Subcortical Aphasia After Stroke

OBJECTIVE: To evaluate the types and severity of subcortical aphasia after stroke and to determine the predictors of the degree of aphasic impairment. METHODS: Medical records of 38 patients with post-stroke subcortical aphasia (19 males; mean age, 61.7±13.8 years) were reviewed retrospectively with respect to the following tests: the Korean version of the Western Aphasia Battery (K-WAB), the Korean version of the Modified Barthel Index (K-MBI), and the Fugl-Meyer Index (FMI). The severity of aphasia was evaluated by the aphasia quotient (AQ) and the language quotient (LQ). RESULTS: Anomic aphasia was the most frequent type of aphasia (n=15, 39.5%), and the lesion most frequently observed in subcortical aphasia was located in the basal ganglia (n=19, 50.0%). Patients with lesions in the basal ganglia exhibited the lowest scores on the FMI for the upper extremities (p=0.04). Severity of aphasia was significantly correlated with the K-MBI (Pearson correlation coefficient: γ=0.45, p=0.01 for AQ and γ=0.53, p=0.01 for LQ) and FMI scores for the lower extremities (γ=0.43, p=0.03 for AQ and γ=0.49, p=0.05 for LQ). In a multivariate logistic regression analysis, K-MBI remained the only explanatory variable closely associated with aphasia severity. CONCLUSION: This study showed the general characteristics of post-stroke subcortical aphasia, and it revealed that K-MBI was an associated and explanatory factor for aphasia severity.

The Factors Associated with Good Responses to Speech Therapy Combined with Transcranial Direct Current Stimulation in Post-stroke Aphasic Patients

OBJECTIVE: To determine factors associated with good responses to speech therapy combined with transcranial direct current stimulation (tDCS) in aphasic patients after stroke. METHOD: The language function was evaluated using Korean version of Western aphasia battery (K-WAB) before and after speech therapy with tDCS in 37 stroke patients. Patients received speech therapy for 30 minutes over 2 to 3 weeks (10 sessions) while the cathodal tDCS was performed to the Brodmann area 45 with 1 mA for 20 minutes. We compared the improvement of aphasia quotient % (AQ%) between two evaluation times according to age, sex, days after onset, stroke type, aphasia type, brain lesion confirmed by magnetic resonance image and initial severity of aphasia. The factors related with good responses were also checked. RESULTS: AQ% improved from pre- to post-therapy (14.94+/-6.73%, p<0.001). AQ% improvement was greater in patients with less severe, fluent type of aphasia who received treatment before 30 days since stroke was developed (p<0.05). The adjusted logistic regression model revealed that patients with hemorrhagic stroke were more likely to achieve good responses (odds ratio=4.897, p<0.05) relative to infarction. Initial severity over 10% in AQ% was also found to be significantly associated with good improvement (odds ratio=8.618, p<0.05). CONCLUSION: Speech therapy with tDCS was established as a treatment tool for aphasic patients after stroke. Lower initial severity was associated with good responses.

Severity of Post-stroke Aphasia According to Aphasia Type and Lesion Location in Koreans

To determine the relations between post-stroke aphasia severity and aphasia type and lesion location, a retrospective review was undertaken using the medical records of 97 Korean patients, treated within 90 days of onset, for aphasia caused by unilateral left hemispheric stroke. Types of aphasia were classified according to the validated Korean version of the Western Aphasia Battery (K-WAB), and severities of aphasia were quantified using WAB Aphasia Quotients (AQ). Lesion locations were classified as cortical or subcortical, and were determined by magnetic resonance imaging. Two-step cluster analysis was performed using AQ values to classify aphasia severity by aphasia type and lesion location. Cluster analysis resulted in four severity clusters: 1) mild; anomic type, 2) moderate; Wernicke's, transcortical motor, transcortical sensory, conduction, and mixed transcortical types, 3) moderately severe; Broca's aphasia, and 4) severe; global aphasia, and also in three lesion location clusters: 1) mild; subcortical 2) moderate; cortical lesions involving Broca's and/or Wernicke's areas, and 3) severe; insular and cortical lesions not in Broca's or Wernicke's areas. These results revealed that within 3 months of stroke, global aphasia was the more severely affected type and cortical lesions were more likely to affect language function than subcortical lesions.