Although reconstructions of medical service systems for acute stroke have rapidly progressed in the United States and Europe, the current status of medical service systems remains not so changed in Japan. We investigated the factors which influence arrival time after stroke onset to a tertiary care center, and surveyed the current status of primary stroke care in the northern part of Osaka prefecture. The subjects for the "arrival time study" consisted of 518 consecutive patients with acute stroke (364 men and 154 women ; mean age, 65.9 years), who were admitted to our stroke care unit between March 1991 and August 1996. We divided the patients into three groups according to their arrival time : early admission ( ≤ 3 hours ; group E, n = 97), intermediately early admission (3 to 6 hours ; group M, n = 68), and late admission (> 6 hours ; group L, n = 345). We examined age, sex, distance from place of onset to our hospital, time of stroke onset, admission via other clinics or hospitals, stroke subtypes, initial neurologic deficits, NIH Stroke Scale (NIHSS) score on admission, history of visit to our hospital, and means of transportation, among the three groups. Factors associated with delay in arrival were stroke onset during sleep (18%, 48% and 37% in groups E, M and L, respectively, p = 0.0001), and admission via other clinics or hospitals (33%, 51% and 66%, p<0.0001). Patients with mild deficits at stroke onset were less frequent in group E as compared to the other groups. The mean values for the NIHSS score were 8.5, 5.8 and 5.2 in groups E, M and L, respectively (p<0.0001). Lacunar infarction was observed more frequently in groups M (40%) and L (45%) than in group E (16%). Conversely, cardioembolic stroke was less frequent in the former two groups (12% and 14%) than in the latter group (36%, p<0.0001) . In the "primary stroke care study", we sent out a questionnaire concerning acute stroke to 585 clinics without beds in the northem Osaka territory, which has a population of about 1, 500, 000. We received 407 replies (69.6 %) . About 24% of patients with mild deficits or TIA were not transferred to hospital within a day of onset. About 56% of primary care physicians experienced difficulties in finding a referral hospital. To begin acute stroke treatment effectively within 3 to 4 hours, we need to establish better emergency care and transportation systems for acute stroke patients, and to educate the public and health workers about "brain attacks".

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We developed a system for measuring reaction times to high-cortical recognition tasks using a personal computer. The following tasks were employed : simple reaction time (SRT), choice reaction time (CRT), visual searching time (VST), memory scanning time (MST) and modified Stroop test (ST). The reaction times to the 5 tasks were measured in 134 normal volunteers who demonstrated full Mini-mental scores. The reaction times to each task showed a significant positive linear correlation with the age of the volunteers ranging from 20 to 69 years old, and were prolonged by approximately 60-80 msec/10 years. The reaction times to 2 of the tasks (SRT and CRT) were significantly shorter than those to the remaining 3 tasks (VST, MST and ST) . These findings indicate that reaction times can be applied to the evaluation of high-cortical recognition functions.

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In Germany and France, Ginkgo biloba extract (GBE) has been used as a standard and authorized pharmaceutrical for the treatment of chronic cerebral circulatory insufficiency for about 30 years. GBE contains several flavonoids and terpenoids acting as free radical scavengers, vasodilators and enhancers of neurotransmission. GBE has recently proved to exert a favorable effect on cognitive and behavioral disturbance in patients with Alzheimer as well as vascular dementia. We examined the effect of GBE on local cerebral blood flow (LCBF) in 10 patients with chronic ischemic stroke and on their clinical status as well. The patients took 240 mg of GBE, daily p.o. for 4 weeks. Single photon emission tomography (123I IMP) was performed before and after the treatment. We placed 4 regions of interest (ROT, 8 mmΦ) in the bilateral cerebral cortices and cere-bellum and utilized the count ratio of the cortical ROls and cerebellum as a measure of the LCBF (CT: cerebel-lar index). Eight out of the 10 patients revealed an improvement of LCBF in the diseased hemisphere follow-ing the GBE treatment. The mean CI values before and after the treatment were 70.0±8.8% and 77.1±8.1%, respectively (p<0.05). The clinical symptoms and signs exhibiting a high improvement rate were as follows : headache (86%) dizziness (50%), depressive state (100%) and willingness (100%). The above data provide a cerebral circulatory basis for the clinical effectiveness of GBE. It is anticipated that Japanese neurologists, neurosurgeons and strokologists will come to recognize and understand this useful drug as one choice of treatment for stroke patients.

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We investigated the prevalence of carotid atherosclerosis and its correlates among 419 elderly men aged 65-74 years in two rural communities (I town in Akita prefecture and N town in Kochi prefecture) and an urban community (Y city in Osaka). Carotid atherosclerosis was assessed by high-resolution B-mode ultrasonography. Of the participants. 25-30% displayed thickening (maximum intima-media thickness (IMT)≥1.1 mm) in the common carotid arteries (CCA) and 40-55% had thickening (maximum IMT≥1.5 mm) in the internal carotid arteries (ICA). Both the CCA and ICA walls were thicker and the outer and inner CCA diameters were greater in the rural communities than in the urban community. The regional differences in IMT and CCA diameter appeared to be explicable in part by the difference in prevalence of hyperension extending over a long period. Multiple logistic regression models adjusting for covariants indicated that hypertension and smoking were significant risk factors for ICA wall thickning in the rural communities, while total serum cholesterol and HDL cholsterol were significantly associated with CCA wall thickening in the urban residents whose total cholesterol level was righer than that of the rural residents.

