Coronal MRI in the diagnosis of corona radiata infarcts adjacent to the lateral ventricles.

To clarify the vascular lesions with pathophysiological changes in the corona radiata infarcts adjacent to the body of the lateral ventricle (CRILV), 17 patients with CRILV were studied clinically with neuroradiological images. Based on the MRI findings in coronal images obtained between the anterior and posterior commissures, patients were divided into a PER group and a COR group. The PER group was defined as having infarcts localized bellow a line (IC-CC line) extending from the upper edge of the insular cistern (IC) to the external angle of the lateral ventricle adjacent to the corpus callosum (CC), while the COR group had lesions located above this line towards the centrum semiovale. The 11 patients in the PER group were mostly hypertensive men, as well as 6 patients in the COR group.<BR>In both groups, the stepwise deterioration of symptoms and the completion of stroke in a morning was frequent, though the time from onset to completion was longer in the COR group. Comparing the clinical manifestations of the PER and COR groups, pure motor hemiparesis was seen in 5 and 3 patients, and sensorimotor stroke in 2 and 1 patients, respectively. Drowsiness was found in 2 patients of the PER group, while aphasia was occurred in 2 of the COR group. Furthermore, one patient had pseudobulbar palsy and another was asymptomatic in the PER group. The outcome in both groups was good, except that the 2 drowsy patients died of aspiration pneumonia. Eleven of 13 infarcts in the PER group were small well-defined lesions less than 15 mm in diameter on CT scans, and angiography showed sclerotic changes of the main arteries without obstruction. In contrast, the COR group demonstrated ill-defined and rather large low-density areas on CT and main trunk obstructions of the internal carotid or middle cerebral arteries was found on angiography. ¹²³I-IMP single photon emmission computed tomography (SPECT) showed diffuse defects in the COR group, though the SPECT images of the PER group varied from normal to having diffuse or multiple defects.<BR>These findings suggest that the PER group had lacunar lesions caused by ischemia of the perforators, while the COR group had terminal zone infarcts in the territory of the cortical branches or watershed infarcts induced by main trunk obstruction. In conclusion, a demarcating line (IC-CC line) on coronal MRI was a useful diagnostic technique for differentiating CRILV due to two different types of vascular lesions.