Ischemic Cerebrovascular Disorders Research Articles

Effect of Cyclosporin H on ischemic injury and neutrophil infiltration in cerebral infarct model of rats via PET imaging.

Brain ischemia-reperfusion injury is a complex process, and neuroinflammation is an important secondary contributing pathological event. Neutrophils play major roles in ischemic neuroinflammation. Once activated, neutrophils express formyl peptide receptors (FPRs), which are special receptors of a class of chemoattractants and may be potential targets to regulate the activity of neutrophils and control cerebral ischemic injury. This study was aimed to explore the ameliorating effect of Cyclosporin H (CsH), a potent FPR antagonist, on brain ischemic injury by inhibiting the activation and migration of neutrophils, and improving cerebral blood flow. We employed a middle cerebral artery occlusion (MCAO) Model on rats and performed behavioral, morphological, and microPET imaging assays to investigate the potential restoring efficacy of CsH on cerebral ischemic damages. Peptide N-cinnamoyl-F-(D)L-F-(D)L-F (cFLFLF), an antagonist to the neutrophil FPR with a high binding affinity, was used for imaging neutrophil distribution. We found that CsH had similar effect with edaravone on improving the neurobehavioral deficient symptoms after cerebral ischemia-reperfusion, and treatment with CsH also alleviated ischemic cerebral infarction. Compared with the MCAO Model group, [18F]FDG uptake ratios of the CsH and edaravone treatment groups were significantly higher. The CsH-treated groups also showed significant increases in [18F]FDG uptake at 144h when compared with that of 24h. This result indicates that like edaravone, treatment with both doses of CsH promoted the recovery of blood supply after cerebral ischemic event. Moreover, MCAO-induced cerebral ischemia significantly increased the radiouptake of [68Ga]Ga-cFLFLF at 72h after ischemia-reperfusion operation. Compared with MCAO Model group, radiouptake values of [68Ga]-cFLFLF in both doses of CsH and edaravone groups were all decreased significantly. These results showed that both doses of CsH resulted in a similar therapeutic effect with edaravone on inhibiting neutrophil infiltration in cerebral infarction. Potent FPR antagonist CsH is promisingly beneficial in attenuating neuroinflammation and improving neurobehavioral function against cerebral infarction. Therefore, FPR may become a novel target for regulating neuroinflammation and improving prognosis for ischemic cerebrovascular disorders.

Comparison of Medical and Mental Health Sequelae Following Hospitalization for COVID-19, Influenza, and Sepsis

People who survive hospitalization for COVID-19 are at risk for developing new cardiovascular, neurological, mental health, and inflammatory autoimmune conditions. It is unclear how posthospitalization risks for COVID-19 compare with those for other serious infectious illnesses. To compare risks of incident cardiovascular, neurological, and mental health conditions and rheumatoid arthritis in 1 year following COVID-19 hospitalization against 3 comparator groups: prepandemic hospitalization for influenza and hospitalization for sepsis before and during the COVID-19 pandemic. This population-based cohort study included all adults hospitalized for COVID-19 between April 1, 2020, and October 31, 2021, historical comparator groups of people hospitalized for influenza or sepsis, and a contemporary comparator group of people hospitalized for sepsis in Ontario, Canada. Hospitalization for COVID-19, influenza, or sepsis. New occurrence of 13 prespecified conditions, including cardiovascular, neurological, and mental health conditions and rheumatoid arthritis, within 1 year of hospitalization. Of 379 366 included adults (median [IQR] age, 75 [63-85] years; 54% female), there were 26 499 people who survived hospitalization for COVID-19, 299 989 historical controls (17 516 for influenza and 282 473 for sepsis), and 52 878 contemporary controls hospitalized for sepsis. Hospitalization for COVID-19 was associated with an increased 1-year risk of venous thromboembolic disease compared with influenza (adjusted hazard ratio, 1.77; 95% CI, 1.36-2.31) but with no increased risks of developing selected ischemic and nonischemic cerebrovascular and cardiovascular disorders, neurological disorders, rheumatoid arthritis, or mental health conditions compared with influenza or sepsis cohorts. In this cohort study, apart from an elevated risk of venous thromboembolism within 1 year, the burden of postacute medical and mental health conditions among those who survived hospitalization for COVID-19 was comparable with other acute infectious illnesses. This suggests that many of the postacute consequences of COVID-19 may be related to the severity of infectious illness necessitating hospitalization rather than being direct consequences of infection with SARS-CoV-2.

