Natalia Egorova-Brumley

University of Melbourne | MSD · Melbourne School of Psychological Sciences

Motor outcomes after stroke relate to corticospinal tract (CST) damage. Concurrent damage from white matter hyperintensities (WMHs) might impact neurological capacity for recovery after CST injury. Here, we evaluated if WMHs modulate the relationship between CST damage and post-stroke motor impairment outcome. We included 223 individuals from the E...

Osteoarthritis (OA) affects 240 million people worldwide. Neuroimaging has been increasingly used to investigate brain changes in OA, however, there is considerable heterogeneity in reported results. The goal of this systematic review and meta-analysis was to synthesise existing literature and identify consistent brain alterations in OA. Six databa...

Females have increased pain sensitivity and are more vulnerable to chronic pain conditions. Sleep disturbances are comorbid with chronic pain and exacerbate pain symptoms. Different types of sleep disturbance affect pain perception distinctly, but it is not clear if these effects are equal in men and women. This systematic review investigated poten...

Humans and other animals value information that reduces uncertainty or leads to pleasurable anticipation, even if it cannot be used to gain tangible rewards or change outcomes. In exchange, they are willing to incur significant costs, sacrifice rewards or invest effort. We investigated whether human participants were also willing to endure pain—a h...

Background The hippocampus plays an important role in learning and integrating events to form episodic memory. Many ischemic stroke survivors experience memory impairments, and some report decline in memory function. We examined changes in functional connectivity (FC) of the hippocampus and its subregions in stroke survivors over 3 years compared t...

Background and objectives: Functional outcomes after stroke are strongly related to focal injury measures. However, the role of global brain health is less clear. Here, we examined the impact of brain age, a measure of neurobiological aging derived from whole brain structural neuroimaging, on post-stroke outcomes, with a focus on sensorimotor perf...

Diffusion-weighted imaging has been widely used in the research on post-stroke verbal fluency but acquiring diffusion data is not always clinically feasible. Achieving comparable reliability for detecting brain variables associated with verbal fluency impairments, based on more readily available anatomical, non-diffusion images (T1, T2 and FLAIR),...

Background and Objectives Cerebral white matter health can be estimated by MRI-derived indices of microstructure. White matter dysfunction is increasingly recognized as a contributor to neurodegenerative disorders affecting cognition and to functional outcomes after stroke. Reduced indices of white matter microstructure have been demonstrated cross...

The relationship between pain and depression is thought to be bidirectional and the underlying neurobiology ‘shared’ between the two conditions. However, these claims are often based on qualitative comparisons of brain regions implicated in pain or depression, while focused quantitative studies of the neurobiology of pain-depression comorbidity are...

Introduction Sleep disturbances are comorbid with chronic pain, exacerbating pain conditions. Experimental studies have implemented different sleep loss paradigms combined with quantitative sensory testing to better understand the sleep-pain relationship. However, knowledge of which sleep loss paradigms are most detrimental regarding hyperalgesia i...

Poor performance on verbal fluency tasks is associated with an increased risk of post-stroke cognitive impairment. Grey matter regions supporting verbal fluency have been identified via lesion–symptom mapping, but the links between verbal fluency and white matter structure remain less well described. We examined white matter correlates of semantic...

Cortical thinning has been described in many neurodegenerative diseases and used for both diagnosis and disease monitoring. The imaging signatures of post-stroke vascular cognitive impairment have not been well described. We investigated the trajectory of cortical thickness over 3 years following ischaemic stroke compared to healthy stroke-free age...

Background Persistent sensorimotor impairments after stroke can negatively impact quality of life. The hippocampus is vulnerable to poststroke secondary degeneration and is involved in sensorimotor behavior but has not been widely studied within the context of poststroke upper‐limb sensorimotor impairment. We investigated associations between non‐l...

Sensorimotor performance after stroke is strongly related to focal injury measures such as corticospinal tract lesion load. However, the role of global brain health is less clear. Here, we examined the impact of brain age, a measure of neurobiological aging derived from whole brain structural neuroimaging, on sensorimotor outcomes. We hypothesized...

