Introduction Apathy is a prevalent non-motor symptom in Parkinson's disease (PD), potentially linked to social cognition impairments. However, the relationship between distinct apathy dimensions and multiple domains of social cognition in early-stage PD remains unclear. This study investigated these associations. Methods Forty PD patients (Hoehn and Yahr ≤3) and their partners (informants and healthy controls) were included. Apathy was assessed using the Apathy Motivation Index (self- and informant-report). Social cognition covered emotion recognition (ERT), Theory of Mind (SET), alexithymia (TAS-20), and everyday social functioning (OSCARS). Group differences and multiple linear regression analyses were conducted. Results Moderate to severe apathy was reported in 15% of PD patients, while 32.5% of informants rated the patients as having moderate to severe apathy. Informant-rated apathy was significantly associated with both social cognition and everyday social functioning (R2 = 0.555, p < .001), with the strongest contribution from everyday social functioning (β = 0.788, p < .001), followed by Theory of Mind (β = 0.282, p = .048, in an unexpected direction) and emotion recognition (β = −0.289, p = .042). Self-reported apathy was neither significantly associated with social cognition nor with everyday social functioning. Exploratory subscale analyses showed modest associations of self-reported apathy with alexithymia and everyday social functioning which require replication. Furthermore, PD patients reported higher levels of alexithymia than controls (d = 0.43, p = .030), while no significant group differences were found for emotion recognition (d = −0.34, p = .054) or Theory of Mind (d = −0.31, p = .061) after correction for multiple testing. Conclusion In early-to-moderate-stage PD, informant-rated apathy was strongly associated with informant-rated everyday social functioning, partly reflecting shared informant ratings, and more weakly with emotion recognition. Associations of self-reported apathy with alexithymia and social functioning were limited to specific apathy dimensions and are exploratory. These findings support multi-informant assessment of apathy in clinical practice.
Background Differentiation of clinical features among Parkinson’s disease (PD), progressive supranuclear palsy (PSP), and multiple system atrophy parkinsonism (MSAp) is challenging, with a paucity of comparative studies on comprehensive and overlapped clinical features across three of them. Objective Comprehensive data from the Automated Imaging Differentiation for Parkinsonism (AIDP) study could offer valuable insights into their diagnostic differentiation among PD, PSP and MSAp. Methods Demographics, comprehensive motor and non-motor features, daily living function and quality of life (QoL) data were prospectively collected from individuals with PD, probable PSP, and probable MSAp at their second AIDP study visit. Clinical diagnoses were confirmed independently by three movement disorder neurologists. Cross-sectional group comparisons were conducted using Bonferroni-adjusted pairwise tests. Median and logistic regression models were applied to assess differences, adjusting for age, sex, disease duration and levodopa equivalent dosage. Results Among 168 individuals (90 PD, 56 probable PSP, 22 probable MSAp), overall motor, non-motor, daily living functions and QoL measures were found to be more impaired in MSAp and PSP than PD. Individuals with PSP experienced more oculomotor and cognitive impairment than PD and MSAp. Systolic and diastolic orthostatic blood pressure (BP) drop, orthostatic lightheadedness, and urinary incontinence were associated with MSAp. The presence of systolic orthostatic BP drop was also against the diagnosis of PSP. There were no differences in anxiety, depression, fatigue and constipation across three parkinsonism subtypes. Conclusion Distinct impairments across PD, PSP, and MSAp in this well-characterized, prospectively collected, comprehensive motor and non-motor dataset provide valuable information for clinical differentiation.
Objective Continuous subcutaneous foslevodopa/foscarbidopa (LDp/CDp) infusion is a non-surgical device-aided therapy for advanced Parkinson's disease (PD). We retrospectively analyzed 1-year treatment persistence, changes in oral medication burden, and safety. Methods Twenty-one patients with advanced PD in whom LDp/CDp infusion was initiated between October 2023 and October 2025 were evaluated for levodopa equivalent daily dose (LEDD), oral levodopa-containing compound (LCC) dose, infusion rate settings, and psychiatric and skin-related adverse events. Baseline characteristics were compared between the 1-year continuation group (n = 16) and the discontinuation group (n = 5). Results In the selected single-center cohort, 16 of the 21 patients continued this therapy at the 12-month mark. Among patients for whom long-term assessment was possible, a reduction in the oral LCC dose was observed. All five discontinuations were directly attributable to psychiatric symptoms that emerged or worsened within 1 month of initiation; concomitant skin-related events were observed but were not decisive. Total LEDD increased from 1169.0 to 1354.8 mg/day at 12 months. Psychiatric symptoms were frequently recorded early in the treatment course, whereas skin indurations were frequently observed at assessment time points from the mid-treatment period onward. Conclusion LDp/CDp showed treatment persistence and sustained reduction in oral LCC burden over one year. Management should be adapted to the treatment phase: psychiatric symptoms cluster early, whereas skin-related events accumulate over the mid-to-long term.
