Faculty Bibliography

OBJECTIVE:The force that an electrocorticography (ECoG) array exerts on the brain manifests when it bends to match the curvature of the skull and cerebral cortex. This force can negatively impact both short-term and long-term patient outcomes. Here we provide a mechanical characterization of a novel Liquid Crystal Polymer (LCP) ECoG array prototype to demonstrate that its thinner geometry reduces the force potentially applied to the cortex of the brain. APPROACH/METHODS:We built a low-force flexural testing machine to measure ECoG array bending forces, calculate their effective flexural moduli, and approximate the maximum force they could exerted on the human brain. MAIN RESULTS/RESULTS:The LCP ECoG prototype was found to have a maximal force less than 20% that of any commercially available ECoG arrays that was tested. However, as a material, LCP was measured to be as much as 24x more rigid than silicone, which is traditionally used in ECoG arrays. This suggests that the lower maximal force resulted from the prototype's thinner profile (2.9x-3.25x). SIGNIFICANCE/CONCLUSIONS:While decreasing material stiffness can lower the force an ECoG array exhibits, our LCP ECoG array prototype demonstrated that flexible circuit manufacturing techniques can also lower these forces by decreasing ECoG array thickness. Flexural tests of ECoG arrays are necessary to accurately assess these forces, as material properties for polymers and laminates are often scale dependent. As the polymers used are anisotropic, elastic modulus cannot be used to predict ECoG flexural behavior. Accounting for these factors, we used our four-point flexure testing procedure to quantify the forces exerted on the brain by ECoG array bending. With this experimental method, ECoG arrays can be designed to minimize force excerted on the brain, potentially improving both acute and chronic clinical utility.

BACKGROUND:Genetic mutations in beta-glucocerebrosidase (GBA) represent the major genetic risk factor for Parkinson's disease (PD). GBA participates in both the endo-lysosomal pathway and the immune response, two important mechanisms involved in the pathogenesis of PD. However, modifiers of GBA penetrance have not yet been fully elucidated. METHODS:We characterized the transcriptomic profiles of circulating monocytes in a population of patients with PD and healthy controls (CTRL) with and without GBA variants (n = 23 PD/GBA, 13 CTRL/GBA, 56 PD, 66 CTRL) and whole blood (n = 616 PD, 362 CTRL, 127 PD/GBA, 165 CTRL/GBA). Differential expression analysis, pathway enrichment analysis, and outlier detection were performed. Ultrastructural characterization of isolated CD14+ monocytes in the four groups was also performed through electron microscopy. RESULTS:We observed hundreds of differentially expressed genes and dysregulated pathways when comparing manifesting and non-manifesting GBA mutation carriers. Specifically, when compared to idiopathic PD, PD/GBA showed dysregulation in genes involved in alpha-synuclein degradation, aging and amyloid processing. Gene-based outlier analysis confirmed the involvement of lysosomal, membrane trafficking, and mitochondrial processing in manifesting compared to non-manifesting GBA-carriers, as also observed at the ultrastructural levels. Transcriptomic results were only partially replicated in an independent cohort of whole blood samples, suggesting cell-type specific changes. CONCLUSIONS:Overall, our transcriptomic analysis of primary monocytes identified gene targets and biological processes that can help in understanding the pathogenic mechanisms associated with GBA mutations in the context of PD.

In analyzing the neural correlates of naturalistic and unstructured behaviors, features of neural activity that are ignored in a trial-based experimental paradigm can be more fully studied and investigated. Here, we analyze neural activity from two patients using electrocorticography (ECoG) and stereo-electroencephalography (sEEG) recordings, and reveal that multiple neural signal characteristics exist that discriminate between unstructured and naturalistic behavioral states such as "engaging in dialogue" and "using electronics". Using the high gamma amplitude as an estimate of neuronal firing rate, we demonstrate that behavioral states in a naturalistic setting are discriminable based on long-term mean shifts, variance shifts, and differences in the specific neural activity's covariance structure. Both the rapid and slow changes in high gamma band activity separate unstructured behavioral states. We also use Gaussian process factor analysis (GPFA) to show the existence of salient spatiotemporal features with variable smoothness in time. Further, we demonstrate that both temporally smooth and stochastic spatiotemporal activity can be used to differentiate unstructured behavioral states. This is the first attempt to elucidate how different neural signal features contain information about behavioral states collected outside the conventional experimental paradigm.

