Role of the autonomic nervous system in young, middle-aged, and older individuals with essential hypertension and sleep-related changes in neurocardiac regulation

Essential hypertension involves complex cardiovascular regulation. The autonomic nervous system function fluctuates throughout the sleep-wake cycle and changes with advancing age. However, the precise role of the autonomic nervous system in the development of hypertension during aging remains unclear. In this study, we characterized autonomic function during the sleep-wake cycle in different age groups with essential hypertension. This study included 97 men (53 with and 44 without hypertension) aged 30-79 years. They were stratified by age into young (< 40 years), middle-aged (40-59 years), and older (60-79 years) groups. Polysomnography and blood pressure data were recorded for 2 min before and during an hour-long nap. Autonomic function was assessed by measuring heart rate variability and blood pressure variability. Data were analyzed using t tests, correlation analyses, and two-way analysis of variance. During nonrapid eye movement (nREM), a main effect of age was observed on cardiac parasympathetic measures and baroreflex sensitivity (BRS), with the highest and lowest levels noted in the younger and older groups, respectively. The coefficients of the correlations between these measures and age were lower in patients with hypertension than in normotensive controls. The BRS of young patients with hypertension was similar to that of their middle-aged and older counterparts. However, cardiac sympathetic activity was significantly higher (p = 0.023) and BRS was significantly lower (p = 0.022) in the hypertension group than in the control group. During wakefulness, the results were similar although some of the above findings were absent. Autonomic imbalance, particularly impaired baroreflex, plays a more significant role in younger patients with hypertension. The nREM stage may be suitable for gaining insights into the relevant mechanisms.

2020 Guideline for Prehospital Management, Emergency Evaluation and Treatment of Patients With Acute Ischemic Stroke: A Guideline for Healthcare Professionals from the Taiwan Society of Emergency Medicine and Taiwan Stroke Society

To improve the clinical outcomes of patients with acute ischemic stroke, the public, pre-hospital care system, and hospitals should cooperate to achieve quick assessment and management for such patients and to start treatment as soon as possible. To reach the goal, the Consensus Group, including emergency physicians and neurologists in the Taiwan Society of Emergency Medicine and Taiwan Stroke Society, performed an updated review and discussion for the local guidelines. The guidelines consist of 12 parts, including public education program, evaluation and management in the emergency medical system, emergency medical system, assessment of stroke care capability of the hospital by independent parties, stroke team of the hospital, telemedicine, organization, and multifaceted integration, improvement of quality of care process of stroke system, initial clinical and imaging evaluations after arriving at the hospital, imaging evaluation for indications of intravenous thrombolysis, imaging evaluation for indications of endovascular thrombectomy, and other diagnostics. For detailed contents in Chinese, please refer to the Taiwan Stroke Society Guideline and Taiwan Emergency Medicine Bulletin.

Osthole ameliorates cartilage degradation by downregulation of NF-κB and HIF-2α pathways in an osteoarthritis murine model

Osteoarthritis (OA) is a common and disabling joint disease mainly characterized by cartilage degradation, with the knees most commonly affected. No effective treatment for the cartilage degradation of OA exists. Preliminary studies have revealed the protective and osteogenic effects of osthole, a natural coumarin first isolated from Cnidium monnieri (Fructus Cnidii); however, no evidence of osthole in an OA-related model has been published to date. This study further explored the effects of osthole in a monoiodoacetate (MIA)-induced OA-related animal model and focused on the molecular mechanism(s) behind the anti-inflammatory and cartilage protective effects of osthole. This study revealed that the cartilage protective effect of osthole in a MIA-induced osteoarthritis (OA) murine model can be explained by downregulation of COX-2 and RUNX2 by inhibition of NF-κB and HIF-2α up-regulated by OA induction, resulting in downregulation of MMP-13, Syndecan IV and ADAMTS-5. In addition, osthole might have anti-inflammatory and analgesic effects due to COX-2 inhibition. Osthole can be considered as a potential component of the treatment of OA, for it possesses a cartilage protective effect, as well as anti-inflammation, analgesic, and movement improving effects. Further preclinical and human clinical studies are needed to examine the efficacy and safety profile of long-term therapy.

Ergostatrien-7,9(11),22-trien-3β-ol from Antrodia camphorata ameliorates ischemic stroke brain injury via downregulation of p65NF-κ-B and caspase 3, and activation of Akt/GSK3/catenin-associated neurogenesis

Antrodia camphorata is a well-known traditional Chinese mushroom used as a functional food and nutraceutical in Taiwan and China. The aim of this study was to explore the protective effects and mechanism(s) of the ethyl acetate crude extract of A. camphorata (EtOAc-AC) and its active constituent ergostatrien-7,9(11),22-trien-3β-ol (EK100) in an acute ischemic stroke (AIS) murine model. Treating mice with induced AIS injury by using EtOAc-AC (0.3-0.6 g kg^-1, p.o.) and EK100 (60 and 120 mg kg^-1, p.o.) 2 h after AIS induction significantly increased the tracking distance and reduced brain infarction. Both EtOAc-AC and EK-100 reduced the expression levels of p65NF-κB and caspase 3 near the peri-infarct cortex and promoted the expression of neurogenesis-associated protein doublecortin (DCX) near the hippocampus, accompanied by glycogen synthase kinase 3 (GSK-3) inhibition and β-catenin upregulation. Signaling pathway analysis revealed that the advantageous effects of EtOAc-AC and EK-100 involved triggering the activation of PI3K/Akt and inhibition of GSK-3. Our findings suggest that EtOAc-AC and its active constituent EK100 display anti-inflammatory and anti-apoptotic activities. Both EtOAc-AC and EK100 reduce ischemic brain injury by decreasing p65NF-κB and caspase 3 expression, and they promote neurogenesis (DCX) and neuroprotection (Bcl2) by activating the PI3k/Akt-associated GSK3 inhibition and β-catenin activation.

Bleeding and New-Onset Cancers in Patients With Atrial Fibrillation Receiving Nonvitamin K Antagonist Oral Anticoagulants

Whether bleeding should be considered a sufficient sign to justify thorough cancer surveillance in atrial fibrillation (AF) patients receiving nonvitamin K antagonist oral anticoagulants (NOACs) remains unclear. We investigated the relationships between bleeding events and new-onset cancers in AF patients receiving NOACs in a prospective cohort (n = 395, mean follow-up duration of 2.8 years). There were 18 patients who were diagnosed with new-onset cancers 584 ± 372 days after the initiation of NOACs. The patients with new-onset cancers had higher HAS-BLED scores (no, preexisting and new-onset cancer: 1.51 ± 0.81, 1.69 ± 0.87, and 2.11 ± 0.96, respectively; p = 0.006) and a higher incidence of bleeding events (22%, 33%, 67%, respectively; p<0.001) than did patients without new-onset cancers. Bleeding events that preceded the diagnosis of new-onset cancers were independently correlated with new-onset cancers (odds ratio: 7.89, p = 0.001) in the multivariate logistic regression. More than half of the patients (61%) with new-onset cancers had either a significant period of drug interruption for at least 2 months or discontinued NOACs. In conclusions, bleeding in AF patients receiving NOACs could be an alerting sign of new-onset cancers and should prompt the initiation of thorough surveillance to detect early cancers.

Prevalence and clinical characteristics of stroke patients with p.R544C NOTCH3 mutation in Taiwan

Objective

Features of cerebral autosomal dominant arteriopathy with subcortical infarct and leukoencephalopathy (CADASIL) caused by NOTCH3 mutations vary between ethnicities and regions. In Taiwan, more than 70% of CADASIL patients carry the mutation hot spot of p.R544C. We investigated the prevalence of NOTCH3 p.R544C mutation in stroke patients in Taiwan.

Methods

This prospective, multicenter study recruited acute stroke patients within 10 days of symptom onset. The p.R544C mutation was identified by polymerase chain reaction with confronting two‐pair primers and sequencing. Clinical parameters, vascular risk factors, stroke subtypes, and stroke outcomes were analyzed.

Results

Of the 1970 stroke patients (mean age 61.1 ± 13.6 years, male 69.5%) included, 1705 (86.5%) had ischemic stroke and 265 (13.5%) had intracerebral hemorrhage. The prevalence of p.R544C in the study population was 2.8% (95% confidence interval [CI] = 2.1–3.5%). The prevalence was highest in patients with small vessel occlusion type of ischemic stroke (5.6%), followed by intracerebral hemorrhage (5.3%), and infarct of undetermined etiology (2.7%), and was low in patients with cardioembolism (0.8%) and large artery atherosclerosis (0.7%). All p.R544C patients with intracerebral hemorrhage were nonlobar hemorrhage. Sibling history of stroke (odds ratio [OR] = 4.50, 95% CI = 1.67–12.14 in ischemic stroke; OR = 6.03, 95% CI = 1.03–35.47 in intracerebral hemorrhage, respectively) and small vessel occlusion (OR, 4.03, 95% CI, 1.26–12.92) were significantly associated with p.R544C.

Interpretation

p.R544C NOTCH3 mutation is underdiagnosed in stroke patients in Taiwan, especially in those with small vessel occlusion and sibling history of stroke.

