Precision targeting in the globus pallidus interna: insights from the multicenter, prospective, blinded VA/NINDS CSP 468 study.

OBJECTIVE: Deep brain stimulation (DBS) targeting the globus pallidus interna (GPi) has been shown to significantly improve motor symptoms for the treatment of medication-refractory Parkinson's disease. Yet, heterogeneity in clinical outcomes persists, possibly due to suboptimal target identification within the GPi. By leveraging robust sampling of the GPi and 6-month postsurgical outcomes, this study aims to determine optimal symptom-specific GPi DBS targets. METHODS: In this study, the authors analyzed the anatomical lead location and 6-month postsurgical, double-blinded outcome measures of 86 patients who underwent bilateral GPi DBS. These patients were selected from the multicenter Veterans Affairs (VA)/National Institutes of Neurological Disorders and Stroke (NINDS) Cooperative Studies Program (CSP) 468 study to identify the optimal target zones ("sweet spots") for the control of overall motor (United Parkinson's Disease Rating Scale [UPDRS]-III), axial, tremor, rigidity, and bradykinesia symptoms. Lead coordinates were normalized to Montreal Neurological Institute space and the optimal target zones were identified and validated using a leave-one-patient-out approach. RESULTS: The authors' findings revealed statistically significant optimal target zones for UPDRS-III (R = 0.37, p < 0.001), axial (R = 0.22, p = 0.042), rigidity (R = 0.20, p = 0.021), and bradykinesia (R = 0.23, p = 0.004) symptoms. These zones were localized within the primary motor and premotor subdivisions of the GPi. Interestingly, these zones extended beyond the GPi lateral border into the GPi-globus pallidus externa (GPe) lamina and into the GPe, but they did not reach the GPi ventral border, challenging traditional surgical approaches based on pallidotomies. CONCLUSIONS: Drawing upon a robust dataset, this research effectively delineates specific optimal target zones for not only overall motor improvement but also symptom subscores. These insights hold the potential to enhance the precision of targeting in subsequent bilateral GPi DBS surgical procedures.

Management of rare atlantoaxial synovial cyst case with extension to the cerebellopontine angle: illustrative case.

BACKGROUND: Synovial cysts are a common finding in degenerative spine disease, most frequently involving the facet joints of the lumbar spine. Synovial cysts are less common in the cervical spine and rarely involve the atlantoaxial junction. OBSERVATIONS: In this case report, the authors detail a unique presentation of a left atlantoaxial synovial cyst with large intracranial extension into the cerebellopontine angle causing progressive cranial nerve palsies resulting in tinnitus, vertigo, diminished hearing, gait imbalance, left trigeminal hypesthesia, left facial weakness, and dysarthria. The patient underwent a retromastoid craniectomy for resection of the synovial cyst, resulting in improvement and resolution of symptoms. Follow-up occurred at 6 weeks, 3 months, and 5 months postoperatively without recurrence on imaging. LESSONS: The authors describe acute and long-term management of a unique presentation of an atlantoaxial synovial cyst including retromastoid craniectomy, intervals for follow-up for recurrence, and possible treatment options in cases of recurrence. A systematic literature review was also performed to explore all reported cases of craniocervical junction synovial cysts and subsequent surgical management.

Investigation of Asleep versus Awake Motor Mapping in Resective Brain Surgery.

