[A case of transient ischemic attack of hemodynamic origin induced by postprandial hypotension].

An 82-year-old man had a transient ischemic attack (TIA) with symptoms of consciousness disturbance and right hemiparesis while resting in a sitting position after breakfast. His symptoms improved around 1 h after onset when he lied in a supine position and received intravenous hydration. Duplex carotid ultrasonography revealed severe stenosis of the left common carotid artery. A decrease in the brain perfusion reserve was confirmed by acetazolamide-stress brain perfusion scintigraphy. Moreover, ambulatory blood pressure monitoring revealed a reduction in systolic blood pressure below 90 mmHg after each meal, indicating postprandial hypotension (PPH). The PPH was improved by oral administration of α-glucosidase inhibitor without any subsequent recurrences of TIA. The patient was diagnosed with TIA of hemodynamic origin that was induced by PPH and exhibited severe carotid stenosis. PPH is common in elderly people, and it should be recognized as a significant trigger for ischemic cerebrovascular disease.

Brain natriuretic peptide upon admission as a biological marker of short-term mortality after intracerebral hemorrhage.

BACKGROUND AND PURPOSE: The purpose of the present study was to test the hypothesis that plasma brain natriuretic peptide (BNP) is associated with short-term mortality after intracerebral hemorrhage (ICH). METHODS: We prospectively enrolled 271 patients (median age 72 years; 109 females) who were admitted within 24 h of ICH onset between April 2007 and July 2011 and in whom plasma BNP levels were measured upon admission. The patients were assigned to two groups according to survival within 1 month of ICH. Factors associated with mortality were determined by multivariate logistic regression analysis. RESULTS: Within 1 month of ICH, 48 (17.7%) of the 271 enrolled patients died. The median (interquartile range) level of plasma BNP was significantly higher in the group of non-survivors than in the group of survivors [102.5 (48.7-205.0) vs. 32.4 (17.3-85.0) pg/ml; p < 0.001]. A cutoff BNP level of 60.0 pg/ml could predict death within 1 month of ICH. Multivariate logistic regression analysis showed that a plasma BNP of >60.0 pg/ml (OR 4.7; 95% CI 1.43-15.63; p = 0.011) was independently associated with mortality within 1 month after ICH. CONCLUSIONS: A high BNP level upon admission is associated with mortality within 1 month after ICH.

Dolichoectatic vertebrobasilar dissecting aneurysm originating from atherosclerosis: an autopsy case.

We herein report an unusual case of profound brain infarction of the posterior circulation due to a dolichoectatic vertebrobasilar dissecting aneurysm (DVDA) originating from atherosclerosis. On autopsy, diffuse atherosclerosis was observed with a multi-fusiform aneurysm measuring 1 to 2 cm in diameter ranging from the left vertebral artery to the basilar artery. The microscopic findings of the aneurysm revealed severe stenosis of the artery caused by intimal thickening, intimal flap formation and thrombosis, indicating the presence of a dissecting aneurysm originating from atherosclerosis. The DVDA observed in this case was considered to be slowly progressive and associated with the development of atherosclerosis. The etiology of structural destabilization in patients with DVDA involves rupture of the internal elastic lamina, which is dislodged by massive hematomas that form atheromatous lesions.

Association between the intima-media thickness of the brachiocephalic trunk and white matter hyperintensity in brain MRI.

The intima-media thickness (IMT) of the brachiocephalic trunk (BCT) can be measured using duplex carotid ultrasonography, which is used for imaging the common carotid artery (CCA). However, the clinical significance of the BCT-IMT has not been studied. We reviewed 1109 stroke-free participants in the registry of the Okinawa General Health Maintenance Association. We compared the association between the BCT-IMT or the CCA-IMT with deep and subcortical white matter hyperintensity (DSWMH). The BCT-IMT was correlated with the CCA-IMT, and like CCA-IMT, it increased with advancing age. The increase in both the BCT-IMT and the CCA-IMT quartiles was correlated with the development of DSWMH. The multivariate logistic regression analysis indicated that, as observed for the CCA-IMT, the increase in the BCT-IMT was associated with a higher prevalence of significant DSWMH (Fazekas grade 2 or 3 per 0.1 mm increase in IMT; OR 1.02, 95% confidence interval 1-1.04; P=0.04). The increase in quartiles of the BCT-IMT was only associated with a higher prevalence of significant DSWMH in subjects with lower CCA-IMT (1st and 2nd quartiles, R(2)=0.18, P<0.05) but not in subjects with higher CCA-IMT (3rd and 4th quartiles). Combinations of the CCA-IMT and BCT-IMT quartiles failed to have an additive effect on the prevalence of significant DSWMH. The BCT-IMT has a similar clinical profile to the CCA-IMT in terms of its association with DSWMH. However, the CCA-IMT and the BCT-IMT did not predict DSWMH in an additive manner, and distinct mechanisms might underlie the observed thickening of the IMT in the CCA and BCT.