Prevalence of baseline comorbidities in patients with atopic dermatitis: A population-based cohort study in Taiwan

BackgroundAtopic dermatitis has been linked to increased risk of many comorbidities. However, the risks of certain comorbidities are still debated.ObjectiveTo better characterize the basic demographics, treatment patterns, and associations between atopic dermatitis and comorbidities and to further investigate the influence of severity on comorbidities.MethodsWe used a sample cohort of 999,992 people from the National Health Insurance Research Database of Taiwan to evaluate atopic dermatitis in the general population.ResultsA total of 12,780 patients with atopic dermatitis in 2010 were identified. The prevalence was 1.28%. The proportions of severe and moderate cases were 7.43% and 19.26%, respectively. The most commonly used systemic treatment was corticosteroids. Compared with the general population, atopic dermatitis patients showed increased risks of all 9 groups of comorbidities, including autoimmune disorders, atopic disorders, chronic urticaria, ocular disorders, metabolic disorders, hypertensive disorders, ischemic heart disorders, cerebrovascular disorders, and psychiatric disorders. The severity and persistence of atopic dermatitis were correlated with the development of certain comorbidities.LimitationsMiscoding and misclassification might have occurred, and only patients with active disease were enrolled.ConclusionPatients with atopic dermatitis have higher risks of various comorbidities. Comprehensive monitoring and treatment plans are needed to better manage these patients.

Psychosomatic unity of human from the position of chronopsychology on the example of ischemic disorders and heart diseases

Objective: To distinguish peculiarities of subjective time perception and dominant emotion in persons with ischemic violations of cerebellar circulation and heart disease. Method: A chronometric sample method using an electronic chronoscope; the form and level of anxiety in accordance with the method of C. Spielberg, Y. Hanin “Scale of the level of reactive and personal anxiety”; methods of mathematical statistics: descriptive statistics, methods for determining the mean arithmetic deviation and the use of correlation relations between the value of the individual unit time of the individual and the form and level of anxiety. Results: It has been experimentally proved that patients with coronary heart disease (I20 for ICD10) predominate in the range of the continuous spectrum of “τ-types”: 0.8 s <τ <0.86 s, and their dominant emotion provoking exacerbation of the disease is a high level of situational anxiety; Patients with ischemic cerebrovascular disorder (cerebral infarction) (I63 for ICD-10) are mainly localized in the range of the continuous spectrum of “τ-types”: 0.94 s <τ <1.0 s, and their dominant emotion provoking exacerbation of the disease is high level of personal anxiety. Levels of anxiety in these categories of patients are consistent with the duration of the biological cycle of a human, who suffers from ischemic disorders. Conclusion: Experimentally proved the holistic view of psychosomatic unity of a person from the position of “locus minoris resistentiae”. The exacerbation of the ischemic cerebrovascular disorders manifestation and heart disease is consistent with the duration of the biological cycle of the individual’s life from the standpoint of the relational concept of time, and the emotional factor is dominant in the course of cardiopulmonary and cerebrovascular diseases, which confirms the effectiveness of the concept of psychosomatic diseases course chronopsychological prediction.

Tackling endothelium remodeling in cardiovascular disease

Endothelial dysfunction is considered an early marker of atherosclerosis. Herein, we address the molecular mechanisms affecting endothelium remodeling in disease. Vascular calcification is highly prevalent in patients with ischemic cardiovascular disease, cerebrovascular disorder, and renal failure, being a common feature in aging, diabetes, dyslipidemia, abnormal valve biomechanics, end-stage renal disease and atherosclerosis, a major cause of mortality and morbidity. Oxidative stress promotes calcification of vascular smooth muscle cells (SMC) by increasing osteogenic transcription factors expression and activity in atherosclerotic plaques. Various markers of osteogenic differentiation are expressed by SMC in calcified atherosclerotic lesions. Interestingly, decreased levels of some bone factors and microRNAs accelerate vascular calcification and injured tissue regeneration. Another key player in endothelial remodeling is amino acids metabolism. Branched-chain amino acids are catabolized in several nonhepatic tissues including cardiac muscle. Immune activation and inflammation in cardiovascular disease patients associate with higher phenylalanine/tyrosine ratios. Understanding the whole process that underlies endothelium dysfunction is of paramount importance for the development of new therapeutic approaches.

