Short-term and long-term predictors of balance function in stroke patients: a 6-month follow-up study

We aimed to determine early predictors of balance function (Berg Balance Scale, BBS) at 3 and 6 months after stroke using clinical, neurophysiological, and neuroimaging variables. Seventy-nine patients with hemiparesis after a stroke were included. Demographics, stroke characteristics, and clinical variables [Mini-Mental State Examination, BBS, strength in the hemiparetic hip, knee, and ankle muscles, and Fugl-Meyer Assessment Lower Extremity (FMA-LE)] were evaluated 2 weeks post-stroke, on average. Somatosensory-evoked potentials (SEP) from both tibial nerves and diffusion tensor imaging data were collected respectively within 3 weeks and 4 weeks post-onset to calculate the SEP amplitude ratio and the laterality index of fractional anisotropy of the corticospinal tract. In multiple linear regression analysis, younger age, higher FMA-LE score, and stronger hemiparetic hip extensors were independent predictors of higher BBS at 3 months post-stroke (adjusted R2  = 0.563, P  < 0.001). At 6 months post-stroke, significant predictors of higher BBS were younger age, higher FMA-LE, stronger hemiparetic hip extensors, and larger SEP amplitude ratio (adjusted R2  = 0.552, P  < 0.001), although the incremental contribution of the latter was rather small ( R2  = 0.019). We conclude that age and the initial motor impairment of the affected lower limb can inform the state of balance function at 3 and 6 months after stroke.

Structural Changes in the Arcuate Fasciculus and Recovery of Post-stroke Aphasia: A 6-Month Follow-up Study using Diffusion Tensor Imaging

BACKGROUND

Temporal changes in the structural connectivity of major language tracts after stroke and their contribution to aphasia recovery are unclear.

OBJECTIVE

To investigate longitudinal arcuate fasciculus (AF) integrity changes and their relationship with post-stroke aphasia recovery using diffusion tensor imaging (DTI).

METHODS

Thirty-five patients with aphasia due to first-ever left hemispheric stroke underwent the Korean version of the Western Aphasia Battery and DTI at 1- and 6-month post stroke onset. Fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity (AD) of both AF tracts were analyzed to evaluate the temporal changes in tract integrity and determine the correlation between changes (Δ; follow-up - initial) in DTI parameters and language scores.

RESULTS

At 6 months post-stroke, the mean FA decreased, and mean MD and RD increased in both hemispheres; however, compared with mean AD observed after 1 month, the mean observed at 6 months increased only in the left hemisphere (P < .05). ΔFA of the left AF and proportional change in the aphasia quotient showed a significant positive correlation (r = 0.365, P = .031). No correlation was found between changes in the right AF parameters and language score. The group with increased FA in the left AF showed more significant language improvement than the group with decreased FA.

CONCLUSIONS

During the subacute stage, the integrity of AF decreased in both hemispheres in patients with aphasia, and the change in structural connectivity of the left AF was associated with language improvement.

Language systems from lesion-symptom mapping in aphasia: A meta-analysis of voxel-based lesion mapping studies

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Meta-analysis of 2,007 individuals with aphasia from 25 voxel-based lesion mapping studies.

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Distinctive patterns of lesions in aphasia are associated with different language functions.

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The patterns of lesion in aphasia support the dual pathway model of language processing.

Background

Aphasia is one of the most common causes of post-stroke disabilities. As the symptoms and impact of post-stroke aphasia are heterogeneous, it is important to understand how topographical lesion heterogeneity in patients with aphasia is associated with different domains of language impairments. Here, we aim to provide a comprehensive overview of neuroanatomical basis in post-stroke aphasia through coordinate based meta-analysis of voxel-based lesion-symptom mapping studies.

Methods

We performed a meta-analysis of lesion-symptom mapping studies in post-stroke aphasia. We obtained coordinate-based structural neuroimaging data for 2,007 individuals with aphasia from 25 studies that met predefined inclusion criteria.

