Publications by authors named "Varan Govind"

Background: Both alcohol consumption and HIV infection are associated with worse brain, cognitive, and clinical outcomes in older adults. However, the extent to which brain and cognitive dysfunction is reversible with reduction or cessation of drinking is unknown.

Objective: The 30-Day Challenge study was designed to determine whether reduction or cessation of drinking would be associated with improvements in cognition, reduction of systemic and brain inflammation, and improvement in HIV-related outcomes in adults with heavy drinking.

View Article and Find Full Text PDF

Human immunodeficiency virus-1 (HIV-1) clade C is the most prevalent form of HIV-1 comprising nearly 46% of global infections and is the dominant subtype in India. Despite its predominance, the impact of HIV-1 clade C infection on cognitive function has been understudied in comparison with other subtypes, notably clade B, which is primarily found in Europe and North America. Few studies have assessed cognitive impairment in antiretroviral therapy (ART) naïve men and women with HIV-1 clade C infection.

View Article and Find Full Text PDF

Background: Infants with congenital Zika syndrome (CZS) are known to exhibit characteristic brain abnormalities. However, the brain anatomy of Zika virus (ZIKV)-exposed infants, born to ZIKV-positive pregnant mothers, who have normal-appearing head characteristics at birth, has not been evaluated in detail. The aim of this prospective study is, therefore, to compare the cortical and subcortical brain structural volume measures of ZIKV-exposed normocephalic infants to age-matched healthy controls.

View Article and Find Full Text PDF

Background: Heavy alcohol use in people living with HIV (PLWH) has widespread negative effects on neural functioning. It remains unclear whether experimentally-induced reduction in alcohol use could reverse these effects. We sought to determine the effects of 30-days drinking cessation/reduction on resting state functional connectivity in people with and without HIV.

View Article and Find Full Text PDF
Article Synopsis
  • Perinatally acquired HIV (PHIV) is linked to brain abnormalities and cognitive deficits, even with antiretroviral therapy, but research using proton magnetic resonance spectroscopy (MRS) on brain metabolite levels is limited and often contradictory.
  • This study utilizes a whole-brain proton magnetic resonance spectroscopy imaging (MRSI) method to compare metabolite levels in 28 young adults with PHIV to a control group of the same size, focusing on total N-acetylaspartate, choline, and creatine levels.
  • Results show significant metabolic disturbances, including increased creatine and choline levels and decreased N-acetylaspartate, indicating neuronal dysfunction and inflammation, which correlate with lower CD4 cell
View Article and Find Full Text PDF

Traumatic brain injury (TBI) can lead to a variety of comorbidities, including chronic pain. Although brain tissue metabolite alterations have been extensively examined in several chronic pain populations, it has received less attention in people with TBI. Thus, the primary aim of this study was to compare brain tissue metabolite levels in people with TBI and chronic pain ( = 16), TBI without chronic pain ( = 17), and pain-free healthy controls ( = 31).

View Article and Find Full Text PDF

More than 50% of individuals develop chronic pain following traumatic brain injury (TBI). Research suggests that a significant portion of post-TBI chronic pain conditions is neuropathic in nature, yet the relationship between neuropathic pain, psychological distress, and somatosensory function following TBI is not fully understood. This study evaluated neuropathic pain symptoms, psychological and somatosensory function, and psychosocial factors in individuals with TBI (TBI, = 38).

