Publications by authors named "Rao Gullapalli"

Aircraft cabins are routinely pressurized to the equivalent of 8000 ft altitude. Exposure of lab animals to aeromedical evacuation relevant hypobaria after traumatic brain injury worsens neurological outcomes, which is paradoxically exacerbated by hyperoxia. This study tested the hypothesis that exposure of rats to hypobaria following cortical impact reduces cerebral blood flow, increases neuroinflammation, and alters brain neurochemistry.

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Article Synopsis
  • Traumatic brain injury (TBI), even mild, can lead to long-lasting symptoms and a higher risk of dementia, possibly due to problems in the brain's glymphatic system, which normally clears waste.
  • This study evaluated the enlarged perivascular space (ePVS) and the ALPS index in 44 mTBI patients at two points: about 14 days and 6-12 months after injury, also comparing them to 37 control participants.
  • Key results showed significant correlations where higher ePVS was linked to more memory problems shortly after injury, and an increase in the ALPS index over time was associated with better sleep, suggesting these markers may help predict recovery outcomes for TBI patients.
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Blindness and visual impairment affect the quality of life of the individual and their family members. Corneal opacities are a key cause of vision loss around the world, especially in low-income and middle-income countries (LMIC). Corneal blindness and vision loss impacts every age group, and the risk factors and the causes are also varied.

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Traumatic brain injury (TBI) even in the mild form may result in long-lasting post-concussion symptoms. TBI is also a known risk to late-life neurodegeneration. Recent studies suggest that dysfunction in the glymphatic system, responsible for clearing protein waste from the brain, may play a pivotal role in the development of dementia following TBI.

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  • Blast-related traumatic brain injury (bTBI) is a significant neurological issue for military personnel, leading to long-term health problems and impacts on quality of life, with varying manifestations that complicate understanding.
  • Research into blast injuries has shifted from rodent models to ferrets, as their brain structure more closely resembles that of humans, allowing for better insights into the effects of bTBI.
  • Findings from this study on ferrets exposed to blasts revealed issues like impulsivity in decision-making, increased glutamate levels linked to behavioral deficits, high levels of brain -acetylaspartate indicating potential metabolic disruptions, and pre-frontal cortex/auditory cortex signaling dysfunction that may relate to psychiatric disorders.
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Background: MR spectroscopy (MRS) is a noninvasive tool for evaluating biochemical alterations, such as glutamate (Glu)/gamma-aminobutyric acid (GABA) imbalance and depletion of antioxidative glutathione (GSH) after traumatic brain injury (TBI). Thalamus, a critical and vulnerable region post-TBI, is challenging for MRS acquisitions, necessitating optimization to simultaneously measure GABA/Glu and GSH.

Purpose: To assess the feasibility and optimize acquisition and processing approaches for simultaneously measuring GABA, Glx (Glu + glutamine (Gln)), and GSH in the thalamus, employing Hadamard encoding and reconstruction of MEscher-GArwood (MEGA)-edited spectroscopy (HERMES).

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Background: To report 15-year incidence rate of primary open angle glaucoma (POAG) in the Andhra Pradesh Eye Disease Study (APEDS).

Methods: A population-based longitudinal study was carried out at three rural study sites. Phakic participants aged ≥40 years who participated at baseline (APEDS I) and the mean 15-year follow-up visit (APEDS III) were included.

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Article Synopsis
  • The perivascular space (PVS) plays a crucial role in brain waste clearance, and enlarged PVS (ePVS) can be detected using T2-weighted MRI images, although quantifying it accurately is challenging with standard 2D images.
  • This study explores the use of a deep-learning super-resolution technique to enhance ePVS quantification from 2D T2-weighted images in patients with traumatic brain injury (TBI), validating it against higher-resolution 3D images.
  • The results show that the super-resolved images yield comparable ePVS volume measurements, indicating a potential method for better assessing the impact of sleep quality on ePVS in TBI patients.
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Background And Objectives: Magnetic resonance-guided focused ultrasound (MRgFUS) central lateral thalamotomy (CLT) has not yet been validated for treating refractory neuropathic pain (NP). Our aim was to assess the safety and potential efficacy of MRgFUS CLT for refractory NP.

Methods: In this prospective, nonrandomized, single-arm, investigator-initiated phase I trial, patients with NP for more than 6 months related to phantom limb pain, spinal cord injury, or radiculopathy/radicular injury and who had undergone at least one previous failed intervention were eligible.

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  • The study evaluates the feasibility of using CEST-based creatine mapping in the brain at a magnetic field strength of 3T, focusing on guanidino protons.
  • Wild type and genetically modified mice with low creatine concentrations were analyzed to understand contributions to the GuanCEST signal and to quantify creatine's proton exchange rates.
  • Results indicate a clear Guan proton peak and suggest that CEST mapping can effectively detect changes in intracellular pH and creatine concentration in the brain.
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Introduction: Parkinson's Disease (PD) is a progressive neurodegenerative disorder affecting both motor and cognitive function. Previous neuroimaging studies have reported altered functional connectivity (FC) in distributed functional networks. However, most neuroimaging studies focused on patients at an advanced stage and with antiparkinsonian medication.