OBJECTIVE: To develop an asleep motor mapping paradigm for accurate detection of the corticospinal tract during glioma surgery and compare outcomes with awake patients undergoing glioma resection. METHODS: A consecutive cohort of adult patients undergoing craniotomy for suspected diffuse glioma with tumor in a perirolandic location who had awake or asleep cortical and subcortical motor mapping with positive areas of motor stimulation were assessed for postoperative extent of resection (EOR), permanent neurological deficit, and proximity of stimulation to diffusion tensor imaging-based corticospinal tract depiction on preoperative magnetic resonance imaging. Outcome data were compared between asleep and awake groups. RESULTS: In the asleep group, all 16 patients had improved or no change in motor function at last follow-up (minimum 3 months of follow-up). In the awake group, all 23 patients had improved function or no change at last follow-up. EOR was greater in the asleep group (mean [SD] EOR 88.71% [17.56%]) versus the awake group (mean [SD] EOR 80.62% [24.44%]), although this difference was not statistically significant (P = 0.3802). Linear regression comparing distance from stimulation to corticospinal tract in asleep (n = 14) and awake (n = 4) patients was r = -0.3759, R2 = 0.1413, P = 0.1853, and 95% confidence interval = -0.4453 to 0.09611 and r = 0.7326, R2 = 0.5367, P = 0.2674, and 95% confidence interval = -7.042 to 14.75, respectively. CONCLUSION: In this small patient series, asleep motor mapping using commonly available motor evoked potential hardware appears to be safe and efficacious in regard to EOR and functional outcomes.

Atrial fibrillation catheter ablation complications in obese and diabetic patients: Insights from the US Nationwide Inpatient Sample 2005-2013.

BACKGROUND: Obesity and diabetes are risk factors for atrial fibrillation (AF) incidence and recurrence after catheter ablation. However, their impact on post-ablation complications in real-world practice is unknown. OBJECTIVES: We examine annual trends in AF ablations and procedural outcomes in obese and diabetic patients in the US and whether obesity and diabetes are independently associated with adverse outcomes. METHODS: Using the Nationwide Inpatient Sample (2005-2013), we identified obese and diabetic patients admitted for AF ablation. Common complications were identified using ICD-9-CM codes. The primary outcome included the composite of any in-hospital complication or death. Annual trends of the primary outcome, length-of-stay (LOS) and total-inflation adjusted hospital charges were examined. Multivariate analyses studied the association of obesity and diabetes with outcomes. RESULTS: An estimated 106 462 AF ablations were performed in the US from 2005 to 2013. Annual trends revealed a gradual increase in ablations performed in obese and diabetic patients and in complication rates. The overall rate of the primary outcome in obese was 11.7% versus 8.2% in non-obese and 10.7% in diabetic versus 8.2% in non-diabetic patients (p < .001). CONCLUSIONS: Obesity was independently associated with increased complications (adjusted OR, 95% CI:1.39, 1.20-1.62), longer LOS (1.36, 1.23-1.49), and higher charges (1.16, 1.12-1.19). Diabetes was only associated with longer LOS (1.27, 1.16-1.38). Obesity, but not diabetes, in patients undergoing AF ablation is an independent risk factor for immediate post-ablation complications and higher costs. Future studies should investigate whether weight loss prior to ablation reduces complications and costs.

Characteristics of Designated Institutional Officials and Sponsoring Institutions of ACGME-Accredited Training Programs.

BACKGROUND: Since the Accreditation Council for Graduate Medical Education (ACGME) established the designated institutional official (DIO) role in 1998, there have been major changes in sponsoring institutions (SIs) and DIO responsibilities. Yet there remains a large gap in our knowledge regarding baseline SI and DIO characteristics as well as a need for institutions wanting to increase diversity in the DIO role and other leadership positions within the medical education community. OBJECTIVE: We sought to characterize demographics of DIOs and the SIs they oversee. METHODS: We identified SIs and DIOs on the ACGME website on February 15, 2020. Reviewed data included SI accreditation status, number of programs and resident/fellow positions, and DIO characteristics. RESULTS: We identified 831 SIs. SIs with continued accreditation sponsored more programs (median 4.0) than SIs with initial accreditation (median 1.0, P < .001). DIO age ranged from 29-81 years (median 57 years). Two-hundred eighty-three of 831 (34%) DIOs were women. Of 576 DIOs with known academic rank, 356 (62%) DIOs held senior academic rank. A higher proportion of male DIOs had senior academic rank (68% vs 52%; OR 1.90 [95% CI 1.34-2.70]; P < .001) and professor rank (39% vs 24%; OR 2.01 [95% CI 1.38-2.94]; P < .001) compared to female DIOs. Female gender was associated with a greater number of ACGME-accredited programs and filled resident/fellow positions per SI (P < .001 for both). CONCLUSIONS: This study describes characteristics of DIOs and SIs and offers insights for those pursuing a DIO position.

