Publications by authors named "Raviteja Kotikalapudi"

Objectives: Temporal lobe epilepsy (TLE) is commonly associated with mesiotemporal pathology and widespread alterations of grey and white matter structures. Evidence supports a progressive condition although the temporal evolution of TLE is poorly defined. This ENIGMA-Epilepsy study utilized multimodal magnetic resonance imaging (MRI) data to investigate structural alterations in TLE patients across the adult lifespan.

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Background And Objectives: Genetic generalized epilepsy (GGE) is the most common form of generalized epilepsy. Although individual patients with GGE typically present without structural alterations, group differences have been demonstrated in GGE and some GGE subtypes like juvenile myoclonic epilepsy (GGE-JME). Previous studies usually involved only small cohorts from single centers and therefore could not assess imaging markers of multiple GGE subtypes.

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Article Synopsis
  • Genetic generalized epilepsy (GGE) is a brain disorder characterized by widespread connectivity issues, which can be studied using simultaneous EEG and fMRI, but there are challenges due to MRI-related artifacts affecting the EEG data.
  • This study explored the effects of these artifacts on group comparisons of EEG power and functional connectivity between GGE patients and healthy controls, finding that while some power differences were reduced in significance, measures of functional connectivity (ImCoh) remained consistent across conditions.
  • Notably, increased functional connectivity was observed in GGE patients, particularly from the thalamus to the precuneus cortex, suggesting that using ImCoh for EEG analysis within the MRI is valid and that group differences can be effectively maintained despite the measurement conditions
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Optimism bias is the tendency to believe desirable events are more likely to happen than undesirable ones. People often display optimistic biases for themselves (personal optimism), but also for members of groups they like or identify with (social optimism). However, the neural bases of and connections between these two concepts are poorly understood.

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Sensitivity to pain shows a remarkable interindividual variance that has been reported to both forecast and accompany various clinical pain conditions. Although pain thresholds have been reported to be associated to brain morphology, it is still unclear how well these findings replicate in independent data and whether they are powerful enough to provide reliable pain sensitivity predictions on the individual level. In this study, we constructed a predictive model of pain sensitivity (as measured with pain thresholds) using structural magnetic resonance imaging-based cortical thickness data from a multicentre data set (3 centres and 131 healthy participants).

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Image templates are a common tool for neuroscience research. Often, they are used for spatial normalization of magnetic resonance imaging (MRI) data, which is a necessary procedure for analyzing brain morphology and function via voxel-based analysis. This allows the researcher to reduce individual shape differences across images and make inferences across multiple subjects.

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People have been shown to be optimistically biased when their future outcome expectancies are assessed. In fact, we display optimism bias (OB) toward our own success when compared to a rival individual's (personal OB [POB]). Similarly, success expectancies for social groups we like reliably exceed those we mention for a rival group (social OB [SOB]).

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Epilepsy is associated with genetic risk factors and cortico-subcortical network alterations, but associations between neurobiological mechanisms and macroscale connectomics remain unclear. This multisite ENIGMA-Epilepsy study examined whole-brain structural covariance networks in patients with epilepsy and related findings to postmortem epilepsy risk gene expression patterns. Brain network analysis included 578 adults with temporal lobe epilepsy (TLE), 288 adults with idiopathic generalized epilepsy (IGE), and 1328 healthy controls from 18 centres worldwide.

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Objective: Recent work has shown that people with common epilepsies have characteristic patterns of cortical thinning, and that these changes may be progressive over time. Leveraging a large multicenter cross-sectional cohort, we investigated whether regional morphometric changes occur in a sequential manner, and whether these changes in people with mesial temporal lobe epilepsy and hippocampal sclerosis (MTLE-HS) correlate with clinical features.

Methods: We extracted regional measures of cortical thickness, surface area, and subcortical brain volumes from T1-weighted (T1W) magnetic resonance imaging (MRI) scans collected by the ENIGMA-Epilepsy consortium, comprising 804 people with MTLE-HS and 1625 healthy controls from 25 centers.

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Objective: Genetic generalized epilepsy (GGE) is characterized by aberrant neuronal dynamics and subtle structural alterations. We evaluated whether a combination of magnetic and electrical neuronal signals and cortical thickness would provide complementary information about network pathology in GGE. We also investigated whether these imaging phenotypes were present in healthy siblings of the patients to test for genetic influence.

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Article Synopsis
  • Temporal lobe epilepsy (TLE) is mainly a limbic network disorder characterized by unilateral hippocampal issues and has been studied using structural MRI for brain grey matter changes.
  • The study utilized the ENIGMA-Epilepsy dataset to compare grey matter asymmetry and atrophy in TLE patients versus healthy controls, finding distinct patterns: atypical asymmetry showed a temporo-limbic signature, while atrophy appeared diffuse and bilateral.
  • Results indicated that cortical atrophy correlates with factors like disease duration and age at seizure onset, while asymmetry levels did not, suggesting that these two measures capture different but complementary aspects of TLE pathology.
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Individuals often anticipate an unrealistically favorable future for themselves (personal optimism bias) or others (social optimism bias). While such biases are well established, little is known about their neuroanatomy. In this study, participants engaged in a soccer task and estimated the likelihood of successful passes in personal and social scenarios.

