Predominance of caudate nucleus lesions in acute ischaemic stroke patients with impairment in language and speech

Background and purpose: Whereas traditional views of language processing in the brain have assumed that the language function is concentrated to a limited number of cortical areas (Broca's and Wernicke's areas), current knowledge points at a much more complex system of language and speech processing involving many brain areas, both cortical and subcortical. The purpose of the current study was to make an unbiased assessment of which cerebral areas are affected in first-ever acute ischaemic stroke patients identified as having language and speech impairments according to the National Institutes of Health Stroke Scale (NIHSS). Methods: Data from 34 patients with language and speech impairment, with a score of 1-3 on item 9 of the NIHSS, following ischaemic stroke were collected from the Lund Stroke Register. Magnetic resonance images acquired up to 20 days after stroke onset were used to create an overlap lesion image using MRIcron software. Results: The classical language areas, Wernicke's and Broca's areas, were affected in less than one-fourth of the patients. The most frequently affected region was a subcortical region -the left caudate nucleus and the adjacent corona radiata. Conclusions: These findings contribute to the growing body of evidence that the basal ganglia have a crucial role in the control over language and speech processing.