Retrospective analysis of hemispheric structural network change as a function of location and size of glioma.

Gliomas are neoplasms that arise from glial cell origin and represent the largest fraction of primary malignant brain tumours (77%). These highly infiltrative malignant cell clusters modify brain structure and function through expansion, invasion and intratumoral modification. Depending on the growth rate of the tumour, location and degree of expansion, functional reorganization may not lead to overt changes in behaviour despite significant cerebral adaptation. Studies in simulated lesion models and in patients with stroke reveal both local and distal functional disturbances, using measures of anatomical brain networks. Investigations over the last two decades have sought to use diffusion tensor imaging tractography data in the context of intracranial tumours to improve surgical planning, intraoperative functional localization, and post-operative interpretation of functional change. In this study, we used diffusion tensor imaging tractography to assess the impact of tumour location on the white matter structural network. To better understand how various lobe localized gliomas impact the topology underlying efficiency of information transfer between brain regions, we identified the major alterations in brain network connectivity patterns between the ipsilesional versus contralesional hemispheres in patients with gliomas localized to the frontal, parietal or temporal lobe. Results were indicative of altered network efficiency and the role of specific brain regions unique to different lobe localized gliomas. This work draws attention to connections and brain regions which have shared structural susceptibility in frontal, parietal and temporal lobe glioma cases. This study also provides a preliminary anatomical basis for understanding which affected white matter pathways may contribute to preoperative patient symptomology.

YouTube as a Source of Medical Information About Spinal Cord Stimulation.

BACKGROUND: Social media platforms may play an important role in the dissemination of medical information on interventional pain procedures. This cross-sectional study quantitatively assessed the reliability and quality of information from YouTube regarding spinal cord stimulation. MATERIALS AND METHODS: YouTube was queried on May 20, 2020 using keywords "spinal cord stimulator," "spinal cord stimulation experience," and "spinal cord stimulation risks." The top 50 viewed videos from each search were analyzed. The primary outcome was video quality, which was analyzed using the modified DISCERN (mDISCERN) criteria. RESULTS: Seventy-nine of 103 (77%) videos were classified as useful. Fifteen of 103 (14%) videos were classified as misleading and contained nonfactual information on spinal cord stimulation. Hospitals, group practices, or physicians produced a greater proportion of useful videos compared to misleading videos (63.3% vs. 26.7%, p = 0.008). Nonmedical independent users produced a greater proportion of misleading videos compared to useful videos (73.3% vs. 16.4%, p < 0.001). Useful videos had significantly higher mDISCERN scores compared to misleading videos (2.6 vs. 1.9, p = 0.009). Nonmedical independent users produced a greater proportion of low-quality videos (mDISCERN score < 3) than high-quality videos (mDISCERN score ≥ 3; 50.8% vs. 2.4%, respectively, p < 0.001). Educational videos from professional pain medicine societies were not captured. CONCLUSION: YouTube is an accessible platform for medical information on spinal cord stimulation, yet a significant amount of nonfactual information is present. As social media platforms continue to gain prominence in health care, future efforts to appraise the quality of medical content delivered to the public are warranted. In addition, reputable sources including professional pain medicine societies should consider collaborating with producers to disseminate high-quality video content that reaches a wider audience.

YouTube as a source of medical information on the novel coronavirus 2019 disease (COVID-19) pandemic.