View Article and Find Full Text PDF
Article Synopsis
  • More than half of individuals with bipolar depression (BD) are often misdiagnosed with unipolar depression (UD) due to a lack of clear diagnostic criteria; this study aimed to identify neuroimaging markers to differentiate these two conditions.
  • The research involved a total of 62 participants, including those diagnosed with BD, UD, and healthy controls, who underwent advanced brain imaging techniques to measure various diffusion and kurtosis metrics across different brain regions.
  • Results indicated specific microstructural changes in the left amygdala and right hemi-cerebellum for BD, while UD showed distinct changes in the right external capsule and right amygdala, highlighting the potential of diffusion kurtosis imaging as a tool for better diagnosing and managing
View Article and Find Full Text PDF

Background: Imbalance in tryptophan (TRP) metabolism and its neuroactive metabolites, serotonin and kynurenine (KYN), is a known pathogenic mechanism underlying neurocognitive impairment. Gut microbiota plays an important role in TRP metabolism, and the production of these neuroactive molecules affects neurocognitive function. Although both HIV infection and normal aging independently induce gut dysbiosis and influence TRP metabolism, their interactive effects on compositional/functional changes in gut microbiota and consequent alterations in TRP metabolites remain largely undetermined.

View Article and Find Full Text PDF
Article Synopsis
  • - Minimal hepatic encephalopathy (MHE) causes cognitive and psychomotor deficits without obvious clinical symptoms, linked to hyperammonemia and neuroinflammation, and detectable via advanced MRI techniques at early stages.
  • - A study analyzing diffusion kurtosis imaging (DKI) in 15 MHE patients revealed significant microstructural changes in the brain compared to controls, specifically in kurtosis metrics across various regions related to cognitive functions.
  • - Findings indicated decreased kurtosis parameters in MHE, particularly in white matter, with moderate to strong correlations between these metrics and psychometric scores, highlighting brain abnormalities associated with cognitive impairment.
View Article and Find Full Text PDF

Objective: Comparative evaluation of diffusion kurtosis imaging (DKI) and diffusion tensor imaging (DTI) using a whole-brain atlas to comprehensively evaluate microstructural changes in the brain of Alzheimer disease (AzD) patients.

Methods: Twenty-seven AzD patients and 25 age-matched controls were included. MRI data was analyzed using a whole-brain atlas with inclusion of 98 region of interests.

View Article and Find Full Text PDF

Purpose: The association between obstructive sleep apnea (OSA) and cognitive impairment is well-recognized, but little is known about neural derangements that underlie this phenomenon. The purpose of this study was to evaluate the utility of diffusion kurtosis imaging (DKI) using a whole-brain atlas to comprehensively assess microstructural tissue changes in the brain of patients with OSA.

Methods: This prospective study was conducted in 20 patients with moderate-to-severe OSA and 20 age- and gender-matched controls.

View Article and Find Full Text PDF

Background And Purpose: Brain trauma is known to result in heterogeneous patterns of tissue damage and altered neuronal and glial metabolism that evolve over time following injury; however, little is known on the longitudinal evolution of these changes. In this study, magnetic resonance spectroscopic imaging (MRSI) was used to map the distributions of altered metabolism in a single subject at five time points over a period of 28 months following injury.

Methods: Magnetic resonance imaging and volumetric MRSI data were acquired in a subject that had experienced a moderate traumatic brain injury (Glasgow Coma Scale 13) at five time points, from 7 weeks to 28 months after injury.

View Article and Find Full Text PDF

Glutathione (GSH) is a major antioxidant in humans that is involved in the detoxification of reactive radicals and peroxides. The molecular structural conformations of GSH depend on the surrounding micro-environment, and it has been experimentally evaluated using NMR and Raman spectroscopic techniques as well as by molecular dynamics simulation studies. The converging report indicates that GSH exists mainly in two major conformations, i.

View Article and Find Full Text PDF

Perinatal HIV is associated with significant neurocognitive morbidities, but few studies have examined cognitive impact of early HIV infection on patients surviving to adulthood. The purpose of this study was to evaluate neurocognitive outcomes among a cohort of perinatally infected young adults. Individuals between the ages of 18 and 24 with perinatal infection were recruited for this cross-sectional study along with similarly aged healthy controls.