Trends in the incidence of stroke and cardiovascular risk factors on the isolated island of Okinawa: the Miyakojima study.

BACKGROUND: Rapid deterioration of cardiovascular risk control, especially obesity, has occurred in Okinawa; this may affect cardiovascular disease incidence, including stroke. METHODS: Cross-sectional field studies were conducted in 2 periods, 1988-1991 as the first period, and 2002-2005 as the second period, in the isolated island of Okinawa, Miyakojima. To evaluate population backgrounds related to cardiovascular risk factors, data from the health checkup programs conducted in 1987 and 2001 were surveyed. RESULTS: Total of 257 patients in the first period and 370 in the second were diagnosed with first-time stroke. The age-adjusted annual incidence rate of first-time stroke of the first and second periods was 124 and 144 per 100,000 standard population of Japan. The age-adjusted annual incidence rate showed an upward trend for brain infarction (50 to 73) and downward trend for brain hemorrhage (61 to 54); however, those trends were not significant. The health checkup surveys illustrated that blood pressure decreased in all age groups during the second survey period. However, the body mass index increased in patients aged 50 years or more. Fasting blood glucose levels of patients aged 30-79 years and non-HDL cholesterol levels of patients aged 50-79 years significantly increased. CONCLUSIONS: In Miyakojima, the incidence of first-time stroke and all of its subtypes did not change significantly between two periods, even though blood pressure decreased significantly in the second period. Metabolic deterioration may be associated with the upward trend in incidence of brain infarction.

High glycated hemoglobin levels and intracranial artery stenosis are predictive factors for early motor worsening events in patients with penetrating artery infarction.

BACKGROUND: The purpose of this study was to identify typical clinical characteristics to predict early motor worsening (EMW) of patients with penetrating artery infarction. METHODS: We reviewed 65 consecutive patients with pure motor hemiparesis, sensorimotor stroke, and ataxic hemiparesis. EMW was defined as deterioration by ≥1 point on the National Institutes of Health Stroke Scale for motor function within 5 days of admission. RESULTS: EMW was observed in 22 patients (34%). HbA1c levels were higher in patients with EMW than in those without EMW (7.9 ± 2.6 vs. 6.3 ± 1.6%; p < 0.01). The percentage of EMW patients with intracranial artery stenosis (ICAS) was greater than that of non-EMW patients with ICAS (13/22 patients, 59% vs. 8/43 patients, 19%; p < 0.01). Multivariate logistic regression analysis indicated that HbA1c levels ≥7.0% (OR 3.0, 95% CI 1.5-6.8; p < 0.005) or ICAS (OR 2.3, 95% CI 1.2-4.8; p < 0.05) increased the risk of EMW, and the combination of these factors increased the risk in an additive manner (OR 7.6, 95% CI 2.5-40; p < 0.005). CONCLUSION: HbA1c levels ≥7.0% and/or ICAS in patients with penetrating artery infarction are associated with EMW.

Transoral carotid ultrasonography using a micro convex probe with B-flow imaging for extracranial internal carotid artery dissection.

We report on transoral carotid ultrasonography using a micro convex probe with B-flow imaging for determining spontaneous extracranial internal carotid artery dissection just below the petrous portion. A 49-year-old man suffered cortical and subcortical infarction in the region of the right middle cerebral artery. Magnetic resonance angiography on the third day of admission revealed spontaneous recanalization of the right internal carotid artery associated with an intimal flap-like structure at the petrous portion. Transoral carotid ultrasonography using a micro convex probe revealed right extracranial internal carotid artery dissection, showing an increased diameter of the right extracranial internal carotid artery with double lumen formation, stenosis of the true lumen, and a mobile intimal flap in B-flow imaging. Transoral carotid ultrasonography using a micro convex probe was helpful to attempt a self-expanding stent for recanalizing right extracranial internal carotid artery dissection. The patient recovered and was discharged ambulatory. The size of the micro convex probe was optimum for transoral carotid ultrasonography in our patient. Micro convex probe is more commonly used than the standard transoral carotid ultrasonography probe, which lacks versatility. We consider that transoral carotid ultrasonography using a micro convex probe could be routinely used for ultrasonographic evaluation of extracranial internal carotid artery dissection.