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We investigated the current status of reperfusion therapies for acute ischemic stroke in the Kyushu and Okinawa districts employing a questionnaire. Among 195 neurological or neurosurgical institutions, 117 (60.0%) submitted replies to the questionnaire. Of these 117 institutions, 109 had conducted some treatments for acute ischemic stroke and were enrolled in the present study. Examinations for site of occlusion in the acute stroke patients without any abnormality on computed tomography (CT) were performed in 67.0% of the institutions. mainly by digital subtraction angiography (DSA) or magnetic resonance angiography (MRA) . The use of ultrasonography (US) and CT angiography (CTA) was less frequent (in only 20-30% of the institutions). Reperfusion therapies were performed in only 58.7% of the institutions. In 53.3% of the neurological and 28.1% of the neurosurgical institutions, no reperfusion therapies were considered at all Among the various reperfusion therapies intravenous urokinase infusion was the most widely employed therapy (51.6%). Intraarterial local and regional thrombolysis was performed in 50.0% and 46.9% of the institutions respectively.

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Although diabetes mellitus (DM) has been found to be a strong risk factor for ischemic stroke and is correlated with the worst of outcomes, it has yet to be determined whether or not the stroke subtypes and distribution of ischemic lesions differ in patients with DM as compared to other ischemic stroke patients. We studied 215 consecutive patients with first-time episodes of ischemic stroke at Kyoto Second Red Cross Hospital. Patients with cardiogenic embolism were excluded. MRI examinations were performed on all patients and 158 of the patients underwent cerebral angiography. The patients were classified into 4 groups according to their symptomatic lesions : 118 patients with lacunar infarcts, 62 with non-lacunar infarcts in the supratentorial region, 20 with brainstem infarcts, and 15 with TIAs. The distribution of ischemic lesions, based on the MRIs, was subsequently evaluated for all patients. The lesions included lacunar infarcts (3-15 mm in diameter), cortical and subcortical non-lacunar infarcts, brainstem infarcts, and cerebrallar infarcts. The lacunar infarcts were further divided into 2 subgroups : those located in the territory of the lenticulostriate and subcortical perforating arteries, and those in the thalamoperforating and thalamogeniculate arteries. The brainstem infarcts were also divided into 2 subgroups : the branch atheromatous type (infarcts extending to the surface of the pontine basis), and the lipohyalinosis type (infarcts located within the pons, but not extending to the pontine surface). The relationship between the distribution of ischemic lesions and risk factors, including hypertension (HT), DM, hyperlipidemia (HL), smoking (SM), and heart disease, was investigated. The complication rate of DM was significantly higher in patients with pontine infarcts of the branch atheromatous type than in those without pontine lesions. In contrast, the complication rates of HT, HL, SM, and heart disease were not statistically different between the two groups. The numbers of lacunae were counted, and classified according to the following scheme : 0 (absent), single lacuna (one lacuna), and multiple lacunae (more than two lacunae). Although multiple lacunae, in both the lenticulostriate artery and thalamoperforant artery territories, were found to be significantly correlated with HT, there was no correlation with DM, HL, or SM. Non-lacunar supratentorial infarcts, and cerebellar infarcts showed no correlation with HT, DM, HL, or SM. The stenotic lesions in the extracranial and intracranial arteries identified by cerebral angiography were classified into 4 groups : Grade 0, <30% stenosis ; Grade 1, 30-60% ; Grade 2, 60-99% ; and Grade 3, occlusion. Although higher-grade stenotic lesions tended to be correlated with aging, such lesions were not significantly correlated with other risk factors. DM was also correlated with pontine infarcts of the branch atheromatous type. However, DM showed no correlation with brainstem infarcts of the lipohyalinosis type, thalamic lacunae, or cerebellar infarcts. It was thus not possible to conclude that all infarcts within the territory of vertebrobasilar arteries were associated with DM. The mechanism whereby DM is associated with such lesions requires further clarification.

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The second European Stroke Prevention Study (ESPS-2) reported additivistic effects of dipyridamole (DP) when combined with aspirin (ASA) in the secondary prevention of ischemic stroke. We therefore investigated the inhibitory effects of DP and ASA on platelet aggregation and ATP release from platelets in whole blood from 10 healthy male volunteers in vitro. ADP-induced platelet aggregation in the whole blood was inhibited by 20 μM DP but not by 20 pM ASA. ADP-or collagen-induced ATP release from platelets in the whole blood was inhibited by 20 ltM ASA but not by 20 μM DP. These findings suggest that a combination of DP and ASA is more effective than either alone for the secondary prevention of stroke by simultaneously inhibiting platelet aggregation and dense granule release from platelets in vitro. We also examined the effects of DP and ASA on the plasma levels of adenosine. DP, but not ASA, displayed a tendency towards increasing the plasma levels of adenosine. This effect might be related to inhibition of platelet aggregation by DP.

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We examined the influence of carotid stenting on mean blood pressure (MBP) and pulse rate (PR) . Seventeen patients who underwent carotid stenting between January and December 1998 were divided into 2 groups : 12 patients whose stents reached from the internal carotid artery (ICA) to the common carotid artery (CCA) were termed the CCA group, and 5 patients whose stents were localized within the ICA were termed the ICA group. The MBP and PR just before and during carotid stenting, and the patterns of circadian rhythm of MBP at 4 days before and 18 days after carotid stenting, were analyzed. A compartson of the 2 groups revealed that the CCA group manifested significant hypotension and bradycardia during carotid stenting (p<0.001). In other words, patients whose lesions included the CCA tended to have a strong carotid sinus reflex during carotid stenting, and had a risk of cerebral ischemia induced by hemodynamic changes. However, no patients displayed persistent hypotensive or bradycardia effects after carotid stenting, and there was no significant difference in the circadian rhythm of MBP. Thus, carotid stenting for lesions including the CCA requires strict perioperative management for hemodynamic ischemia.

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