Faculty Bibliography

Liquid biopsy has emerged as a novel noninvasive tool in cancer diagnostics. While significant strides have been made in other malignancies using liquid biopsy for diagnosis, disease monitoring, and treatment selection, development of these assays has been more challenging for brain tumors. Recently, research in primary and metastatic brain tumors has begun to harness the potential utility of liquid biopsy-particularly using circulating tumor DNA (ctDNA). Initial studies to identify ctDNA in plasma of brain tumor patients have shown feasibility, but the yield of ctDNA is far below that for other malignancies. Attention has therefore turned to the cerebrospinal fluid (CSF) as a more robust source of ctDNA. This review discusses the unique considerations in liquid biopsy for glioma and places them in the context of the work to date. We address the utility of CSF liquid biopsy for diagnosis, longitudinal monitoring, tracking tumor evolution, clinical trial eligibility, and prognostication. We discuss the differences in assay requirements for each clinical application to best optimize factors such as efficacy, cost, and speed. Ultimately, CSF liquid biopsy has the potential to transform how we manage primary brain tumor patients.

INTRODUCTION/BACKGROUND:The lack of ideal measurement of treatment efficacy is a well acknowledged problem in the epilepsy community, both in clinical care and clinical trials. Whilst still the current gold-standard, self-reported seizure frequency significantly underestimates the true number of seizures and does not account for any other at least equally important outcome parameters, such as neurodevelopment and cognition. With the rise of disease modifying treatments, the need for more reliable endpoints in practice and clinical trials becomes more pressing. In this paper we assembled an expert panel to discuss the nature of these needs, current limitations, and obstacles based on a survey amongst these experts who were queried about the most important issues regarding the use of electroencephalography (EEG) parameters as endpoints in clinical drug and device development. METHODS:A structured survey was sent to a group of experts in the design and conduct of epilepsy trials in adults and children. This was followed by a virtual in-person meeting discussing the results of the trial and identifying a list of most important issues. RESULTS:Six clinical trialists and 5 individuals from pharmaceutical companies returned the survey containing 14 questions, and 8 clinical trialists and 10 pharma-representatives attended the meeting. Three main issues were identified (1) lack of accuracy of seizure diaries due to nocturnal seizures, subtle motor seizures, impairment of consciousness and lack of awareness of the seizure by the patient (2) inter-rater variability of EEG assessment (3) lack of standardization regarding definition(s) of seizures (clinical and electrographic), EEG recording methods and EEG data management. Recommended solutions included (1) validation of EEG parameters as biomarkers and use of wearables (2) development of a manual that describes EEG rating criteria, protocol for validation by > 1 central reader and use of a resolution of disagreements reporting template (3) standardization of EEG recording, data management and reporting. DISCUSSION & CONCLUSION/CONCLUSIONS:Current developments in research and technology seem promising to advance the use of EEG parameters as potential endpoints and offer partial solutions to the current needs. However, continuous, focused and collaborative efforts of all stakeholders (academia, industry and regulatory agencies) are needed to formulate guidelines, validate emerging technologies and approve them for use in trials. It is the intent of this opinion "position paper" to stimulate those efforts.

BACKGROUND/UNASSIGNED:Botulinum neurotoxin (BoNT) injection is an established therapy for limb spasticity and focal limb dystonia. Comparative benefits of injection guidance procedures have not been rigorously studied. OBJECTIVES/UNASSIGNED:We compared 2 targeting techniques for onabotulinumtoxin-A (onabotA) injection for the treatment of focal hand dystonia and upper limb spasticity: electrophysiologic guidance using electrical stimulation (E-stim) and ultrasound (US). METHODS/UNASSIGNED:This was a 2-center, randomized, crossover, assessor-blinded trial. Participants with focal hand dystonia or upper limb spasticity, on stable onabotA therapy for at least 2 previous injection cycles, were randomly assigned to either E-stim or US with crossover at 3 months. The primary outcome was improvement in dystonia or spasticity severity on a visual analog scale (VAS; 0-100) measured 1 month after each injection. The secondary outcome was participant discomfort assessed on a VAS. Repeated-measures analysis of covariance was used with linear mixed-model covariate selection. RESULTS/UNASSIGNED:A total of 19 participants (13 men) completed the study, 10 with upper limb spasticity and 9 with dystonia. Benefit was equivalent between the 2 techniques (VAS least-square mean [LSmean] 51.5 mm with US and 53.1 with E-stim). E-stim was perceived as more uncomfortable by participants (VAS LSmean 34.5 vs. 19.9 for E-stim and US, respectively). Procedure duration was similar with the 2 procedures. There were no serious adverse events related to either approach. CONCLUSIONS/UNASSIGNED:US and E-Stim localization guidance techniques provide equivalent efficacy in onabotA injections for spasticity and dystonia. US guidance injections are more comfortable for participants. Both techniques are effective guidance methods, with US potentially preferable based on participant comfort.

