Outcome Prediction of Patients with Intracerebral Hemorrhage by Measurement of Lesion Volume in the Corticospinal Tract on Computed Tomography

Outcome Prediction by Combining Initial Clinical Severity With Corticospinal Tract Lesion Load in Patients With Intracerebral Hemorrhage

OBJECTIVE

This study aimed to assess the predictive accuracy of motor outcomes in patients with intracerebral hemorrhage by integrating the initial severity of hemiparesis and the corticospinal tract lesion load (CST-LL).

MATERIALS AND METHODS

A retrospective analysis was conducted on patients diagnosed with putaminal and/or thalamic hemorrhage who underwent computed tomography (CT) shortly after stroke onset. The CT images were aligned with a standardized brain template to calculate CST-LL. The initial severity of hemiparesis was evaluated using the summed Brunnstrom Recovery Stage (BRS total; range: 3-18). Motor outcomes at the time of discharge from a rehabilitation facility were assessed using the motor component total score of the Stroke Impairment Assessment Set (SIAS-motor total; range: 0-25). A multivariate regression analysis was performed with BRS total and CST-LL as independent variables and SIAS-motor total as the dependent variable.

RESULTS

A total of 61 patients were included in the analysis. The median CST-LL was 1.974 mL (interquartile range (IQR): 1.113-3.311 mL), the median BRS total was 8 (IQR: 4-13), and the median SIAS-motor total was 20 (IQR: 9.5-24.5). Both BRS total and CST-LL were found to be significant predictors of motor outcomes. The estimated t-values were 4.79 for BRS total and -3.29 for CST-LL, indicating comparable contributions of both factors. The developed regression model explained 60.4% of the variance in SIAS-motor outcomes.

CONCLUSIONS

The combination of initial clinical severity and CST-LL enhances the predictive accuracy of motor recovery in patients with intracerebral hemorrhage.

Associations Between Stroke Outcome Assessments and Automated Tractography Fractional Anisotropy Incorporating Age

OBJECTIVE

To evaluate the association between outcomes, including affected extremity functions and activities of daily living (ADL), and fractional anisotropy (FA) derived from automated tractography incorporating age among patients after stroke.

METHODS

This study enrolled stroke patients, and diffusion-tensor imaging was conducted during the second week. Standardized automated tractography was utilized to compute FA values in the corticospinal tract (CST), the inferior fronto-occipital fasciculus (IFOF), and the superior longitudinal fasciculus (SLF). Outcome evaluations were performed at discharge from our affiliated rehabilitation facility. Extremity functions were assessed using the total scores of the motor component of the Stroke Impairment Assessment Set (SIAS-motor). Independence levels in ADL were appraised through the motor and cognition components of the Functional Independence Measure (FIM). For each outcome measure, multivariate regression analysis incorporated the FA values of the CST, the IFOF, and the SLF, along with age.

RESULTS

Forty-two patients were enrolled in the final analytical database. Among the four explanatory variables, the CST emerged as the most influential factor for SIAS-motor scores. Conversely, age proved to be the primary determinant for both the motor and cognition components of FIM, surpassing the impact of FA metrics, including the CST and the IFOF.

CONCLUSION

The key influencing factors exhibited significant variations based on the targeted outcome assessments. Clinicians should be aware of these differences when utilizing neuroimaging techniques to predict stroke outcomes.

Usefulness of automated tractography for outcome prediction in patients with recurrent stroke

[Purpose] To examine the usefulness of automated tractography for predicting outcomes in patients with recurrent stroke. [Participants and Methods] Diffusion tensor imaging was performed in the second week after stroke, and fractional anisotropy was calculated using automated tractography. Three patients with recurrent strokes were included in this study. [Results] Initial computed tomography findings of a 62-year-old man with stuttering speech revealed a hemorrhage in the left thalamus. Fractional anisotropy indicated slight neural damage in the association fibers of both hemispheres. The patient returned to work with mild attention deficit and aphasia. Initial diffusion-weighted imaging of a 75-year-old man with right upper extremity paresis showed high-intensity areas in the left corona radiata. Fractional anisotropy indicated bilateral neural damage to the corticospinal tract. The patient was discharged with severe right upper extremity impairment and a modified gait. Initial diffusion-weighted imaging of a 60-year-old woman with moyamoya disease who experienced a sudden loss of consciousness showed high-intensity areas in the left anterior circulation territories. Fractional anisotropy indicated severe damage to the right hemisphere, the corticospinal tract, and the superior longitudinal fasciculus of the left hemisphere. She was transferred to a nursing home and remained bedridden. [Conclusion] The symptoms identified in this study agreed with automated tractography findings, which suggests that this methodology is useful for predicting recurrent stroke outcomes.

Outcome Prediction by Combining Corticospinal Tract Lesion Load with Diffusion-tensor Fractional Anisotropy in Patients after Hemorrhagic Stroke

Objectives

The objective of this study was to evaluate the predictive precision of combining the corticospinal tract lesion load (CST-LL) with the diffusion-tensor fractional anisotropy of the corticospinal tract (CST-FA) in the lesioned hemispheres regarding motor outcomes.