Reliability of diagnosing acute ischemic cerebrovascular on magnetic resonance imaging disorders using iPads.

The use of tablet terminals has been explored in various medical settings; however, caution should be exercised when performing image diagnosis using this technology. The present study examined the characteristics of an iPad Air™ monitor and assessed radiographic image interpretations to verify the reliability of the telediagnosis of acute cerebral infarction based on magnetic resonance imaging (MRI) using a tablet terminal. The luminance of the iPad Air™ was measured using a UA-10 analyzer, and radiographic image interpretation experiments were performed in 100 patients who underwent MRI within 6h of symptom onset. Ten physicians viewed the images on the iPad Air™ and a medical monitor, with an interval of 2months between each interpretation. When the iPad Air™ screen was pure white, the contour lines revealed nonuniform luminance distribution. In the reading experiment, the areas under the curve of the medical monitor and the iPad Air™ were 0.9311 and 0.9431, respectively. No significant difference was observed between the medical monitor and the iPad Air™ (p = 0.113). The results of the observer performance studies for detecting acute ischemic cerebrovascular disorders on an iPad Air™ were found to be similar to those on a medical monitor.

Транзиторная ишемическая атака вследствие интракраниальной диссекции средней мозговой артерии

Dissection of the cervicocephalic arteries is one of the main causes of acute ischemic cerebrovascular disorders in the young. Intramural hematoma is formed by blood penetration between the layers of arterial wall through the arterial intima defect and narrows the lumen of the artery, which is clinically manifested by symptoms of cerebral ischemia. A lot of cases of cervicocephalic dissection occurs in internal carotid and less common in vertebral arteries. Often fast movements in the neck, head and neck trauma or physical exercises provoke the development of dissection. Dissection of the middle cerebral artery is a rare localization and in the period from 1966 to 2013 only 59 cases of stroke and 2 cases of transient ischemic attack were described.

THE EFFICACY OF LONG-TERM WARFARIN THERAPY: THE IMPACT ON THE INCIDENCE OF ISCHEMIC CEREBROVASCULAR DISORDERS AND CLINICAL PREDICTORS OF DEVELOPING SUCH DISORDERS. (Results of a prospective 10-year follow-up study)

Atrial fibrillation (AF) is the most common indication for the long-term oral anticoagulation therapy. For several decades, vitamin K antagonists have been the mainstay of routine clinical practice. A prospective 10-year follow-up of patients with atrial fibrillation receiving warfarin therapy showed that the incidence of all cerebral circulation disorders was 2.59 per 100 patient-years. The warfarin therapy contributed to the prevailing of non-fatal events among the cerebral circulation disorders which occurred during the therapy. The incidence of fatal ischemic strokes was 0.91 per 100 patient-years over the 10-year follow-up study. If the duration of a patient within the target therapeutic range (TTR) was <70%, it increased the relative risk of ischemic cerebrovascular disorders by 2.77 times (95% CI 1.367--5.633) compared with patients with a mean value of TTR ≥ 70%. The study demonstrated that 86.5% of patients with the mean TTR values ≥ 70% had no ischemic cerebrovascular disorders for 10 years. A separate analysis of patients with high thromboembolic risk (who had 4 or more points on the CHA2DS2-VASc) showed that achieving a TTR ≥ 70% resulted in 70.7% patients who had no stroke for 10 years. The stepwise discriminant analysis revealed that the initial cognitive function decline, history of stroke and TTR <70% were predictors of developing ischemic cerebrovascular disorders (strokes and transient ischemic attacks) in patients receiving warfarin.