OBJECTIVE:Although relatively costly and non-scalable, non-invasive neuromodulation interventions are treatment alternatives for neuropsychiatric disorders. The recent developments of highly-deployable transcranial electric stimulation (tES) systems, combined with mobile-Health technologies, could be incorporated in digital trials to overcome methodological barriers and increase equity of access. The study aims are to discuss the implementation of tES digital trials by performing a systematic scoping review and strategic process mapping, evaluate methodological aspects of tES digital trial designs, and provide Delphi-based recommendations for implementing digital trials using tES. METHODS:We convened 61 highly-productive specialists and contacted 8 tES companies to assess 71 issues related to tES digitalization readiness, and processes, barriers, advantages, and opportunities for implementing tES digital trials. Delphi-based recommendations (>60% agreement) were provided. RESULTS:The main strengths/opportunities of tES were: (i) non-pharmacological nature (92% of agreement), safety of these techniques (80%), affordability (88%), and potential scalability (78%). As for weaknesses/threats, we listed insufficient supervision (76%) and unclear regulatory status (69%). Many issues related to methodological biases did not reach consensus. Device appraisal showed moderate digitalization readiness, with high safety and potential for trial implementation, but low connectivity. CONCLUSIONS:Panelists recognized the potential of tES for scalability, generalizability, and leverage of digital trials processes; with no consensus about aspects regarding methodological biases. SIGNIFICANCE/CONCLUSIONS:We further propose and discuss a conceptual framework for exploiting shared aspects between mobile-Health tES technologies with digital trials methodology to drive future efforts for digitizing tES trials.

OBJECTIVE:Prolonged postictal generalized electroencephalographic suppression (PGES) is a potential biomarker for sudden unexpected death in epilepsy (SUDEP), which may be associated with dysfunctional autonomic responses and serotonin signaling. To better understand molecular mechanisms, PGES duration was correlated to 5HT1A and 5HT2A receptor protein expression and RNAseq from resected hippocampus and temporal cortex of temporal lobe epilepsy patients with seizures recorded in preoperative evaluation. METHODS:Analyses included 36 cases (age = 14-64 years, age at epilepsy onset = 0-51 years, epilepsy duration = 2-53 years, PGES duration = 0-93 s), with 13 cases in all hippocampal analyses. 5HT1A and 5HT2A protein was evaluated by Western blot and histologically in hippocampus (n = 16) and temporal cortex (n = 9). We correlated PGES duration to our previous RNAseq dataset for serotonin receptor expression and signaling pathways, as well as weighted gene correlation network analysis (WGCNA) to identify correlated gene clusters. RESULTS: = .25). WGCNA identified four modules correlated with PGES duration, including positive correlation with synaptic transcripts (p = .040, Pearson correlation r = .52), particularly potassium channels (KCNA4, KCNC4, KCNH1, KCNIP4, KCNJ3, KCNJ6, KCNK1). No modules were associated with serotonin receptor signaling. SIGNIFICANCE/CONCLUSIONS:Higher hippocampal 5HT2A receptor protein and potassium channel transcripts may reflect underlying mechanisms contributing to or resulting from prolonged PGES. Future studies with larger cohorts should assess functional analyses and additional brain regions to elucidate mechanisms underlying PGES and SUDEP risk.

INTRODUCTIONS:Excessive mechanical stress is closely associated with cell death in various conditions. Exposure of chondrocytes to excessive mechanical loading leads to a catabolic response as well as exaggerated cell death. Ferroptosis is a recently identified form of cell death during cell aging and degeneration. However, it's potential association with mechanical stress remains to be illustrated. OBJECTIVES:To identify whether excessive mechanical stress can cause ferroptosis. To explore the role of mechanical overloading in chondrocyte ferroptosis. METHODS:) mice OA model and chondrocytes cultured with high strain mechanical stress. Furthermore, the role of Piezo1 ion channel in chondrocyte ferroptosis and OA development was explored by using its inhibitor (GsMTx4) and agonist (Yoda1). Additionally, chondrocyte was cultured in calcium-free medium with mechanical stress, and ferroptosis phenotype was tested. RESULTS:Human cartilage and mouse chondrocyte experiments revealed that mechanical overloading can induce GPX4-associated ferroptosis. Conditional knockout of GPX4 in cartilage aggravated experimental OA process, while additional treatment with ferroptosis suppressor protein (FSP-1) and coenzyme Q10 (CoQ10) abated OA development in GPX4-CKO mice. In mouse OA model and chondrocyte experiments, inhibition of Piezo1 channel activity increased GPX4 expression, attenuated ferroptosis phenotype and reduced the severity of osteoarthritis. Additionally, high strain mechanical stress induced ferroptosis damage in chondrocyte was largely abolished by blocking calcium influx through calcium-free medium. CONCLUSIONS:Our findings show that mechanical overloading induces ferroptosis through Piezo1 activation and subsequent calcium influx in chondrocytes, which might provide a potential target for OA treatment.