GSK-3 inhibition through GLP-1R allosteric activation mediates the neurogenesis promoting effect of P7C3 after cerebral ischemic/reperfusional injury in mice

An aminopropyl carbazole compound, P7C3, has been shown to be a potent neurogenesis promoting agent; however, its fundamental signaling action has yet to be elucidated. A cerebral ischemic/reperfusional (CI/R) injury model in mice was implemented to elucidate the neuronal protective mechanism(s) of P7C3. Treating CI/R mice using P7C3 (50-100 μg/kg, i.v.) significantly improved tracking distance and walking behavior, and reduced brain damage. Specifically, P7C3 promoted the expression of neurogenesis-associated proteins, including doublecortin, beta tubulin III (β-tub3), adam11 and adamts20, near the peri-infarct cortex, accompanied by glycogen synthase kinase 3 (GSK-3) inhibition and β-catenin upregulation. The application of a specific inhibitor against glucagon-like peptide 1 receptor (GLP-1R), exendin(9-39), revealed that the beneficial effects of P7C3 involved triggering the activation of GLP-1R-associated PKA/Akt signaling. P7C3 elicited the GLP-1R-dependent intracellular cAMP increment and the insulin secretion in cellular models. Surface plasmon resonance assay of P7C3 showed a Kd value of 0.53 μM for GLP-1R binding, and the docking of P7C3 to the putative active site on GLP-1R was successfully predicted by molecular modeling. Our findings indicate that P7C3 promotes the expression of neurogenesis proteins by activation of the cAMP/PKA-dependent and Akt/GSK3-associated β-catenin through positive allosteric stimulation of GLP-1R. Within the P7C3 class of neuroprotective molecules, this mechanism appears to be unique to the prototypical P7C3 molecule, as other active derivatives such as P7C2-A20 and P7C3-S243 they do not engage this same pathway and have been shown to work by nicotinamide phosphoribosyltransferase (NAMPT) stimulation.

Intake of potassium- and magnesium-enriched salt improves functional outcome after stroke: a randomized, multicenter, double-blind controlled trial

Background: Stroke is one of the leading causes of mortality and neurologic deficits. Management measures to improve neurologic outcomes are in great need. Our previous intervention trial in elderly subjects successfully used salt as a carrier for potassium, demonstrating a 41% reduction in cardiovascular mortality by switching to potassium-enriched salt. Dietary magnesium has been associated with lowered diabetes and/or stroke risk in humans and with neuroprotection in animals.Objective: Because a large proportion of Taiwanese individuals are in marginal deficiency states for potassium and for magnesium and salt is a good carrier for minerals, it is justifiable to study whether further enriching salt with magnesium at an amount near the Dietary Reference Intake (DRI) amount may provide additional benefit for stroke recovery.Design: This was a double-blind, randomized controlled trial comprising 291 discharged stroke patients with modified Rankin scale (mRS) ≤4. There were 3 arms: 1) regular salt (Na salt) (n = 99), 2) potassium-enriched salt (K salt) (n = 97), and 3) potassium- and magnesium-enriched salt (K/Mg salt) (n = 95). The NIH Stroke Scale (NIHSS), Barthel Index (BI), and mRS were evaluated at discharge, at 3 mo, and at 6 mo. A good neurologic performance was defined by NIHSS = 0, BI = 100, and mRS ≤1.Results: After the 6-mo intervention, the proportion of patients with good neurologic performance increased in a greater magnitude in the K/Mg salt group than in the K salt group and the Na salt group, in that order. The K/Mg salt group had a significantly increased OR (2.25; 95% CI: 1.09, 4.67) of achieving good neurologic performance compared with the Na salt group. But the effect of K salt alone (OR: 1.58; 95% CI: 0.77, 3.22) was not significant.Conclusions: This study suggests that providing the DRI amount of magnesium and potassium together long term is beneficial for stroke patient recovery from neurologic deficits. This trial was registered at clinicaltrials.gov as NCT02910427.

Salvianolic acid A alleviates ischemic brain injury through the inhibition of inflammation and apoptosis and the promotion of neurogenesis in mice

Salvianolic acid A (SalA), a chemical type of caffeic acid trimer, has drawn great attention for its potent bioactivities against ischemia-induced injury both in vitro and in vivo. In this study, we evaluated SalA's protective effects against acute ischemic stroke by inducing middle cerebral artery occlusion/reperfusion (MCAO) injuries in mice. Treatment of the mice with SalA (50 and 100μg/kg, i.v.) at 2h after MCAO enhanced their survival rate, improved their moving activity, and ameliorated the severity of brain infarction and apoptosis seen in the mice by diminishing pathological changes such as the extensive breakdown of the blood-brain barrier (BBB), nitrosative stress, and the activation of an inflammatory transcriptional factor p65 nuclear factor-kappa B (NF-κB) and a pro-apoptotic kinase p25/Cdk5. SalA also intensively limited cortical infarction and promoted the expression of neurogenesis protein near the peri-infarct cortex and subgranular zone of the hippocampal dentate gyrus by compromising the activation of GSK3β and p25/Cdk5, which in turn upregulated β-catenin, doublecortin (DCX), and Bcl-2, most possibly through the activation of PI3K/Akt signaling via the upregulation of brain-derived neurotrophic factor. We conclude that SalA blocks inflammatory responses by impairing NF-κB signaling, thereby limiting inflammation/nitrosative stress and preserving the integrity of the BBB; SalA also concomitantly promotes neurogenesis-related protein expression by compromising GSK3β/Cdk5 activity to enhance the expression levels of β-catenin/DCX and Bcl-2 for neuroprotection.

Quality Improvement in Acute Ischemic Stroke Care in Taiwan: The Breakthrough Collaborative in Stroke

In the management of acute ischemic stroke, guideline adherence is often suboptimal, particularly for intravenous thrombolysis or anticoagulation for atrial fibrillation. We sought to improve stroke care quality via a collaborative model, the Breakthrough Series (BTS)-Stroke activity, in a nationwide, multi-center activity in Taiwan. A BTS Collaborative, a short-term learning system for a large number of multidisciplinary teams from hospitals, was applied to enhance acute ischemic stroke care quality. Twenty-four hospitals participated in and submitted data for this stroke quality improvement campaign in 2010–2011. Totally, 14 stroke quality measures, adopted from the Get With The Guideline (GWTG)-Stroke program, were used to evaluate the performance and outcome of the ischemic stroke patients. Data for a one-year period from 24 hospitals with 13,181 acute ischemic stroke patients were analyzed. In 14 hospitals, most stroke quality measures improved significantly during the BTS-activity compared with a pre-BTS-Stroke activity period (2006–08). The rate of intravenous thrombolysis increased from 1.2% to 4.6%, door-to-needle time ≤60 minutes improved from 7.1% to 50.8%, symptomatic hemorrhage after intravenous thrombolysis decreased from 11.0% to 5.6%, and anticoagulation therapy for atrial fibrillation increased from 32.1% to 64.1%. The yearly composite measures of five stroke quality measures revealed significant improvements from 2006 to 2011 (75% to 86.3%, p<0.001). The quarterly composite measures also improved significantly during the BTS-Stroke activity. In conclusion, a BTS collaborative model is associated with improved guideline adherence for patients with acute ischemic stroke. GWTG-Stroke recommendations can be successfully applied in countries besides the United States.

Validation of NINDS-VCI Neuropsychology Protocols for Vascular Cognitive Impairment in Taiwan

Objective

To validate the three time-difference neuropsychological protocols developed by the National Institute of Health/National Institute of Neurological Disorders and Stroke (NINDS) and the Canadian Stroke Network for assessment of vascular cognitive impairment (VCI) in Mandarin-speaking subjects and to investigate the clinical application of the shortest form.

Methods

Patients aged 50 years or older who had a stroke were invited to participate in the study. Clinical diagnosis of VCI was made. The NINDS-VCI Neuropsychology Protocols, 60-, 30-, and two 5-minute protocols, were administered. The criteria validities of the cognitive protocols against the diagnoses of stroke and VCI were determined via Receiver Operating Characteristic (ROC) analysis. The optimal cut-off point for the 5-minute protocols total score was estimated for clinical use in screening.

Results

Eighty-three patients and 53 controls were recruited during the study period. Patients with stroke performed more poorly than the control group in the three neuropsychological protocols. Forty-two patients with stroke were diagnosed with VCI. VCI was used as the standard to estimate the criteria validities. The area under the ROC curve was 0.78, 0.80, 0.75, and 0.73 for the 60-, 30-, 5-mintue protocol-A and 5-minute protocol-B, respectively.

Conclusion

These modified neuropsychological protocols can be used as valid instruments when performing comprehensive cognitive assessment or for screening of VCI in Taiwan.

Sympathetic Hyperactivity, Sleep Fragmentation, and Wake-Related Blood Pressure Surge During Late-Light Sleep in Spontaneously Hypertensive Rats

BACKGROUND

Many cardiovascular disease events occur before morning awaking and are more severe in hypertensive patients. Sleep-related cardiovascular regulation has been suggested to play an important role in the pathogenesis. In this study, we explored whether such impairments are exaggerated during late sleep (before the active phase) in spontaneously hypertensive rats (SHRs).

METHODS

Polysomnographic recording was performed through wireless transmission in freely moving SHRs and Wistar-Kyoto rats (WKYs) over 24 hours. The SHRs were injected with saline and an α1-adrenergic antagonist (prazosin: 5 mg/kg) on 2 separate days. Cardiovascular and autonomic functions were assessed by cardiovascular variability and spontaneous baroreflex analysis.