View Article and Find Full Text PDF

Objective: Damage to the cerebral tissue structural connectivity associated with amyotrophic lateral sclerosis (ALS), which extends beyond the motor pathways, can be visualised by diffusion tensor imaging (DTI). The effective translation of DTI metrics as biomarker requires its application across multiple MRI scanners and patient cohorts. A multicentre study was undertaken to assess structural connectivity in ALS within a large sample size.

View Article and Find Full Text PDF

Persistent pain is experienced by more than 50% of persons who sustain a traumatic brain injury (TBI), and more than 30% experience significant pain as early as 6 weeks after injury. Although neuropathic pain is a common consequence after CNS injuries, little attention has been given to neuropathic pain symptoms after TBI. Magnetic resonance spectroscopy (MRS) studies in subjects with TBI show decreased brain concentrations of N-acetylaspartate (NAA), a marker of neuronal density and viability.

View Article and Find Full Text PDF

Magnetic resonance spectroscopy (MRS) and diffusion tensor imaging (DTI) studies have demonstrated that measures of altered metabolism and axonal injury can be detected following traumatic brain injury. The aim of this study was to characterize and compare the distributions of altered image parameters obtained by these methods in subjects with a range of injury severity and to examine their relative sensitivity for diagnostic imaging in this group of subjects. DTI and volumetric magnetic resonance spectroscopic imaging data were acquired in 40 subjects that had experienced a closed-head traumatic brain injury, with a median of 36 d post-injury.

View Article and Find Full Text PDF

Purpose: To assess the impact of accelerated acquisitions on the spectral quality of volumetric magnetic resonance spectroscopic imaging (MRSI) and to evaluate their ability in detecting metabolic changes with mild injury.

Materials And Methods: The implementation of a generalized autocalibrating partially parallel acquisition (GRAPPA) method for a high-resolution whole-brain echo planar SI (3D-EPSI) sequence is first described and the spectral accuracy of the GRAPPA-EPSI method is investigated using lobar and voxel-based analyses for normal subjects and patients with mild traumatic brain injuries (mTBI). The performance of GRAPPA was compared with that of fully encoded EPSI for five datasets collected from normal subjects at the same scanning session, as well as on 45 scans (20 normal subjects and 25 mTBI patients) for which the reduced k-space sampling was simulated.

View Article and Find Full Text PDF

Background And Purpose: To examine the distributions of proton magnetic resonance spectroscopy (MRS) observed metabolites in Parkinson's disease (PD) throughout the whole brain.

Methods: Twelve PD patients and 18 age-matched controls were studied using neuropsychological testing, MRI and volumetric MR spectroscopic imaging. Average values of signal normalized metabolite values for N-acetyl-aspartate, total-creatine, and total-choline (NAA, total-Cre, total-Cho, respectively) and their ratios were calculated for gray matter (GM) and white matter (WM) in each lobar brain region.

View Article and Find Full Text PDF

The catastrophic system failure in amyotrophic lateral sclerosis is characterized by progressive neurodegeneration within the corticospinal tracts, brainstem nuclei and spinal cord anterior horns, with an extra-motor pathology that has overlap with frontotemporal dementia. The development of computed tomography and, even more so, MRI has brought insights into neurological disease, previously only available through post-mortem study. Although largely research-based, radionuclide imaging has continued to provide mechanistic insights into neurodegenerative disorders.

View Article and Find Full Text PDF

Changes in the distribution of the proton magnetic resonance spectroscopy (MRS) observed metabolites N-acetyl aspartate (NAA), total-choline (Cho), and total-creatine (Cre) in the entire intracranial corticospinal tract (CST) including the primary motor cortex were evaluated in patients with amyotrophic lateral sclerosis (ALS). The study included 38 sporadic definite-ALS subjects and 70 age-matched control subjects. All received whole-brain MR imaging and spectroscopic imaging scans at 3T and clinical neurological assessments including percentage maximum forced vital capacity (FVC) and upper motor neuron (UMN) function.

View Article and Find Full Text PDF