Results

Overall, our results revealed that the distinctive patterns of lesions in aphasia are associated with different language functions and tasks. Damage to the insular-motor areas impaired speech with preserved comprehension and a similar pattern was observed when the lesion covered the insular-motor and inferior parietal lobule. Lesions in the frontal area severely impaired speaking with relatively good comprehension. The repetition-selective deficits only arise from lesions involving the posterior superior temporal gyrus. Damage in the anterior-to-posterior temporal cortex was associated with semantic deficits.

Conclusion

The association patterns of lesion topography and specific language deficits provide key insights into the specific underlying language pathways. Our meta-analysis results strongly support the dual pathway model of language processing, capturing the link between the different symptom complexes of aphasias and the different underlying location of damage.

Clinical Factors Associated With Balance Function in the Early Subacute Phase After Stroke

OBJECTIVE

The aim of the study was to investigate the key factors of balance function in the early subacute phase after stroke.

DESIGN

Ninety-four stroke patients were included. Multiple variables were evaluated, including demographic factors, clinical variables (stroke type; lesion site; Mini-Mental State Examination; motor strength of the hip, knee, and ankle joints; Fugl-Meyer Assessment of lower extremity), neurophysiological variables (amplitude ratio of somatosensory evoked potential of the tibial nerves), and laterality index of fractional anisotropy of the corticospinal tract using diffusion tensor imaging. Balance function was measured using the Berg Balance Scale.

RESULTS

The Berg Balance Scale score was significantly negatively correlated with age and laterality index of fractional anisotropy and positively correlated with Mini-Mental State Examination; Fugl-Meyer Assessment of lower extremity; motor strength of the affected hip, knee, and ankle joint; and somatosensory evoked potential amplitude ratio (P < 0.05). The abnormal somatosensory evoked potential group and poor integrity of the corticospinal tract group showed significantly decreased Berg Balance Scale scores. In multivariable logistic regression analysis, age, Fugl-Meyer Assessment of lower extremity score, and ankle plantar flexion strength were significantly associated with balance function (odds ratios = 0.919, 1.181, and 15.244, respectively, P < 0.05).

CONCLUSIONS

Higher age, severe initial motor impairment, and strength of the affected lower limb muscles, especially the ankle plantar flexor, are strongly associated with poor balance function early after stroke.

TO CLAIM CME CREDITS

Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME.

CME OBJECTIVES

Upon completion of this article, the reader should be able to: (1) Enhance ability to evaluate motor and balance function of stroke patients by learning common assessment tools including clinical tests, neurophysiological and neuroimaging studies; (2) Explain the important factors associated with balance function impairment in early subacute stroke patients; and (3) Enhance planning rehabilitation strategies for improvement of balance function according to recovery stage after stroke.

LEVEL

Advanced.

ACCREDITATION

The Association of Academic Physiatrists is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.The Association of Academic Physiatrists designates this Journal-based CME activity for a maximum of 1.0 AMA PRA Category 1 Credit(s)™. Physicians should only claim credit commensurate with the extent of their participation in the activity.

Development of a categorical naming test in Korean: Standardization and clinical application for patients with stroke

Purpose

The purpose of this study was to develop and standardize a new categorical naming test, titled the Categorical Naming Test (CNT), for stroke patients, and to investigate its validity and clinical usefulness for patients with stroke.

Materials and methods

The CNT was developed based on semantic category, imageability, and psycholinguistic factors such as word frequency and word length. The test materials included two main semantic categories (living objects and artificial objects) comprising 60 items. We standardized the CNT on 221 healthy adults and administered the CNT to 112 stroke patients.

Results

Internal consistency and concurrent validity of the test were high. The mean total CNT scores varied significantly according to participants’ age, sex, and education. Among healthy controls, the scores for naming living objects were significantly higher than those for artificial objects. The analysis of stroke patients showed that the total CNT score revealed a statistically significant difference based on the patients’ lesion laterality and presence of aphasia, after controlling for age, sex, and education. However, the categorical scores achieved by comparing the naming scores for living and artificial objects showed no significant differences according to lesion laterality, stroke type, and presence of aphasia.

Conclusion

The CNT is a newly developed version of an overt naming task with high internal consistency validity for stroke patients in Korea. The newly developed CNT can prove useful in evaluating naming ability in stroke patients.

