Faculty Bibliography
Searched for:
school:SOM
Department/Unit:Neurology
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22914
A novel, semi-automatic procedure for generating slow change blindness stimuli
Change blindness is the phenomenon that occurs when an observer fails to notice what would seem to be obvious changes in the features of a visual stimulus. Researchers can induce this experimentally by including visual disruptions (such as brief blanks) that coincide with the changes in question. However, change blindness can also occur in the absence of these disruptions if a change occurs sufficiently slowly. This "slow" or "gradual" change blindness phenomenon has not been extensively researched. Two plausible practical reasons for this are that there are few slow-change stimuli available, and that it is difficult to collect trial-specific responses without affecting expectations on later trials. Here, we describe a novel, semi-automatic procedure for quickly generating many slow-change stimuli. This procedure creates stimuli that have been specifically designed to allow assessment of change blindness on individual trials without influencing subsequent trials. We include the results of three validation experiments that demonstrate that these stimuli are effective and suitable for use in systematic studies of slow change blindness.
PMCID:10860497
PMID: 38348333
ISSN: 2057-2107
CID: 5635662
A Severe Case of Streptococcus pneumoniae Meningoencephalitis in an Infant Resulting in Fatal Strokes [Case Report]
PMCID:11097696
PMID: 38766553
ISSN: 2329-048x
CID: 5654132
Longitudinal changes in sodium concentration and in clinical outcome in mild traumatic brain injury
Ionic imbalances and sodium channel dysfunction, well-known sequelae of traumatic brain injury (TBI), promote functional impairment in affected subjects. Therefore, non-invasive measurement of sodium concentrations using 23Na MRI has the potential to detect clinically relevant injury and predict persistent symptoms. Recently, we reported diffusely lower apparent total sodium concentrations (aTSC) in mild TBI patients compared to controls, as well as correlations between lower aTSC and worse clinical outcomes. The main goal of this study was to determine whether these aTSC findings, and their changes over time, predict outcomes at 3- and 12-month from injury. Twenty-seven patients previously studied with 23Na MRI and outcome measures at 22 ± 10 days (average ± standard deviation) after injury (visit-1, v1) were contacted at 3- (visit-2, v2) and 12-month after injury (visit-3, v3) to complete the Rivermead post-concussion symptoms questionnaire (RPQ), the extended Glasgow outcome scale (GOSE), and the brief test of adult cognition by telephone (BTACT). Follow-up 1H and 23Na MRI were additionally scheduled at v2. Linear regression was used to calculate aTSC in global grey and white matters. Six hypotheses were tested in relation to the serial changes in outcome measures and in aTSC, and in relation to the cross-sectional and serial relationships between aTSC and outcome. Twenty patients contributed data at v2 and fifteen at v3. Total RPQ and composite BTACT z-scores differed significantly for v2 and v3 in comparison to v1 (each P < 0.01), reflecting longitudinally reduced symptomatology and improved performance on cognitive testing. No associations between aTSC and outcome were observed at v2. Previously lower grey and white matter aTSC normalized at v2 in comparison to controls, in line with a statistically detectable longitudinal increase in grey matter aTSC between v1 and v2 (P = 0.0004). aTSC values at v1 predicted a subset of future BTACT subtest scores, but not future RPQ scores nor GOSE-defined recovery status. Similarly, aTSC rates of change correlated with BTACT rates of change, but not with those of RPQ. Tissue aTSC, previously shown to be diffusely decreased compared to controls at v1, was no longer reduced by v2, suggesting normalization of the sodium ionic equilibrium. These changes were accompanied by marked improvement in outcome. The results support the notion that early aTSC from 23Na MRI predicts future BTACT, but not RPQ scores, nor future GOSE status.
PMCID:11258572
PMID: 39035416
ISSN: 2632-1297
CID: 5723412
Brain Fluid Clearance After Traumatic Brain Injury Measured Using Dynamic Positron Emission Tomography
Brain fluid clearance by pathways including the recently described paravascular glymphatic system is a critical homeostatic mechanism by which metabolic products, toxins, and other wastes are removed from the brain. Brain fluid clearance may be especially important after traumatic brain injury (TBI), when blood, neuronal debris, inflammatory cells, and other substances can be released and/or deposited. Using a non-invasive dynamic positron emission tomography (PET) method that models the rate at which an intravenously injected radiolabeled molecule (in this case 11C-flumazenil) is cleared from ventricular cerebrospinal fluid (CSF), we estimated the overall efficiency of brain fluid clearance in humans who had experienced complicated-mild or moderate TBI 3-6 months before neuroimaging (n = 7) as compared to healthy controls (n = 9). While there was no significant difference in ventricular clearance between TBI subjects and controls, there was a significant group difference in dependence of ventricular clearance upon tracer delivery/blood flow to the ventricles. Specifically, in controls, ventricular clearance was highly, linearly dependent upon blood flow to the ventricle, but this relation was disrupted in TBI subjects. When accounting for blood flow and group-specific alterations in blood flow, ventricular clearance was slightly (non-significantly) increased in TBI subjects as compared to controls. Current results contrast with past studies showing reduced glymphatic function after TBI and are consistent with possible differential effects of TBI on glymphatic versus non-glymphatic clearance mechanisms. Further study using multi-modal methods capable of assessing and disentangling blood flow and different aspects of fluid clearance is needed to clarify clearance alterations after TBI.
