediatric population: A systematic review and illustrative case report.

Giant intracranial aneurysms represent a complex pathology that pose challenges for management, especially in the pediatric population. With emerging endovascular techniques, combined endovascular and open surgical approaches may be a favorable alternative for complex cases. In this systematic review, we characterize the treatment modalities of giant aneurysms in the pediatric population and provide an update on the number of giant aneurysms reported in the literature by anatomic location. We conducted a literature search of PubMed, Embase, and Medline databases with the following terms: 'pediatric' AND 'giant' AND 'intracranial aneurysm.' Studies were included if data on treatment modality and aneurysm location were available for pediatric patients with giant intracranial aneurysms. The literature search yielded a total of 188 papers, with 82 pediatric patients from 33 articles ultimately meeting inclusion criteria. There were significantly more male than female patients (p = 0.011), with 52 and 29 respectively. Patients presenting with a ruptured aneurysm were significantly younger than patients presenting without rupture (p = 0.018), with a median age of 8.0 and 12.0 years, respectively. There were 45 giant aneurysms reported in the anterior circulation and 37 in the posterior circulation. Anterior aneurysms were most often treated with surgical approaches, while posterior aneurysms were typically treated with endovascular interventions (p = 0.002). Although combined surgical and endovascular approaches were the least frequently utilized, we suggest a combined approach may be particularly useful for patients with complex cases that require a management plan tailored to their needs.

A connectivity model of the anatomic substrates underlying ideomotor apraxia: A meta-analysis of functional neuroimaging studies.

BACKGROUND: Patients with ideomotor apraxia (IMA) present with selective impairments in higher-order motor cognition and execution without damage to any motor or sensory pathways. Although extensive research has been conducted to determine the regions of interest (ROIs) underlying these unique impairments, previous models are heterogeneous and may be further clarified based on their structural connectivity, which has been far less described. OBJECTIVE: The goal of this research is to propose an anatomically concise network model for the neurophysiologic basis of IMA, specific to the voluntary pantomime, imitation and tool execution, based on intrinsic white matter connectivity. METHODS: We utilized meta-analytic software to identify relevant ROIs in ideomotor apraxia as reported in the literature based on functional neuroimaging data with healthy participants. After generating an activation likelihood estimation (ALE) of relevant ROIs, cortical parcellations overlapping the ALE were used to construct an anatomically precise model of anatomic substrates using the parcellation scheme outlined by the Human Connectome Project (HCP). Deterministic tractography was then performed on 25 randomly selected, healthy HCP subjects to determine the structural connectivity underlying the identified ROIs. RESULTS: 10 task-based fMRI studies met our inclusion criteria and the ALE analysis demonstrated 6 ROIs to constitute the IMA network: SCEF, FOP4, MIP, AIP, 7AL, and 7PC. These parcellations represent a fronto-parietal network consisting mainly of intra-parietal, U-shaped association fibers (40%) and long-range inferior fronto-occipital fascicle (IFOF) fibers (50%). These findings support previous functional models based on dual-stream motor processing. CONCLUSION: We constructed a preliminary model demonstrating the underlying structural interconnectedness of anatomic substrates involved in higher-order motor functioning which is seen impaired in IMA. Our model provides support for previous dual-stream processing frameworks discussed in the literature, but further clarification is necessary with voxel-based lesion studies of IMA to further refine these findings.

Women in Neurosurgery Around the World: A Systematic Review and Discussion of Barriers, Training, Professional Development, and Solutions.

BACKGROUND: Women have been a minority in neurosurgery since the foundation of the specialty. Women who choose to pursue neurosurgery or advance in their career must overcome various obstacles. In this article, we discuss the proportion of women in neurosurgery globally and the obstacles they face, as well as the solutions being implemented. METHODS: A systematic review of studies concerning international women in neurosurgery was conducted. Article inclusion was assessed based on relevance to women of neurosurgery, geographic region, date, and classification (rates/data, barriers, or solutions). RESULTS: From the specified search, 127 articles were retrieved, and 27 met the inclusion criteria. Of the total, 25 countries were represented and discussed in the articles. Primary classification of articles resulted in 50 for data/rates, 22 for barriers, and 17 for possible solutions. DISCUSSION: Despite cultural differences among unique regions of the globe, women face similar challenges when pursuing neurosurgery, such as difficulty advancing their careers, balancing duties at work and at home, meeting social and cultural expectations, and finding support and mentorship. Encouragingly, measures are already being implemented worldwide to allow women to fulfill their multiple other roles through maternity leave policies, increasing their access to mentors, and enabling promotions throughout their careers. CONCLUSIONS: With the shortage of neurosurgeons in many regions of the world, the recruitment of female neurosurgeons plays a vital role in meeting those demands. Our cultures and professional societies should celebrate their inclusion and promotion and accommodate the complex role of women as neurosurgeons, mothers, partners, scientists, and leaders.

Akinetic mutism reversed by inferior parietal lobule repetitive theta burst stimulation: Can we restore default mode network function for therapeutic benefit?

BACKGROUND: Transcranial magnetic stimulation is a noninvasive treatment used to modulate cortical excitability. Its use over the last two decades has expanded, ranging from psychiatric disorders to traumatic brain injury and poststroke rehabilitation. OBJECTIVES: We present the case of a 59-year-old male patient who presented in a decreased state of consciousness due to a right frontal glioblastoma, wherein his state was not improved by a successful surgery and could not be explained by any other condition. Due to his poor prognosis, we examine the benefits of receiving transcranial magnetic stimulation treatment to improve his akinetic mutism. METHODS: We utilized independent component analysis with resting-state functional magnetic resonance imaging (rsfMRI) to better understand his cortical functionality. The imaging suggested absence of the default mode network (DMN). The patient underwent five sessions of navigated intermittent theta burst stimulation to the ipsilesional inferior parietal lobule and inferior frontal gyrus, with the aim of improving his default mode network functionality. RESULTS: No other treatments resulted in an improvement of this patient's condition; however, 3 weeks following transcranial magnetic stimulation treatment, the patient was more alert and interactive, and his follow-up rsfMRI scan demonstrated a partially intact default mode network. CONCLUSION: This case raises important questions regarding the clinical utility of transcranial magnetic stimulation to improve the connectivity of important cerebral networks and subsequent related functional recovery.