RESULTS

Compared with the early-light period (Zeitgeber time (ZT) 0-6 hours), both the WKYs and SHRs during the late-light period (ZT 6-12 hours) showed sleep fragmentation, sympathovagal imbalance, and baroreflex impairment, which were exaggerated and more advanced in the SHRs. Like the morning blood pressure (BP) surge in humans, we found that there was a wake-related blood pressure surge (WBPS) during the late-light period in both groups of rats. The WBPS was also greater and occurred earlier in the SHRs, and was accompanied by a surge in vascular sympathetic index. Under α1-adrenergic antagonism, the late-light period-related sleep fragmentation and BP surge in the SHRs were partially reversed.

CONCLUSIONS

Our results reveal that sleep-related sympathetic overactivity, baroreflex sensitivity impairment, WBPS, and sleep fragmentation in SHRs deteriorates during the late-light period can be partially alleviated by treatment with an α1-adrenoceptor antagonist.

Cold Exposure Can Induce an Exaggerated Early-Morning Blood Pressure Surge in Young Prehypertensives

Prehypertension is related to a higher risk of cardiovascular events than normotension. Our previous study reported that cold exposure elevates the amplitude of the morning blood pressure surge (MBPS) and is associated with a sympathetic increase during the final sleep transition, which might be critical for sleep-related cardiovascular events in normotensives. However, few studies have explored the effects of cold exposure on autonomic function during sleep transitions and changes of autonomic function among prehypertensives. Therefore, we conducted an experiment for testing the effects of cold exposure on changes of autonomic function during sleep and the MBPS among young prehypertensives are more exaggerate than among young normotensives. The study groups consisted of 12 normotensive and 12 prehypertensive male adults with mean ages of 23.67 ± 0.70 and 25.25 ± 0.76 years, respectively. The subjects underwent cold (16°C) and warm (23°C) conditions randomly. The room temperature was maintained at either 23°C or 16°C by central air conditioning and recorded by a heat-sensitive sensor placed on the forehead and extended into the air. BP was measured every 30 minutes by using an autonomic BP monitor. Electroencephalograms, electrooculograms, electromyograms, electrocardiograms, and near body temperature were recorded by miniature polysomnography. Under cold exposure, a significantly higher amplitude of MBPS than under the warm condition among normotensives; however, this change was more exaggerated in prehypertensives. Furthermore, there was a significant decrease in parasympathetic-related RR and HF during the final sleep transition and a higher early-morning surge in BP and in LF% among prehypertensives, but no such change was found in normotensives. Our study supports that cold exposure might increase the risk of sleep-related cardiovascular events in prehypertensives.

A clinical study of integrating acupuncture and Western medicine in treating patients with Parkinson's disease

Complementary therapy with acupuncture for Parkinson's disease (PD) has been studied for quite a long time, but the effectiveness of the treatment still remains unclear. The aim of this study is to evaluate the integrated effects of acupuncture treatment in PD patients who received western medicine. In the short-term acupuncture treatment study, 20 patients received acupuncture therapy twice a week in acupoints DU 20, GB 20, LI 11, LI 10, LI 4, GB 31, ST 32, GB 34 and GB 38 along with western medicine for 18 weeks, and 20 controlled patients received western medicine only. In the long-term acupuncture treatment, 13 patients received acupuncture treatment twice a week for 36 weeks. The outcome parameters include Unified Parkinson's disease rating scale (UPDRS), Beck Anxiety Inventory (BAI), Beck Depression Inventory-Version 2 (BDI-II), and WHO quality of life (WHOQOL). In the short-term clinical trial, a higher percentage of patients in the acupuncture group had score improvement in UPDRS total scores (55% vs. 15%, p = 0.019), sub-score of mind, behavior and mood (85% vs. 25%, p < 0.001), activity of daily living (65% vs. 15%, p = 0.003), mobility (40% vs. 15%, p = 0.155) and complication of treatment (75% vs. 15%, p < 0.001), BDI-II score (85% vs. 35%, p = 0.003), and WHOQOL score (65% vs. 15%, p = 0.003) when compared to control group at the end of the 18 weeks' follow up. After 36 weeks of long-term acupuncture treatment, the mean UPDRS total scores and sub-score of mentation, behavior and mood, sub-score of complications of therapy and BDI-II score decreased significantly when compared to the pretreatment baseline. In conclusion, acupuncture treatment had integrated effects in reducing symptoms and signs of mind, behavior, mood, complications of therapy and depression in PD patients who received Western medicine.

Differential changes and interactions of autonomic functioning and sleep architecture before and after 50 years of age

We hypothesize that the time when age-related changes in autonomic functioning and in sleep structure occur are different and that autonomic functioning modulates sleep architecture differently before and after 50 years of age. Sixty-eight healthy subjects (aged 20 to 79 years old, 49 of them women) were enrolled. Correlation analysis revealed that wake after sleep onset, the absolute and relative value of stage 1 (S1; S1%), and relative value of stage 2 (S2) were positively correlated with age; however, sleep efficiency, stage 3 (S3), S3%, and rapid-eye-movement latency (REML) were negatively correlated with age. Significant degenerations of sleep during normal aging were occurred after 50 years of age; however, significant declines of autonomic activity were showed before 50 years of age. Before 50 years of age, vagal function during sleep was negatively correlated with arousal index; however, after 50 years of age, it was positively correlated with S1 and S1%. In addition, sympathetic activity during wake stage was positively related to S2% only after 50 years of age. Our results imply that the age-related changes in autonomic functioning decline promptly as individuals leave the younger part of their adult life span and that age-related changes in sleep slowly develop as individuals enter the older part of their adult life span. Furthermore, while various aspects of sleep architecture are modulated by both the sympathetic and vagal nervous systems during adult life span, the sleep quality is mainly correlated with the sympathetic division after 50 years of age.

Characterization of CADASIL among the Han Chinese in Taiwan: Distinct Genotypic and Phenotypic Profiles

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is originally featured with a strong clustering of mutations in NOTCH3 exons 3–6 and leukoencephalopathy with frequent anterior temporal pole involvement. The present study aims at characterizing the genotypic and phenotypic profiles of CADASIL in Taiwan. One hundred and twelve patients with CADASIL from 95 families of Chinese descents in Taiwan were identified by Sanger sequencing of exons 2 to 24 of NOTCH3. Twenty different mutations in NOTCH3 were uncovered, including 3 novel ones, and R544C in exon 11 was the most common mutation, accounting for 70.5% of the pedigrees. Haplotype analyses were conducted in 14 families harboring NOTCH3 R544C mutation and demonstrated a common haplotype linked to NOTCH3 R544C at loci D19S929 and D19S411. Comparing with CADASIL in most Caucasian populations, CADASIL in Taiwan has several distinct features, including less frequent anterior temporal involvement, older age at symptom onset, higher incidence of intracerebral hemorrhage, and rarer occurrence of migraine. Subgroup analyses revealed that the R544C mutation is associated with lower frequency of anterior temporal involvement, later age at onset and higher frequency of cognitive dysfunction. In conclusion, the present study broadens the spectrum of NOTCH3 mutations and provides additional insights for the clinical and molecular characteristics of CADASIL patients of Han-Chinese descents.

The efficacy and safety of cilostazol in ischemic stroke patients with peripheral arterial disease (SPAD): protocol of a randomized, double-blind, placebo-controlled multicenter trial

RATIONALE

It is not uncommon for patients with ischemic stroke to have peripheral arterial disease (PAD). Patients with polyvascular diseases carry greater burden of atherosclerosis and higher risks of developing vascular events and death. More effective regimens, such as dual antiplatelet agents, may be more effective for controlling progression of atherosclerosis in secondary prevention.

AIM

This study aims to evaluate whether cilostazol plus aspirin is more efficacious than aspirin alone for preventing progression of atherosclerosis in patients with ischemic stroke or transient ischemic attack (TIA) who also have peripheral arterial disease.

DESIGN

The Safety and Efficacy of Cilostazol in Ischemic Stroke Patients with Peripheral Arterial Disease (SPAD) study is a randomized double-blinded placebo-controlled trial. Patients with previous ischemic stroke or TIA who had been taking aspirin (100 mg per day), aged 50 years or older, with PAD in the lower limbs based on ankle-brachial index (ABI) <1·0 will be randomized into the treatment group with cilostazol (200 mg/day) or the placebo group on 1:1 basis.

STUDY OUTCOMES

Patients will be evaluated at 1, 3, 6, 9 and 12 months after randomization. The primary endpoint is difference in change in ABI between groups. The secondary and tertiary endpoints are the difference between groups in change in carotid intima-media thickness (IMT) and incidence rate of major cardiovascular events, including recurrent stroke, myocardial infarction, unstable angina, other vascular events, and death; and the safety measures, including major bleeding events, hemorrhagic stroke and death of any cause.

CONCLUSION

The SPAD trial is the first study to evaluate the safety and efficacy of dual antiplatelet agents, aspirin plus cilostazol, in comparison with aspirin alone in patients with both ischemic stroke or TIA and PAD. Results from this trial will provide important information on the merit of adding cilostazol to aspirin for slowing down progression of atherosclerosis in patients with ischemic stroke and PAD.

Impact of carotid stenting in dizzy patients with carotid stenosis

BACKGROUND

Little is known about the impact of severe carotid stenosis on health-related quality of life (HRQoL). The aim of this study was to assess the effects of carotid stenting (CAS) on HRQoL in dizzy patients with carotid stenosis.

METHODS

Patients with symptomatic (≥60%) or asymptomatic (≥80%) severe carotid stenosis and who complained of dizziness and received CAS were recruited. Two HRQoL questionnaires-a generic survey, the 36-item Short-Form Health Survey and a disease-specific instrument, the Dizziness Handicap Inventory-served as outcome measures. Patients were followed 1 week prior to CAS and 6 months postprocedurally.

