![]() ![]() However, MRI research also demonstrates the involvement of other cortical and subcortical networks, like the Papez circuit, in the neurodegenerative process leading to AD ( 9). This emphasis is coherent with the pivotal role of the hippocampus in episodic memory and navigation ( 8), two cognitive domains that are significantly impacted in early AD. In particular, atrophy and metabolic alterations in the hippocampal and entorhinal regions have emerged as potential clinical markers of the progression to AD ( 5– 7). Magnetic Resonance Imaging (MRI) is a non-invasive tool for exploring macrostructural changes across the AD spectrum ( 2– 4). Since the neurodegenerative process leading to AD begins more than a decade before a clinical diagnosis can be made ( 1), the detection of early signs of the future conversion from MCI to AD is of great clinical importance for the decision to initiate both pharmacological and non-pharmacological interventions. The clinical manifestations usually initiate with a prodromal state known as Mild Cognitive Impairment (MCI), which may eventually progress to subsequent AD in a fraction of subjects (10–15%). We also propose a theoretical model to explain the evolving dysfunction of subcortical brain networks in the disease process.Īlzheimer’s disease (AD) is one of the most common age-related neurodegenerative diseases, with a growing incidence worldwide. In line with the pathophysiological relevance of the nucleus reuniens proposed by seminal post-mortem studies on patients with AD, we confirm the pivotal role of this nucleus as a critical hub in the clinical progression to AD. The discriminant function analysis confirmed the nucleus reuniens as a significant predictor of AD conversion, with a sensitivity of 0.73 and a specificity of 0.69. Compared to s-MCI, c-MCI individuals displayed significant atrophy of the nucleus reuniens and a trend toward significant atrophy in the anteroventral and laterodorsal nuclei. In contrast, no significant structural differences were observed between s-MCI and HC subjects. ResultsĪD and c-MCI patients showed generalized atrophy of thalamic nuclei compared to HC. The corresponding predictive performance was evaluated through a Receiver Operating Characteristic approach. A stepwise discriminant function analysis identified which feature most effectively predicted the conversion to AD. MeasurementsĪ multivariate analysis of variance (MANOVA) assessed group differences in the volumetric features of distinct thalamic nuclei obtained from magnetic resonance (MR) images. The MCI group was further divided into two subgroups depending on whether patients remained stable (s-MCI, n=22) or progressed to AD (s-MCI, n=36) in the 48 months following the diagnosis. The dataset was obtained from the AD Neuroimaging Initiative (ADNI-3) database. We analyzed data from 84 healthy control subjects (HC), 58 individuals with MCI, and 102 AD patients. Investigating between-group differences in the volumetric features of distinct thalamic nuclei across the AD spectrum. To characterize the structural integrity of distinct thalamic nuclei across the AD spectrum, testing whether MCI patients who convert to AD (c-MCI) show a distinctive pattern of thalamic structural alterations compared to patients who remain stable (s-MCI). However, given the anatomical complexity of this brain structure, it is still unclear whether atrophy affects specific thalamic nuclei and modulates the clinical progression from a prodromal stage, known as Mild Cognitive Impairment (MCI), to full-fledged AD. ![]() Patients with Alzheimer’s Disease (AD) exhibit structural alterations of the thalamus that correlate with clinical symptoms. ![]()
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