Relevance of Behavioral Test in the Photothrombotic Stroke Rat Model

OBJECTIVE: The purpose of this study was to find reliable behavioral measures for the evaluation of motor dysfunction in photothrombotic ischemia rat model. METHOD: Male Sprague-Dawley rats were trained for behavioral test including tray reaching task (TRT), single pellet reaching task (SPRT), and rotarod task (RRT) for more than 2 weeks. Photothrombotic ischemia was induced in a stereotactically held rats using Rose Bengal dye (20 mg/kg) and cold light. Rats were assigned to either control (n=10) or experimental ischemic group (n=10). Post-lesional behavioral tests were performed for 4 weeks after confirmation of lesion by magnetic resonance imaging (MRI), followed by histological examination. RESULTS: RRT showed no difference between control and experimental group. SPRT and TRT showed significant difference between control and experimental group (p<0.05). SPRT could well demonstrate the recovery of motor dysfunction after over time. CONCLUSION: SPRT could be the most reliable test to measure not only motor dysfunction but also motor recovery in unilateral motor cortex lesion of photothrombotic ischemia rat model.

Current Epidemiological Status of Cerebrovascular Disease

There have been many reports on cerebrovascular disease in Korea, almost all of which were done at the Department of Neurosurgery, Neurology, and Internal Medicine. It is established that hemorrhagic stroke(HS) occurs at a higher rate than ischemic stroke(IS) compared to Western societies. However, many patients with IS visit to Oriental Medicine in Korea. Because of the paucity of published information including stroke data of Oriental Medicine, it was our purpose to analyse characteristic pattern of stroke occurrence, clinical data, and outcome for 762 patients visited to emergency room or admitted to the University Hospital and Oriental Medicine for a twelve month period. The incidence of IS was at least 1.5 times that of HS(IS: 309, HS: 453). Among age groups, those in sixties and seventies were the most predominant. The distribution of patients according to each Departments and Oriental Medicine was 118(HS: 2, IS: 116) in Department of Internal Medicine, 286(HS: 251, IS: 35) in Neurosurgery, and 358(HS: 56, IS: 302) in Oriental Medicine. The overall outcome for HS are much poorer than those for IS: in HS, 69.6% good, 10.7% morbidity, and 19.7% mortality, and in IS, 83.2%, 13.0% and 3.8%, respectively. Considering the fact that many IS patients with mild symptoms and signs tend to visit private clinics, these results suggest the actual incidence of Is is much higher than HS in Korea, compared with previous reports. We expect that a multicentered cooperative study including Oriental Medicine will be motivated by this study for establishing more accurate characteristics of stroke in Korea in the future.