INTRODUCTION/BACKGROUND:Homebound individuals with advanced Parkinson's disease (PD) are underrepresented in research and care. We tested the impact of interdisciplinary, telehealth-enhanced home visits (IN-HOME-PD) on patient quality of life (QoL) compared with usual care. METHODS:Nonrandomized controlled trial of quarterly, structured, telehealth-enhanced interdisciplinary home visits focused on symptom management, home safety, medication reconciliation, and psychosocial needs (ClinicalTrials.gov NCT03189459). We enrolled homebound participants with advanced PD (Hoehn & Yahr (HY) stage ≥3). Usual care participants had ≥2 visits in the Parkinson's Outcomes Project (POP) registry. We compared within- and between-group one-year change in QoL using the Parkinson's Disease Questionnaire. RESULTS:Sixty-five individuals enrolled in IN-HOME-PD (32.3% women; mean age 78.9 (SD 7.6) years; 74.6% white; 78.5% HY ≥ 4) compared with 319 POP controls, with differences in age, race, and PD severity (37.9% women; mean age 70.1 (7.8) years; 96.2% white; 15.1% HY ≥ 4). Longitudinally, the intervention group's QoL remained unchanged (within-group p = 0.74, Cohen's d = 0.05) while QoL decreased over time in POP controls (p < 0.001, Cohen's d = 0.27). The difference favored the intervention (between-group p = 0.04). POP participants declined in 7/8 dimensions while IN-HOME-PD participants' bodily discomfort improved and hospice use and death at home-markers of goal-concordant care-far exceeded national data. CONCLUSIONS:Telehealth-enhanced home visits can stabilize and may improve the predicted QoL decline in advanced PD via continuity of care and facilitating goal-concordant care, particularly among diverse populations. Extrapolating features of this model may improve continuity of care and outcomes in advanced PD.

OBJECTIVES/OBJECTIVE:As part of the COVID-19 and Epilepsy (COV-E) global study, we aimed to understand the impact of COVID-19 on the medical care and well-being of people with epilepsy (PWE) in the United States, based on their perspectives and those of their caregivers. METHODS:Separate surveys designed for PWE and their caregivers were circulated from April 2020 to July 2021; modifications in March 2021 included a question about COVID-19 vaccination status. RESULTS:We received 788 responses, 71% from PWE (n = 559) and 29% (n=229) from caregivers of persons with epilepsy. A third (n = 308) of respondents reported a change in their health or in the health of the person they care for. Twenty-seven percent (n = 210) reported issues related to worsening mental health. Of respondents taking ASMs (n = 769), 10% (n= 78) reported difficulty taking medications on time, mostly due to stress causing forgetfulness. Less than half of respondents received counseling on mental health and stress. Less than half of the PWE reported having discussions with their healthcare providers about sleep, ASMs and potential side effects, while a larger proportion of caregivers (81%) reported having had discussions with their healthcare providers on the same topics. More PWE and caregivers reported that COVID-19 related measures caused adverse impact on their health in the post-vaccine period than during the pre-vaccine period, citing mental health issues as the primary reason. SIGNIFICANCE/CONCLUSIONS:Our findings indicate that the impact of the COVID-19 pandemic in the US on PWE is multifaceted. Apart from the increased risk of poor COVID-19 outcomes, the pandemic has also had negative effects on mental health and self-management. Healthcare providers must be vigilant for increased emotional distress in PWE during the pandemic and consider the importance of effective counseling to diminish risks related to exacerbated treatment gaps.

PURPOSE/OBJECTIVE:Patients with KRAS-mutant non-small cell lung cancer (NSCLC) with brain metastases (BM) have a poor prognosis. Adagrasib (MRTX849), a potent oral small molecule KRASG12C inhibitor, irreversibly and selectively binds KRASG12C, locking it in its inactive state. Adagrasib has been optimized for favorable pharmacokinetic (PK) properties, including long half-life (~24 hours), extensive tissue distribution, dose-dependent PK, and central nervous system penetration, however BM-specific anti-tumor activity of KRASG12C inhibitors remains to be fully characterized. EXPERIMENTAL DESIGN/METHODS:A retrospective database query identified patients with KRAS-mutant NSCLC to understand their propensity to develop BM. Preclinical studies assessed physiochemical and PK properties of adagrasib. Mice bearing intracranial KRASG12C-mutant NSCLC xenografts (LU99-Luc/H23-Luc/LU65-Luc) were treated with clinically relevant adagrasib doses and levels of adagrasib in plasma, cerebrospinal fluid (CSF), and brain were determined along with anti-tumor activity. Preliminary clinical data were collected from 2 patients with NSCLC with untreated BM who had received adagrasib 600 mg BID in the Phase 1b cohort of the KRYSTAL-1 trial; CSF was collected, adagrasib concentrations measured, and anti-tumor activity in BM evaluated. RESULTS:Patients with KRAS-mutant NSCLC demonstrated high propensity to develop BM ({greater than or equal to}40%). Adagrasib penetrated into CSF and demonstrated tumor regression and extended survival in multiple preclinical BM models. In 2 patients with NSCLC and untreated BM, CSF concentrations of adagrasib measured above the target cellular IC50. Both patients demonstrated corresponding BM regression, supporting potential clinical activity of adagrasib in the brain. CONCLUSIONS:These data support further development of adagrasib in patients with KRASG12C-mutant NSCLC with untreated BM.