DISRUPTION OF THE BLOOD CEREBROSPINAL-FLUID BARRIER BY TRANSIENT CEREBRAL-ISCHEMIA

The influence of transient cerebral ischemia on blood-brain and blood- cerebrospinal fluid (CSF) barrier permeability was studied sequentiall y by magnetic resonance imaging (MRI) contrast enhancement using gadol inium-diethylene triamine pentacetic acid (Gd-DTPA) in rats. The unila teral internal carotid and middle cerebral arteries were transiently o ccluded by inserting a nylon thread into the carotid artery and removi ng it following a variable interval of 5 to 60 min. Contrast enhanceme nt of the lateral ventricle on the affected side was seen in the enhan ced T1-weighted image at the early stage of reperfusion 6 h after the start of ischemia in most of the rats subjected to 30- and 60-min isch emia, and in 3 of 6 rats in the 15-min ischemia group. Autoradiograms of Gd-[C-14]DTPA in rats subjected to 60-min ischemia demonstrated tha t the tracer strongly accumulated in the choroid plexus, the wall of t he lateral ventricle and its surrounding brain tissue. On the other ha nd, parenchymal enhancement of the striatum was seen only in the 60-mi n ischemia group and appeared later on Day 1 or Day 7. These results i ndicate that ventricular enhancement on MRI in this model is caused by disruption of the blood-CSF barrier at the choroid plexus of the late ral ventricle. This is the first reported study to demonstrate blood-C SF barrier disruption by transient ischemia.