Methods

Patients with putaminal and/or thalamic hemorrhage who had undergone computed tomography (CT) soon after onset in our hospital were retrospectively enrolled. The CST-LL was calculated after registration of the CT images to a standard brain. Diffusion-tensor imaging was performed during the second week after onset. Standardized automated tractography was employed to calculate the CST-FA. Outcomes were assessed at discharge from our affiliated rehabilitation facility using total scores of the motor component of the Stroke Impairment Assessment Set (SIAS-motor total; null to full, 0 to 25). Multivariate regression analysis was performed with CST-LL and CST-FA as explanatory variables and SIAS-motor total as a target value.

Results

Twenty-five patients participated in this study. SIAS-motor total ranged from 0 to 25 (median, 17). CST-LL ranged from 0.298 to 7.595 (median, 2.522) mL, and the lesion-side CST-FA ranged from 0.211 to 0.530 (median, 0.409). Analysis revealed that both explanatory variables were detected as statistically significant contributory factors. The estimated t values indicated that the contributions of these two variables were almost equal. The obtained regression model accounted for 63.9% of the variability of the target value.

Conclusions

Incorporation of the CST-LL with the lesion-side CST-FA enhances the precision of the stroke outcome prediction model.

Applicability of fractional anisotropy from standardized automated tractography for outcome prediction of patients after stroke

[Purpose] Diffusion-tensor fractional anisotropy has been used for outcome prediction in stroke patients. We assessed the clinical applicability of the two major fractional anisotropy methodologies-fractional anisotropy derived from segmentation maps in the standard brain (region of interest) and fractional anisotropy derived from standardized automated tractography-in relation to outcomes. [Participants and Methods] The study design was a retrospective survey of medical records collected from October 2021 to September 2022. Diffusion-tensor imaging was conducted in the second week after stroke onset. Outcomes were assessed using the total score of the motor component of the Stroke Impairment Assessment Set (null to full, 0 to 25). Correlations between fractional anisotropy and the outcomes were then assessed. [Results] Fourteen patients with hemorrhagic stroke were sampled. The fractional anisotropy from standardized automated tractography of the corticospinal tract on the lesion side (mean ± standard deviation, 0.403 ± 0.070) was significantly and tightly correlated (r=0.813) with the outcomes (13.4 ± 9.2), whereas the fractional anisotropy from a region of interest set in the cerebral peduncle on the lesion side (0.548 ± 0.064) was not significantly correlated with the outcomes (r=0.507). [Conclusion] The findings suggest that fractional anisotropy derived from standardized automated tractography can be more applicable to outcome prediction than that derived from a region of interest defined in the standard brain.

Predicting Motor Outcomes Using Atlas-Based Voxel Features of Post-Stroke Neuroimaging: A Scoping Review

BACKGROUND

Atlas-based voxel features have the potential to aid motor outcome prognostication after stroke, but are seldom used in clinically feasible prediction models. This could be because neuroimaging feature development is a non-standardized, complex, multistep process. This is a barrier to entry for researchers and poses issues for reproducibility and validation in a field of research where sample sizes are typically small.

OBJECTIVES

The primary aim of this review is to describe the methodologies currently used in motor outcome prediction studies using atlas-based voxel neuroimaging features. Another aim is to identify neuroanatomical regions commonly used for motor outcome prediction.

METHODS

A Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol was constructed and OVID Medline and Scopus databases were searched for relevant studies. The studies were then screened and details about imaging modality, image acquisition, image normalization, lesion segmentation, region of interest determination, and imaging measures were extracted.

RESULTS

Seventeen studies were included and examined. Common limitations were a lack of detailed reporting on image acquisition and the specific brain templates used for normalization and a lack of clear reasoning behind the atlas or imaging measure selection. A wide variety of sensorimotor regions relate to motor outcomes and there is no consensus use of one single sensorimotor atlas for motor outcome prediction.

CONCLUSION

There is an ongoing need to validate imaging predictors and further improve methodological techniques and reporting standards in neuroimaging feature development for motor outcome prediction post-stroke.

Applicability of automated tractography during acute care stroke rehabilitation

[Purpose] To assess the clinical applicability of a novel automated tractography tool named XTRACT during acute stroke rehabilitation. [Participants and Methods] Three patients with left hemisphere stroke were sampled. Diffusion tensor images were acquired on the second week, and automated tractography was then applied. Tractography images and fractional anisotropy (FA) values in the corticospinal tract (CST) and arcuate fasciculus (AF) were assessed in relation to hemiparesis and aphasia. [Results] Patient 1 was nearly asymptomatic; FA in the left CST was 0.610 and that in the AF was 0.509. Patient 2 had severe hemiparesis and mild motor aphasia. Tractography images of the CST and AF were blurred; FA in the left CST was 0.295 and that in the AF was 0.304. Patient 3 showed no hemiparesis or aphasia at initial assessment. Tractography image of the CST was intact but that of the AF was less clear; FA in the left CST was 0.586 and that in the AF was 0.338. Considering the less clear images of the AF and lower FA value in Patients 2 and 3, further examinations for aphasia were performed, which revealed agraphia. [Conclusion] Visualization and quantification of neural fibers using automated tractography promoted planning acute care rehabilitative treatment in patients with stroke.