An update on predicting motor recovery after stroke (original) (raw)
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Scientific Reports, 2019
Corticospinal tract integrity after stroke has been widely investigated through the evaluation of fibres descending from the primary motor cortex. However, about half of the corticospinal tract is composed by sub-pathways descending from premotor and parietal areas, to which damage may play a more specific role in motor impairment and recovery, particularly post-stroke. Therefore, the main aim of this study was to investigate lesion load within corticospinal tract sub-pathways as predictors of upper limb motor impairment after stroke. Motor impairment (Fugl-Meyer Upper Extremity score) was evaluated in 27 participants at one week and six months after stroke, together with other clinical and demographic data. Neuroimaging data were obtained within the first week after stroke. Univariate regression analysis indicated that among all neural correlates, lesion load within premotor fibres explained the most variance in motor impairment at six months (R 2 = 0.44, p < 0.001). Multivariable regression analysis resulted in three independent, significant variables explaining motor impairment at six months; Fugl-Meyer Upper Extremity score at one week, premotor dorsal fibre lesion load at one week, and age below or above 70 years (total R 2 = 0.81; p < 0.001). Early examination of premotor dorsal fibre integrity may be a promising biomarker of upper limb motor impairment after stroke.
Stroke, 2014
Background and Purpose-Although neuroimaging studies have revealed specific patterns of reorganization in the sensorimotor control network after stroke, their role in recovery remains unsettled. To review the existing evidence systematically, we performed activation likelihood estimation meta-analysis of functional neuroimaging studies investigating upper limb movement-related brain activity after stroke. Methods-Twenty-four studies using sensorimotor tasks in standardized coordinates were included, totaling 255 patients and 145 healthy controls. Across the entire brain, we compared task-related activity patterns in good and poor recovery and assessed the magnitude of spatial shifts in sensorimotor activity in cortical motor areas after stroke. Results-When compared with healthy controls, patients showed higher activation likelihood estimation values in contralesional primary motor soon after stroke that abated with time, but were not related to motor outcome. The observed activity changes were consistent with restoration of typical interhemispheric balance. In contrast, activation likelihood estimation values in ipsilesional medial-premotor and primary motor cortex were associated with good outcome, reorganization that may reflect vicarious processes associated with ventral activity shifts from BA4a to 4p. In the anterior cerebellum, a novel finding was the association of poor recovery with increased vermal activity, possibly reflecting behaviorally inadequate compensatory strategies engaging the fastigio-thalamo-cortical and corticoreticulospinal systems. Conclusions-Activity in ipsilesional primary motor and medial-premotor cortices in chronic stroke signals good motor recovery, whereas cerebellar vermis activity signals poor recovery. Functional MRI may be useful in identifying recovery biomarkers. (Stroke.
Stroke, 2005
Background and Purpose-Motor recovery after stroke is associated with cerebral reorganization. However, few studies have investigated the relationship directly, and findings are equivocal. We therefore aimed to characterize the relationship between motor impairment, motor recovery, and task-related changes in regional cerebral blood flow (⌬rCBF) longitudinally. Methods-We obtained a profile of motor impairment and recovery in the upper limb and conducted positron emission tomography motor activation studies using a simple finger-tapping task in 9 stroke patients 2 to 7 weeks after stroke and 6 months later. For correlation analysis, mean images of task-related ⌬rCBF for each individual were linearly regressed with motor impairment scores. Motor recovery was correlated with longitudinal ⌬rCBF images. Results-Patients (7 males; 72.0Ϯ9.8 years) demonstrated a wide range of impairment severity and variable recovery.
Neurorehabilitation and Neural Repair, 2017
Background. Evolution of motor function during the first months after stroke is stereotypically bifurcated, consisting of either recovery to about 70% of maximum possible improvement (“proportional recovery, PROP”) or in little to no improvement (“poor recovery, POOR”). There is currently no evidence that any rehabilitation treatment will prevent POOR and favor PROP. Objective. To perform a longitudinal and multimodal assessment of functional and structural changes in brain organization associated with PROP. Methods. Fugl-Meyer Assessments of the upper extremity and high-density electroencephalography (EEG) were obtained from 63 patients, diffusion tensor imaging from 46 patients, at 2 and 4 weeks (T0) and at 3 months (T1) after stroke onset. Results. We confirmed the presence of 2 distinct recovery patterns (PROP and POOR) in our sample. At T0, PROP patients had greater integrity of the corticospinal tract (CST) and greater EEG functional connectivity (FC) between the affected hemi...