RESULTS

CAS was performed in 178 consecutive patients, 61 of whom complained of dizziness. Forty-one patients (67.2%, 34 male; mean age, 73.3 ± 10.5 years; range, 47-87 years) completed the study. Twenty asymptomatic volunteers (17 male; mean age, 70.3 ± 9.3 years; range, 54-84 years) served as normal controls. Compared to controls, patients tallied lower scores in the overall total and three subscales (physical, functional, and emotional) of the Dizziness Handicap Inventory (p < 0.01). Similar findings were noted in seven out of eight domains of the 36-item Short-Form Health Survey score. After 6 months, CAS resulted in significantly improved HRQoL (role physical, bodily pain, general health, social function, and role emotional) in these patients.

CONCLUSION

CAS resulted in improved HRQoL in patients with severe carotid stenosis who experienced dizziness.

Unique mechanisms of sheng yu decoction ( shèng yù tang) on ischemic stroke mice revealed by an integrated neurofunctional and transcriptome analysis

Sheng Yu Decoction ( Shèng Yù Tang; SYD) is a popular traditional Chinese medicine (TCM) remedy used in treating cardiovascular and brain-related dysfunction clinically; yet, its neuroprotective mechanisms are still unclear. Here, mice were subjected to an acute ischemic stroke to examine the efficacy and mechanisms of action of SYD by an integrated neurofunctional and transcriptome analysis. More than 80% of the mice died within 2 days after ischemic stroke with vehicle treatment. Treatments with SYD (1.0 g/kg, twice daily, orally or p.o.) and recombinant thrombolytic tissue plasminogen activator (rt-PA; 10 mg/kg, once daily, intravenously or i.v.) both significantly extended the lifespan as compared to that of the vehicle-treated stroke group. SYD successfully restored brain function, ameliorated cerebral infarction and oxidative stress, and significantly improved neurological deficits in mice with stroke. Molecular impact of SYD by a genome-wide transcriptome analysis using brains from stroke mice showed a total of 162 out of 2081 ischemia-induced probe sets were significantly influenced by SYD. Mining the functional modules and genetic networks of these 162 genes revealed a significant upregulation of neuroprotective genes in Wnt receptor signaling pathway (3 genes) and regulation of cell communication (7 genes) and downregulation of destructive genes in response to stress (13 genes) and in the induction of inflammation (5 genes), cytokine production (4 genes), angiogenesis (3 genes), vasculature (6 genes) and blood vessel (5 genes) development, wound healing (7 genes), defense response (7 genes), chemotaxis (4 genes), immune response (7 genes), antigen processing and presenting (3 genes), and leukocyte-mediated cytotoxicity (2 genes) by SYD. Our results suggest that SYD could protect mice against ischemic stroke primarily through significantly downregulating the damaging genes involved in stress, inflammation, angiogenesis, blood vessel formation, immune responses, and wound healing, as well as upregulating the genes mediating neurogenesis and cell communication, which make SYD beneficial for treating ischemic stroke.

RBC volume deficiency in patients with excessive orthostatic decrease in cerebral blood flow velocity

BACKGROUND

Orthostatic intolerance (OI) is common but heterogeneous. There is a subgroup of OI patients who have excessive decrease in cerebral blood flow velocity (CBFV) of bilateral middle cerebral arteries (MCAs) during head-up tilt without systemic blood pressure change. This study evaluated the role of blood volume reduction in such patients.

METHODS

Patients with idiopathic OI who had excessive orthostatic decrease (>20% of the supine level) in mean CBFV of bilateral MCAs and who also received blood volume determination were collected. The chromium (⁵¹Cr) dilution method was used for red blood cell (RBC) volume determination in these patients. The blood volume was expressed as a percentage of the expected volume. These patients were further divided into two groups, those with postural tachycardia syndrome (POTS group) and those without (non-POTS group). The data of RBC volume were compared between the two groups. Besides, we used multivariate linear regression to evaluate the factors that predict RBC volume.

RESULTS

Twenty-five patients (13 females, median age = 28 years) were enrolled in this study. Nine of these patients had POTS (5 females, median age = 26 years) and 16 did not (8 females, median age = 29.5 years). Compared with the expected volume, the RBC volume was significantly reduced in all patients (median = 82% of the expected volume). Moreover, the RBC volume was significantly lower in the POTS group than that in the non-POTS group (78% vs. 85% of the expected volume, p = 0.013). The orthostatic decrease of MCA flow velocity was 28.3% in the POTS group and 32.5% in the non-POTS group (p = 0.140). The orthostatic pulsatility index increment was 15.4% in the POTS group and 20.5% in the non-POTS group (p = 0.438). Moreover, basic demography and hemoglobin levels were not different between the two groups. After multivariate linear regression (dependent variables including age, sex, body surface, and groups), only the presence of POTS significantly predicted the RBC volume (p = 0.006).

CONCLUSION

The results of our study indicated that low RBC volume may play an important role in the pathophysiology of OI in this group of patients. Moreover, its role seems even more relevant in patients with POTS than in those without. Further studies for mechanistic evaluation are needed in the future.

Connectivity features for identifying cognitive impairment in presymptomatic carotid stenosis

Severe asymptomatic stenosis of the internal carotid artery (ICA) leads to increased incidence of mild cognitive impairment (MCI) likely through silent embolic infarcts and/or chronic hypoperfusion, but the brain dysfunction is poorly understood and difficult to diagnose. Thirty cognitively intact subjects with asymptomatic, severe (≧70%), unilateral stenosis of the ICA were compared with 30 healthy controls, matched for age, sex, cardiovascular risk factors and education level, on a battery of neuropsychiatric tests, voxel-based morphometry of magnetic resonance imaging (MRI), diffusion tensor imaging and brain-wise, seed-based analysis of resting-state functional MRI. Multivariate regression models and multivariate pattern classification (support vector machines) were computed to assess the relationship between connectivity measures and neurocognitive performance. The patients had worse dizziness scores and poorer verbal memory, executive function and complex visuo-spatial performance than controls. Twelve out of the 30 patients (40%) were considered to have MCI. Nonetheless, the leukoaraiosis Sheltens scores, hippocampal and brain volumes were not different between groups. Their whole-brain mean fractional anisotropy (FA) was significantly reduced and regional functional connectivity (Fc) was significantly impaired in the dorsal attention network (DAN), frontoparietal network, sensorimotor network and default mode network. In particular, the Fc strength at the insula of the DAN and the mean FA were linearly related with attention performance and dizziness severity, respectively. The multivariate pattern classification gave over 90% predictive accuracy of individuals with MCI or severe dizziness. Cognitive decline in stroke-free individuals with severe carotid stenosis may arise from nonselective widespread disconnections of long-range, predominantly interhemispheric non-hippocampal pathways. Connectivity measures may serve as both predictors for cases at risk and therapeutic targets for mitigating vascular cognitive impairment.

Abstract WP372: Quality Improvement in Acute Ischemic Stroke Care in Taiwan: the Breakthrough Collaborative in Stroke

Background and Purpose: Guideline adherence for acute ischemic stroke (AIS) management is often suboptimal, particularly in thrombolytic therapy and anticoagulants for atrial fibrillation. We sought to achieve quality improvement of AIS patients via a collaborative learning model, the Breakthrough Series (BTS)-Stroke, in a nationwide, multi-center activity in Taiwan.

Methods: A BTS Collaborative, a short-term learning system for a large number of multidisciplinary teams from hospitals, was applied to enhance AIS care quality. There were 24 teaching and community hospitals participating in and submitting data for this stroke quality improvement campaign from August 2010 to June 2011. The Get With The Guideline (GWTG)-Stroke measures were adopted to evaluate the performance and outcome of the AIS patients. The results of this study were compared to those of the previous Taiwan Stroke Registry (TSR, 22642 AIS patients from 39 hospitals, 2006-08).

Results: Data from 24 hospitals with 13181 AIS patients during a 1-year period were analyzed. The BTS-Stroke (2010-11) had better performance as compared to the TSR (2006-08): intravenous thrombolysis frequency for all AIS patients (4.1% vs 1.5%), symptomatic hemorrhage after intravenous thrombolysis (6.0% vs 8.2%), early antithrombotics (96.6% vs 94.1%), anticoagulation for atrial fibrillation (57.1% vs 28.3%), lipid lowering drugs for low-density lipoprotein >100 mg/dL (63.4% vs 38.7%), antithrombotics at discharge (94.0% vs 85.5%), and one-month mortality (3.5% vs 4.0%). Temporal improvement was noted in 7 of 14 performance measures when the fourth BTS-Stroke quarter compared with the first quarter: intravenous thrombolysis frequency for all AIS patients (4.1% vs 3.7%), symptomatic hemorrhage after intravenous thrombolysis (3.4% vs 5.5%), lipid lowering drugs for low-density lipoprotein >100 mg/dL (67.3% vs 60.5%), antithrombotics at discharge (95.5% vs 91.4%), dysphagia screening (81.9% vs 63.4%), early rehabilitation (71.7% vs 63.6%), stroke education before discharge (95.6% vs 83.4%).

Conclusions: A BTS collaborative learning and campaign model can improve the guideline adherence of stroke. The GWTG-Stroke can be successfully applied to other countries outside the United States.

Epistasis analysis for estrogen metabolic and signaling pathway genes on young ischemic stroke patients

Background

Endogenous estrogens play an important role in the overall cardiocirculatory system. However, there are no studies exploring the hormone metabolism and signaling pathway genes together on ischemic stroke, including sulfotransferase family 1E (SULT1E1), catechol-O-methyl-transferase (COMT), and estrogen receptor α (ESR1).