PMCID:11035850
PMID: 38655117
ISSN: 2689-288x
CID: 5755892
Targeted detection of sequence variants in cell-free DNA from cerebrospinal fluid in pediatric central nervous system tumors
The emergence of liquid biopsy technologies holds great promise in the cancer setting, including in pediatric central nervous system (CNS) tumors. In contrast to broad lower-depth sequencing, commonly referred to as low pass whole genome sequencing (WGS), targeted platforms with a higher depth of coverage have also been established. Here, we review targeted liquid biopsy techniques with applicability to pediatric CNS tumors. These include polymerase chain reaction (PCR), both droplet digital PCR and reverse transcription-based PCR, Sanger sequencing, and next-generation sequencing approaches that incorporate amplicon- and hybrid capture-based methods. The goal of this paper is to facilitate an understanding of these targeted techniques and provide a context for clinical relevance within disease categories, as well as a discussion on optimizing real-world implementation for pediatric CNS tumors.
PMCID:11743934
PMID: 39834946
ISSN: 2234-943x
CID: 5802152
Researching COVID to enhance recovery (RECOVER) pediatric study protocol: Rationale, objectives and design
IMPORTANCE/OBJECTIVE:The prevalence, pathophysiology, and long-term outcomes of COVID-19 (post-acute sequelae of SARS-CoV-2 [PASC] or "Long COVID") in children and young adults remain unknown. Studies must address the urgent need to define PASC, its mechanisms, and potential treatment targets in children and young adults. OBSERVATIONS/METHODS:We describe the protocol for the Pediatric Observational Cohort Study of the NIH's REsearching COVID to Enhance Recovery (RECOVER) Initiative. RECOVER-Pediatrics is an observational meta-cohort study of caregiver-child pairs (birth through 17 years) and young adults (18 through 25 years), recruited from more than 100 sites across the US. This report focuses on two of four cohorts that comprise RECOVER-Pediatrics: 1) a de novo RECOVER prospective cohort of children and young adults with and without previous or current infection; and 2) an extant cohort derived from the Adolescent Brain Cognitive Development (ABCD) study (n = 10,000). The de novo cohort incorporates three tiers of data collection: 1) remote baseline assessments (Tier 1, n = 6000); 2) longitudinal follow-up for up to 4 years (Tier 2, n = 6000); and 3) a subset of participants, primarily the most severely affected by PASC, who will undergo deep phenotyping to explore PASC pathophysiology (Tier 3, n = 600). Youth enrolled in the ABCD study participate in Tier 1. The pediatric protocol was developed as a collaborative partnership of investigators, patients, researchers, clinicians, community partners, and federal partners, intentionally promoting inclusivity and diversity. The protocol is adaptive to facilitate responses to emerging science. CONCLUSIONS AND RELEVANCE/CONCLUSIONS:RECOVER-Pediatrics seeks to characterize the clinical course, underlying mechanisms, and long-term effects of PASC from birth through 25 years old. RECOVER-Pediatrics is designed to elucidate the epidemiology, four-year clinical course, and sociodemographic correlates of pediatric PASC. The data and biosamples will allow examination of mechanistic hypotheses and biomarkers, thus providing insights into potential therapeutic interventions. CLINICAL TRIALS.GOV IDENTIFIER/BACKGROUND:Clinical Trial Registration: http://www.clinicaltrials.gov. Unique identifier: NCT05172011.
PMCID:11075869
PMID: 38713673
ISSN: 1932-6203
CID: 5658342
Associations between concussion and more severe TBIs, mild cognitive impairment, and early-onset dementia among military retirees over 40 years
BACKGROUND AND OBJECTIVES/UNASSIGNED:As the population of U.S. service members (SMs) who have sustained concussions and more severe traumatic brain injuries (TBIs) during military service ages, understanding the long-term outcomes associated with such injuries will provide critical information that may promote long-term assessment, support, and rehabilitation following military service. The objective of this research was to examine whether concussion and more severe TBIs are associated with greater risk of precursors to dementia (i.e., mild cognitive impairment, memory loss), early-onset dementia, and any dementia. METHODS/UNASSIGNED: = 1,211,972). Diagnoses of concussion and more severe TBI during active duty service recorded in inpatient settings between 1980 and 2020 and in outpatient settings from 2001 to 2020 were identified. Focal outcomes of interest included memory loss, mild cognitive impairment, Alzheimer's, Lewy Body dementia, frontotemporal dementia, and vascular dementia. Dementia diagnoses before age 65 were labeled early-onset. RESULTS/UNASSIGNED:Those with (vs. without) concussion diagnoses during military service were significantly more likely to be diagnosed with memory loss and mild cognitive impairment and any of the dementias examined. However, they were not at greater risk of being diagnosed with early-onset dementia. DISCUSSION/UNASSIGNED:Military SMs diagnosed with concussion may be at elevated risk for long-term neurodegenerative outcomes including memory loss, mild cognitive impairment, and dementia. As the population of SMs who sustained TBI during the Global War on Terror continue to age, the prevalence of dementia will increase and may bring a unique burden to the VHA.