Robotics in spine surgery: A systematic review.

Robotic systems to assist with pedicle screw placement have recently emerged in the field of spine surgery. Here, the authors systematically reviewed the literature for evidence of these robotic systems and their utility. Thirty-four studies that reported the use of spinal instrumentation with robotic assistance and met inclusion criteria were identified. The outcome measures gathered included: pedicle screw accuracy, indications for surgery, rates of conversion to an alternative surgical method, radiation exposure, and learning curve. In our search there were five different robotic systems identified. All studies reported accuracy and the most commonly used accuracy grading scale was the Gertzbein Robbins scale (GRS). Accuracy of clinically acceptable pedicle screws, defined as < 2 mm cortical breech, ranged from 80% to 100%. Many studies categorized indications for robotic surgery with the most common being degenerative entities. Some studies reported rates of conversion from robotic assistance to manual instrumentation due to many reasons, with robotic failure as the most common. Radiation exposure data revealed a majority of studies reported less radiation using robotic systems. Studies looking at a learning curve effect with surgeon use of robotic assistance were not consistent across the literature. Robotic systems for assistance in spine surgery have continued to improve and the accuracy of pedicle screw placement remains superior when compared to free-hand technique, however rates of manual conversion are significant. Currently, these systems are successfully employed in various pathological entities where trained spine surgeons can be safe and accurate regardless of robotic training.

Resolution of symptoms in idiopathic thalamic pain syndrome after implantation of a cervical and thoracic percutaneous spinal cord stimulator.

BACKGROUND: Thalamic pain syndrome is classically described as chronic pain after an infarct of the thalamus. It leads to a decrease in the quality of life, especially for patients with inadequate treatment. Supportive imaging, such as a thalamic lesion or infarct, is widely accepted as necessary to diagnose this condition. CASE DESCRIPTION: In this case report, we describe the case of a patient who developed allodynia and hyperesthesia with a hemibody distribution characteristic of thalamic pain syndrome, despite having no clear inciting event or identifiable thalamic lesion. This patient was successfully treated with cervical and thoracic spinal cord stimulation (SCS). CONCLUSION: We suggest that this patient may have presented with a non-lesional thalamic pain syndrome, supported by the classic hemibody allodynia and hyperesthesia and the response to SCS. Further, we demonstrate that SCS was an effective method to control this central pain disorder.

Parcellation-based modeling of the supplementary motor area.

INTRODUCTION: The supplementary motor area (SMA) plays an important role in the initiation and coordination of internally and externally cued movements. Such movements include reaching, grasping, speaking, and bilateral hand coordination. While many studies discuss the SMA and its relationship to other parts of the motor network, there is minimal literature examining the connectivity of the SMA outside of the motor network. Using region-based fMRI studies, we built a neuroanatomical model to account for these extra-motor connections. METHODS: Thirty region-based fMRI studies were used to generate an activation likelihood estimation (ALE) using BrainMap software. Cortical parcellations overlapping the ALE were used to construct a preliminary model of the SMA connections outside the motor network. DSI-based fiber tractography was performed to determine the connectivity between cortical parcellations. The resulting connections were described using the cortical parcellation scheme developed by the Human Connectome Project (HCP). RESULTS: Four left hemisphere regions were found to comprise the SMA. These included areas SFL, SCEF, 6ma, and 6mp. Across mapped brains, these areas showed consistent interconnections between each other. Additionally, ipsilateral connections to the primary motor cortex, left inferior and middle frontal gyri, the anterior cingulate gyrus, and insula were demonstrated. Connections to the contralateral SMA, anterior cingulate, lateral premotor, and inferior frontal cortices were also identified. CONCLUSIONS: We describe a preliminary cortical model for the underlying structural connectivity of the supplementary motor area outside the motor network. Future studies should further characterize the neuroanatomic underpinnings of this network for the purposes of medical application.

Navigated transcranial magnetic stimulation following awake craniotomy for resection of glioma: Description of two cases.

BACKGROUND: Although transcranial magnetic stimulation (TMS) has been indicated as a potential therapy for several neurologic conditions, there is little known regarding its use during the postoperative rehabilitation period in patients with brain tumors. Furthermore, seizures, a common presentation in these patients, are regarded as a major contraindication for TMS therapy. CASE DESCRIPTION: We demonstrate that postoperative continuous theta burst stimulation (cTBS), a patterned form of repetitive TMS, was safely tolerated in addition to current neurorehabilitation techniques in two brain tumor patients, including one patient with a history of tumor-related epilepsy. We administered navigated 5 Hz cTBS to two patients within 48 h following awake craniotomy for tumor resection. Active motor thresholds were measured in both patients before TBS administration to determine stimulus intensity. We used resting-state fMRI to identify likely damaged networks based on postoperative deficits. This aided in TMS planning and allowed deficit targeted therapy contralateral to the lesioned network node. Both patients tolerated TBS therapy well and had no adverse effects, including posttreatment seizures, despite one patient having a history of tumor-related epilepsy. CONCLUSION: TBS may be safe in the immediate postoperative period for patients following brain tumor resection. Additional studies are needed to quantify the efficacy of TMS in improving neurologic deficits following tumor resection.