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.

This study investigated factors associated with aphasia severity at both 2 weeks and 3 months after stroke using demographic and clinical variables, brain diffusion tensor imaging (DTI) parameters, and lesion volume measurements. Patients with left hemisphere stroke were assessed at 2 weeks (n = 68) and at 3 months (n = 20) after stroke. Demographic, clinical, and neuroimaging data were collected; language functions were assessed using the Western Aphasia Battery. For neuroimaging, DTI parameters, including the laterality index (LI) of fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity, mean diffusivity and fibre density (FD) of the arcuate fasciculus (AF), and lesion volume, were measured. Lesion volume, cortical involvement, and the national institutes of Health Stroke Scale score significantly predicted aphasia severity at 2 weeks after stroke, whereas the aphasia quotient and presence of depression during the early subacute stage were significant predictors at 3 months after stroke. According to Pearson correlation, LI-AD and LI-FD were significantly correlated with the aphasia quotient 2 weeks after ischaemic stroke, and the LI-FA was significantly correlated with the aphasia quotient 2 weeks after haemorrhagic stroke, suggesting that the extent and mechanism of AF injuries differ between ischaemic and haemorrhagic strokes. These differences may contribute to aphasia severity. Aphasia arises from the inability to understand and regulate language after injury to certain areas of the brain 1. Approximately 35-40% of adults admitted to hospital because of strokes are diagnosed with aphasia 2. Furthermore, approximately 85% of stroke patients with aphasia recover from the aphasia within 3-6 months after onset; however, some may require additional time for recovery and others may never fully recover 3,4. Accurately predicting the prognoses of patients with aphasia during the early post-stroke stages can be helpful for determining the appropriate timing of discharge and need for institutional help 5. Patients with poor post-stroke auditory comprehension and naming ability (anomia) are more often discharged to an institution rather than to home 6. Factors associated with recovery from aphasia can be divided into non-lesion-and lesion-related factors 7. Non-lesion-related factors include age, sex, handedness, and years of education, whereas lesion-related factors include acute-stage aphasia severity, diagnosed aphasia type, and location and size of any corresponding brain lesions 8-10. Stroke-related variables are robust predictors of recovery; however, patient-related variables have been reported to have minimal or no significant prognostic value 7,9. Recently, newly developed techniques, such as diffusion tensor imaging (DTI), voxel-based lesion symptom mapping, and functional magnetic resonance imaging (MRI), have been used to study the effects of brain lesion locations and sizes on aphasia 11-13. DTI can provide information regarding the degree of damage to and structure of white matter in th...

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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 poststroke, 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 R 2 = 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 R 2 = 0.552, P < 0.001), although the incremental contribution of the latter was rather small (R 2 = 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.