OBJECTIVE:We explored the relationship between markers of infection and inflammation and mortality in patients with acute ischemic stroke who underwent thrombectomy. METHODS:We performed retrospective chart review of stroke patients who underwent thrombectomy at two tertiary academic centers between December 2018 and November 2020. Associations between discharge mortality, WBC count, neutrophil percentage, fever, culture data, and antibiotic treatment were analyzed using the Wilcoxon rank sum test, Student's t-test, and Fisher's exact test. Independent predictors of mortality were identified with multivariable analysis. Analyses were repeated excluding COVID-positive patients. RESULTS:Of 248 patients who underwent thrombectomy, 41 (17 %) died prior to discharge. Mortality was associated with admission WBC count (11 [8-14] vs. 9 [7-12], p = 0.0093), admission neutrophil percentage (78 % ± 11 vs. 71 % ± 14, p = 0.0003), peak WBC count (17 [13-22] vs. 12 [9-15], p < 0.0001), fever (71 % vs. 27 %, p < 0.0001), positive culture (44 % vs. 15 %, p < 0.0001), and days treated with antibiotics (3 [1-7] vs. 1 [0-4], p < 0.0001). After controlling for age, admission NIHSS and post-thrombectomy ASPECTS score, mortality was associated with admission WBC count (OR 13, CI 1.32-142, p = 0.027), neutrophil percentage (OR 1.03, CI 1.0-1.07, p = 0.045), peak WBC count (OR 301, CI 24-5008, p < 0.0001), fever (OR 24.2, CI 1.77-332, p < 0.0001), and positive cultures (OR 4.24, CI 1.87-9.62, p = 0.0006). After excluding COVID-positive patients (n = 14), peak WBC count, fever and positive culture remained independent predictors of mortality. CONCLUSION/CONCLUSIONS:Markers of infection and inflammation are associated with discharge mortality after thrombectomy. Further study is warranted to investigate the causal relationship of these markers with clinical outcome.

The classification of multiple sclerosis (MS) has been established by Lublin in 1996 and revised in 2013. The revision includes clinically isolated syndrome, relapsing-remitting, primary progressive and secondary progressive MS, and has added activity (i.e., formation of white matter lesions or clinical relapses) as a qualifier. This allows for the distinction between active and nonactive progression, which has been shown to be of clinical importance. We propose that a logical extension of this classification is the incorporation of additional key pathological processes, such as chronic perilesional inflammation, neuroaxonal degeneration, and remyelination. This will distinguish MS phenotypes that may present as clinically identical but are driven by different combinations of pathological processes. A more precise description of MS phenotypes will improve prognostication and personalized care as well as clinical trial design. Thus, our proposal provides an expanded framework for conceptualizing MS and for guiding development of biomarkers for monitoring activity along the main pathological axes in MS.

BACKGROUND:Stroke mimics are non-vascular conditions that present with acute focal neurological deficits, simulating an acute ischemic stroke. Susumber berry (SB) toxicity is a rare cause of stroke mimic with limited case reports available in the literature. OBJECTIVES/OBJECTIVE:We report four new cases of SB toxicity presenting as stroke mimic, and we performed a systematic review. METHODS:MEDLINE/EMBASE/WoS were searched for "susumber berries," "susumber," or "solanum torvum." RESULTS:531 abstracts were screened after removal of duplicates; 5 articles and 2 conference abstracts were selected describing 13 patients. A total of 17 patients who ingested SB and became ill were identified, including our 4 patients. All but one presented with acute neurologic manifestation; 16 (94%) presented with dysarthria, 16 (94%) with unstable gait, 8 (47%) with nystagmus/gaze deviation, 10 (59%) with blurry vision, and 5 (29%) with autonomic symptoms. Six (35%) required ICU admission, and 3 (18%) were intubated. Fourteen (82%) had a rapid complete recovery, and 3 were hospitalized up to 1 month. CONCLUSIONS:SB toxicity can cause neurological symptoms that mimic an acute stroke typically with a posterior circulation symptom complex. Altered SB toxins (from post-harvest stressors or temperature changes) might stimulate muscarinic/nicotinic cholinergic receptors or inhibit acetylcholinesterase, causing gastrointestinal, neurological, and autonomic symptoms. In cases of multiple patients presenting simultaneously to the ED with stroke-like symptoms or when stroke-like symptoms fail to localize, a toxicological etiology (such as SB toxicity) should be considered.