Methods

A case-control study was conducted on 305 young ischemic stroke subjects aged ≦ 50 years and 309 age-matched healthy controls. SULT1E1 -64G/A, COMT Val158Met, ESR1 c.454−397 T/C and c.454−351 A/G genes were genotyped and compared between cases and controls to identify single nucleotide polymorphisms associated with ischemic stroke susceptibility. Gene-gene interaction effects were analyzed using entropy-based multifactor dimensionality reduction (MDR), classification and regression tree (CART), and traditional multiple regression models.

Results

COMT Val158Met polymorphism showed a significant association with susceptibility of young ischemic stroke among females. There was a two-way interaction between SULT1E1 -64G/A and COMT Val158Met in both MDR and CART analysis. The logistic regression model also showed there was a significant interaction effect between SULT1E1 -64G/A and COMT Val158Met on ischemic stroke of the young (P for interaction = 0.0171). We further found that lower estradiol level could increase the risk of young ischemic stroke for those who carry either SULT1E1 or COMT risk genotypes, showing a significant interaction effect (P for interaction = 0.0174).

Conclusions

Our findings support that a significant epistasis effect exists among estrogen metabolic and signaling pathway genes and gene-environment interactions on young ischemic stroke subjects.

Melatonin ameliorates neural function by promoting endogenous neurogenesis through the MT2 melatonin receptor in ischemic-stroke mice

Melatonin has many protective effects against ischemic stroke, but the underlying neuroprotective mechanisms are not fully understood. Our aim was to explore the relationship between melatonin's neuroprotective effects and activation of the MT2 melatonin receptor in a murine ischemic-stroke model. Male ICR mice were subjected to a transient middle cerebral ischemic/reperfusional injury, and melatonin (5 and 10 mg/kg, ip) was administrated once daily starting 2 h after ischemia. More than 80% of the mice died within 5 days after stroke without treatment. Melatonin treatment significantly improved the survival rates and neural functioning with modestly prolonged life span of the stroke mice by preserving blood-brain barrier (BBB) integrity via a reduction in the enormous amount of stroke-induced free radical production and significant gp91(phox) cell infiltration. These protective effects of melatonin were reversed by pretreatment with MT2 melatonin receptor antagonists (4-phenyl-2-propionamidotetralin (4P-PDOT) and luzindole). Moreover, treatment with melatonin after stroke dramatically enhanced endogenous neurogenesis (doublecortin positive) and cell proliferation (ki67 positive) in the peri-infarct regions. Most ki67-positive cells were nestin-positive and NG2-positive neural stem/progenitor cells that coexpressed two neurodevelopmental proteins (adam11 and adamts20) and the MT2 melatonin receptor. RT-PCR revealed that the gene expression levels of doublecortin, ki67, adamts20, and adam11 are markedly reduced by stroke, but are restored by melatonin treatment; furthermore, pretreatment with 4P-PDOT and luzindole antagonized melatonin's restorative effect. Our results support the hypothesis that melatonin is able to protect mice against stroke by activating MT2 melatonin receptors, which reduces oxidative/inflammatory stress. This results in the preservation of BBB integrity and enhances endogenous neurogenesis by upregulating neurodevelopmental gene/protein expression.

Neuroprotection effects of retained acupuncture in neurotoxin-induced Parkinson's disease mice

The aim of this study was to investigate the role of retained acupuncture (RA) in neurotoxin-induced Parkinson's disease (PD) mice. Male C57BL/6 mice were injected with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to induce the PD model. The mice were divided into four groups, namely, (1) normal; (2) MPTP+retained acupuncture (RA); (3) MPTP+electroacupuncture (EA); (4) MPTP+sham acupuncture (SA). After mice being manipulated with/without acupuncture at acupoints (Daling, PC 7), groups 2-4 were injected with MPTP (15 mg/kg/d). The mice were evaluated for behavioral changes, in terms of time of landing, after acupuncture treatment. The animals were sacrificed and their brains assayed for dopamine and its metabolites and tyrosine hydroxylase (TH) expression by using HPLC and immunohistochemistry/Western blotting, respectively. [(123)I] IBZM-SPECT imaging between SA and RA groups were compared. The results showed that the time of landing of the three groups with treatment was significant longer than group 1 (normal) (4.33±0.15 s). Nonetheless, group 2 (RA) (7.13±0.20 s) had a shorter time of landing than group 4 (SA) (7.89±0.46 s). The number of TH (+) neurons and the expression of TH proteins were significantly higher in the RA group than in the SA/EA groups. RA also increased the uptake of [(123)I] IBZM into the triatum compared to the SA group. We conclude that RA possibly attenuates neuronal damage in MPTP-induced PD mice, which suggests RA may be useful as a complementary strategy when treating human PD.

Andrographolide inhibits PI3K/AKT-dependent NOX2 and iNOS expression protecting mice against hypoxia/ischemia-induced oxidative brain injury

This study aimed to explore the mechanisms by which andrographolide protects against hypoxia-induced oxidative/nitrosative brain injury provoked by cerebral ischemic/reperfusion (CI/R) injury in mice. Hypoxia IN VITRO was modeled using oxygen-glucose deprivation (OGD) followed by reoxygenation of BV-2 microglial cells. Our results showed that treatment of mice that have undergone CI/R injury with andrographolide (10-100 µg/kg, i. v.) at 1 h after hypoxia ameliorated CI/R-induced oxidative/nitrosative stress, brain infarction, and neurological deficits in the mice, and enhanced their survival rate. CI/R induced a remarkable production in the mouse brains of reactive oxygen species (ROS) and a significant increase in protein nitrosylation; this primarily resulted from enhanced expression of NADPH oxidase 2 (NOX2), inducible nitric oxide synthase (iNOS), and the infiltration of CD11b cells due to activation of nuclear factor-kappa B (NF- κB) and hypoxia-inducible factor 1-alpha (HIF-1 α). All these changes were significantly diminished by andrographolide. In BV-2 cells, OGD induced ROS and nitric oxide production by upregulating NOX2 and iNOS via the phosphatidylinositol-3-kinase (PI3K)/AKT-dependent NF- κB and HIF-1 α pathways, and these changes were suppressed by andrographolide and LY294002. Our results indicate that andrographolide reduces NOX2 and iNOS expression possibly by impairing PI3K/AKT-dependent NF- κB and HIF-1 α activation. This compromises microglial activation, which then, in turn, mediates andrographolide's protective effect in the CI/R mice.

Prodigiosin inhibits gp91(phox) and iNOS expression to protect mice against the oxidative/nitrosative brain injury induced by hypoxia-ischemia

This study aimed to explore the mechanisms by which prodigiosin protects against hypoxia-induced oxidative/nitrosative brain injury induced by middle cerebral artery occlusion/reperfusion (MCAo/r) injury in mice. Hypoxia in vitro was modeled using oxygen-glucose deprivation (OGD) followed by reoxygenation of BV-2 microglial cells. Our results showed that treatment of mice that have undergone MCAo/r injury with prodigiosin (10 and 100μg/kg, i.v.) at 1h after hypoxia ameliorated MCAo/r-induced oxidative/nitrosative stress, brain infarction, and neurological deficits in the mice, and enhanced their survival rate. MCAo/r induced a remarkable production in the mouse brains of reactive oxygen species (ROS) and a significant increase in protein nitrosylation; this primarily resulted from enhanced expression of NADPH oxidase 2 (gp91(phox)), inducible nitric oxide synthase (iNOS), and the infiltration of CD11b leukocytes due to breakdown of blood-brain barrier (BBB) by activation of nuclear factor-kappa B (NF-κB). All these changes were significantly diminished by prodigiosin. In BV-2 cells, OGD induced ROS and nitric oxide production by up-regulating gp91(phox) and iNOS via activation of the NF-κB pathway, and these changes were suppressed by prodigiosin. In conclusion, our results indicate that prodigiosin reduces gp91(phox) and iNOS expression possibly by impairing NF-κB activation. This compromises the activation of microglial and/or inflammatory cells, which then, in turn, mediates prodigiosin's protective effect in the MCAo/r mice.

Contribution of intracranial vertebral artery asymmetry to vestibular neuropathy

OBJECTIVES

To test the hypothesis that vertebral artery hypoplasia (VAH) may affect the lateralisation of vestibular neuropathy (VN), probably through haemodynamic effect on the vestibular labyrinth.

METHODS

69 patients with unilateral VN were examined with a magnetic resonance angiographic (MRA) and caloric test. 50 healthy subjects served as controls. The diagnosis of intracranial VAH was based on MRA if <0.22 cm in VA diameter and a diameter asymmetry index >40%. The authors then correlated the canal paretic side with the VAH side.

RESULTS

MRA study revealed 29 VAH (right/left: 23/6) in VN subjects and six VAH in controls (right/left: 5/1). The RR of VAH in VN subjects compared with controls was elevated (RR=2.2; 95% CI 1.8 to 2.8). There was a high accordance rate between the side of VAH and VN. Among 29 patients with unilateral VAH, 65.5% (N=19) had an ipsilateral VN, in which left VAH showed a higher accordance rate (83.3%) than the right side (60.9%). VN subjects with vascular risk factors also had a higher VAH accordance rate (81%) than those without (25%).

CONCLUSIONS

VAH may serve as a regional haemodynamic negative contributor and impede blood supply to the ipsilateral vestibular labyrinth, contributing to the development of VN, which could be enhanced by atherosclerotic risk factors and the left-sided location.

