Piramide N1, Sarasso E1,2, Volontè MA3, Canu E1, Galantucci S3, Gatti R4, Tettamanti A2, Agosta F1, Filippi M5
1San Raffaele Scientific Institute, Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, Milano, Italy, 2San Raffaele Scientific Institute, Laboratory of Movement Analysis, Milano, Italy, 3San Raffaele Scientific Institute, Department of Neurology, Institute of Experimental Neurology, Division of Neuroscience, Milano, Italy, 4Hunimed University, Physiotherapy Degree Course, Rozzano, Milano, Italy, 5San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, Milano, Italy
Background: To date, few studies have investigated task-based fMRI alterations underlying gait difficulties in Parkinson's disease (PD) patients with freezing of gait (PD-FoG).
Purpose: The aim of the study was to assess brain functional MRI (fMRI) activity during a feet movement task in PD-FoG patients, PD patients without FoG (PD-noFoG) and healthy controls.
Methods: 10 PD-noFoG, 17 PD-FoG patients and 18 matched healthy controls were recruited. PD-FoG patients were classified as having mild (9) or moderate (8) FoG according to the New FoG-Questionnaire (NFoG-Q). Patients underwent motor (Timed Up and Go test, 10-meters-walking test, UPDRSIII) and neuropsychological evaluations (executive-attentive, visuo-spatial and memory domains). All participants performed an fMRI task consisting of alternate dorsal/plantar feet flexion movements according to an auditory stimulus of 0.5 Hz.
Results: PD-FoG and PD-noFoG patients were similar for all motor variables, except for the presence of FoG. Only PD-FoG patients performed worse than healthy controls in executive-attentive, visuo-spatial and memory functions, whereas both PD-FoG and PD-noFoG patients showed decreased activity in sensorimotor areas at fMRI relative to healthy controls. PD-noFoG patients showed an increased activation of frontal-striatal network, while PD-FoG subjects had an increased recruitment of the parieto-occipital and cerebellar cortices compared to healthy subjects. PD-FoG showed a decreased basal ganglia activity relative to PD-noFoG. Analysing PD-FoG subgroups, mild PD-FoG subjects revealed increased fronto-parietal activation relative to moderate PD-FoG patients. Correlation analysis between clinical and fMRI findings in PD-FoG patients showed that: more severe FoG presentation correlated with lower activation of fronto-parietal circuits and higher activation of occipital lobes; worse performances in executive-attentive and visuo-spatial cognitive domains positively correlated with a decrease recruitment in fronto-parietal and basal ganglia circuits; lower memory function was associated with a reduced activity of parietal cortex and hippocampus.
Conclusion(s): All PD subjects showed a decrease recruitment of sensorimotor areas during feet movements relative to healthy controls. However, this study revealed the presence of two different patterns of brain activity during feet movements in PD-FoG and PD-noFoG patients, suggesting a compensatory role of parieto-occipital network to overcome the fronto-striatal failure in PD-FoG subjects.
Implications: Task-based fMRI should be considered as a useful outcome measure to monitor specific rehabilitative training effects in PD-FoG and PD-noFoG patients.
Keywords: Parkinson's disease, freezing of gait, task-based fMRI
Funding acknowledgements: This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
Purpose: The aim of the study was to assess brain functional MRI (fMRI) activity during a feet movement task in PD-FoG patients, PD patients without FoG (PD-noFoG) and healthy controls.
Methods: 10 PD-noFoG, 17 PD-FoG patients and 18 matched healthy controls were recruited. PD-FoG patients were classified as having mild (9) or moderate (8) FoG according to the New FoG-Questionnaire (NFoG-Q). Patients underwent motor (Timed Up and Go test, 10-meters-walking test, UPDRSIII) and neuropsychological evaluations (executive-attentive, visuo-spatial and memory domains). All participants performed an fMRI task consisting of alternate dorsal/plantar feet flexion movements according to an auditory stimulus of 0.5 Hz.
Results: PD-FoG and PD-noFoG patients were similar for all motor variables, except for the presence of FoG. Only PD-FoG patients performed worse than healthy controls in executive-attentive, visuo-spatial and memory functions, whereas both PD-FoG and PD-noFoG patients showed decreased activity in sensorimotor areas at fMRI relative to healthy controls. PD-noFoG patients showed an increased activation of frontal-striatal network, while PD-FoG subjects had an increased recruitment of the parieto-occipital and cerebellar cortices compared to healthy subjects. PD-FoG showed a decreased basal ganglia activity relative to PD-noFoG. Analysing PD-FoG subgroups, mild PD-FoG subjects revealed increased fronto-parietal activation relative to moderate PD-FoG patients. Correlation analysis between clinical and fMRI findings in PD-FoG patients showed that: more severe FoG presentation correlated with lower activation of fronto-parietal circuits and higher activation of occipital lobes; worse performances in executive-attentive and visuo-spatial cognitive domains positively correlated with a decrease recruitment in fronto-parietal and basal ganglia circuits; lower memory function was associated with a reduced activity of parietal cortex and hippocampus.
Conclusion(s): All PD subjects showed a decrease recruitment of sensorimotor areas during feet movements relative to healthy controls. However, this study revealed the presence of two different patterns of brain activity during feet movements in PD-FoG and PD-noFoG patients, suggesting a compensatory role of parieto-occipital network to overcome the fronto-striatal failure in PD-FoG subjects.
Implications: Task-based fMRI should be considered as a useful outcome measure to monitor specific rehabilitative training effects in PD-FoG and PD-noFoG patients.
Keywords: Parkinson's disease, freezing of gait, task-based fMRI
Funding acknowledgements: This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
Topic: Neurology: Parkinson's disease
Ethics approval required: Yes
Institution: San Raffaele Scientific Institute
Ethics committee: Human Research Ethics Committee
Ethics number: AOT in PD FOG-JGGF
All authors, affiliations and abstracts have been published as submitted.
