Differential Changes in Arteriolar Cerebral Blood Volume between Parkinson’s Disease Patients with Normal and Impaired Cognition and Mild Cognitive Impairment (MCI) Patients without Movement Disorder—An Exploratory Study

Abstract

Cognitive impairment amongst Parkinson’s disease (PD) patients is highly prevalent and associated with an increased risk of dementia. There is growing evidence that altered cerebrovascular functions contribute to cognitive impairment. Few studies have compared cerebrovascular changes in PD patients with normal and impaired cognition and those with mild-cognitive-impairment (MCI) without movement disorder. Here, we investigated arteriolar-cerebral-blood-volume (CBVa), an index reflecting the homeostasis of the most actively regulated segment in the microvasculature, using advanced MRI in various brain regions in PD and MCI patients and matched controls. Our goal is to find brain regions with altered CBVa that are specific to PD with normal and impaired cognition, and MCI-without-movement-disorder, respectively. In PD patients with normal cognition (n=10), CBVa was significantly decreased in the substantia nigra, caudate and putamen when compared to controls. In PD patients with impaired cognition (n=6), CBVa showed a decreasing trend in the substantia nigra, caudate and putamen, but was significantly increased in the presupplementary motor area and intracalcarine gyrus compared to controls. In MCI-patients-without-movement-disorder (n=18), CBVa was significantly increased in the caudate, putamen, hippocampus and lingual gyrus compared to controls. These findings provide important information for efforts towards developing biomarkers for the evaluation of potential risk of PD dementia (PDD) in PD patients. The current study is limited in sample size and therefore is exploratory in nature. The data from this pilot study will serve as the basis for power analysis for subsequent studies to further investigate and validate the current findings.

Magnetic Resonance Imaging Markers for Cognitive Impairment in Parkinson’s Disease: Current View

“…Using the inflow-based vascular-space-occupancy (iVASO) MRI approach, potential arteriolar CBV (CBVa) abnormalities reflecting the homeostasis of the most actively regulated segment in the microvasculature can be calculated. A decreasing trend of CBVa in the substantia nigra, caudate nucleus and putamen, and an increasing trend of CBVa in the pre-supplementary motor area and intracalcarine gyrus have been reported in PD-CI patients relative to HCs ( Paez et al, 2020 ). These exploratory findings provide important information for efforts toward developing potential biomarkers for the risk of CI in PD.…”

On the optimization of 3D inflow‐based vascular‐space‐occupancy (iVASO) MRI for the quantification of arterial cerebral blood volume (CBVa)

“…In this study, the 3D TFE iVASO sequence 15,16,26,27 was adopted. This experiment was designed to compare the 3D TFE iVASO protocols with the original single-slice 2D GRE EPI iVASO scans, and to assess the scan-rescan reproducibility of 3D TFE iVASO.…”

Imaging the Limbic System in Parkinson’s Disease—A Review of Limbic Pathology and Clinical Symptoms

“…The severity of volume loss has also been found to be predictive of conversion to dementia [ 53 , 98 , 99 ]. Additionally, PD-related alterations in iron content [ 61 , 100 , 101 ], texture [ 34 ], microstructural integrity [ 102 , 103 , 104 ], arteriolar-cerebral-blood-volume [ 105 ], connectivity [ 106 , 107 , 108 ], but not synaptic density [ 109 ] have been reported in combination with reduced cognitive performance. Serotonergic binding in the hippocampus of PD patients was not associated with cognitive performance [ 110 ].…”