PMCID:11408918
PMID: 39296958
ISSN: 1664-2295
CID: 5721622
INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE [Meeting Abstract]
ISI:001313316206082
ISSN: 0146-0404
CID: 5765622
Journal of neuropsychiatry & clinical neurosciences. 2024:36(4):316-324.DOI: 10.1176/appi.neuropsych.20230114
Relationship Between Hemorrhage Type and Development of Emotional and Behavioral Dyscontrol After Hemorrhagic Stroke
OBJECTIVE/UNASSIGNED:Emotional and behavioral dyscontrol (EBD), a neuropsychiatric complication of stroke, leads to patient and caregiver distress and challenges to rehabilitation. Studies of neuropsychiatric sequelae in stroke are heavily weighted toward ischemic stroke. This study was designed to compare risk of EBD following intracerebral hemorrhage (ICH) and subarachnoid hemorrhage (SAH) and to identify risk factors for EBD following hemorrhagic stroke. METHODS/UNASSIGNED:The authors conducted a prospective cohort study of patients hospitalized for nontraumatic hemorrhagic stroke between 2015 and 2021. Patients or legally authorized representatives completed the Quality of Life in Neurological Disorders (Neuro-QOL) EBD short-form inventory 3 months after hospitalization. Univariable and multivariable analyses identified risk factors for EBD after hemorrhagic stroke. RESULTS/UNASSIGNED:The incidence of EBD was 21% (N=15 of 72 patients) at 3 months after hemorrhagic stroke. Patients with ICH were more likely to develop EBD; 93% of patients with EBD (N=14 of 15) had ICH compared with 56% of patients without EBD (N=32 of 57). The median Glasgow Coma Scale (GCS) score at hospital admission was lower among patients who developed EBD (13 vs. 15 among those without EBD). Similarly, admission scores on the National Institutes of Health Stroke Scale (NIHSS) and the Acute Physiology and Chronic Health Evaluation II (APACHE II) were higher among patients with EBD (median NIHSS score: 7 vs. 2; median APACHE II score: 17 vs. 11). Multivariable analyses identified hemorrhage type (ICH) and poor admission GCS score as predictors of EBD 3 months after hemorrhagic stroke. CONCLUSIONS/UNASSIGNED:Patients with ICH and a low GCS score at admission are at increased risk of developing EBD 3 months after hemorrhagic stroke and may benefit from early intervention.
PMID: 38650464
ISSN: 1545-7222
CID: 5711292
Delivering Multidisciplinary Rehabilitation Care in Parkinson's Disease: An International Consensus Statement
BACKGROUND:Parkinson's disease (PD) is a complex neurodegenerative disorder impacting everyday function and quality of life. Rehabilitation plays a crucial role in improving symptoms, function, and quality of life and reducing disability, particularly given the lack of disease-modifying agents and limitations of medications and surgical therapies. However, rehabilitative care is under-recognized and under-utilized in PD and often only utilized in later disease stages, despite research and guidelines demonstrating its positive effects. Currently, there is a lack of consensus regarding fundamental topics related to rehabilitative services in PD. OBJECTIVE:The goal of the international Parkinson's Foundation Rehabilitation Medicine Task Force was to develop a consensus statement regarding the incorporation of rehabilitation in PD care. METHODS:The Task Force, comprised of international multidisciplinary experts in PD and rehabilitation and people directly affected by PD, met virtually to discuss topics such as rehabilitative services, existing therapy guidelines and rehabilitation literature in PD, and gaps and needs. A systematic, interactive, and iterative process was used to develop consensus-based statements on core components of PD rehabilitation and discipline-specific interventions. RESULTS:The expert-based consensus statement outlines key tenets of rehabilitative care including its multidisciplinary approach and discipline-specific guidance for occupational therapy, physical therapy, speech language pathology/therapy, and psychology/neuropsychology across all PD stages. CONCLUSIONS:Rehabilitative interventions should be an essential component in the comprehensive treatment of PD, from diagnosis to advanced disease. Greater education and awareness of the benefits of rehabilitative services for people with PD and their care partners, and further evidence-based and scientific study are encouraged.
PMID: 38277303
ISSN: 1877-718x
CID: 5625422