Preventive effect of silymarin in cerebral ischemia-reperfusion-induced brain injury in rats possibly through impairing NF-κB and STAT-1 activation

Silymarin and silibinin are bioactive components isolated from Silybum marianum. They have been reported to exhibit anti-oxidative and anti-inflammatory effects. Many studies revealed that drugs with potent anti-inflammatory potential can protect animals against inflammation-associated neurodegenerative disease, e.g., stroke. In this current work we established an animal model of acute ischemic stroke injury by inducing cerebral ischemic/reperfusion (CI/R) in rats to elucidate whether silymarin or silibinin can protect animals from CI/R injury. Pretreatment with silymarin, but not silibinin, dose-dependently (1-10μg/kg, i.v.) reduced CI/R-induced brain infarction by 16-40% and improved neurological deficits in rats with a stroke. Elevated pathophysiological biomarkers for CI/R-induced brain injury, including lipid peroxidation, protein nitrosylation, and oxidative stress, were all reduced by silymarin. In addition, expression of inflammation-associated proteins (e.g., inducible nitric oxide synthase, cyclooxygenase-2 and myeloperoxidase), and transcriptional factors (e.g., nuclear factor (NF)-kappa B and signal transducer and activator of transcription (STAT)-1), as well as production of proinflammatory cytokine (e.g., interleukin-1β and tumor necrosis factor-α) was all significantly prevented by silymarin. Furthermore, an in vitro study on microglial BV2 cells showed that silymarin could inhibit nitric oxide and superoxide anion production, possibly by interfering with NF-κB nuclear translocation/activation. Likewise, silymarin pretreatment also inhibited IκB-α degradation and NF-κB nuclear translocation in brain tissues of ischemic rats. Our results reveal that silymarin, but not its active component silibinin, protected rats against CI/R-induced stroke injury by amelioration of the oxidative and nitrosative stresses and inflammation-mediated tissue injury through impeding the activation of proinflammatory transcription factors (e.g., NF-κB and STAT-1) in the upregulation of proinflammatory proteins and cytokines in stroke-damaged sites. In conclusion, silymarin displays beneficial effects of preventing inflammation-related neurodegenerative disease, e.g., stroke, which needs further investigation and clinical evidences.

Rehabilitation outcome in home-based versus supervised exercise programs for chronically dizzy patients

We aimed to evaluate the effectiveness of vestibular rehabilitation (VR) exercise between supervised and home-based programs in young and senior age groups of patients with chronic dizziness. Dizziness Handicap Inventory (DHI), Dynamic gait index (DGI), Tinetti fall risk performance scales and Timed "Up and Go" test (TUG) were administered to patients on their initial and follow-up visits for forty-one patients suffering from chronic dizziness. Twenty-eight patients received three 30-min vestibular training exercise sessions per week. Thirteen patients who could not visit our clinic on regular basis were instructed to do the same set of exercises at home, with the same duration and frequency. All scales were evaluated again on their follow-up visits 2 months later. Patients in both groups showed statistically significant improvement in DHI and Tinetti scales. A higher percentage of patients in the supervised-exercise-program (SP) group showed clinically significant outcome improvements. Age was not a predictive factor for rehabilitation outcome. We concluded that for all ages of chronically dizzy patients, 2 months of VR can reduce handicap, improve balance function and a consequent improvement of life quality. Health care professionals need to be educated about the importance of rehabilitation program for treatment of chronic dizziness.

Balance improvement in patients with benign paroxysmal positional vertigo

Objective: To investigate the effect of an additional vestibular stimulated exercise programme on balance for patients with benign paroxysmal positional vertigo.

Design: Randomized controlled trial.

Setting: Medical centre.

Subjects: Twenty-six subjects with benign paroxysmal positional vertigo involving the unilateral posterior semicircular canal.

Interventions: Subjects were randomized into experimental or control groups. Thirteen subjects in the experimental group received the canalith repositioning manoeuvre and vestibular stimulated exercise training three times a week for four weeks. Thirteen subjects in the control group received only the canalith repositioning manoeuvre.

Main measures: Static balance tests, tandem walk test, Dynamic Gait Index and subjective rating of the intensity of vertigo were measured at baseline, two-week and four-week assessments.

Results: Compared with the control group, subjects in the experimental group demonstrated a statistically significant improvement in single leg stance with eyes closed at the two-week assessment (P<0.05). Furthermore, stance on foam surface with eyes closed, single-leg stance with eyes closed, and Dynamic Gait Index at the four-week assessment were also significantly improved (P<0.05).

Conclusion: The present study demonstrated that additional exercise training, which emphasizes vestibular stimulation, can improve balance ability and functional gait performance among patients with benign paroxysmal positional vertigo who had already undergone the canalith repositioning manoeuvre.

Treatment of focal cerebral ischemia with liposomal nerve growth factor

Liposomal nerve growth factor (NGF) was used for the treatment of focal cerebral ischemia in a rat model. Positive charge inducing agents of sphingosine (SP) and stearylamine (S) were formulated in the liposomal NGF. Dose-response of intraventricular injection of liposomal NGF showed significant reduction in infarct volume at the dose of 5 and 10 microg/rat of NGF. The liposomal NGF formulated with SP or S demonstrated similar results in the reduction of total infarct volume in rats. When we increased the molar ratio of SP and S from 0.15 to 0.3, the infarct volume from rats showed a similar value as that of the control treated with NGF solution. Liposomal NGF was given prior to the development of ischemia. We found that NGF was effective in prevention of neuronal death. The NGF concentrations in brain for liposomal NGF were maintained in a level significantly higher than those for NGF solution. This was attributed to the positively charged liposomal NGF bound effectively in brain ventricle and caused longer retention time than free NGF for localization in brain. Therefore, the effect of liposomal NGF on reduction of infarct volume was significant. We assumed that the transportation of NGF might go through the cerebrospinal fluid pathway throughout the ventricular system and subarachnoid system to cerebral cortex to produce a therapeutic effect on ischemia.

A Pilot Study of a New Thrombolytic Agent for Acute Ischemic Stroke in Taiwan Within A Five-Hour Window

Background and Purpose— This study was the first clinical trial in Taiwan of a new thrombolytic agent human tissue urokinase type plasminogen activator (HTUPA) in patients with acute ischemic stroke.

Methods— Patients were treated with a single bolus intravenous HTUPA under an open-label dose escalation design within 5 hours after symptom onset. Safety outcomes were assessed by symptomatic and asymptomatic intracerebral hemorrhage (ICH) as well as other bleeding episodes. Preliminary efficacy was measured by National Institutes of Health Stroke Scale (NIHSS).

Results— Three doses of HTUPA (0.3 mg/kg, 0.35 mg/kg, and 0.4 mg/kg) were administered to 33 patients, with the majority of patients (n=29) receiving 0.3 mg/kg. Two cases of fatal ICH occurred: 1 in the patient who received 0.4 mg/kg and the other in the 0.3 mg/kg group. Asymptomatic ICH occurred in 6 patients. Other treatment-related serious adverse events were ecchymosis, hematuria, and upper gastrointestinal bleeding, which were completely recovered. At day 90, in patients treated with 0.3 mg/kg within a 0- to 5-hour window, 34% reached NIHSS scores 0 to 1, whereas of those treated within 0 to 3 hours, 86% reached this score.

Conclusion— Intravenous HTUPA, given at 0.3 mg/kg as a bolus injection within 5 hours after symptom onset, had an acceptable safety and efficacious profile in patients with acute ischemic stroke.

Effects of Atenolol and Losartan on Baroreflex Sensitivity and Heart Rate Variability in Uncomplicated Essential Hypertension

Baroreflex sensitivity (BRS) and heart rate variability (HRV) are potential therapeutic targets. The present study was conducted to assess changes in BRS and HRV after monotherapy with losartan versus that of atenolol in uncomplicated essential hypertension. Thirty subjects with uncomplicated essential hypertension were randomized to receive atenolol 50 mg to 100 mg (n = 15) or losartan 50 mg to 100 mg (N = 15) daily for 6 months. Instantaneous systolic blood pressure (SBP) and heart rate were assessed using servo-controlled infrared finger plethysmography before treatment and at the end of 3 months and 6 months after treatment. The fluctuation in SBP and interpulse interval (IPI) was divided into three specific frequency ranges by fast Fourier transform as high frequency (HF; 0.15 Hz-0.4 Hz), low frequency (LF; 0.04 Hz-0.15 Hz), and very low frequency (VLF; 0.004 Hz-0.04 Hz). The BRS was expressed as (1) SBP-IPI transfer function with its magnitude in the HF and LF ranges and (2) BRS index alpha. The HRV was expressed as total power and power in the LF and HF ranges of interpulse interval. Blood pressure was reduced to a similar extent in both groups. Compared with the baseline, BRS did not improve in both groups at month 3. However, BRS was significantly improved in the losartan group (P < 0.05) but not in the atenolol group at month 6. In addition, BRS was significantly higher in the losartan group than the atenolol group at month 3 and month 6 (P < 0.05). Moreover, heart rate variability was significantly reduced in the atenolol group at month 6 (P < 0.05), but not in the losartan group. The HRV in the losartan group was significantly higher than that in the atenolol group at month 6 (P < 0.05). These findings suggest superior effects of losartan on BRS and HRV than atenolol in uncomplicated essential hypertension, which may be beyond blood pressure reduction/resetting.

