Neural correlates of anxiety symptoms in mild Parkinson's disease: A prospective longitudinal voxel-based morphometry study

• Published in: Journal of the neurological sciences 2016-12, Vol.371, p.131-136
• Main Authors: Wee, Natalie, Wen, Ming-Ching, Kandiah, Nagaendran, Chander, Russell J, Ng, Aloysius, Au, Wing Lok, Tan, Louis C.S
• Format: Article
• Language: English
• Subjects: Aged; Antiparkinson Agents - therapeutic use; Anxiety; Anxiety - diagnostic imaging; Anxiety - drug therapy; Brain - diagnostic imaging; Female; Follow-Up Studies; Gray Matter - diagnostic imaging; Humans; Longitudinal; Longitudinal Studies; Magnetic Resonance Imaging; Male; Neurology; Organ Size; Parkinson Disease - diagnostic imaging; Parkinson Disease - drug therapy; Parkinson Disease - psychology; Parkinson's disease; Precuneus; Prospective Studies; Psychiatric Status Rating Scales; Psychotropic Drugs - therapeutic use; Severity of Illness Index; Voxel-based morphometry
• ISSN: 0022-510X; 1878-5883
• DOI: 10.1016/j.jns.2016.10.021

Abstract Background Anxiety is prevalent in patients with Parkinson's disease (PD) and may affect patients' quality of life. Yet, little is known about the neural basis of anxiety in PD, and none have used a longitudinal design. Methods 73 patients with mild PD were recruited and followed up for 18 months. A whole-brain analysis was first used to identify brain regions associated with anxiety symptoms, followed by a regional analysis focusing on a priori hypothesised regions at baseline. A multivariate generalized estimating equations analysis was then conducted to determine the longitudinal association between grey matter (GM) volumetric changes of these significant regions and changes of anxiety symptoms. Results At baseline, anxiety symptom severity was associated with decreased GM volumes in the bilateral precuneus and anterior cingulate cortex (ACC). Over 18 months, increased severity of anxiety symptoms was associated with decreased GM volume in the left precuneus and ACC, independent of age, gender, education, depressive symptom severity or use of psychiatric medication. Conclusions These results mainly implicate the precuneus and ACC in the pathogenesis of anxiety in PD. We speculate that these structural changes could reflect the disrupted default mode network due to PD pathology, contributing to spontaneous anxiety-related self-focused thoughts.