Diffusion-weighted imaging has produced useful biomarkers of verbal fluency post-stroke but acquiring diffusion data is not always clinically feasible. Further, it has been demonstrated that subcortical regions may contribute to verbal fluency, though the predominant focus in the literature has been on cortical contributions to verbal fluency. Fina...

Dynamic whole-brain changes occur following stroke, and not just in association with recovery. We tested the hypothesis that the presence of a specific behavioural deficit after stroke would be associated with structural decline (atrophy) in the brain regions supporting the affected function, by examining language deficits post-stroke. We quantifie...

Damage to specific brain circuits can cause specific neuropsychiatric symptoms. Therapeutic stimulation to these same circuits may modulate these symptoms. To determine whether these circuits converge, we studied depression severity after brain lesions (n = 461, five datasets), transcranial magnetic stimulation (n = 151, four datasets) and deep bra...

Background We aimed to chart white matter integrity over 3 years after stroke, to examine if post‐stroke loss of white matter continues to be accelerated compared to control participants. Method We applied a longitudinal “fixel”‐based analysis, sensitive to fibre tract‐specific differences within a voxel, to assess axonal loss in stroke (N=71, 22...

Background The structural integrity of hippocampal subfields has been investigated in many neurological disorders and was shown to be better associated with cognitive performance than whole hippocampus. In stroke, hippocampal atrophy is linked to cognitive impairment, but it is unknown whether the hippocampal subfields atrophy differently. Purpose...

Persistent sensorimotor impairments after stroke can negatively impact quality of life. The hippocampus is involved in sensorimotor behavior but has not been widely studied within the context of post-stroke upper limb sensorimotor impairment. The hippocampus is vulnerable to secondary degeneration after stroke, and damage to this region could furth...

Up to two-thirds of stroke survivors experience persistent sensorimotor impairments. Recovery relies on the integrity of spared brain areas to compensate for damaged tissue. Deep grey matter structures play a critical role in the control and regulation of sensorimotor circuits. The goal of this work is to identify associations between volumes of sp...

Background: Stroke survivors are at high risk of dementia, associated with increasing age and vascular burden and with pre-existing cognitive impairment, older age. Brain atrophy patterns are recognised as signatures of neurodegenerative conditions, but the natural history of brain atrophy after stroke remains poorly described. We sought to determi...

Background: Stroke survivors are at high risk of dementia, associated with increasing age and vascular burden and with pre-existing cognitive impairment, older age. Brain atrophy patterns are recognised as signatures of neurodegenerative conditions, but the natural history of brain atrophy after stroke remains poorly described. We sought to determi...

Diffusion MRI has provided the neuroimaging community with a powerful tool to acquire in-vivo data sensitive to microstructural features of white matter, up to 3 orders of magnitude smaller than typical voxel sizes. The key to extracting such valuable information lies in complex modelling techniques, which form the link between the rich diffusion M...

Supplementary Document 3 for Dhollander, T., Clemente, A., Singh, M., Boonstra, F., Civier, O., Duque, J. D., Egorova, N., Enticott, P., Fuelscher, I., Gajamange, S., Genc, S., Gottlieb, E., Hyde, C., Imms, P., Kelly, C., Kirkovski, M., Kolbe, S., Liang, X., Malhotra, A., Mito, R., Poudel, G., Silk, T.J., Vaughan, D.N., Zanin, J., Raffelt, D., Caey...

Supplementary Document 2 for Dhollander, T., Clemente, A., Singh, M., Boonstra, F., Civier, O., Duque, J. D., Egorova, N., Enticott, P., Fuelscher, I., Gajamange, S., Genc, S., Gottlieb, E., Hyde, C., Imms, P., Kelly, C., Kirkovski, M., Kolbe, S., Liang, X., Malhotra, A., Mito, R., Poudel, G., Silk, T.J., Vaughan, D.N., Zanin, J., Raffelt, D., Caey...