Comparison of Critical Closing Pressures Extracted from Carotid Tonometry and Finger Plethysmography

BACKGROUND

The reliability of critical closing pressure (CrCP) estimates derived from peripheral blood pressure (BP) measurements is unclear. We attempted to evaluate the influences of peripheral circulation on determining CrCP.

METHODS

Twenty-five young healthy volunteers were studied. BP waves were obtained with plethysmography (Portapres) and carotid applanatory tonometry, respectively, for analysis. Transcranial Doppler was used to monitor cerebral flow velocity. Using linear regression analysis, beat-to-beat CrCP was calculated at rest, during voluntary hyperventilation and during 5% CO2 inhalation.

RESULTS

Twenty of 25 participants demonstrating satisfactory tonometric tracings for both tests were included in the analysis. The systolic BP measured using plethysmography was higher than that derived from tonometry (139.4 +/- 24.7 vs. 105.5 +/- 29.6, p < 0.001). CrCP values derived from tonometry were all positive and higher than CrCP values derived from plethysmography (62.9 +/- 19.9 vs. 11.1 +/- 17.8, p < 0.001). The changes in CrCP induced by 5% CO2 inhalation and hyperventilation had a correlation between two BP monitoring methods (r = 0.52, p = 0.001).

CONCLUSIONS

Pressure waveform is an important determinant in calculating CrCP by linear regression analysis. The relative changes in CrCP induced by hemodynamic challenges remained a relevant indicator of cerebrovascular regulation regardless of the methods used for non-invasive BP recording.

Quality of life in elderly patients with dizziness: analysis of the Short-Form Health Survey in 197 patients

CONCLUSION

Elderly patients with chronic dizziness had a poor HRQoL, which could be successfully assessed using the SF-36, a generic health-status instrument. The frequency of dizziness and comorbid psychological distress were predictive of impairment in QoL.

OBJECTIVES

To evaluate health-related quality of life (HRQoL) and its relationship to characteristics of dizziness in elderly persons with chronic dizziness.

MATERIAL AND METHODS

A standardized dizziness questionnaire was used to evaluate characteristics of dizziness as well as medical, functional and demographic data in 197 consecutive patients with chronic dizziness aged > or =60 years. HRQoL was evaluated using the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) and the Hospital Anxiety and Depression Scale (HADS).

RESULTS

Compared with normative data, results from patients with dizziness indicated a pervasive multidimensional decline in SF-36 scores. This decline was most notable in terms of role limitations in the physical and emotional dimensions. The frequency of attacks of dizziness correlated with perceived disability. Patients with chronic dizziness also had great psychological distress, as measured by the HADS score, which had a detrimental influence on their QoL.

Protein S deficiency associated with progressive loss of vision and intracranial venous sinus thrombosis

We report a 27-year-old male who presented with headache and rapid visual impairment. He had been diagnosed with venous sinus thrombosis 3 months earlier, when he had diffuse headache, nausea and vomiting, which subsided after incomplete thrombolytic therapy. Warfarin was then prescribed without screening for coagulopathy. Ophthalmic examination revealed bilateral papilloedema, splinter hemorrhage and lipid exudates. Neuroradiological studies including magnetic resonance imaging and cerebral angiography revealed chronic partial thrombosis over superior sagittal sinus, left side transverse sinus, right side transverse and venous confluence with engorged cortical veins and secondary dural arteriovenous malformation (AVM) and reversed flow over bilateral superior orbital veins, and thrombolytic therapy was considered not feasible. Clot-assay protein S activity was decreased (25%, normal range: 65-140%). No underlying connective tissue diseases or other coagulopathies were noted. The patient's vision failed to respond to aggressive medical treatment, and he received lumboperitoneal shunt in another hospital. His vision was improved. For young patients with occlusive cerebrovascular disorder, extensive hematological investigation for coagulopathy is strongly recommended.

Correlations among critical closing pressure, pulsatility index and cerebrovascular resistance

We attempted to explore the relationships among critical closing pressure (CrCP), resistance-area product (RAP) and traditional resistance indices of cerebral hemodynamics. Twenty healthy volunteers were studied. Blood pressure was obtained with servo-controlled plethysmography. Cerebral blood flow velocity (CBFV) was monitored by transcranial Doppler. Hemodynamic changes were induced by hyperventilation and by 5% CO(2) inhalation. Beat-to-beat CrCP and RAP values were extracted by linear regression analysis of instantaneous arterial blood pressure (ABP) and CBFV tracings. Gosling's pulsatility index (PI) and cerebrovascular resistance (CVR) were calculated. RAP correlated well with CVR at rest and during provocative tests (p = 0.006 approximately <0.001). There was no correlation among CrCP, CVR and PI. The changes in CVR correlated with those in RAP (p = 0.008 for the 5% CO(2) test and p = 0.014 for the hyperventilation test). The changes in PI and CrCP showed significant correlation (p = 0.004 for the 5% CO(2) test and p = 0.003 for the hyperventilation test). RAP reliably reflected cerebrovascular resistance. The changes in CrCP were valuable in assessing cerebrovascular regulation. Estimating changes in CrCP and RAP provided better understanding of the nature of cerebrovascular regulation.

Mechanisms underlying phase lag between systemic arterial blood pressure and cerebral blood flow velocity

To explore the mechanisms underlying the phase lag between oscillations in arterial blood pressure (ABP) and cerebral blood flow velocity (CBFV), ABP and CBFV signals were recorded noninvasively from normal volunteers who lay quietly in a supine position. Mean ABP (MAP) and CBFV (MFV) were calculated beat-to-beat by means of integration. Cerebral vascular resistance (CVR) was calculated by dividing MAP with MFV. Frequency domain analysis of MAP, MFV and CVR signals revealed very-low frequency (VLF, 0.016-0.04 Hz), low-frequency (LF, 0.04-0.15 Hz), and high-frequency (HF, 0.15-0.4 Hz) components. The transfer phase of MAP-CVR coupling in the LF and HF range was frequency-dependent, which is equivalent to a time delay of 2 s. However, the transfer phase differed in the CVR-MFV coupling in that the phase was distributed around 180 degrees across the LF and HF ranges. Cross-correlation analysis revealed a positive relationship between MAP-CVR coupling, with MAP leading by 2 s, and a negative relationship between CVR-MFV coupling, with CVR leading by 0.3 s. We concluded that the phase lag between oscillations in ABP and CBFV was chiefly contributed to by the starting latency of cerebral autoregulation (i.e. cerebral vasomotion, revealed by MAP-CVR coupling). Moreover, the negative correlation of the CVR-MFV coupling could offer a different explanation for the physiologic significance of the phase lead of CBFV-ABP oscillations.

Noninvasive assessment of spontaneous baroreflex sensitivity and heart rate variability in patients with carotid stenosis

BACKGROUND

Previous limited observations have suggested that atherosclerosis may affect the distensibility of the carotid sinus and then impair the baroreflex sensitivity (BRS). No studies have been done to compare the BRS and heart rate variability (HRV) in patients with carotid stenosis and normal controls.

METHODS

A convenience-consecutive sample of 118 patients with transient ischemic attack or minor stroke 3 months to 1 year before (mean 6 months) who met the study criteria were referred to the neurovascular laboratory of the study hospital. Forty-three age-matched healthy adults were recruited as the normal controls. The inclusion criteria for participation were (1) no diabetes mellitus, (2) no history, symptoms or ECG signs of coronary artery disease or myocardial infarction, and (3) presence of carotid stenosis greater than or equal to 50%. The diagnosis of carotid stenosis was made using color-coded duplex ultrasound with published criteria. We categorized the patients into two groups: group 1 had moderate stenosis (50-75%) and group 2 had high-grade stenosis (75-99%). Instantaneous systolic blood pressure (SBP) and heart rate of all participants were assessed noninvasively using servo-controlled infrared finger plethysmography. The fluctuation in SBP as well as the interpulse interval (IPI) was divided into three components at specific frequency ranges by fast Fourier transform as high frequency (HF; 0.15-0.4 Hz), low frequency (LF; 0.04-0.15 Hz) and very low frequency (VLF; 0.004-0.04 Hz). The BRS was expressed as (1) transfer function with its magnitude in the HF and LF ranges, (2) BRS index alpha, and (3) regression coefficient by sequence analysis. The HRV was expressed as total power and power in the three frequency ranges (HF, LF and VLF).

RESULTS

The final analysis included 99 patients (mean age 72 +/- 6 years, 79 male) and 43 healthy controls (mean age 68 +/- 7 years, 30 male). Forty-three patients were classified as group 1 (stenosis 50-75%) and 56 as group 2 (stenosis 75-99%). There was no significant difference in the IPI between patients and controls (p value = 0.8637). We observed a significant decrease in all three HRV components (VLF, LF and HF) in the patients; however, there were no differences between the two patient groups with various degrees of stenosis. All the indices of BRS, including the magnitude of SBP-IPI transfer function at LF and HF, the computed BRS index alpha and the regression coefficient of sequence analysis, revealed similar results. Patients exhibited a significant reduction in the BRS (p < 0.001) compared with controls, and no difference was found between the two groups of patients.

CONCLUSIONS

Our study linked significant carotid stenosis to two important autonomic markers (BRS and HRV) that may have prognostic value for patients with cardiovascular events. Further prospective studies are needed to explore whether or not the decreased BRS and HRV can be predictors for poor cardiovascular prognosis, or even for shortened life span in general, in patients with significant carotid stenosis.

