Alterations of subcortical structures are associated with anxiety in early Parkinson’s disease patients: a cross-sectional 7T MRI study

Anxiety is a prevalent non-motor symptom in Parkinson’s disease (PD), yet its neurobiological markers remain poorly understood. This study aimed to identify volumetric and morphological changes in subcortical structures associated with anxiety in early PD. In this cross-sectional study from the TRACK-PD cohort (Dutch Trial Register - NL7558), 105 non-demented PD patients (31 with anxiety [AnxPD], 74 without [nonAnxPD]) and 37 healthy controls (HC) underwent 7 T MRI. Subcortical regions including the amygdala, hippocampus, accumbens, caudate, putamen, and thalamus were segmented using FastSurfer. Shape analyses were performed via the Spherical Harmonics Point Distribution Model (SPHARM-PDM). Anxiety severity in PD was significantly associated with a bilateral reduction in caudate volume. Furthermore, AnxPD patients exhibited distinct shape deformations in the bilateral caudate, bilateral thalamus, left nucleus accumbens, and left amygdala compared to non-anxious patients. Significant shape differences in the left amygdala and left thalamus were also observed between AnxPD and HC groups. PD-related anxiety is linked to distinct structural remodeling of the striatum, thalamus, and amygdala. These morphometric changes represent potential imaging markers for the occurrence and progression of anxiety in early PD.