Supplementary Document 4 for Dhollander, T., Clemente, A., Singh, M., Boonstra, F., Civier, O., Duque, J. D., Egorova, N., Enticott, P., Fuelscher, I., Gajamange, S., Genc, S., Gottlieb, E., Hyde, C., Imms, P., Kelly, C., Kirkovski, M., Kolbe, S., Liang, X., Malhotra, A., Mito, R., Poudel, G., Silk, T.J., Vaughan, D.N., Zanin, J., Raffelt, D., Caey...

Supplementary Document 1 for Dhollander, T., Clemente, A., Singh, M., Boonstra, F., Civier, O., Duque, J. D., Egorova, N., Enticott, P., Fuelscher, I., Gajamange, S., Genc, S., Gottlieb, E., Hyde, C., Imms, P., Kelly, C., Kirkovski, M., Kolbe, S., Liang, X., Malhotra, A., Mito, R., Poudel, G., Silk, T.J., Vaughan, D.N., Zanin, J., Raffelt, D., Caey...

Introduction: Hippocampal subfield volumes are more closely associated with cognitive impairment than whole hippocampal volume in many diseases. Both memory and whole hippocampal volume decline after stroke. Understanding the subfields' temporal evolution could reveal valuable information about post-stroke memory. Methods: We sampled 120 partici...

Objective/Background Sleep-wake dysfunction is bidirectionally associated with the incidence and evolution of acute stroke. It remains unclear whether sleep disturbances are transient post-stroke or are potentially enduring sequelae in chronic stroke. Here, we characterize sleep architectural dysfunction, sleep-respiratory parameters, and hemispher...

Background and Purpose. Fatigue is associated with poor functional outcomes and increased mortality following stroke. Survivors identify fatigue as one of their key unmet needs. Despite the growing body of research into post-stroke fatigue, the specific neural mechanisms remain largely unknown. Methods. This observational study included 63 stroke s...

Background Cardiovascular risk factors and stroke are associated with increased risk of all‐cause dementia. More than one third of stroke patients will develop dementia, but mechanisms are unclear. Vascular brain burden from accumulated risk factors may contribute to cognitive impairment at the time of stroke, with the stroke being yet another mani...

The final peer reviewed version of this work was published in NeuroImage. The full text and supplementary documents are available open access via https://doi.org/10.1016/j.neuroimage.2021.118417 — Abstract: Diffusion MRI has provided the neuroimaging community with a powerful tool to acquire in-vivo data sensitive to microstructural features of whi...

Objective To identify associations between atrophy of spared subcortical nuclei and sensorimotor behavior at different timepoints after stroke. Methods We pooled high-resolution T1-weighted MRI brain scans and behavioral data in 828 individuals with unilateral stroke from 28 cohorts worldwide. Cross-sectional analyses using linear mixed-effects mo...

Executive dysfunction affects 40% of stroke patients, but is poorly predicted by characteristics of the stroke itself. Stroke typically occurs on a background of cerebrovascular burden, which impacts cognition and brain network structural integrity. We used structural equation modelling to investigate whether measures of white matter microstructura...

Study objectives: Sleep-wake dysfunction is bidirectionally associated with the pathogenesis and evolution of stroke. Longitudinal and prospective measurement of sleep after chronic stroke remains poorly characterised due to a lack of validated objective and ambulatory sleep measurement tools in neurological populations. This study aimed to valida...

Background and Purpose Brain atrophy can be regarded as an end-organ effect of cumulative cardiovascular risk factors. Accelerated brain atrophy is described following ischemic stroke, but it is not known whether atrophy rates vary over the poststroke period. Examining rates of brain atrophy allows the identification of potential therapeutic window...

Objective Executive dysfunction affects 40% of stroke patients and is associated with poor quality of life. Stroke severity and lesion volume rarely predict whether a patient will have executive dysfunction. Stroke typically occurs on a background of cerebrovascular burden, which impacts cognition and brain network structural integrity. We investig...

Introduction Long sleep duration in aging populations has recently been proposed as a key modifiable risk factor and sequela of stroke. It is unclear whether the pathogenesis of post-stroke sleep-wake dysfunction is due to focal infarction to regional sleep-wake hubs in the brain, or to accelerated whole-brain neurodegeneration. We utilise a novel...

