Impaired interhemispheric synchrony in Parkinson’s disease with depression

Abstract

The alterations of interhemispheric resting-state functional connectivity (FC) in Parkinson’s disease (PD) with depression remain unclear, so we aimed to explore the differences of interhemispheric FC between PD with and without depression. Twenty-one depressed PD (DPD) patients, 49 non-depressed PD (NDPD) patients and 50 matched healthy controls (HC) participated in this study. Resting-state functional magnetic resonance imaging (fMRI) data were analyzed with the voxel-mirrored homotopic connectivity (VMHC) approach. The DPD patients showed lower VMHC values in the bilateral dorsolateral prefrontal cortex (DLPFC) and calcarine cortex compared to both NDPD and HC groups, and further receiver operating characteristic curves (ROC) analyses revealed that the VMHC in these two brain areas could be used as biomarkers to distinguish DPD from NDPD and from HC. The pooled PD patients (both DPD and NDPD) exhibited decreased VMHC in the bilateral putamen, middle occipital gyrus (MOG), postcentral gyrus (PoCG), paracentral lobule (PCL) and cerebellum posterior lobe when compared with HC. Decreased VMHC values within the DLPFC and calcarine cortex appeared to be unique features for DPD and might be used as potential neuroimaging markers to distinguish DPD patients from NDPD and HC groups. These findings may underlie the neural mechanisms of depression in PD.

Altered Functional and Causal Connectivity of Cerebello-Cortical Circuits between Multiple System Atrophy (Parkinsonian Type) and Parkinson’s Disease

“…A PET study suggested that MSA patients with memory and frontal executive dysfunction tended to show hypometabolism in the anterior cerebellum and frontal cortex in the early stage of the disease ( Lyoo et al, 2008 ). In addition, the hypoactivity of the DLPFC in PD patients with depression has also been identified in previous studies ( Zhu et al, 2016 ). The impaired striatal cells in parkinsonism could lead to secondary frontal lobe dysfunction, including disruption of the cognitive loop linking the striatum with the DLPFC ( Jokinen et al, 2013 ).…”

Structural Brain Network Alteration and its Correlation With Structural Impairments in Patients With Depression in de novo and Drug-Naïve Parkinson's Disease

“…One study showed that depression was correlated with impaired color vision in PD patients through clinical observation and inferred that the visual system is crucial in the depressive pathology in PD patients ( 26 ). Some fMRI studies have shown that the value of regional homogeneity in the occipital lobe was decreased ( 27 ) and the synchrony of interhemispheric resting-state functional connectivity was impaired in the occipital lobe in d-PD patients ( 28 ).…”

Impaired long contact white matter fibers integrity is related to depression in Parkinson's disease

“…Compared to our findings in depressed PD patients, white matter damage is more extensive in patients with primary depression, but all these impaired WM regions or fibers mainly located in the prefrontal cortex, limbic system, and the contact fibers between them. Studies using RS‐fMRI have also shown decreased functional connectivity between the prefrontal‐limbic networks and impaired interhemispheric synchrony in PD with depression patients. Therefore, the abnormal sensory integration and evaluation caused by white matter deficits which we found might be an important reason for depression in PD.…”