Abstract TP154: Arcuate Fasciculus Integrity and Outcome of Post-stroke Aphasia: A 6-month Follow-up DTI Study

Objectives: We evaluated the changes of arcuate fasciculus (AF), an important connecting pathway for language function, using DTI at 1-month and 6-month after stroke and investigated the relationship between structural changes of AF and improvement of post-stroke aphasia.

Methods: We collected data from the STroke Outcome Prediction (STOP) database that is prospective data collecting system for functional recovery prediction after stroke based on neuroimaging study. Twenty-six patients with aphasia (PWA) who had first-ever stroke, presence of aphasia evaluated by Western Aphasia Battery (WAB) and no previous neurological or psychiatric diagnosis. The WAB and DTI data within 1 month (initial) and 6 months after (follow-up) stroke onset were used for analysis. And fractional anisotropy (FA), mean diffusivity (MD), fiber number (FN) and differences (Δ) at two time points of these parameters were obtained in bilateral AF in diffusion tensor tractography (DTT). Three types (I: not reconstructed, II: disrupted, discontinued or shallow, III: preserved) of classification according to integrity of AF was also included.

Results: DTT parameters of bilateral AF showed statistically significant decrease in FA and increase in MD. Types of AF were changed in 6 patients (23%): 3 patients from type III to type II, 2 patients from type II to type I, and 1 patient from type II to type III. In Pearson’s correlation analysis, significant correlation was observed between 6-mon aphasia quotient (AQ) and parameters of left AF; positive correlation with FA (r=0.707, p<0.001), and negative correlation with MD (r=-.540, p<0.001). However, there was no correlation between 6-mon AQ score and FN of left AF, and all parameters of right AF. In addition, ΔDTT parameters were not correlated with either 6-mon AQ or ΔAQ.

Conclusions: The AF changes over time not only in dominant but also in nondominant hemispheres in patients with aphasia after stroke. But amount of changes (Δ) in AF parameters were not associated with language recovery.

Acknowledgement: This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (No. 2019R1A2C2003020).

Prognostic significance of Id-1 and its association with EGFR in renal cell cancer

AIMS

Epidermal growth factor receptor (EGFR) is suggested as one of the positive regulators in the invasive progression of renal cell cancer (RCC). Recently, Id-1 (inhibitor of differentiation or DNA binding), a helix-loop-helix transcription factor, has been identified as one of the key factors in the EGFR signalling pathway. The aim of this study was to investigate the significance of Id-1 expression in renal cell cancer and to study its relationship with EGFR.

METHODS AND RESULTS

Id-1 and EGFR expression was examined in tissue microarray (TMA) samples of 107 RCC and 32 normal kidney specimens by immunohistochemistry. Relative Id-1 and EGFR protein expression was quantified by estimating the staining intensity on a four-grade scale. We found that while negative to weak expression of Id-1 and EGFR was observed in non-malignant kidney tissues, most RCCs showed significant positive Id-1 and EGFR expression in tumour cells. In addition, Id-1 immunostaining intensity was positively associated with increased tumour staging, grading and EGFR expression.

CONCLUSION

Overexpression of Id-1 is a novel marker for advanced RCC which is positively correlated with EGFR expression. Our results suggest that Id-1 may play an important role in the development of RCC and indicate that Id-1 is a potential marker of patients with a poor prognosis.

Global analysis of differentially expressed genes in androgen-independent prostate cancer

Progression to androgen independent (AI) is the main cause of death in prostate cancer, and the mechanism is still unclear. By reviewing the expression profiles of 26 prostate cancer samples in a holistic view, we found a group of genes differentially expressed in AI compared with androgen-dependent groups (P-value<0.01, t-test). Focusing on apoptosis, proliferation, hormone and angiogenesis, we found a group of genes such as thioredoxin domain containing 5 , tumor necrosis factor receptor superfamily, member 10a , ribosomal protein S19 and Janus kinase 2 upregulated in AI prostate cancer, could play important roles in the transition from AD to AI and could be biomarkers of prognosis.