Since there have been very few reports on mPICA infarction, we describe here 3 patients with mPICA infarction detected brain MRI or CT. Our patients consisted of a 65-year-old man, a 69-year-old man, and a 70-year-old woman. We evaluated their clinical characteristics such as neurlological signs and symptoms, MRI images, risk factors, and results of both angiography and cardiac echograms. All patients had rotatory vertigo, nausea, vomiting lateropulsion, wide-based gait, inability for tandem gait and Romberg' s sign on the ipsilateral side. Among these the lateropulsion was severe in all patients. Nystagmus, dysarthria and lack of coordination were detected in 2 patients, but these signs were slight. One patient had hyperlipidemia, and one patient had both hypertension and atrial fibrillation. Occlusion of the vertebro-basilar artery was revealed by DSA in one patient. Mitral stenosis was detected on a cardiac echogram in one patient. The prominent neurological characteristics of mPICA infarction in our patients included both gait ataxia and lateropulsion in the ipsilateral direction despite slight, if any, lack of coordination in the 4 extremities, consistent with previous observations. It may therefore be difficult to differentiate mPICA infarction from vestibular disorder in some patients based on their neurological findings alone. We consider brain MRI to be useful for the diagnosis of mPICA in such difficult cases.

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Ceredral blood flow (CBF) at the early stage of ruptured cerebral aneurysm after surgery was evaluated in relation to clinical grade, course and outcome of subarachnoid hemorrhage (SAH) which is commonly associated with delayed cerebral vasospasm. Employing ¹²³I-IMP SPECT by the modified early method, CBF values at rest and in Diamox (Dx) studies were obtained in 26 consecutive cases, mainly on the 5 th day of SAH, when the cerebral vasospasm was expected to start with reduction of the CBF. The patients were commonly treated by hypervolemic therapy and cisternal drainage after aneurysmal neck clipping within the 2nd day of SAH. Their prognoses resulted in a good outcome group consisting of 21 cases, including 17 good recovery (GR) and 4 moderately disabled (MD) patients, and a poor outcome group consisting of 5 cases, including 2 severely disabled (SD), 2 vegetative survival (VS) and on dead patient. The mean CBF values of the good group were : minimum regional (r) CBF = 31.0, hemispheric (h) CBF = 38.8, rDx = 44.8, and hDx = 53.3 (ml /100 g/minx). Those of the poor group were : minimum rCBF = 19.2, hCBF = 30.2, rDx = 25.3, and hDx = 38.1. Comparative statistical analysis between the two groups showed the most significant difference in the minimum rCBF values (p<0.002) and also significant differences in the other CBF values (p<0.05). The CBF values at the early stage of SAH were lower than those at the steady state of normal candidates (hCBF = 47.9 ± 7.1), although their clinical grades and courses were good. These findings suggest that early estimation and preservation of CBF are useful for the treatment of cerebral vasospasm following SAH.

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To evaluate the clinical characteristics of cases demonstrating plaque formation without increases in intima-media thickness (IMT) of the common carotid artery (CCA), we compared the clinical characteristics statistically between subgroups of plaque-positive cases divided according to their IMT. Of 1079 serial cases who underwent carotid B-mode ultrasound with a 10 MHz linear transducer, 108 cases with plaque formation (mean age, 67.5±9.4 years; mean IMT, 0.70±0.08 mm) were available for the present study. The ultrasound examinations involved scanning of the CCAs, the carotid bifurcations, and the origin of the internal carotid arteries. The IMT of the CCA was measured on the far wall without focal formation of plaque on the distal CCA in off-line photographs. The definition of plaque formation was taken as a focal protruding lesion with a clear boundary from the adjacent wall surface and with a thickness of greater than 1 mm. The study group consisting of plaque-positive cases was divided into 2 subgroups according to the IMT of the CCA (group L, IMTS≤0.65 mm; group H, IMT>0.65 mm), and the clinical characteristics of each subgroup, including the prevalence of major risk factors such as diabetes mellitus (DM) and hypertension (HT), were compared statistically. This comparison of clinical characteristics between group L (number of cases, 41:males, 32) and group H (67; 52) revealed significant (P<0.05) differences in the prevalence of "DM without HT" (group L, 56.1%; group H, 19.4%), The prevalences of "both DM and HT" and "HT without DM" were statistically similar but higher in group H. These findings suggest a relationship between "DM without HT" and "the formation of plaque without any increase in IMT of the CCA". Diabetes mellitus and hypertension are equally important risk factors for arteriosclerosis. However, the roles of these diseases in atherosclerosis of the carotid arteries, especially in the formation of atheromatous plaque, are thought to involve different pathological mechanisms. Our data clearly revealed a link between pathological and clinical data using ultrasound.

