Table. 2.2.
Functional MRI studies in PD-FOG - Resting state fMRI.
| Tessitore et al. (2012b) | 16 PD-FOG (67±6) 13 PD-nFOG (66±6) 15 HS (65±6) | Brain Voyager QX (ICA) | FC | Lower FC in executive-attention and visual networks | Between executive-attention, visual networks and FOG-Q |
|---|---|---|---|---|---|
| Fling et al. (2014) | 8 PD-FOG (65±6) 7 PD-nFOG (64±6) 14 HS (67±8) | Seed: SMA, STN, MLR, and CLR. | FC | Higher FC in SMA, left CLR, and MLR | Between SMA-MLR FC and FOG-Q |
| Canu et al. (2015) | 35 PD-FOG (68±8) 23 HS (67±8) | FSL (ICA) | FC | Lower FC in SMC, DMN, and visual associative networks | No correlation |
| Lenka et al. (2016) | 15 PD-FOG (54±11) 13 PD-nFOG (50±9) 30 HS (52±10) | CONN (multiple seeds) | FC | Lower FC of left parietal opercular cortex with primary SMC and auditory areas | Between left parietal opercular cortex FC and FOG-Q |
| Vervoort et al. (2016) | 13 PD-FOG (66±10) 60 PD-nFOG (58±10) 20 HS (58±9) | SPM (seeds on motor network and FPN) | FC | Lower FC within the striatum Higher FC between the dorsal putamen and precuneus Lower FC between the caudate and superior temporal lobe | Between FC and gait kinematics |
| Wang et al. (2016) | 14 PD-FOG (72±6) 16 PD-nFOG (69±6) 16 HS (68±2) | SPM (Seeds on bilateral PPN) | FC | Lower FC of right PPN with inferior temporal gyri and cerebellum Higher FC of the left PPN with right middle temporal gyrus | Not performed |
| Mi et al. (2017) | 31 PD-FOG (61±8) 31 PD-nFOG (58±10) 32 HS (58±7) | REST version 1.8 | ALFF | Higher in right ACC and left inferior parietal lobule Lower in superior frontal gyrus, cerebellum and left thalamus | Between ALFF in superior frontal gyrus, subcortical and sensorimotor areas, ACC and FOG-Q |
| Bharti et al. (2019a) | 15 PD-FOG (71+7) 16 PD-nFOG (66+11) 16 HS (67 ± 8) | FSL (Seeds on CLR, fastigial nucleus, and dentate). | FC | Higher FC between CLR, fastigial nucleus and cerebellar, posterior cortical cortices Lower FC between dentate and brainstem, right basal ganglia, frontal, prefrontal, parieto-occipital cortices | Between CLR FC and FOG-Q |
| Gilat et al. (2018) | 19 PD-FOG (68±7) 21 PD-nFOG (67±8) | FSL (seeds on bilateral amygdala, bilateral nucleus accumbens, caudate nucleus, and putamen). | FC | Higher FC between right amygdala and right putamen; between FPN and right putamen Lower FC between FPN and left amygdala | Between limbic FC and FOG-Q and fear of falling |
| Li et al. (2018) | 21 PD-FOG (70±6) 33 PD-nFOG (66±9) 24 HS (66±4) | Voxel-mirrored homotopic approach | FC | Lower voxel-mirrored homotopic connectivity in the inferior parietal lobule | Between voxel-mirrored homotopic connectivity in inferior parietal lobe and FOG-Q |
| Zhou et al. (2018) | 14 PD-FOG (62 ±10) 20 PD-nFOG (63±8) 18 HS (64±10) | REST (regional homogeneity) | Local FC | Lower regional homogeneity in left SMA and left superior frontal region | No correlation was performed |
| Bharti et al. (2019b) | 15 PD-FOG (71±7) 16 PD-nFOG (66±11) 16 HS (67±8) | FSL (Within - and Between- network analysis) | FC | Within-network results: higher right fronto-parietal, orbitofrontal, frontal, sensorimotor and basal ganglia FC Between-network results: Lower FC between anterior default mode and sensorimotor networks, between right fronto-parietal and executive control networks | Between basal ganglia within-network FC and TUG duration during ON state Between FC right fronto-parietal versus executive-control networks and FOG-Q |
| Hu et al. (2019) | 18 PD-FOG (63±11) 18 PD-nFOG (61±8) 17 HS (61±8) | SPM12 | ALFF | In frequency band slow-5, lower ALFF in the bilateral putamen In frequency band slow-4, higher ALFF in left inferior temporal gyrus and lower ALFF in right middle frontal gyrus In classical frequency band, higher ALFF in inferior temporal gyrus | No correlation was performed |
| Maidan et al. (2019) | 26 PD-FOG (72±1) 11 PD-nFOG (74±1) 20 HS (70±1) | Graph theory analysis | FC | Lower global efficiency of dorsal attention network Higher local efficiency of dorsal attention network | Between global efficiency of dorsal attention network and FOG-Q |
PD-FOG: Parkinson's disease patients with freezing of gait; PD-nFOG: Parkinson's disease patients without freezing of gait; HS: healthy controls; FC: Functional connectivity; FOG-Q: Freezing of Gait Questionnaire; SMA: supplementary motor area; STN: subthalamic nucleus; CLR: cerebellar locomotor region; MLR: mesencephalic locomotor region; ICA: Independent component analysis; SMC: supplementary motor complex; DMN: default mode network; PPN: pedunculopontine nucleus; ACC: anterior cingulate cortex; FPN: frontoparietal network; ALFF: Amplitude of Low Frequency Fluctuation; TUG: Time Up and Go.
FOG-Q represents severity of freezing of gait (FOG)
*NA: not available