Journal of neuroimaging : official journal of the American Society of Neuroimaging
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Little evidence exists on the role of type 1 metabotropic glutamate receptor (mGluR1) in the pathophysiology of Alzheimer's disease (AD), although mGluR1 may be involved in the regulation of neuronal excitability and synaptic plasticity. We have recently reported that mGluR1 availability in the early stage of AD is equivalent to that in healthy subjects. This study aimed to address whether mGluR1 availability changes with the progression of AD. ⋯ This study suggests that mGluR1 availability is unchanged in the follow-up period of a few years during the early-to-middle stages of AD.
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While diffusely abnormal white matter (DAWM) is a nonlesional MRI abnormality identified in ∼25% of patients with multiple sclerosis (MS), it has yet to be investigated in patients at an earlier disease stage, namely clinically isolated syndrome (CIS). The goals of this study were to (1) determine the prevalence of DAWM in patients with a CIS suggestive of MS, (2) evaluate the association between DAWM and demographic, clinical, and MRI features, and (3) evaluate the prognostic significance of DAWM on conversion from CIS to MS. ⋯ DAWM is present in a similar proportion of patients with CIS and clinically definite MS, and it is associated with increased risk of conversion to MS over 6 months.
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Axonal injury is a key player of disability in persons with multiple sclerosis (pwMS). Yet, detecting and measuring it in vivo is challenging. The neurite orientation dispersion and density imaging (NODDI) proposes a novel framework for probing axonal integrity in vivo. NODDI at 3.0 Tesla was used to quantify tissue damage in pwMS and its relationship with disease progression. ⋯ NODDI is sensitive to tissue injury but its relationship with clinical progression remains limited.
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The prediction of radiotherapy outcome in head and neck paragangliomas is clinically important. We investigated perfusion and diffusion markers for evaluation of response to radiotherapy of head and neck paragangliomas. ⋯ Ktrans has predictive potential to predict the response to radiation therapy of head and neck paragangliomas.
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Functional MRI neurofeedback (fMRI-nf) leverages the brain's ability to self-regulate its own activity. However, self-regulation processes engaged during fMRI-nf are incompletely understood. Here, we used matched feedback in an fMRI-nf experimental protocol to investigate whether brain processes recognize true neurofeedback signals. ⋯ These findings suggest that fMRI neurofeedback paradigms that monitor or incorporate activity from regions reported here would provide enhanced efficacy for research investigation and clinical intervention.