Media coverage on coronavirus disease 2019 (COVID-19) has been extensive, yet large gaps remain in our understanding of the role of social media platforms during worldwide health crisis. The purpose of this study was to assess the most viewed YouTube videos on COVID-19 for medical content. We coded video characteristics, source, and medical content of the 113 most-widely viewed videos about COVID-19. Seventy-nine (69.9%) videos were classified as useful, and 10 (8.8%) videos were classified as misleading. Independent users were more likely to post misleading videos than useful videos (60.0% vs 21.5%, P = 0.009). News agencies were more likely to post useful videos than misleading videos (72.2% vs 40.0%, P = 0.039). Useful videos were more likely to present any information on prevalence or incidence (79.7% vs 20.0%, P < 0.001), as well as information on outcomes or prognosis (84.8% vs 30.0%, P < 0.001) compared to misleading videos. The World Health Organization contributed one useful video (1.3%), while no videos from the Center for Disease Control were included. Although YouTube generally is a useful source of medical information on the COVID-19 pandemic, increased efforts to disseminate accurate information from reputable sources is desired to help mitigate disease spread and decrease unnecessary panic in the general population.

Fiber-tract localized diffusion coefficients highlight patterns of white matter disruption induced by proximity to glioma.

Gliomas account for 26.5% of all primary central nervous system tumors. Recent studies have used diffusion tensor imaging (DTI) to extract white matter fibers and the diffusion coefficients derived from MR processing to provide useful, non-invasive insights into the extent of tumor invasion, axonal integrity, and gross differentiation of glioma from metastasis. Here, we extend this work by examining whether a tract-based analysis can improve non-invasive localization of tumor impact on white matter integrity. This study retrospectively analyzed preoperative magnetic resonance sequences highlighting contrast enhancement and DTI scans of 13 subjects that were biopsy-confirmed to have either high or low-grade glioma. We reconstructed the corticospinal tract and superior longitudinal fasciculus by applying atlas-based regions of interest to fibers derived from whole-brain deterministic streamline tractography. Within-subject comparison of hemispheric diffusion coefficients (e.g., fractional anisotropy and mean diffusivity) indicated higher levels of white matter degradation in the ipsilesional hemisphere. Novel application of along-tract analyses revealed that tracts traversing the tumor region showed significant white matter degradation compared to the contralesional hemisphere and ipsilesional tracts displaced by the tumor.

Current Applications of Diffusion Tensor Imaging and Tractography in Intracranial Tumor Resection.

In the treatment of brain tumors, surgical intervention remains a common and effective therapeutic option. Recent advances in neuroimaging have provided neurosurgeons with new tools to overcome the challenge of differentiating healthy tissue from tumor-infiltrated tissue, with the aim of increasing the likelihood of maximizing the extent of resection volume while minimizing injury to functionally important regions. Novel applications of diffusion tensor imaging (DTI), and DTI-derived tractography (DDT) have demonstrated that preoperative, non-invasive mapping of eloquent cortical regions and functionally relevant white matter tracts (WMT) is critical during surgical planning to reduce postoperative deficits, which can decrease quality of life and overall survival. In this review, we summarize the latest developments of applying DTI and tractography in the context of resective surgery and highlight its utility within each stage of the neurosurgical workflow: preoperative planning and intraoperative management to improve postoperative outcomes.

Effects of prophylactic anticholinergic medications to decrease extrapyramidal side effects in patients taking acute antiemetic drugs: a systematic review and meta-analysis.