Angiotensin-converting enzyme inhibition, but not AT(1) receptor blockade, in the solitary tract nucleus improves baroreflex sensitivity in anesthetized transgenic hypertensive (mRen2)27 rats.

Transgenic hypertensive (mRen2)27 rats overexpress the murine Ren2 gene and have impaired baroreflex sensitivity (BRS) for control of the heart rate. Removal of endogenous angiotensin (Ang)-(1-7) tone using a receptor blocker does not further lower BRS. Therefore, we assessed whether blockade of Ang II with a receptor antagonist or combined reduction in Ang II and restoration of endogenous Ang-(1-7) levels with Ang-converting enzyme (ACE) inhibition will improve BRS in these animals. Bilateral solitary tract nucleus (nTS) microinjections of the AT(1) receptor blocker, candesartan (CAN, 24 pmol in 120 nl, n=9), or a peptidic ACE inhibitor, bradykinin (BK) potentiating nonapeptide (Pyr-Trp-Pro-Arg-Pro-Gln-Ile-Pro-Pro; BPP9α, 9 nmol in 60 nl, n=12), in anesthetized male (mRen2)27 rats (15-25 weeks of age) show that AT(1) receptor blockade had no significant effect on BRS, whereas microinjection of BPP9α improved BRS over 60-120 min. To determine whether Ang-(1-7) or BK contribute to the increase in BRS, separate experiments using the Ang-(1-7) receptor antagonist D-Ala(7)-Ang-(1-7) or the BK antagonist HOE-140 showed that only the Ang-(1-7) receptor blocker completely reversed the BRS improvement. Thus, acute AT(1) blockade is unable to reverse the effects of long-term Ang II overexpression on BRS, whereas ACE inhibition restores BRS over this same time frame. As the BPP9α potentiation of BK actions is a rapid phenomenon, the likely mechanism for the observed delayed increase in BRS is through ACE inhibition and elevation of endogenous Ang-(1-7).

Angiotensin peptides and central autonomic regulation.

Aging, hypertension, and fetal-programmed cardiovascular disease are associated with a functional deficiency of angiotensin (Ang)-(1-7) in the brain dorsomedial medulla. The resulting unrestrained activity of Ang II in brainstem regions negatively impacts resting mean arterial pressure, sympathovagal balance, and baroreflex sensitivity for control of heart rate. The differential effects of Ang II and Ang-(1-7) may be related to the cellular sources of these peptides as well as different precursor pathways. Long-term alterations of the brain renin-angiotensin system may influence signaling pathways including phosphoinositol-3-kinase and mitogen-activated protein kinase and their downstream mediators, and as a consequence may influence metabolic function. Differential regulation of signaling pathways in aging and hypertension by Ang II versus Ang-(1-7) may contribute to the autonomic dysfunction accompanying these states.

Correlation between the degree of left subclavian artery stenosis and the left vertebral artery waveform by pulse Doppler ultrasonography.

BACKGROUND: Development of retrograde blood flow may be observed in the vertebral artery and is associated with progressive ipsilateral proximal subclavian or innominate artery stenosis. The subclavian steal phenomenon is more prevalent in the left subclavian artery (LSA). The purpose of this study was to analyze the correlation between the degree of LSA stenosis and pulse Doppler waveforms of the left vertebral artery (LVA). METHODS: A retrospective analysis of LVA waveforms was performed in 22 cases with LSA proximal stenosis before the origin of the LVA in conventional angiograms. The degree of LSA stenosis was classified into 5 groups (<50, 50-59, 60-69, 70-89, 90-100%). Pulse Doppler waveforms of the LVA were also classified into 5 subtypes depending on the depth of the mid-systolic notch representing retrograde blood flow (normal, mid-systolic notch, retrograde flow smaller than antegrade flow, retrograde flow larger than antegrade flow, retrograde flow without antegrade flow). RESULTS: A statistically significant correlation (R(2) = 0.646, p < 0.0001) was found between the degree of LSA stenosis and the LVA waveform. CONCLUSIONS: The pattern analysis of LVA pulse Doppler waveforms seems to be useful in determining the degree of LSA stenosis.

Angiotensin-(1-12) requires angiotensin converting enzyme and AT1 receptors for cardiovascular actions within the solitary tract nucleus.

