Faculty Bibliography
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school:SOM
Department/Unit:Neurology
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23438
Federated learning enables big data for rare cancer boundary detection
Although machine learning (ML) has shown promise across disciplines, out-of-sample generalizability is concerning. This is currently addressed by sharing multi-site data, but such centralization is challenging/infeasible to scale due to various limitations. Federated ML (FL) provides an alternative paradigm for accurate and generalizable ML, by only sharing numerical model updates. Here we present the largest FL study to-date, involving data from 71 sites across 6 continents, to generate an automatic tumor boundary detector for the rare disease of glioblastoma, reporting the largest such dataset in the literature (n = 6, 314). We demonstrate a 33% delineation improvement for the surgically targetable tumor, and 23% for the complete tumor extent, over a publicly trained model. We anticipate our study to: 1) enable more healthcare studies informed by large diverse data, ensuring meaningful results for rare diseases and underrepresented populations, 2) facilitate further analyses for glioblastoma by releasing our consensus model, and 3) demonstrate the FL effectiveness at such scale and task-complexity as a paradigm shift for multi-site collaborations, alleviating the need for data-sharing.
PMCID:9722782
PMID: 36470898
ISSN: 2041-1723
CID: 5381682
Clinical Implications of Internal Carotid Arterial Tortuosity in Patients with White Matter Hyperintensities
Background: White matter hyperintensities (WMHs) are observed frequently on MRI in elderly and associated with cognitive dysfunction. Many studies focused on intracranial small vessel disease (SVD), however, few studies linked WMHs with changes of extracranial large feeding arteries. We aimed to investigate the effects of internal carotid artery (ICA) tortuosity changes through quantitative MR Angiography. Method: Fifty-seven patients (age: 72.98±5.62; 32 females/25 males) with WMHs were included. WMHs lesions were semi-automatically segmented on FLAIR images. ICAs were segmented on the TOF images to generate tortuosity quantitative metrics, including tortuosity index (TI), inflection count metric (ICM), and ICA angle (Figure 1). According to the Fazekas scores, patients were categorized into mild, moderate and severe groups as summarized in Table 1. One-way ANOVA analyses were applied to reveal the difference of averaged bilateral ICAs' tortuosity measurements. Pearson's correlation coefficients were calculated to quantitatively investigate the relationship between tortuosity and volumes of lesions that are apart from the ventricle in subcortical white matter, i.e., deep white matter lesions (DWMLs), as well as the lesions attached with the ventricular system, i.e., periventricular white matter lesions (PVWMLs). Result: Patients with higher Fazekas scores have higher TI and ICM, indicating higher tortuosity (Figure 2). The correlation results showed that TI and ICM were positively correlated with DWMLs volumes (r = 0.33, P< 0.05; r = 0.4, P< 0.01), however, they did not show associations with PVWMLs. While there's no correlation between averaged bilateral ICA angles and DWMLs or PVWMLs, we found significant correlations between left ICA angles and DWML volumes on left brain (r =0.56, P < 0.005) as well as between right ICA angles and DWML volumes on right brain (r = 0.49, P < 0.05) (Figure 3). Conclusion: Tortuosity measurements derived from TOF images showed that subjects with higher degree of ICA tortuosity had higher lesion volumes of DWMLs not PVWMLs, indicating DWMLs may have different etiologies such as ischemic origin. The findings also highlight the importance of ICA angle as a risk factor for WMHs development which might be associated with the local hemodynamic shear stress at the bulb, where the ICA plaques are often developed.
