A Neuropsychiatric and Neuroimaging Study of Unilateral and Bilateral Striatal Ischemic Lesions

Neuropsychiatric disorders after striatal territory stroke have not been studied systematically. The investigators aimed to study the spectrum of cognitive and behavioral disorders following striatal infarcts.

Different aspects of cognitive functions, including executive, frontal lobe, memory, visuospatial, language, and semantic processing, were assessed among patients with striatal infarct. Structural MRI data sets were obtained 3 months after stroke to delineate affected territories of the striatum. MRIcroGL software was used to acquire multiple layers of images, generate volume renderings, and draw volumes of interest. To determine the brain locus most frequently affected in patients with distinct cognitive disorders, ischemic area distributions in patients with cognitive dysfunction versus those without cognitive impairment were contrasted.

Among 60 patients in this study, six different striatal infarction types were significantly associated with seven different cognitive categories (p<0.001). Unilateral caudate lesion was characterized by attention, planning, and executive disorders (38%), and unilateral lentiform infarct was characterized by executive (36%) and frontal (36%) dysfunctions. Bilateral caudate infarcts caused impairments in frontal and executive functions (75%), as well as in autobiographical (50%) and episodic (50%) memory. In those with bilateral caudate plus lentiform infarcts, all components of frontal and executive functions were dramatically impaired. The anteromedial striatum was affected more frequently in patients with language impairment compared with patients with other types of cognitive dysfunction (p<0.001).

Following striatal stroke, a wide range of frontal-like cognitive impairments occurred, along with impaired working memory, declarative memory, executive function, speech fluency, and motor function.