The novel peptide, angiotensin (ANG)-(1-12), elicits a systemic pressor response and vasoconstriction. These effects are blocked by ANG converting enzyme (ACE) inhibitors or AT(1) receptor antagonists, suggesting a role as an ANG II precursor. However, ANG-(1-12) can serve as a substrate for either ANG II or ANG-(1-7) formation, depending on the local tissue enzymes. Although levels of ANG-(1-12) are higher than ANG I or ANG II in brain, the role and processing of this peptide for autonomic control of heart rate (HR) has yet to be considered. Thus we examined the effects of nucleus tractus solitarii (NTS) microinjection of ANG-(1-12) on baroreflex sensitivity for control of HR, resting arterial pressure (AP) and HR, and indexes of sympathovagal balance in urethane/chloralose anesthetized Sprague-Dawley rats. NTS injection of ANG-(1-12) (144 fmol/120 nl) significantly impaired the evoked baroreflex sensitivity to increases in AP [n = 7; 1.06 +/- 0.06 baseline vs. 0.44 +/- 0.07 ms/mmHg after ANG-(1-12)], reduced the vagal component of spontaneous baroreflex sensitivity and HR variability, and elicited a transient depressor response (P < 0.05). NTS pretreatment with an AT(1) receptor antagonist or ACE inhibitor prevented ANG-(1-12)-mediated autonomic and depressor responses. ANG-(1-12) immunostaining was observed in cells within the NTS of Sprague-Dawley rats, providing a potential intracellular source for the peptide. However, acute NTS injection of an ANG-(1-12) antibody did not alter resting baroreflex sensitivity, AP, or HR in these animals. Collectively, these findings suggest that exogenous ANG-(1-12) is processed to ANG II for cardiovascular actions at AT(1) receptors within the NTS. The lack of acute endogenous ANG-(1-12) tone for cardiovascular regulation in Sprague-Dawley rats contrasts with chronic immunoneutralization in hypertensive rats, suggesting that ANG-(1-12) may be activated only under hypertensive conditions.

Chronic immunoneutralization of brain angiotensin-(1-12) lowers blood pressure in transgenic (mRen2)27 hypertensive rats.

Angiotensin-(1-12) [ANG-(1-12)] is a newly identified peptide detected in a variety of rat tissues, including the brain. To determine whether brain ANG-(1-12) participates in blood pressure regulation, we treated male adult (mRen2)27 hypertensive rats (24-28 wk of age) with Anti-ANG-(1-12) IgG or Preimmune IgG via an intracerebroventricular cannula for 14 days. Immunoneutralization of brain ANG-(1-12) lowered systolic blood pressure (-43 +/- 8 mmHg on day 3 and -26 +/- 7 mmHg on day 10 from baseline, P < 0.05). Water intake was lower on intracereroventricular day 6 in the Anti-ANG-(1-12) IgG group, accompanied by higher plasma osmolality on day 13, but there were no differences in urine volume, food intake, or body weight during the 2-wk treatment. In Preimmune IgG-treated animals, there were no significant changes in these variables over the 2-wk period. The antihypertensive effects produced by endogenous neutralization of brain ANG-(1-12) suggest that ANG-(1-12) is functionally active in brain pathways regulating blood pressure.

Transoral carotid ultrasonography for evaluating internal carotid artery occlusion.

BACKGROUND AND PURPOSE: Transoral carotid ultrasonography (TOCU) has enabled the assessment of the distal portion of the extracranial internal carotid artery (ICA). We evaluated the ultrasonographic features of ICA occlusion using TOCU. METHODS: We studied 50 occluded ICAs in 42 stroke patients. The mechanism of ICA occlusion was embolic (group E) in 14 arteries and thrombotic (group T) in the other 36 arteries. We used a color flow imaging system equipped with special convex array transducers, and placed the probe on the postero-lateral pharyngeal wall to identify the distal extracranial ICA. We evaluated intraluminal echodensity (lucent or opaque) and measured the diameter of the ICA. Then, we examined the relationship of these early (<1 week after onset) and chronic (>4 weeks after onset) phase TOCU findings to the mechanism of ICA occlusion and the site of occlusion. RESULTS: In the early phase of a stroke, the intraluminal echodensity was more frequently lucent (9/11, 81.8%) in group E than in group T (5/20, 20%, p<0.05). In the chronic phase, echodensity became opaque in both groups. In the early phase, the lucent echodensity was more frequently seen in patients with distal occlusion than in those with proximal occlusion. Thus, it may represent blood or fresh thrombus formation. In patients with unilateral ICA occlusion, the occluded ICA was significantly smaller in diameter than the non-occluded contralateral artery both in the early and chronic phases. CONCLUSION: The echodensity and diameter of the extracranial ICA distal portion as found on TOCU can help to identify the mechanism of ICA occlusion.