Background and Purpose— We examined if ischemic stroke is associated with white matter degeneration predominantly confined to the ipsi-lesional tracts or with widespread bilateral axonal loss independent of lesion laterality. Methods— We applied a novel fixel-based analysis, sensitive to fiber tract–specific differences within a voxel, to assess a...

White matter hyperintensities (WMHs) are frequently observed on brain scans of older individuals and are associated with cognitive impairment and vascular brain burden. Recent studies have shown that WMHs may only represent an extreme end of a diffuse pathological spectrum of white matter (WM) degeneration. The present study investigated the micros...

Sleep-wake disruption is a key modifiable risk factor and sequela of stroke. The pathogenesis of post-stroke sleep dysfunction is unclear. It is not known whether post-stroke sleep pathology is due to focal infarction to sleep-wake hubs, or to accelerated post-stroke neurodegeneration in subcortical structures after stroke. We characterise the firs...

Aging is a known non-modifiable risk factor for stroke. Usually, this refers to chronological rather than biological age. Biological brain age can be estimated based on cortical and subcortical brain measures. For stroke patients, it could serve as a more sensitive marker of brain health than chronological age. In this study, we investigated whethe...

Background: In experimental placebo and nocebo studies, neutral control treatments are often administered for comparison with active treatments, but are of little interest, as, on average, they result in little change. Yet, when considered at an individual level, they fluctuate between baseline and subsequent measurements and may reveal important...

We assessed first-year hippocampal atrophy in stroke patients and healthy controls using manual and automated segmentations: AdaBoost, FIRST (fsl/v5.0.8), FreeSurfer/v5.3 and v6.0, and Subfields (in FreeSurfer/v6.0). We estimated hippocampal volumes in 39 healthy controls and 124 stroke participants at three months, and 38 controls and 113 stroke p...

Background: Focal brain lesions can lend insight into the causal neuroanatomical substrate of depression in the human brain. However, studies of lesion location have led to inconsistent results. Methods: Five independent datasets with different lesion etiologies and measures of postlesion depression were collated (N = 461). Each 3-dimensional le...

Background: The apolipoprotein E (APOE) gene ɛ4 allele is a risk factor for Alzheimer's disease and cardiovascular disease. However, its relationship with cognition and brain volume after stroke is not clear. Objective: We compared cognition and medial temporal lobe volumes in APOEɛ4 carriers and non-carriers in the first year after ischemic str...

White matter hyperintensities (WMH) are a key feature of small vessel cerebrovascular disease and are highly prevalent in the elderly. WMH are associated with cognitive decline, a high risk of dementia and stroke. Despite accumulating evidence implicating WMH as a neurodegenerative marker, its pathological mechanisms remain unclear. Moreover, the h...

Ischaemic stroke leads not only to focal lesions in the region of infarction but can also result in neurodegeneration remote to infarction. While loss of gray matter distal to the lesion and disruptions in global functional connectivity have been characterised, little is known about remote and global white matter degeneration. Previous studies have...

Background: Cerebrospinal fluid circulation is crucial for the functioning of the brain. Aging and brain pathologies such as Alzheimer's disease have been associated with a change in the morphology of the ventricles and the choroid plexus. Despite the evidence from animal models that the cerebrospinal fluid system plays an important role in neuroi...

Introduction Sleep-wake dysfunction contributes to the pathogenesis and progression of ischemic stroke. Lesions to sleep-wake circuitry may compromise post-stroke recovery; however, the neuroanatomical correlates of post-stroke sleep-wake disruption remain unclear. We hypothesized that sleep-wake dysfunction after stroke, characterized by prolonged...

Classical theories suggest placebo analgesia and nocebo hyperalgesia are based on expectation and conditioned experience. Whereas the neural mechanism of how expectation modulates placebo and nocebo effects during pain anticipation have been extensively studied, little is known about how experience may change brain networks to produce placebo and n...