SCOPUS:85144449727
ISSN: 1552-5260
CID: 5393902
Functional Outcomes of a Comprehensive, Individualized, Person-Centered Management Program in Advanced Alzheimer"™s Disease(AD): Results from a 52-Week Randomized Controlled Trial
Background: We conducted a 28-week, single-blind, randomized, controlled trial of the efficacy of Comprehensive, Individualized, Person-Centered Management (CI-PCM) and memantine treatment (Reisberg et al., Dement Geriatr Cogn Disord, 2017) in advanced AD persons. CI-PCM and memantine was approximately 7.5 times more beneficial to AD persons on the Functional Assessment Staging Tool (FAST) (Kenowsky et. al., Alzheimer"™s and Dementia, 2017) than to AD persons who received memantine alone in the memantine FDA approval pivotal trial conducted by Reisberg et. al., (NEJM 2003). We also conducted a 24-week extension study. Herein, we report the difference in functional outcomes between the CI-PCM and Usual Community Care (UCC+FC) groups at 52-weeks on the FAST and the ADCS-ADLSev-Abv. See Figures 1 and 2. Method: After screening, 20 eligible subject-carepartner dyads were randomized equally to the CI-PCM and UCC+FC groups. All 20 dyads completed the 28-week study and entered the 24-week extension study. One subject in the UCC+FC group died during the extension study. The FAST and ADCS-ADLsev-abv were conducted at baseline, and weeks 4, 12, 28, and 52. P values were calculated using the Wilcoxon Mann Whitney test. Result: The mean FAST total score from baseline (6.6±0.1SE) to week 52 (6.5±0.01SE) showed an improvement of functional limitations in the CI-PCM group. The mean FAST total score for the UCC+FC group showed a functional decline from baseline (6.6±0.1SE) to week 52 (6.8±0.1SE), displaying a robustly significant difference between the two groups (p<0.0014). The mean ADCS-ADL-sev-abv total score for the CI-PCM group demonstrated a 20.9% improvement in functioning from baseline (15.3±2.0SE) to week 52 (18.5±2.5SE). The mean ADCS-ADL-sev-abv total score for the UCC+FC group showed a decline of 48.6% from baseline (14.8±2.1SE) to week 52 (7.6±2.3SE), indicating a significant difference between the two groups (p<0.009). Conclusion: The CI-PCM program is the only evidenced-based treatment to date that can significantly improve and reverse functional deterioration in advanced AD persons. The functional success of the CI-PCM program may primarily be attributed to care partners learning to memory coach AD persons to perform daily activities such as bathing, dressing, feeding and toileting themselves, and to become/maintain urinary and fecal continence.
SCOPUS:85144362721
ISSN: 1552-5260
CID: 5393842
Normative Data and Conversion Equation for Spectral-Domain Optical Coherence Tomography in an International Healthy Control Cohort
BACKGROUND:Spectral-domain (SD-) optical coherence tomography (OCT) can reliably measure axonal (peripapillary retinal nerve fiber layer [pRNFL]) and neuronal (macular ganglion cell + inner plexiform layer [GCIPL]) thinning in the retina. Measurements from 2 commonly used SD-OCT devices are often pooled together in multiple sclerosis (MS) studies and clinical trials despite software and segmentation algorithm differences; however, individual pRNFL and GCIPL thickness measurements are not interchangeable between devices. In some circumstances, such as in the absence of a consistent OCT segmentation algorithm across platforms, a conversion equation to transform measurements between devices may be useful to facilitate pooling of data. The availability of normative data for SD-OCT measurements is limited by the lack of a large representative world-wide sample across various ages and ethnicities. Larger international studies that evaluate the effects of age, sex, and race/ethnicity on SD-OCT measurements in healthy control participants are needed to provide normative values that reflect these demographic subgroups to provide comparisons to MS retinal degeneration. METHODS:Participants were part of an 11-site collaboration within the International Multiple Sclerosis Visual System (IMSVISUAL) consortium. SD-OCT was performed by a trained technician for healthy control subjects using Spectralis or Cirrus SD-OCT devices. Peripapillary pRNFL and GCIPL thicknesses were measured on one or both devices. Automated segmentation protocols, in conjunction with manual inspection and correction of lines delineating retinal layers, were used. A conversion equation was developed using structural equation modeling, accounting for clustering, with healthy control data from one site where participants were scanned on both devices on the same day. Normative values were evaluated, with the entire cohort, for pRNFL and GCIPL thicknesses for each decade of age, by sex, and across racial groups using generalized estimating equation (GEE) models, accounting for clustering and adjusting for within-patient, intereye correlations. Change-point analyses were performed to determine at what age pRNFL and GCIPL thicknesses exhibit accelerated