The promising approaches to determining the rehabilitation potential of ischemic stroke (IS) patients include an assessment of the microstructural integrity of the brain matter by diffusion tensor imaging (DTI), the main indicator of which is fractional anisotropy (FA). The role of the intact hemisphere in the rehabilitation process after IS remains a controversial subject. The hypothesis for the investigation is that the development of a diffusion and perfusion model (DPM) based on the assessment of FA in combination with data on cerebral blood flow velocity (CBFV) and the impact of the focus will be able to predict the patients' neurological status by the end of the acute period of IS.
Objective: to investigate the role of diffusion and perfusion characteristics of the intact hemisphere in determining the rehabilitation potential in the acute period of IS and to develop a prognostic DPM.
Patients and methods. The investigation enrolled 100 patients with IS and 10 individuals in the control group. All the examinees underwent brain MRI. Perfusion-weighted sequence without bolus injection of a contrast agent was used to quantify CBFV in 10 areas according to the Alberta stroke program early CT score (ASPECTS). Values for FA in 10 areas of both hemispheres were calculated using DTI findings. Neurological and functional statuses were evaluated over time with the National Institute of Health Stroke Scale (NIHSS) and the modified Rankin scale.
Results. The NIHSS score at discharge was associated with FA and CBFV in 4 and 6 of the 10 areas of the intact hemisphere, respectively. DPM for predicting the rehabilitation potential included the key parameters correlating with a discharge NIHSS score (in order of decreasing the significance): admission NIHSS value (r = 0.55; p < 0.001), the size of a focus (r = 0.42; p < 0.001), FA in the contralateral cingulum bundle FA (r = -0.28; p = 0.007), and CBFV in M2 white matter [r = -0.24; p = 0.025; R2 = 0.642; p(F) <0.001].
Conclusion. In addition to the NIHSS score at admission, the size of a focus, DPM values (FA in the contralateral cingulum bundle and CBFV in the white matter) allow prediction of the rehabilitation potential in IS.
Fractional anisotropy (FA) estimated using diffusion tensor magnetic resonance imaging (dMRI) is considered as a promising biomarker in ischemic stroke (IS). The basis of this study is the assumption that the assessment of FA indices for different white matter tracts will be able to predict the main aspects of the rehabilitation potential even without determining the structural and functional bases of these influences.
Objective: to study the diagnostic significance of changes in FA indices to assess various aspects of the rehabilitation potential in acute IS.
Patients and methods. Examinations were made in 100 patients with IS and in 10 individuals without stroke and cognitive impairment. All the patients underwent dMRI and assessments of rehabilitation potential indicators on days 3 and 10 of the disease and at discharge.
Results and discussion. The indices of FA of the ipsilateral upper longitudinal and cingulum bundles, FA and the size of an infarct focus, asymmetry of FA of the cingulum bundle (rFA), corticospinal tract (at the level of the knee of the internal capsule and bridge) and the anterior limb of the internal capsule, as well as the FA of the splenium and knee of the internal capsule of the intact hemisphere are of the most value for the functional outcome of acute IS. The microstructure of these zones determines the state of most rehabilitation domains. With respect to global outcome, the integrity of the associative tracts of the affected hemisphere is more valuable than the microstructure of the intact hemisphere and rFA. The tracts of the intact hemisphere are of particular importance for the restoration of complex rehabilitation spheres, such as cognitive status and daily living and social skills, which is necessary to ensure patient independence.
Conclusion. The FA indices of the tracts under study seem to be a clinically acceptable biomarker of various aspects of the rehabilitation potential in acute IS.
Patent foramen ovale (PFO) is an important cause of embolic cryptogenic stroke (ECS) in young patients. The main mechanism in this case is paradoxical embolism (PE), the basis for which is a right-to-left (R-L) shunt. Objective: to comparatively characterize patients who have undergone ECS, with and without an R-L shunt, as evidenced by transcranial Doppler with the bubble test (TCD-BT).