Magnetisation transfer imaging revealed microstructural changes related to apathy symptoms after ischaemic stroke

Abstract

Objectives Apathy after stroke is common and has a negative impact on functional recovery. Neuroimaging correlates of poststroke apathy remain unclear. We aimed to investigate microstructural changes associated with the severity of poststroke apathy symptoms. Methods We assessed 67 patients with cerebral ischaemia who underwent magnetisation transfer brain imaging 12–15 months after stroke. We used magnetisation transfer ratio (MTR) to represent microstructural integrity. We performed whole‐brain voxel‐based analysis and subsequent region of interest analysis to investigate the association between MTR and symptoms of poststroke apathy. To assess apathy symptoms, we used clinician‐reported version of the Apathy Evaluation Scale. Results Voxel‐based analysis showed the association between symptoms of apathy and decreased MTR in areas overlapping with structures located in both hemispheres: left thalamus, bilateral hippocampus, bilateral fornix/stria terminalis, right amygdala, splenium of the corpus callosum, the retrolenticular part of left internal capsule and left sagittal stratum. In the region of interest analysis, only lower MTR in right fornix/stria terminalis was associated with greater poststroke apathy symptoms in a multivariate logistic model (odds ratio: 1.25, 95% CI: 1.09–1.46, p = 0.003). These associations were independent of depressive symptoms. Conclusion Magnetisation transfer brain imaging 12–15 months after stroke revealed changes in microstructural integrity associated with apathy symptoms in brain areas related to processing emotional information and reward valuation.

Macrostructural and Microstructural White Matter Alterations Are Associated with Apathy across the Clinical Alzheimer’s Disease Spectrum

“…Both decreased FA and increased RD were found in the fornix of apathetic patients. This is in line with previous observations linking alterations in FA and MD in this fiber bundle with apathy in amnestic MCI [ 38 ], small vessel disease [ 61 ] and stroke [ 62 ]. The fornix primarily connects structures involved in episodic memory functions (i.e., the hippocampus and mamillary bodies), that are particularly affected in AD.…”

Associations of maternal emotion regulation with child white matter connectivity in Black American mother–child dyads

“…The fornix also plays an important role in emotion regulation, memory, and hippocampal–accumbens‐dependent reward processing (Dalgleish, 2004). Fornix lesions have been associated with reward‐learning impairments (Gaffan et al., 1984) and disruptions in fornix connectivity have been linked to reward deficits, including anhedonia in the context of PTSD and apathy in the aftermath of ischemic stroke (Harnett et al., 2021; Klimiec‐Moskal et al., 2021). Parents are a major source of reward and reward learning throughout their children's development.…”

Neuroimaging of neuropsychological disturbances following ischaemic stroke (CONNECT): a prospective cohort study protocol

“…In addition, many studies are small-sample, cross-sectional studies and only use single-modality imaging, making the results less reliable 23–26. There is evidence that structural and functional brain changes in chronic ischaemic stroke may be associated with neuropsychiatric disorders 27 28. Therefore, it is imperative to establish a longitudinal cohort with multimodal imaging data.…”

“… 23–26 There is evidence that structural and functional brain changes in chronic ischaemic stroke may be associated with neuropsychiatric disorders. 27 28 Therefore, it is imperative to establish a longitudinal cohort with multimodal imaging data. This approach will enable us to track the temporal evolution of brain changes, thereby providing a more comprehensive and reliable understanding of the neuropathological mechanisms underlying NDIS.…”