rates of decline. RESULTS:The healthy control cohort (n = 546) was 54% male and had a wide distribution of ages, ranging from 18 to 87 years, with a mean (SD) age of 39.3 (14.6) years. Based on 346 control participants at a single site, the conversion equation for pRNFL was Cirrus = -5.0 + (1.0 × Spectralis global value). Based on 228 controls, the equation for GCIPL was Cirrus = -4.5 + (0.9 × Spectralis global value). Standard error was 0.02 for both equations. After the age of 40 years, there was a decline of -2.4 μm per decade in pRNFL thickness ( P < 0.001, GEE models adjusting for sex, race, and country) and -1.4 μm per decade in GCIPL thickness ( P < 0.001). There was a small difference in pRNFL thickness based on sex, with female participants having slightly higher thickness (2.6 μm, P = 0.003). There was no association between GCIPL thickness and sex. Likewise, there was no association between race/ethnicity and pRNFL or GCIPL thicknesses. CONCLUSIONS:A conversion factor may be required when using data that are derived between different SD-OCT platforms in clinical trials and observational studies; this is particularly true for smaller cross-sectional studies or when a consistent segmentation algorithm is not available. The above conversion equations can be used when pooling data from Spectralis and Cirrus SD-OCT devices for pRNFL and GCIPL thicknesses. A faster decline in retinal thickness may occur after the age of 40 years, even in the absence of significant differences across racial groups.
PMID: 36049213
ISSN: 1536-5166
CID: 5337812
Amyotrophic Lateral Sclerosis Clinical Trials and Interpretation of Functional End Points and Fluid Biomarkers: A Review
IMPORTANCE:Clinical trial activity in amyotrophic lateral sclerosis (ALS) is dramatically increasing; as a result, trial modifications have been introduced to improve efficiency, outcome measures have been reassessed, and considerable discussion about the level of data necessary to advance a drug to approval has occurred. This review discusses what recent pivotal studies can teach the community about these topics. OBSERVATIONS:By restricting inclusion and exclusion criteria, recent trials have enrolled populations distinct from previous studies. This has led to efficacy signals being observed in studies that are smaller and shorter than was thought feasible previously. However, such trials raise questions about generalizability of results. Small trials with equivocal clinical results also raise questions about the data necessary to lead to regulatory approval. The ALS Functional Rating Scale-Revised remains the most commonly used primary outcome measure; this review discusses innovations in its use. Blood neurofilament levels can predict prognosis in ALS and may be a sensitive indicator of biologic effect; current knowledge does not yet support its use as a primary outcome. CONCLUSIONS AND RELEVANCE:It is now possible to use specific inclusion criteria to recruit a homogeneous patient population progressing at a specific rate; this will likely impact trials in the future. Generalizability of results on limited populations remains a concern. Although clinical outcomes remain the most appropriate primary outcome measures, fluid markers reflecting biologically important processes will assume more importance as more is learned about the association between such markers and clinical end points. The benefit of use of analytic strategies, such as responder analyses, is still uncertain.
PMID: 36251310
ISSN: 2168-6157
CID: 5874222
Tackling the Unmet Therapeutic Needs in Nonsurgical Treatments for Epilepsy
PMID: 36066899
ISSN: 2168-6157
CID: 5332412
Updates on efficacy and safety outcomes of new and emerging disease modifying therapies and stem cell therapy for Multiple Sclerosis: A review
Multiple Sclerosis (MS) is a chronic neurodegenerative autoimmune disorder of the central nervous system (CNS) and the most common cause of serious physical disability in working-age adults. Drug development and research in this field have rapidly evolved over the past two decades, leading to the broad array of treatment options available today. These disease-modifying therapies (DMTs) work through distinct mechanisms of action and exhibit varying safety and efficacy profiles to help manage symptoms and reduce exacerbations in MS patients. Our extensive understanding of this condition has also led to novel approaches, such as the discovery of specific biomarkers that allow us to monitor the therapeutic response towards DMTs. The development of new DMTs continues to progress quickly today, and it can be difficult for clinicians to remain up to date on the most recent advancements and new treatment options for their patients. In this comprehensive review, we provide an outline of current MS medications in the pipeline including emerging DMTs and stem cell therapy, as well as the unique characteristics of these medications, including their indications, pharmacokinetic effects, and the relevant advancements.