Spectral analysis of cerebrovascular regulation in patients with autonomic dysfunction

BACKGROUND

Regulation of cerebral blood flow during orthostatic stress has been a major research topic in patients with orthostatic intolerance such as autonomic dysfunction. Spontaneous fluctuations of middle cerebral artery blood flow velocity (MCAFV) recorded with transcranial Doppler (TCD) have been found to contain information related to cerebrovascular regulation, which can be deciphered with spectral analysis. The purpose of this study was to evaluate the differences in cerebrovascular regulation between healthy volunteers and patients with autonomic dysfunction and orthostatic dizziness for using spectral analysis of MCAFV information derived from TCD during supine rest and orthostasis.

METHODS

Thirteen patients with autonomic dysfunction and orthostatic dizziness were found to have impaired cerebral autoregulation because of failure to maintain adequate cerebral blood flow velocity during a 30-minute head-up tilt study with concomitant TCD and cuff sphygomanometer monitoring. The data of bilateral MCAFV were compared between these 13 patients and 9 healthy volunteers using spectral analysis.

RESULTS

Spectral analysis of the MCAFV showed significantly decreased low frequency (LF) power in supine position in the patient group (p = 0.0002). In addition, the spectral power in the very low and low frequency (VLF & LF) ranges remained significantly lower in the patient group after tilting up (p < 0.05).

CONCLUSIONS

(1). Our study results further support the previous findings that the LF component of the spontaneous fluctuations of MCAFV is important for cerebrovascular regulation. (2) The decreased LF MCAFV power may be a useful indicator or marker of impaired cerebrovascular regulation in patients with autonomic dysfunction.

Dynamic cerebrovascular regulation in patients with autonomic dysfunction: a transcranial Doppler study

BACKGROUND

Regulation of cerebral blood flow during orthostatic stress has been a major research interest. The purpose of this study was to scan healthy volunteers and patients with orthostatic dizziness and autonomic dysfunction for differences in cerebral hemodynamic patterns during orthostasis.

METHODS

Thirteen patients with orthostatic dizziness and autonomic dysfunction and 9 healthy volunteers were recruited for monitoring of variations in intracranial hemodynamics with transcranial Doppler ultrasound during a 30-minute head-up tilt. Heart rate and blood pressure were monitored with surface electrocardiography and cuff sphygmomanometer, respectively. Cerebral blood flow velocity was continuously monitored using transcranial Doppler ultrasonography.

RESULTS

The baseline mean cerebral blood flow velocity was significantly lower in the patient group (p < 0.05). After tilting up, the extent of immediate decreases in systolic blood pressure and in the mean blood flow velocity were significantly more in the patients (p < 0.05). However, the mean blood flow velocity remained significantly more retarded for up to 90 seconds after the initial drop in the patient group, while the blood pressure showed no significant difference between the patients and controls.

CONCLUSIONS

Impaired dynamic cerebrovascular regulation can be documented as a delayed recovery of cerebral blood flow velocity upon orthostatic challenges, which may help verify the status of cerebrovascular regulation in patients with autonomic dysfunction.

Increased arterial wave reflection may predispose syncopal attacks

BACKGROUND

The incidence of syncope increases with age, while aging is also associated with increased arterial wave reflection.

HYPOTHESIS

The study was undertaken to determine whether increased arterial wave reflection is a predisposing factor of syncope.

METHODS

We recruited 38 patients (28 men and 10 women, mean age 57.2 +/- 20.3 years, range 17-87 years) with a history of syncope within 6 months of entry. The etiology of syncope was documented for each patient by a complete assessment of vasomotor function and cerebral flow. All patients received a comprehensive echocardiographic evaluation of cardiac structure and function. Carotid augmentation index (AI) was estimated noninvasively with the tonometry technique. The results were compared with those from 54 age- and gender-matched controls.

RESULTS

The most frequent diagnoses of syncope were postural hypotension (13 patients) and cerebrovascular dysautoregulation (10 patients), and the cause could not be determined in 9 patients. Compared with the control group, the syncope group had a greater AI (20 +/- 21 vs. 10 +/- 15%, p = 0.013). Subgroup analysis of 20 patients aged > 50 years and with the aforementioned diagnoses showed even more striking results: AI, 29 +/- 10 vs. 11 +/- 15%, p < 0.001. The enhanced augmentation in the patients remained when age, systolic blood pressure, height, and heart rate were accounted for. Analysis of the carotid pulse wave suggested that both the timing and intensity of wave reflection were enhanced in patients with a history of syncope compared with controls.

CONCLUSIONS

Our results support the hypothesis that enhanced arterial wave reflection is associated with the occurrence of syncope, especially in the elderly.

Spectral analysis of arterial blood pressure and cerebral blood flow velocity during supine rest and orthostasis

This study evaluates the effect of orthostasis on the low frequency (LF, 0.04 to 0.15 Hz) fluctuations in the blood flow velocity of the middle cerebral artery (MCAFV) in relation to its arterial blood pressure (ABP) equivalent to further define and quantify this relationship in cerebrovascular regulation. Spectral analysis was performed on 22 healthy subjects during supine rest and head-up tilt. The power in the LF range can be used to quantify the LF fluctuations, and four types of LF power data could be obtained for each individual: LF power of supine MCAFV, LF power of supine ABP, LF power of tilt MCAFV, and LF power of tilt ABP. By comparing LF power of MCAFV with LF power of ABP, two power ratios could be generated to describe the flow-pressure relationship during supine rest and head-up tilt, respectively, supine power ratio (LF power of supine MCAFV/ LF power of supine ABP) and tilt power ratio (LF power of tilt MCAFV/ LF power of tilt ABP). In addition, an index for dynamic autoregulation in response to orthostasis can be calculated from these two power ratios (tilt power ratio/supine power ratio). The authors found that this index was dependent on the extent of orthostatic MCAFV changes, and the dependency could be mathematically expressed (r = 0.61, P = .0001), suggesting its involvement in cerebrovascular regulation. Moreover, these data further support the previous observation that the LF fluctuations of MCAFV might result from modulation of its ABP equivalent, and the modulation effect could be quantified as the power ratio (LF power of MCAFV/ LF power of ABP). These observations could be an important step toward further insight into cerebrovascular regulation, which warrants more research in the future.

Colour doppler imaging for diagnosis of intracranial hypotension

BACKGROUND

Measurement of CSF pressure is the only known way to confirm the diagnosis of intracranial hypotension. We aimed to assess colour doppler flow imaging (CDFI) for measurement of blood flow of the superior ophthalmic vein for the diagnosis of intracranial hypotension.

METHODS

We enrolled 25 consecutive patients with orthostatic headache who had clinical features of intracranial hypotension. We defined low-pressure headache as cerebrospinal-fluid pressure below 60 mm H2O. We used CDFI to measure the diameter and maximum flow velocity of the superior ophthalmic vein in all patients. Magnetic resonance imaging of the brain and lumbar puncture with measurement of cerebrospinal-fluid pressure within 24 h were also done after sonographic examination. The control group comprised 13 healthy individuals of a similar age; in addition, those patients who had orthostatic headache without low pressure served as a control group for the patients.

FINDINGS

Of the 25 patients recruited for this study, 13 satisfied the criteria for low-pressure headache. The remaining 12 patients with normal cerebrospinal-fluid pressure had transformed migraine (five patients) or chronic tension-type headache (seven patients), and therefore served as the control group for the patients. The mean diameter of the superior ophthalmic vein was substantially larger in the patients with intracranial hypotension (3.9 [SD 0.2] mm) than in the healthy controls (2.6 [0.4] mm) and the controls from the patients' group (2.7 [0.2] mm) (p<0.0001). The mean maximum flow velocity was significantly higher in the intracranial-hypotension group (17.0 [SD 3.4] cm/s) than in the healthy controls (7.9 [1.1] cm/s) and the other patients (7.3 [1.7] cm/s) (p<0.0001). Seven patients with intracranial hypotension were reassessed after treatment with epidural blood patch. After this treatment the clinical symptoms were relieved and there was a striking reversal of the superior ophthalmic vein flow.

INTERPRETATION

CDFI to measure blood flow of the superior ophthalmic vein provides a practical, simple, and non-invasive diagnostic method for suspected intracranial hypotension.

Transcranial Doppler monitoring with head-upright tilting in patients with syncope

BACKGROUND

The aim of our study was to evaluate the effects of orthostatic stress produced by the head-upright tilt test on human cerebral hemodynamics by transcranial Doppler sonography.

METHODS

We studied 60 subjects who were divided into two groups; one of normal controls (n = 43) and one of patients suffering from syncope (n = 17). A 30-minute head-upright tilt test was conducted on all subjects, and heart rate and blood pressure were monitored by surface electrocardiography and cuff sphygmomanometry, respectively. Cerebral blood flow velocity and cerebral vasoreactivity were continuously monitored using transcranial Doppler sonography.

RESULTS

The maximal decreases in mean blood pressure of controls and patients with syncope were 2.6 +/- 7.8% and 0.5 +/- 7.9% of baseline, respectively. The maximal decreases in mean blood flow velocity in the middle cerebral artery between the two groups reached 19.6 +/- 6.2% and 30.7 +/- 14.1% of baseline, respectively (p < 0.05). The increases in pulsatility index between the two groups were 15.4 +/- 14.3% and 16.9 +/- 21.1% of baseline, respectively.

CONCLUSION

The responses of cerebral blood flow to upright tilting differed significantly between normal controls and patients with syncope, implying that the latter may suffer an impairment of cerebral autoregulation. Further studies are needed to ascertain what clinical implications this finding might have.