Abstract Background Apathy is a common early symptom of Parkinson's disease (PD), often co‐occurring with cognitive decline and associated with fronto‐striatal and mesocortico‐limbic dysfunctions. Discrepancies between self‐ and caregiver‐reported apathy have been preliminarily associated with cognitive impairments affecting patients’ awareness and self‐report accuracy. Objectives This study investigates discrepancies between PD patient‐ and informant‐reported apathy in relation to the cognitive status (unimpaired‐CU vs. impaired‐CI), and explores neural correlates of apathy using magnetic resonance imaging (MRI). Methods Apathy was assessed in 23 PD participants using self‐report (AES‐S) and informant (AES‐I) versions of the Italian Apathy Evaluation Scale. Discrepancy scores (ΔAES) were compared between groups and correlated with cognitive performance. Resting‐state fMRI examined associations between AES indices and connectivity from the bilateral nucleus accumbens, while whole‐brain structural analyses assessed associations with gray matter (GM) volume. Results PD‐CI participants showed higher ΔAES, underestimating their apathy compared to PD‐CU. ΔAES values correlated with attentional and visuospatial functioning. Higher AES‐I scores were associated with hyperconnectivity between right nucleus accumbens, paracingulate, and medial frontal cortices. Structural analyses revealed associations between both AES‐I and ΔAES values and GM volume in the cingulate gyrus. Discussion These findings highlight the impact of cognitive dysfunction on apathy evaluation in PD, emphasizing the importance of caregiver perspective. Neuroimaging results further validated caregiver ratings, showing an association between fronto‐striatal network changes and apathy. Further research is needed to clarify the role of such discrepancy in apathy assessment in predicting disease progression.
Funghi et al. (Sat,) studied this question.