Publications by authors named "Leonardo Bonilha"

This study examines the relationship between comorbid seizures and dementia among stroke patients using the 2017 Nationwide Inpatient Sample (NIS), the largest publicly available inpatient healthcare database in the United States. We analyzed data from 128,341 stroke patients, including those with ischemic and hemorrhagic strokes, to determine the prevalence of seizures and dementia, and the association between these conditions. Our findings reveal that 7.

View Article and Find Full Text PDF

Background And Purpose: Despite comprehensive evidence that supports the utility of aphasia therapy in persons with chronic (≥6 months) stroke-induced aphasia, the amount of therapy provided to patients in the United States is typically far less than what is likely necessary to maximize recovery. Two potential contributors to this discrepancy are limited access to rehabilitation services due to the availability of providers and logistical difficulties with transportation. One way to increase access to aphasia therapy is to rely on telerehabilitation.

View Article and Find Full Text PDF

Background: The high incidence of dysphagia after acute stroke is likely the result of cumulative effects of the stroke and pre-stroke brain health. While cerebral small vessel disease (cSVD) is recognized as a marker of compromised brain health, it's unclear which neuroanatomical pathologies of cSVD impact post-stroke dysphagia. We assessed the relation between cSVD pathologies, i.

View Article and Find Full Text PDF

The dual-stream model of speech processing describes a cortical network involved in speech processing. However, it is not yet known if the dual-stream model represents actual intrinsic functional brain networks. Furthermore, it is unclear how disruptions after a stroke to the functional connectivity of the dual-stream model's regions are related to speech production and comprehension impairments seen in aphasia.

View Article and Find Full Text PDF

Convolutional neural networks (CNN) show great promise for translating decades of research on structural abnormalities in temporal lobe epilepsy into clinical practice. Three-dimensional CNNs typically outperform two-dimensional CNNs in medical imaging. Here we explore for the first time whether a three-dimensional CNN outperforms a two-dimensional CNN for identifying temporal lobe epilepsy-specific features on MRI.

View Article and Find Full Text PDF

The contribution of age-related structural brain changes to the well-established link between aging and cognitive decline is not fully defined. While both age-related regional brain atrophy and cognitive decline have been extensively studied, the specific mediating role of age-related regional brain atrophy on cognitive functions is unclear. This study introduces an open-source software tool with a graphical user interface that streamlines advanced whole-brain mediation analyses, enabling researchers to systematically explore how the brain acts as a mediator in relationships between various behavioral and health outcomes.

View Article and Find Full Text PDF

Multivariate lesion-symptom mapping (MLSM) considers lesion information across the entire brain to predict impairments. The strength of this approach is also its weakness-considering many brain features together synergistically can uncover complex brain-behavior relationships but exposes a high-dimensional feature space that a model is expected to learn. Successfully distinguishing between features in this landscape can be difficult for models, particularly in the presence of irrelevant or redundant features.

View Article and Find Full Text PDF
Article Synopsis
  • Intracranial EEG helps identify networks associated with focal epilepsy, but how these network structures affect post-surgery seizure outcomes is not well understood.
  • The study tested whether better surgical outcomes are linked to removing key brain regions (hubs) involved in seizure activity, measured by a new metric called Resection-Hub Alignment Degree (RHAD).
  • Results indicated that a significant difference in RHAD was found between patients with good and bad surgical results, suggesting that analyzing network hubs offers better insights than traditional methods in predicting post-surgery epilepsy outcomes.
View Article and Find Full Text PDF

Sharing neuroimaging datasets enables reproducibility, education, tool development, and new discoveries. Neuroimaging from many studies are publicly available, providing a glimpse into progressive disorders and human development. In contrast, few stroke studies are shared, and these datasets lack longitudinal sampling of functional imaging, diffusion imaging, as well as the behavioral and demographic data that encourage novel applications.

View Article and Find Full Text PDF

Patients with drug-resistant temporal lobe epilepsy often undergo intracranial EEG recording to capture multiple seizures in order to lateralize the seizure onset zone. This process is associated with morbidity and often ends in postoperative seizure recurrence. Abundant interictal (between-seizure) data are captured during this process, but these data currently play a small role in surgical planning.

View Article and Find Full Text PDF

Among stroke survivors, linguistic and non-linguistic impairments exhibit substantial inter-individual variability. Stroke lesion volume and location do not sufficiently explain outcomes, and the neural mechanisms underlying the severity of aphasia or non-verbal cognitive deficits remain inadequately understood. Converging evidence supports the idea that white matter is particularly susceptible to ischaemic injury, and long-range fibres are commonly associated with verbal and non-verbal function.

View Article and Find Full Text PDF

Chronic stroke results in significant downstream changes at connected cortical sites. However, less is known about the impact of cortical stroke on cerebellar structure. Here, we examined the relationship between chronic stroke, cerebellar volume, cerebellar symmetry, language impairment, and treatment trajectories in a large cohort ( = 249) of chronic left hemisphere (LH) stroke patients with aphasia, using a healthy aging cohort ( = 244) as control data.

View Article and Find Full Text PDF

Restoring motor function after stroke necessitates involvement of numerous cognitive systems. However, the impact of damage to motor and cognitive network organization on recovery is not well understood. To discover correlates of successful recovery, we explored imaging characteristics in chronic stroke subjects by combining noninvasive brain stimulation and fMRI.