OBJECTIVES: To determine the effectiveness of prophylactic anticholinergic medications in reducing extrapyramidal symptoms in patients taking acute antiemetics with a dopamine D2 receptor antagonist effect. METHODS: Systematic searches of all published studies through March 2017 were identified from PubMed, Cochrane library, Embase, Web of Science and Scopus. Only randomised controlled trials of patients receiving dopamine D2 antagonist antiemetic therapy for acute migraine in which an anticholinergic or placebo was compared were included. Pooled ORs were calculated for incidence of extrapyramidal symptoms and sedation. RESULTS: Four placebo-controlled randomised controlled trials consisting of 737 patients met the inclusion criteria for our meta-analysis. The effect of diphenhydramine differed depending on the method of administration of the antiemetic. When the antiemetic was delivered as a 2 min antiemetic bolus, the odds of extrapyramidal symptoms were significantly reduced in the diphenhydramine group compared with placebo (OR 0.42; 95% CI 0.22 to 0.81; P=0.01). However, when the antiemetic was given as a 15 min infusion, there was no significant difference in extrapyramidal symptoms with or without diphenhydramine (OR 1.06; 95% CI 0.58 to 1.91; P=0.85). The lowest incidence of extrapyramidal symptoms was observed in patients receiving a 15 min antiemetic infusion without diphenhydramine prophylaxis (9.8%). In two trials including 351 patients that dichotomously reported sedation scales, diphenhydramine had significantly higher rates of sedation (31.6%vs19.2%, OR 2.01, 95% CI 1.21 to 3.33; P=0.007). CONCLUSION: Prophylactic diphenhydramine reduces extrapyramidal symptoms in patients receiving bolus antiemetic therapy with a dopamine D2 antagonist effect, but not when it is given as an infusion. Because of significantly greater sedation with diphenhydramine, the most effective strategy is to administer the D2 antagonist antiemetic as a 15 min infusion without prophylaxis.

Global and Targeted Pathway Impact of Gliomas on White Matter Integrity Based on Lobar Localization.

Primary brain tumors comprise 28% of all tumors and 80% of malignant tumors. Pathophysiology of high-grade gliomas includes significant distortion of white matter architecture, necrosis, the breakdown of the blood brain barrier, and increased intracranial pressure. Diffusion tensor imaging (DTI), a diffusion weighted imaging technique, can be used to assess white matter architecture. Use of DTI as a non-invasive pathophysiological tool to analyze glioma impact on white matter microstructure has yet to be fully explored. Preliminary assessment of DTI tractography was done as a measure of intracranial tumor impact on white matter architecture. Specifically, we addressed three questions: 1) whether glioma differentially affects local white matter structure compared to metastasis, 2) whether glioma affects tract integrity of major white matter bundles, 3) whether glioma lobe localization affects tract integrity of different white matter bundles. In this study, we retrospectively investigated preoperative DTI scans from 24 patients undergoing tumor resection. Fiber tractography was estimated using a deterministic fiber tracking algorithm in DSI (diffusion spectrum imaging) Studio. The automatic anatomical labeling (AAL) atlas was used to define the left and right (L/R) hemisphere regions of interest (ROI). In addition, the John Hopkins University (JHU) White Matter Atlas was used to auto-segment major white matter bundle ROIs. For all tracts derived from ROI seed targets, we computed the following parameters: tract number, tract length, fractional anisotropy (FA), axial diffusivity (AD), mean diffusivity (MD), and radial diffusivity (RD). The DTI tractography analysis revealed that white matter integrity in the hemisphere ipsilateral to intracranial tumor was significantly compromised compared to the control contralateral hemisphere. No differences were observed between high vs low-grade gliomas, however, gliomas induced significantly greater white matter degradation than metastases. In addition, targeted analysis of major white matter bundles important for sensory/motor function (i.e., corticospinal tract and superior longitudinal fasciculus) revealed tract-parameter specific susceptibility due to the presence of the tumor. Finally, major tract bundles were differentially affected based on lobar localization of the glioma. These DTI-based tractographic analyses complement findings from gross histopathological examination of glioma impact on neural tissue. Global and focal white matter architecture, ipsilateral to glioma, shows higher rates of degradation or edema - based on DTI tractographic metrics - in comparison to normal brain or metastases. Gliomas, which arise in the parietal lobe, also have a higher negative impact (potentially due to increased edema) on white matter integrity of the superior longitudinal fasciculus(SLF) than those which arise in the frontal lobe. Future studies will focus on using preoperative and postoperative tractography to predict functional deficits following resective surgery.