PMID: 36057173
ISSN: 2211-0356
CID: 5843552
Tribute to Steven Schachter, MD [Letter]
PMID: 36463058
ISSN: 1525-5069
CID: 5383822
The clinical spectrum of SMA-PME and in vitro normalization of its cellular ceramide profile
OBJECTIVE:The objectives of this study were to define the clinical and biochemical spectrum of spinal muscular atrophy with progressive myoclonic epilepsy (SMA-PME) and to determine if aberrant cellular ceramide accumulation could be normalized by enzyme replacement. METHODS:Clinical features of 6 patients with SMA-PME were assessed by retrospective chart review, and a literature review of 24 previously published cases was performed. Leukocyte enzyme activity of acid ceramidase was assessed with a fluorescence-based assay. Skin fibroblast ceramide content and was assessed by high performance liquid chromatography, electrospray ionization tandem mass spectroscopy. Enzyme replacement was assessed using recombinant human acid ceramidase (rhAC) in vitro. RESULTS:The six new patients showed the hallmark features of SMA-PME, with variable initial symptom and age of onset. Five of six patients carried at least one of the recurrent SMA-PME variants observed in two specific codons of ASAH1. A review of 30 total cases revealed that patients who were homozygous for the most common c.125C > T variant presented in the first decade of life with limb-girdle weakness as the initial symptom. Sensorineural hearing loss was associated with the c.456A > C variant. Leukocyte acid ceramidase activity varied from 4.1%-13.1% of controls. Ceramide species in fibroblasts were detected and total cellular ceramide content was elevated by 2 to 9-fold compared to controls. Treatment with rhAC normalized ceramide profiles in cultured fibroblasts to control levels within 48 h. INTERPRETATION/CONCLUSIONS:This study details the genotype-phenotype correlations observed in SMA-PME and shows the impact of rhAC to correct the abnormal cellular ceramide profile in cells.
PMID: 36325744
ISSN: 2328-9503
CID: 5358692
Orofacial pain among Chinese older adults in the last year of life
OBJECTIVE:To examine the prevalence of orofacial pain and associated factors in Chinese older adults at the end of life. METHODS:This cross-sectional study included 1646 participants (65Â years or older) in their last year of life from the Chinese Longitudinal Healthy Longevity Survey (CLHLS). We used the 6-month prevalence questions to measure two specific orofacial pain symptoms: toothache, and jaw or facial pain. Logistic regression analyses were used to examine factors, such as socioeconomic status, health behaviours and chronic diseases, that were associated with these two orofacial pain symptoms in the last year of life. RESULTS:The 6-month prevalence estimates for toothache and jaw pain or facial pain for older adults in the last year of life were 14.1% and 4.5% respectively. Higher socioeconomic status was associated with lower odds of toothache and jaw pain or facial pain. Smoking was associated with high odds of toothache. Participants who brushed their teeth at least once a day were more likely to have toothache and jaw or facial pain than those who did not. Having any chronic conditions was associated with higher odds of toothache and jaw or facial pain. Older adults who had at least one tooth were more likely to have jaw or facial pain than those without any teeth. CONCLUSION/CONCLUSIONS:A considerable proportion of Chinese older adults in their last year of life reported toothache and/or jaw pain or facial pain. These findings suggest that appropriate measures need to be taken to address the oral health needs in these vulnerable individuals, especially those of low socioeconomic status and chronic conditions.
PMID: 34841577
ISSN: 1741-2358
CID: 5066032