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We investigated the white matter correlates of personality profiles predictive of subjective well-being. Using principal component analysis to first determine the possible personality profiles onto which core personality measures would load, we subsequently searched for whole-brain white matter correlations with these profiles. We found three personality profiles that correlated with the integrity of white matter tracts.

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Sex hormones such as estradiol (E2) have long-lasting influence on brain architecture. Recent studies indicate further structural changes during hormonal transition periods including pregnancy, when women experience the greatest increase in sex hormone levels across their life span. In the present study, three groups of women (n = 44) with different levels of E2 underwent structural magnetic resonance imaging: (1) first-time pregnant women (n = 13, 'extreme E2 group'); (2), nulliparous, naturally cycling women who received 12 mg of E2 valerate (n = 16, 'high E2 group'); and (3) nulliparous, naturally cycling women receiving a placebo and hence low E2 (n = 15, 'low E2 group').

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Article Synopsis
  • The study investigates the causes of reduced cortical thickness in human epilepsies using brain imaging and gene expression data to understand underlying mechanisms.* -
  • Researchers found higher levels of activated microglia and endothelial cells in areas of reduced cortical thickness, both in imaging studies and post-mortem brain tissue from epilepsy patients.* -
  • Targeted depletion of activated microglia in a mouse model prevented cortical thinning and neuronal loss, suggesting microglia play a crucial role in these changes, potentially offering new approaches for epilepsy treatment beyond seizure control.*
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Artificial intelligence has recently gained popularity across different medical fields to aid in the detection of diseases based on pathology samples or medical imaging findings. Brain magnetic resonance imaging (MRI) is a key assessment tool for patients with temporal lobe epilepsy (TLE). The role of machine learning and artificial intelligence to increase detection of brain abnormalities in TLE remains inconclusive.

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Recent research shows that congruent outcomes are more rapidly (and incongruent less rapidly) detected when individuals receive optimistic rather than pessimistic cues, an effect that was termed optimism robustness. In the current voxel-based morphometry study, we examined whether optimism robustness has a counterpart in the brain structure. The participants' task was to detect two different letters (symbolizing monetary gain or loss) in a visual search matrix.

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Objective: To assess whether neuronal signals in patients with genetic generalized epilepsy (GGE) are heritable, we examined magnetoencephalography resting-state recordings in patients and their healthy siblings.

Methods: In a prospective, cross-sectional design, we investigated source-reconstructed power and functional connectivity in patients, siblings, and controls. We analyzed 5 minutes of cleaned and awake data without epileptiform discharges in 6 frequency bands (1-40 Hz).

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An optimism bias refers to the belief in good things happening to oneself in the future with a higher likelihood than is justified. Social optimism biases extend this concept to groups that one identifies with. Previous literature has found that both personal and social optimism biases are linked to brain structure and task-related brain function.

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Epilepsy is increasingly conceptualized as a network disorder. In this cross-sectional mega-analysis, we integrated neuroimaging and connectome analysis to identify network associations with atrophy patterns in 1021 adults with epilepsy compared to 1564 healthy controls from 19 international sites. In temporal lobe epilepsy, areas of atrophy colocalized with highly interconnected cortical hub regions, whereas idiopathic generalized epilepsy showed preferential subcortical hub involvement.

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Article Synopsis
  • The study looked at how epilepsy affects the brain, focusing on certain brain areas called white matter.
  • Researchers collected and analyzed brain scan data from both healthy people and those with different types of epilepsy, like temporal lobe epilepsy and generalized epilepsy.
  • They found that most patients with epilepsy had changes in their brain's white matter, especially in specific areas, showing stronger effects in those with hippocampal sclerosis.
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Epilepsy is a common and serious neurological disorder, with many different constituent conditions characterized by their electro clinical, imaging, and genetic features. MRI has been fundamental in advancing our understanding of brain processes in the epilepsies. Smaller-scale studies have identified many interesting imaging phenomena, with implications both for understanding pathophysiology and improving clinical care.

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We assessed the applicability of MP2RAGE for voxel-based morphometry. To this end, we analyzed its brain tissue segmentation characteristics in healthy subjects and the potential for detecting focal epileptogenic lesions (previously visible and nonvisible). Automated results and expert visual interpretations were compared with conventional VBM variants (i.

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Progressive functional decline in the epilepsies is largely unexplained. We formed the ENIGMA-Epilepsy consortium to understand factors that influence brain measures in epilepsy, pooling data from 24 research centres in 14 countries across Europe, North and South America, Asia, and Australia. Structural brain measures were extracted from MRI brain scans across 2149 individuals with epilepsy, divided into four epilepsy subgroups including idiopathic generalized epilepsies (n =367), mesial temporal lobe epilepsies with hippocampal sclerosis (MTLE; left, n = 415; right, n = 339), and all other epilepsies in aggregate (n = 1026), and compared to 1727 matched healthy controls.

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Background: Writer's cramp (WC) is one of the commonly observed focal dystonias. The pathophysiology of WC has not been fully understood. The role of the cerebellum has been increasingly recognized in the pathogenesis of dystonia.

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