Which is responsible for aphasia by subcortical lesions? Subcortical lesions or the cortical hypoperfusion?

Cerebral lesions causing aphasia involve morphological and functional changes. In this study, it was aimed to explain the connection between aphasia and subcortical lesions with SPECT. The study included 30 patients diagnosed in the first three days of stroke with a single hemorrhagic or ischemic lesion in the dominant hemisphere subcortical area. Gulhane Aphasia Test and SPECT were performed. Aphasia was detected in 19 cases (63.3%). The relationship between aphasia and perfusion dysfunction in cortical and subcortical regions of the brain was evaluated, aphasia was found to be present in 15 (71.4%) of the 21 patients with cortical hypoperfusion in the dominant hemisphere and 4 (44.4%) of the 9 patients without cortical hypoperfusion; the difference was not statistically significant (p = 0.16). In the ischemia group, aphasia was present in 11 (78.5%) of the 14 cases with cortical hypoperfusion in the dominant hemisphere. Aphasia wasn't detected in any of the 5 cases that did not have cortical hypoperfusion, the difference was statistically significant (p = 0.005). When cerebral regions were evaluated separately, significant difference was reported in the aphasia seen with frontal, anterior parietal, and occipital hypoperfusion compared to cases with normal perfusion in these areas, with p = 0.003, p = 0.021, and p = 0.004, respectively. This study showed that aphasia to be more common in cases with cortical hypoperfusion in the dominant hemisphere than in cases without hypoperfusion. Our results provide evidence that direct effect of the lesion in the basal ganglia on the development of aphasia is doubtful.