Functional MRI in Parkinson’s disease with freezing of gait: a systematic review of the literature

Dopaminergic pathways and resting-state functional connectivity in Parkinson’s disease with freezing of gait

“…Neuroimaging studies have thoroughly examined neurobiological correlates of FOG, including investigations using [ 18 F]fluorodeoxyglucose PET ( Park et al, 2009 , Gallardo et al, 2018 , Zhou et al, 2019 , Bartels et al, 2006 , del Olmo et al, 2006 , Chul et al, 2007 , Tard et al, 2015 , Mitchell et al, 2019 ), perfusion studies using single-photon emission computed tomography (SPECT) ( Fabre et al, 1998 , Matsui et al, 2005 , Mito et al, 2006 ), as well as various magnetic resonance imaging (MRI) modalities ( Shine et al, 2013 , Shine et al, 2011 , Snijders et al, 2011 , Shine et al, 2013 , Shine et al, 2013 ). A growing body of studies performing connectivity analyses using diffusion tensor imaging or resting-state functional MRI (rs-fMRI) ( Fling et al, 2014 , Canu et al, 2015 , Lenka et al, 2016 , Vervoort et al, 2016 , Bharti et al, 2019 , Gilat et al, 2018 , Maidan et al, 2019 ) suggests the involvement of tracts and brain regions engaged in frontal executive, visuospatial, limbic and locomotor performance with an emphasis on the right hemisphere ( Bharti et al, 2019 , Fasano et al, 2015 ) (see Song et al ( Song et al, 2021 ) for review). Additionally, structural MRI studies reported volume loss in respective cortical areas ( Snijders et al, 2011 , Kostić et al, 2012 , Rosenberg-Katz et al, 2013 , Herman et al, 2014 , Herman et al, 2013 , Pietracupa et al, 2018 , Vastik et al, 2017 ).…”

“…Despite a growing body of neuroimaging studies, the reported alterations within the above-stated networks in FOG patients have been inconsistent and multimodal studies are required to resolve interdependencies ( Fasano et al, 2015 , Song et al, 2021 ). Furthermore, investigations of changes in dopaminergic signaling have been scarce.…”

Disorganized resting‐state functional connectivity between the dorsal attention network and intrinsic networks in Parkinson's disease with freezing of gait

“…Patients recruited in their study were older and had a longer disease duration and higher depression scores than in our study, whereas the reduced functional connectivity in the frontal-parietal cognitive control network has been found to be associated with increased depressive symptoms in a previous study (Schultz et al, 2019). Recently, Song et al (2021) reviewed 39 fMRI studies (task-based fMRI and rs-fMRI) on PD with FOG. Several hypotheses about the pathogenesis of PD-FOG were summarized: impairment of cognitive control network, abnormal activation and connection of sensorimotor pathways, brainstem inhibition caused by the inhibitory output of basal ganglia and cerebellar compensation.…”

“…Recently, Song et al (2021) reviewed 39 fMRI studies (task‐based fMRI and rs‐fMRI) on PD with FOG. Several hypotheses about the pathogenesis of PD‐FOG were summarized: impairment of cognitive control network, abnormal activation and connection of sensorimotor pathways, brainstem inhibition caused by the inhibitory output of basal ganglia and cerebellar compensation.…”

Alterations of structure and functional connectivity of visual brain network in patients with freezing of gait in Parkinson’s disease

“…The authors interpreted their results as indicating that the hyperactivation of visual-motor circuit might act to compensate the inadequate function in the resting state in gait disturbance of PD-FOG. The selected ROIs in the current study were FOG-related brain regions reported in previous studies ( Bharti et al, 2019 ; Song et al, 2021 ). It would be meaningful to explore how other brain regions interact with visual network in FOG in future studies.…”