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Cerebral venous oxygenation (Y ) is a valuable biomarker for a variety of brain diseases. T relaxation under spin tagging (TRUST) MRI is a widely used method for Y quantification. In this work, there were two main objectives.

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Elevated plasma neurofilament light chain (NfL) is associated with dementia though underlying mechanisms remain unknown. We examined cross-sectional relationships of time-dependent plasma NfL with selected brain structural magnetic resonance imaging (sMRI) prognostic markers of dementia. The sample was drawn from the Healthy Aging in Neighborhoods of Diversity Across the Life Span (HANDLS) study, selecting participants with complete v (2004-2009) and v (2009-2013) plasma NfL exposure and ancillary sMRI data at v (2011-2015, n = 179, mean v to v time: 5.

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Data-driven thalamic nuclei parcellation depends on high-quality manual annotations. However, the small size and low contrast changes among thalamic nuclei, yield annotations that are often incomplete, noisy, or ambiguously labelled. To train a robust thalamic nuclei parcellation model with noisy annotations, we propose a label propagation algorithm based on random walker to refine the annotations before model training.

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Objectives: Rotator cuff (RC) tear is common among adults ≥60 years, with supraspinatus tear most common. Intramuscular fatty infiltration (FI) on imaging is predictive of long-term outcomes following RC tear. Physical therapists routinely diagnose RC tear only by clinical examination since most do not order imaging studies.

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Introduction: Lower socioeconomic status (SES) is associated with poorer executive function, but the neural mechanisms of this association remain unclear. As healthy brain communication is essential to our cognitive abilities, white matter integrity may be key to understanding socioeconomic disparities.

Methods: Participants were 201 African American and White adults (ages 33-72) from the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) SCAN study.

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Plasma neurofilament light chain (NfL)'s link to dementia may be mediated through white matter integrity (WMI). In this study, we examined plasma NfL's relationships with diffusion tensor magnetic resonance imaging markers: global and cortical white matter fractional anisotropy (FA) and trace (TR). Plasma NfL measurements at 2 times (v: 2004-2009 and v: 2009-2013) and ancillary dMRI (v: 2011-2015) were considered (n = 163, mean time v to v = 5.

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Background: To report the 15-year incidence rate of pseudo-exfoliation (PXF),  PXF glaucoma and regional variation among rural participants in the Andhra Pradesh Eye Disease Study (APEDS) III.

Methods: This population-based longitudinal study was carried out at three rural study sites. Individuals of all ages who participated at baseline with a mean 15-year follow-up visit were included.

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Purpose: The goal of this study is to validate the muscle architecture derived from both ex vivo and in vivo diffusion-weighted magnetic resonance imaging (dMRI) of the human tongue with histology of an ex vivo tongue.

Method: dMRI was acquired with a 200-direction high angular resolution diffusion imaging (HARDI) diffusion scheme for both a postmortem head (imaged within 48 hr after death) and a healthy volunteer. After MRI, the postmortem head was fixed and the tongue excised for hematoxylin and eosin (H&E) staining and histology imaging.

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Mild (mTBI) traumatic brain injury (TBI) accounts for the majority of all TBI cases. Evidence has suggested that patients with mTBI can suffer from long-lasting cognitive deficits, persistent symptoms, and decreased quality of life. Sleep disorders are commonly observed after TBI, with the prevalence rate of sleep disturbances in persons with TBI being much higher than that in the general population.

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Introduction: Resting state functional connectivity (FC) is widely used to assess functional brain alterations in patients with chronic pain. However, reports of FC accompanying tonic pain in pain-free persons are rare. A network we term the Descending Pain Modulatory Network (DPMN) is implicated in healthy and pathologic pain modulation.

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Medical image segmentation is one of the core tasks of medical image analysis. Automatic segmentation of brain magnetic resonance images (MRIs) can be used to visualize and track changes of the brain's anatomical structures that may occur due to normal aging or disease. Machine learning techniques are widely used in automatic structure segmentation.

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Introduction: Bidirectional effects between cognition and pain have been extensively reported. Although brain regions involved in cognitive and pain processing seem to partly overlap, it is unknown what specific brain regions are involved in the interaction between pain and cognition. Furthermore, the role of gonadal hormones on these interacting effects has not been examined.

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Aeromedical evacuation-relevant hypobaria after traumatic brain injury (TBI) leads to increased neurological injury and death in rats relative to those maintained under normobaria. Applicability of rodent brain injury research to humans may be limited, however, by differences in neuroanatomy. Therefore, we developed a model in which ferrets are exposed to polytrauma consisting of controlled cortical impact TBI and hemorrhagic shock subjected 24 h later to 6 h of hypobaria or normobaria.

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