View Article and Find Full Text PDF

Background And Objective: The biomarkers of hand function may differ based on level of motor impairment after stroke. The objective of this study was to determine the relationship between resting state functional connectivity (RsFC) and unimanual contralesional hand function after stroke and whether brain-behavior relationships differ based on level of grasp function.

Methods: Sixty-two individuals with chronic, left-hemisphere stroke were separated into three functional levels based on Box and Blocks Test performance with the contralesional hand: Low (moved 0 blocks), Moderate (moved >0% but <90% of blocks relative to the ipsilesional hand), and High (moved ≥90% of blocks relative to the ipsilesional hand).

View Article and Find Full Text PDF

Background: The piriform cortex has been implicated in the initiation, spread and termination of epileptic seizures. This understanding has extended to surgical management of epilepsy, where it has been shown that resection or ablation of the piriform cortex can result in better outcomes. How and why the piriform cortex may play such a crucial role in seizure networks is not well understood.

View Article and Find Full Text PDF

Understanding the neurobiology of semantic knowledge is a major goal of cognitive neuroscience. Taxonomic and thematic semantic knowledge are represented differently within the brain's conceptual networks, but the specific neural mechanisms remain unclear. Some neurobiological models propose that the anterior temporal lobe is an important hub for taxonomic knowledge, whereas the TPJ is especially involved in the representation of thematic knowledge.

View Article and Find Full Text PDF

Stroke is a leading cause of disability, and Magnetic Resonance Imaging (MRI) is routinely acquired for acute stroke management. Publicly sharing these datasets can aid in the development of machine learning algorithms, particularly for lesion identification, brain health quantification, and prognosis. These algorithms thrive on large amounts of information, but require diverse datasets to avoid overfitting to specific populations or acquisitions.

View Article and Find Full Text PDF

Purpose: A diagnosis of dysphagia and/or depression after stroke can impact the physical, psychological, and social welfare of stroke survivors. Although poststroke depression (PSD) and poststroke dysphagia are known to occur concurrently, there is a paucity of research that has specifically investigated their association. Therefore, we aimed to study the relationship between PSD and poststroke dysphagia during acute inpatient hospitalization and within 90 days after discharge.

View Article and Find Full Text PDF
Article Synopsis
  • The study examines the rising rates of spontaneous intracerebral hemorrhage (sICH) and acute seizure (AS) among young Americans (aged 18-64) from 2005 to 2015, finding an increase in AS incidence during this period.
  • Using a large database, researchers identified trends in AS incidence and its association with in-hospital mortality, finding AS incidence rose from 8.1% to 11.0% over the decade.
  • The study concludes that while overall in-hospital mortality decreased for those without AS, mortality for those with AS remained stable, and individuals with AS were 10% more likely to die than those without it.
View Article and Find Full Text PDF

Purpose: Aging increases risk for hearing loss, cognitive decline, and social isolation; however, the nature of their interconnection remains unclear. This study examined the interplay between age-related hearing loss, cognitive decline, and social isolation in adults by testing the ability to understand speech in background noise, a challenge frequently reported by many older adults.

Method: We analyzed data collected from 128 adults (20-79 years of age, = 51 years) recruited as part of the Aging Brain Cohort at the University of South Carolina repository.

View Article and Find Full Text PDF

Background: Few investigations examined the relationship between microstructural white matter integrity and subacute post-stroke linguistic performance or the relationship between microstructural integrity and the recovery of language function. We examined two key questions: (1) How does subacute language performance, measured in single words and discourse, relate to the microstructural integrity of key white matter regions of interest in the language network? and (2) Does the integrity of these regions before treatment predict the improvement or resolution of linguistic symptoms immediately and chronically following treatment?

Methods: 58 participants within the first three months of stroke were enrolled in a randomized, single-center, double-blind, sham-controlled, study of anodal transcranial direct current stimulation combined with a computer-delivered speech and language naming therapy for subacute aphasia and were asked to complete magnetic resonance imaging at enrollment. Microstructural integrity was evaluated using diffusion tensor imaging processed with atlas-based segmentation.

View Article and Find Full Text PDF

While converging research suggests that increased white matter hyperintensity load is associated with poorer cognition, and the presence of hypertension is associated with increased white matter hyperintensity load, the relationship among hypertension, cognition and white matter hyperintensities is not well understood. We sought to determine the effect of white matter hyperintensity burden on the relationship between hypertension and cognition in individuals with post-stroke aphasia, with the hypothesis that white matter hyperintensity load moderates the relationship between history of hypertension and cognitive function. Health history, Fazekas scores for white matter hyperintensities and Wechsler Adult Intelligence Scale Matrix Reasoning subtest scores for 79 people with aphasia collected as part of the Predicting Outcomes of Language Rehabilitation study at the Center for the Study of Aphasia Recovery at the University of South Carolina and the Medical University of South Carolina were analysed retrospectively.

View Article and Find Full Text PDF

Background: Emerging evidence suggests that post-stroke aphasia severity depends on the integrity of the brain beyond the lesion. While measures of lesion anatomy and brain integrity combine synergistically to explain aphasic symptoms, substantial interindividual variability remains unaccounted. One explanatory factor may be the spatial distribution of morphometry beyond the lesion (e.

View Article and Find Full Text PDF

Premature brain aging is associated with poorer cognitive reserve and lower resilience to injury. When there are focal brain lesions, brain regions may age at different rates within the same individual. Therefore, we hypothesize that reduced gray matter volume within specific brain systems commonly associated with language recovery may be important for long-term aphasia severity.

View Article and Find Full Text PDF