Manual quantification of the hippocampal atrophy state and rate is time consuming and prone to poor reproducibility, even when performed by neuroanatomical experts. The automation of hippocampal segmentation has been investigated in normal aging, epilepsy, and in Alzheimer's disease. Our first goal was to compare manual and automated hippocampal se...

We are used to talking to our patients about pain. As neurologists, we talk to people with unusual pain syndromes every day. We talk to them about their trigeminal neuralgia, about their headaches, and about the diverse pains associated with Guillain-Barre syndrome. We talk with people who have complex regional pain syndromes requiring multidiscipl...

The multilingual brain implements mechanisms that serve to select the appropriate language as a function of the communicative environment. Engaging these mechanisms on a regular basis appears to have consequences for brain structure and function. Studies have implicated the caudate nuclei as important nodes in polyglot language control processes, a...

The multilingual brain implements mechanisms that serve to select the appropriate language as a function of the communicative environment. Engaging these mechanisms on a regular basis appears to have consequences for brain structure and function. Studies have implicated the caudate nuclei as important nodes in polyglot language control processes, a...

Introduction Apolipoprotein E (APOE) ε4 allele is a known risk factor for the development of cognitive impairment. APOE ε4 carriers have been reported as having lower hippocampal volume in Alzheimer’s disease, mild cognitive impairment, and in healthy cohorts, 1 but this is not well investigated in stroke. Here, we compared the regional volume in...

Around one-third of people develop depression following ischaemic stroke, yet the underlying mechanisms are poorly understood. Post-stroke depression has been linked to frontal infarcts, mainly lesions in the left dorsolateral prefrontal cortex (DLPFC). But depression is a network disorder that cannot be fully characterised through lesion-symptom m...

Age-related cognitive decline is a significant public health concern. Recently, non-pharmacological methods, such as physical activity and mental training practices, have emerged as promising low-cost methods to slow the progression of age-related memory decline. In this study, we investigated if Tai Chi Chuan (TCC) and Baduanjin modulated the frac...

Disruptions to functional connectivity in subsystems of the default mode network are evident in Alzheimer's disease (AD). Functional connectivity estimates correlations in the time course of low-frequency activity. Much less is known about other potential perturbations to this activity, such as changes in the amplitude of oscillations and how this...

This chapter is intended as a primer to the most widely used neuroimaging methods available in the prediction, diagnosis and monitoring of the neurodegenerative diseases. We describe the imaging methods that allow us to examine brain structure, function and pathology and investigate neurodegenerative mechanisms in vivo. We describe methods to inter...

Depression is a common outcome following stroke, associated with reduced quality of life and poorer recovery. Despite attempts to associate depression symptoms with specific lesion sites, the neural basis of post-stroke depression remains poorly understood. Resting state fMRI has provided new insights into the neural underpinnings of post-stroke de...

Amplitude of low-frequency oscillations and episodic memory dysfunction in Alzheimer’s Disease

Background. Visual cue conditioning is a valuable experimental paradigm to investigate placebo and nocebo effects in pain. However, little attention has been paid to the cues themselves and potential variability of effects (their quantity and quality) stemming from the choice of stimuli. Yet, this seemingly methodological question has important imp...

Cognitive impairment is one of the most common problem saffecting older adults. In this study, we investigated whether Tai Chi Chuan and Baduanjin practice can modulate mental control functionand the resting state functional connectivity (rsFC) of the cognitive control network in older adults. Participants in the two exercise groups practiced eithe...

Transcutaneous vagus nerve stimulation (tVNS), a non-invasive method of brain stimulation through the auricular branch of the vagus nerve, has shown promising results in treating major depressive disorder (MDD) in several pilot studies. However, the neural mechanism by which the effect on depression might be achieved has not been fully investigated...

Previous studies provide evidence that aging is associated with the decline of memory function and alterations in the hippocampal (HPC) function, including functional connectivity to the medial prefrontal cortex (mPFC). In this study, we investigated if longitudinal (12-week) Tai Chi Chuan and Baduanjin practice can improve memory function and modu...