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We conducted a retrospective analysis of anticoagulation with warfarin for the primary prevention of ischemic stroke in patients with nonvalvular atrial fibrillation. The study population comprised 194 patients with a mean age of 65.1 years at the onset of atrial fibrillation, and 69.5 years at the start of warfarin therapy, including 124 men and 70 women. Of the participants, 81% had chronic atrial fibrillation. During a mean followup period of 3.1 years, 11 ischemic strokes (incidence, 1.8% per year) and 3 brain hemorrhages (incidence, 0.5% per year) occurred. According to the mean INR, the patients were divided into 2 groups: 92 patients with low dose warfarin (INR, 1.5 to 2.4) and 102 patients with super low dose warfarin (INR, 1.0 to 1.5). The incidence of ischemic stroke was significantly lower in the low dose warfarin group than in the super low dose warfarin group (0.6 versus 3.1% per year, p=0.028). The rates of brain hemorrhage gave rise to no difference between the 2 groups (0.3 versus 0.7% per year, p=0.522). The present analysis suggests a preference for low dose anticoagulation with warfarin in the primary prevention of stroke among cases of nonvalvular atrial fibrillation in Japan. However, further prospective studies are needed to establish the optimal dose of warfarin.

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We surveyed the current management of acute cerebral infarction in Tokushima prefecture. We distributed a questionnaire concerning acute cerebral infarction to 86 clinical institutions. We received replies from 41 institutions. There were 2, 595 stroke patients within one year. Sixty-six percent of these patients had cerebral infarction, 24% had cerebral hemorrhage, and 10% had subarachnoid hemorrhage. At institutions where the physicians mainly treated stroke (Group a), they saw patients with cerebral infarction at an earlier period after stroke onset than did neurosurgeons (Group b). However, only 21% of patients in Group a were admitted within 6 hr after stroke onset, and as opposed to 24% of Group b. Three percent of patients with cerebral infarction were treated by intra-arterial thrombolysis. Physicians experienced defficulties in finding a referral hospital and in treating patients with cerebral infarction. On the other hand, neurosurgeons also experienced difficulties in finding a rehabilitation institute for stroke patients. We need to educate citizens that if a stroke occurs, the patient should come to hospital using an emergency medical system. We also need to establish an emergency care system for patients with cerebral infarction.

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Eight cases of pure motor monoparesis (PMM) due to cerebral infarction were studied using diffusion-weighted imaging (DWI) of MRI. All cases presented distal dominant paresis of the unilateral upper limb, and 2 cases had mild sensory disturbance. Almost all lesions on DWI were small infarcts measuring less than 15 mm, and 6 cases showed multiple new lesions. Four of the 8 cases had stenosis of the internal carotid artery and 2 cases had a cardiac source for embolism. It is important to examine the mechanisms of PMM using DWI in order to select the apppropriate procedure for secondary prevention.

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A 44-year-old man, who had a past history of diabetes mellitus, was admitted to our hospital suffering from apathy and hypobulia. On admission, neurological examinations revealed bradykinesia and lead pipe-like rigidity psychiatric manifestations such as impaired attention, loss of autonomy, and slurred speech were also observed. Examinations of higher brain functions disclosed amnesia and stereotypy. T 2-weighted MRI of the brain showed a high signal intensity in the bilateral thalamic regions, while a Gd-enhanced study demonstrated an enhancement of these regions. Cerebral angiography failed to reveal either the internal cerebral vein or the vein of Galen. The patient was therefore diagnosed as having deep cerebral vein thrombosis. We suggest that a disorder involving the connection between the thalamus and the frontal lobe may have played a role in his manifestations, because SPECT revealed a reduction in frontal lobe blood flow.

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We investigated the effects of hypertension, diabetes mellitus, and antihypertensives on the onset time of lacunar stroke (n=246). There were peaks of high incidence of stroke during sleeping at night and during activity in the afternoon. In patients with hypertension alone, stroke onset was frequent during sleeping at night in cases under treatment with antihypertensives and during activity in the afternoon in cases receiving no antihypertensives. These findings suggest that stroke may occur in patients whose blood pressure is decreased by antihypertensives at night and in patients whose blood pressure is increased by activity in the afternoon. In patients with both hypertension and diabetes mellitus, stroke onset in cases under treatment with antihypertensives was frequent not only during nighttime sleeping but also during afternoon activity. This implies that diabetes mellitus may impair autoregulation of blood pressure.

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