Aims and objectives
Modern MR-neuroimaging techniques allow the cerebrovascular lesions to be studied in vivo,
non-invasively,
providing new insights into etiology,
pathogenesis,
morphology and brain function recovery prognosis.
Functional MRI (fMRI) being widely used in pre-surgical brain functions mapping,
is still far from being a routine method in daily neurology practices,
although appears to have great potential for implementation.The aim of our research was 1) to develop methodology of fMRI studies instrokepatients,
including indications,
limitations,
optimal paradigms evaluation; 2) to understand fMRI contribution in prognosis for stroke recovery...
Methods and materials
A prospective fMRI study included stroke patients (n=120) in acute,
subacute and chronic stages.
Study protocol included neurological examination.
MRI data were obtained on 1.5 Tesla scanner and included standard brain protocol (T2-WI,
FLAIR,
DWI,
T1-WI) as well as morphometry protocol (T1mpr),
diffusion tensor imaging (DTI) for white matter integrity assessment and BOLD fMRI paradigms.
Different paradigms were used in order to assess the functional outcome.
Group 1 of 50 hemiparetic patients (all stroke stages) performed passive motor paradigm for locomotion function assessment using a...
Results
1) There were no statistical differences along active or passive motor task performance in control group.
2) Widely accepted activation patterns for motor recovery prognosis were not applicable to severe hemiparesis or paralysis 3) DTI data influences fMRI activation patterns and functional outcome; FA index of 50% for posterior limb of internal capsule,
42% - for cerebral peduncle and 65% - for pons are the threshold levels for poor motor recovery prognosis.
4) Left hemisphere activation predomination in aphasic patients is more favorable than right...
Conclusion
FMRI activation patterns could be used as outcome predictors in stroke patients,
and ipsilesional hemisphere predominance activation plays a crucial role in favorable prognosis.
But our results support the idea that functional organizations of the residual distributed brain systems (motor,
language) is related to the degree of disruption to the white matter tracts and lesion localization.
So combination of brain functional and structural connectivity study methods should be used for optimal MR-protocol,
that could routinely be used to distinguish different neurorehabilitation strategies in stroke patients...
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