Emerging Neuroimaging Biomarkers Across Disease Stage in Parkinson Disease

Abstract

Imaging biomarkers in Parkinson disease (PD) are increasingly important for monitoring progression in clinical trials and also have the potential to improve clinical care and management. This Review addresses a critical need to make clear the temporal relevance for diagnostic and progression imaging biomarkers to be used by clinicians and researchers over the clinical course of PD. Magnetic resonance imaging (diffusion imaging, neuromelanin-sensitive imaging, iron-sensitive imaging, T1-weighted imaging), positron emission tomography/single-photon emission computed tomography dopaminergic, serotonergic, and cholinergic imaging as well as metabolic and cerebral blood flow network neuroimaging biomarkers in the preclinical, prodromal, early, and moderate to late stages are characterized.OBSERVATIONS If a clinical trial is being carried out in the preclinical and prodromal stages, potentially useful disease-state biomarkers include dopaminergic imaging of the striatum; metabolic imaging; free-water, neuromelanin-sensitive, and iron-sensitive imaging in the substantia nigra; and T1-weighted structural magnetic resonance imaging. Disease-state biomarkers that can distinguish atypical parkinsonisms are metabolic imaging, free-water imaging, and T1-weighted imaging; dopaminergic imaging and other molecular imaging track progression in prodromal patients, whereas other established progression biomarkers need to be evaluated in prodromal cohorts. Progression in early-stage PD can be monitored using dopaminergic imaging in the striatum, metabolic imaging, and free-water and neuromelanin-sensitive imaging in the posterior substantia nigra. Progression in patients with moderate to late-stage PD can be monitored using free-water imaging in the anterior substantia nigra, R2* of substantia nigra, and metabolic imaging. Cortical thickness and gyrification might also be useful markers or predictors of progression. Dopaminergic imaging and free-water imaging detect progression over 1 year, whereas other modalities detect progression over 18 months or longer. The reliability of progression biomarkers varies with disease stage, whereas disease-state biomarkers are relatively consistent in individuals with preclinical, prodromal, early, and moderate to late-stage PD.CONCLUSIONS AND RELEVANCE Imaging biomarkers for various stages of PD are readily available to be used as outcome measures in clinical trials and are potentially useful in multimodal combination with routine clinical assessment. This Review provides a critically important template for considering disease stage when implementing diagnostic and progression biomarkers in both clinical trials and clinical care settings.

Advanced diffusion imaging to track progression in Parkinson’s disease, multiple system atrophy, and progressive supranuclear palsy

“…Thus, it is likely that corpus callosum neurodegeneration is associated with even more advanced and severe Parkinsonism. We did not detect progression effects in the substantia nigra with any diffusion method which has been previously found in the posterior substantia nigra in early PD and anterior substantia nigra in moderate- to late-stage PD ( Mitchell et al, 2021 ). In the current cohort, we did find elevated FW and Viso in the posterior substantia nigra of PD cross-sectionally compared with controls, and thus it is most likely that extracellular fluid had already increased to a plateau and the 1-year time frame used here was not sufficient for the more advanced disease stage of this PD cohort (4.5 years).…”

Advances in Phenotyping Obesity and in Its Dietary and Pharmacological Treatment: A Narrative Review

“…Biomarkers play an important role in the evaluation of the onset of chronic diseases as well as in the development of drug treatments for these conditions ( 36 ). Biomarkers may also be able to reflect the pathophysiological process of a specific disease and may be able to predict the prognosis and guide clinical decision making ( 37 ). Accuracy, precision, high sensitivity and specificity and low intra-individual variability are important characteristics of an ideal biomarker ( 36 ).…”

Altered Default Mode Network Functional Connectivity in Parkinson’s Disease: A Resting-State Functional Magnetic Resonance Imaging Study

“…Recent advances in functional magnetic resonance imaging (fMRI) approaches have provided a non-invasive method for characterization of central nervous system changes in some specific brain regions in PD (Mitchell et al, 2021), including the basal ganglia (Szewczyk-Krolikowski et al, 2014;Rolinski et al, 2015;Filyushkina et al, 2019), hippocampus (Zeng et al, 2017;Guo et al, 2021), cingulate gyrus (Zhang et al, 2017;Wang et al, 2021), and so on. Zhang et al (2017) found that patients with PD and fatigue had amplitude of low-frequency fluctuation (ALFF) changes in the right middle frontal gyrus within the attention network and in the left insula as well as right middle cingulate gyrus within the salience network.…”