… and Neural Repair, 2011
Background. The relationship between structural and functional integrity of descending motor pathways can predict the potential for motor recovery after stroke. The authors examine the relationship between brain imaging biomarkers within contralesional and ipsilesional hemispheres and hand function in well-recovered patients after subcortical stroke at the level of the internal capsule. Objective. Measures of functional activation and integrity of the ipsilesional corticospinal tract might predict paretic hand function. Methods. A total of 14 patients in the chronic stable phase of motor recovery after subcortical stroke and 24 healthy age-matched individuals participated in the study. Functional MRI was used to examine BOLD contrast during passive wrist flexion-extension and paced or maximum-velocity active fist clenching. Functional integrity of the corticospinal pathway was assessed by transcranial magnetic stimulation to obtain motor-evoked potentials (MEPs) in the first dorsal interosseus muscle of the paretic and nonparetic hands. Fractional anisotropy and the proportion of traces between hemispheres in the posterior limb of both internal capsules were quantified using diffusion-weighted MRI. Results. Patients with smaller MEPs had a weaker paretic hand and more primary motor cortex activation in their affected hemisphere. Asymmetry between white matter tracts of either hemisphere was associated with reduced precision grip strength and increased BOLD activation within the contralesional dorsal premotor cortex for demanding hand tasks. Conclusion. There may be beneficial reorganization in contralesional secondary motor areas with increasing damage to the corticospinal tract after subcortical stroke. Associations between clinical, functional, and structural integrity measures in chronic stroke may lead to a better understanding of motor recovery processes.
Physiotherapy Research International, 2000
Background and Purpose. Only a few studies have been conducted to predict motor recovery of the arm after stroke. The aims of this study were to identify which clinical variables, assessed at different points in time, were predictive of motor recovery, and to construct useful regression equations. Method. One hundred consecutive stroke patients who had an obvious motor deficit of the upper limb were evaluated on entry to the study (two to five weeks post-stroke) and at two, six and 12 months after stroke. The Brunnström-Fugl-Meyer test was used as the outcome measure. Predictors included demographic data, overall disability, clinical neurological features, neuropsychological factors and secondary shoulder complications. Results. In multiple regression analyses, motor performance was invariably retained as the predictive factor with the highest R-square. Other significant predictive variables were overall disability, muscle tone, proprioception and hemi-inattention. Between 53% and 89% of the total amount of variance was accounted for in all selected models. The accuracy of prediction from clinical measurement in the acute phase diminished as the time span of measurement of outcome increased. Similarly, assessment of the variables at two and six months, rather than in the acute stage, resulted in a considerable improvement in the percentage variance explained at 12 months. The highest accuracy was obtained when predictions were made step-by-step in time. Conclusions. It is possible to predict motor recovery of the upper limb accurately through the use of a few clinical measures. Predictive equations are proposed, the use of which are practicable in both clinical practice and research.
European Journal of Neurology, 2020
Background: Various clinical and neuroimaging predictive factors have been identified for the recovery of upper extremity (UE) motor function after stroke. However, few studies have Accepted Article This article is protected by copyright. All rights reserved addressed factors related to the recovery of lower extremity (LE) motor function after stroke or performed direct comparisons of UE and LE motor recovery in the same set of patients. In this study, we investigated predictive factors for UE and LE motor recovery after stroke using clinical and neuroimaging characteristics. Methods: Forty-two subacute ischemic stroke patients underwent structural and functional MRI data acquisition and cognitive/behavioral assessments using the Fugl-Meyer assessment (FMA), NIH Stroke Scale (NIHSS), and Mini-Mental State Examination (MMSE) two weeks after stroke onset. Neuroimaging factors, including corticospinal tract (CST) fractional anisotropy, lesion volume, CST lesion load, and interhemispheric homotopic functional connectivity (IHFC), were extracted. The outcome of motor function was assessed by FMA scores three months after onset. Results: Early clinical and neuroimaging factors for predicting motor recovery were noticeably different for UE and LE. UE motor function recovery was related to age, NIHSS, MMSE, CST lesion load, lesion volume, ipsilesional CST integrity, and IHFC. In contrast, LE motor recovery was related to ipsilesional and contralesional CST integrity, and MMSE. Specifically, LE recovery showed a strong relationship to the preservation of cognitive function compared with motor impairment. Conclusions: Our results indicated that different mechanisms underlie UE and LE motor recovery after stroke. LE motor recovery seemed to be more intensively modulated by cognitive functions than UE.
Upper Limb Recovery After Stroke Is Associated With Ipsilesional Primary Motor Cortical Activity
Stroke, 2014
Background and Purpose— Although neuroimaging studies have revealed specific patterns of reorganization in the sensorimotor control network after stroke, their role in recovery remains unsettled. To review the existing evidence systematically, we performed activation likelihood estimation meta-analysis of functional neuroimaging studies investigating upper limb movement-related brain activity after stroke. Methods— Twenty-four studies using sensorimotor tasks in standardized coordinates were included, totaling 255 patients and 145 healthy controls. Across the entire brain, we compared task-related activity patterns in good and poor recovery and assessed the magnitude of spatial shifts in sensorimotor activity in cortical motor areas after stroke. Results— When compared with healthy controls, patients showed higher activation likelihood estimation values in contralesional primary motor soon after stroke that abated with time, but were not related to motor outcome. The observed activi...