Binocular integrated visual field deficits are associated with changes in local network function in primary open-angle glaucoma: a resting-state fMRI study

Martins

et al. 2022

Sci Rep

The degree to which the adult human visual cortex retains the ability to functionally adapt to damage at the level of the eye remains ill-understood. Previous studies on cortical neuroplasticity primarily focused on the consequences of foveal visual field defects (VFD), yet these findings may not generalize to peripheral defects such as occur in glaucoma. Moreover, recent findings on neuroplasticity are often based on population receptive field (pRF) mapping, but interpreting these results is complicated in the absence of appropriate control conditions. Here, we used fMRI-based neural modeling to assess putative changes in pRFs associated with glaucomatous VFD. We compared the fMRI-signals and pRF in glaucoma participants to those of controls with case-matched simulated VFD. We found that the amplitude of the fMRI-signal is reduced in glaucoma compared to control participants and correlated with disease severity. Furthermore, while coarse retinotopic structure is maintained in all participants with glaucoma, we observed local pRF shifts and enlargements in early visual areas, relative to control participants. These differences suggest that the adult brain retains some degree of local neuroplasticity. This finding has translational relevance, as it is consistent with VFD masking, which prevents glaucoma patients from noticing their VFD and seeking timely treatment.

Section: Ophthalmic Datamentioning

confidence: 99%

Local neuroplasticity in adult glaucomatous visual cortex

Carvalho

Martins

et al. 2022

Sci Rep

“…The resting state fMRI results are reported on in a different paper 63 . Here, we report on the results of the binocular retinotopic mapping scans.…”

Section: Methodsmentioning

confidence: 99%

Local neuroplasticity in adult glaucomatous visual cortex

Carvalho

Martins

et al. 2022

Preprint

Self Cite

The degree to which the adult human visual cortex retains the ability to functionally adapt to damage at the level of the eye remains ill-understood. Previous studies on cortical neuroplasticity primarily focused on the consequences of foveal visual field defects (VFD), yet these findings may not generalize to peripheral defects such as occur in glaucoma. Moreover, recent findings on neuroplasticity are often based on population receptive field (pRF) mapping, but interpreting these results is complicated in the absence of appropriate control conditions. Here, we used fMRI-based neural modeling to assess putative changes in pRFs associated with glaucomatous VFD. We compared the fMRI-signals and pRF estimates in participants with glaucoma to those of controls with case-matched simulated VFD. We found that the amplitude of the fMRI-signal is reduced in glaucoma compared to control participants and correlated with disease severity. Furthermore, while coarse retinotopic structure is maintained in all participants with glaucoma, we observed local pRF shifts and enlargements in early visual areas, relative to control participants. These differences imply that the adult brain retains local neuroplasticity. This finding has translational relevance, as it is consistent with VFD masking, which prevents glaucoma patients from noticing their VFD and seeking timely treatment.

“…In this study, we used eigenvector centrality (EC) 22 derived from rs-fMRI data 23,24 together with data-driven methods to: (a) discriminate and identify shifts in centrality between WTC-PTSD and non-PTSD responders; (b) link these shifts to WTC-exposure, and (c) examine how shifts in centrality associate with PTSD symptom scales. We focused on highly connected (or disconnected) nodes (i.e.…”

Section: Mainmentioning

confidence: 99%

“…WTC-PTSD status was considered 'present' if criteria were reported in the past 3 months at the time of the interview 60 . PTSD symptom subdomains were measured using continuous subscales calculated using reported symptom severity in the SCID-IV for the following symptom domains: re-experiencing, avoidance, hyperarousal, and negative thoughts symptoms (scores ranging from , , , [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24], respectively). Major depressive disorder (MDD) was assessed using the SCID-IV and the presence or absence of current (i.e., active in the past month) MDD diagnosis was determined.…”

mentioning

confidence: 99%

Functional changes in neural mechanisms underlying post-traumatic stress disorder in World Trade Center responders

Rechtman

Curtin

et al. 2022

Preprint

Self Cite

World Trade Center (WTC) responders exposed to traumatic and environmental stressors during rescue and recovery efforts have higher prevalence (23%) of persistent, clinically significant WTC-related post-traumatic stress disorder (WTC-PTSD). Here, we applied eigenvector centrality (EC) metrics and data driven methods on resting state functional magnetic resonance (fMRI) outcomes to investigate neural mechanisms underlying WTC-PTSD and to identify how EC shifts in brain areas relate to WTC-exposure and behavioral symptoms. Nine brain areas differed significantly and contributed the most to differentiate functional neuro-profiles between WTC-PTSD and non-PTSD responders. The association between WTC-exposure and EC values differed significantly between WTC-PTSD and non-PTSD in the right anterior parahippocampal gyrus and left amygdala (p= 0.010; p= 0.005, respectively, adjusted for multiple comparisons). Within WTC-PTSD, the index of PTSD symptoms was positively associated with EC values in the right anterior parahippocampal gyrus and brainstem. Our understanding of functional changes in neural mechanisms underlying WTC-related PTSD is key to advance intervention and treatment.