Controlling for lesions, kinematics and physiological noise: impact on fMRI results of spastic post-stroke patients
MethodsX. 2020-01-01; 7: 101056
DOI: 10.1016/j.mex.2020.101056
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1. MethodsX. 2020 Sep 9;7:101056. doi: 10.1016/j.mex.2020.101056. eCollection
2020.
Controlling for lesions, kinematics and physiological noise: impact on fMRI
results of spastic post-stroke patients.
Brihmat N(1), Boulanouar K(1), Darmana R(1), Biganzoli A(1), Gasq D(1)(2),
Castel-Lacanal E(1)(3), Marque P(1)(3), Loubinoux I(1).
Author information:
(1)ToNIC, Toulouse NeuroImaging Center, Université de Toulouse, Inserm, UPS,
France.
(2)University Hospital of Toulouse, Department of Functional & Physiological
Explorations, Toulouse, France.
(3)University Hospital of Toulouse, Department of Rehabilitation and Physical
Medicine, Toulouse, France.
Functional magnetic resonance imaging (fMRI) is a widely used technique for
assessing brain function in both healthy and pathological populations. Some
factors, such as motion, physiological noise and lesion presence, can contribute
to signal change and confound the fMRI data, but fMRI data processing techniques
have been developed to correct for these confounding effects. Fifteen spastic
subacute stroke patients underwent fMRI while performing a highly controlled
task (i.e. passive extension of their affected and unaffected wrists). We
investigated the impact on activation maps of lesion masking during
preprocessing and first- and second-level analyses, and of adding wrist
extension amplitudes and physiological data as regressors using the Statistical
Parametric Mapping toolbox (SPM12). We observed a significant decrease in
sensorimotor region activation after the addition of lesion masks and
movement/physiological regressors during the processing of stroke patients’ fMRI
data. Our results demonstrate that:•The unified segmentation routine results in
good normalization accuracy when dealing with stroke lesions regardless of their
size;•Adding a group lesion mask during the second-level analysis seems to be a
suitable option when none of the patients have lesions in target regions.
Otherwise, no masking is acceptable;•Movement amplitude is a significant
contributor to the sensorimotor activation observed during passive wrist
extension in spastic stroke patients;•Movement features and physiological noise
are relevant factors when interpreting for sensorimotor activation in studies of
the motor system in patients with brain lesions. They can be added as nuisance
covariates during large patient groups’ analyses.
© 2020 The Authors. Published by Elsevier B.V.
DOI: 10.1016/j.mex.2020.101056
PMCID: PMC7509233
PMID: 32995309
Conflict of interest statement: The Authors declare that there is no conflict of
interest.