Panax notoginseng saponins provide neuroprotection by regulating NgR1/RhoA/ROCK2 pathway expression, in vitro and in vivo

Ethnopharmacological relevancePanax notoginseng saponins (PNS) extracted from a traditional Chinese herbal medicine, Panax notoginseng (Burkill) F.H. Chen (Araliaceae), which has been extensively used in treating coronary heart disease, ischemic cerebrovascular disease and hemorrhagic disorders in China over hundreds of years. Aims of the studyThis study explored whether panax notoginseng saponins (PNS) provided neuroprotective effects by inhibiting the expressions of NgR1, RhoA, and ROCK2 following middle cerebral artery occlusion in rats and oxygen-glucose deprivation/reoxygenation (OGD/R) injury in SH-SY5Y cells. Materials and methods2,3,5-Triphenyltetrazolium chloride staining was used to determine successful middle cerebral artery occlusion establishment in sham-operated and operated Sprague–Dawley rats 1 day after injury. The rats were randomly separated into sham, model, NEP1-40, PNS, and NEP1-40 plus PNS (N+P) groups. After 7 days of treatment, body mass and neurological deficit scores were analyzed. Tissues were harvested and analyzed by hematoxylin-eosin staining and immunohistochemical analysis, western blotting, and quantitative real-time PCR (qRT-PCR). The optimal drug concentration of NEP1-40 and PNS on SH-SY5Y cells exposed to OGD/R injury was determined by CCK8 analysis. qRT-PCR was used to measure mRNA expression profiles of NgR1, RhoA, and ROCK2 in SH-SY5Y cells subjected to OGD/R. ResultsThe results showed that MCAO surgery successfully produced an infarct, and the PNS, NEP1-40, and N+P groups exhibited increased body mass and ameliorated neurological deficits compared with the model group. NEP1-40 treatment markedly reduced NgR1 and RhoA overexpression when compared to the model group, although there was no significant difference in ROCK2 expression. PNS and N+P treatment significantly decreased NgR1, RhoA, and ROCK2 overexpression compared with the model group. However, N+P treatment did not result in a synergistic effect, as assessed by immunohistochemistry, western blotting, and qRT-PCR. Following optimal administration of PNS (160μg/ml) and NEP1-40 (10ng/ml) on SH-SY5Y cells exposed to OGD/R injury, cell viability in the NEP1-40, PNS, and N+P groups significantly increased compared with the model group, as assessed by CCK8 analysis. Additionally, NgR1, RhoA, and ROCK2 mRNA expression profiles were significantly less in the NEP1-40, PNS, and N+P groups compared with the model group. ConclusionPNS provided neuroprotective effects in a rat model of cerebral ischemia and SH-SY5Y cells exposed to oxygen/glucose deprivation injury by inhibiting the overexpression of NgR1, RhoA, and ROCK2.

Choline Alphoscerate (Alpha-Glyceryl-Phosphoryl-Choline) An Old Choline- containing Phospholipid with a Still Interesting Profile As Cognition Enhancing Agent

Cholinergic precursors have represented the first approach to counter cognitive impairment occurring in adultonset dementia disorders. These compounds were early leaved because their clinical efficacy was not clearly demonstrated. This is probably not true for some choline-containing phospholipids including choline alphoscerate. Choline alphoscerate increases the release of acetylcholine in rat hippocampus, facilitates learning and memory in experimental animals, improves brain transduction mechanisms and decreases age-dependent structural changes occurring in rat brain areas involved in learning and memory. The compound exerts neuroprotective effects in models of altered cholinergic neurotransmission and of brain vascular injury. In clinical studies choline alphoscerate improved memory and attention impairment, as well as affective and somatic symptoms in dementia disorders. An ongoing trial indicates that association between the acetylcholinesterase inhibitor donepezil and choline alphoscerate is accompanied by an improvement in several cognitive tests superior to that induced by donepezil alone. It is suggested that this association may represent a therapeutic option to prolong beneficial effects of cholinergic therapies in Alzheimer's disease patients with concomitant ischemic cerebrovascular disorders. In summary, choline alphoscerate has significant effects on cognitive function with a good safety profile and tolerability. Although limited both in terms of size of the samples investigated and of the length of treatment, preclinical and clinical results presented suggest that cognitive enhancing capabilities of choline alphoscerate merit of being further investigated in appropriate trials.

SAT0320 High frequency of cardiovascular disease in patients with knee osteoarthritis in a primary care setting

BackgroundPatients with knee osteoarthritis (KOA), due to age, walking functional impairment and/or a high prevalence of obesity, are at a high risk of metabolic disorders and cardiovascular (CV) comorbidities, especially...

FRI0305 Higher frequency of metabolic syndrome in patients with hand osteoarthritis is more pronounced in OBESE patients

BackgroundPatients with knee osteoarthritis (OA), due to age, walking functional impairment and/or a high prevalence of obesity, are at a high risk of metabolic disorders and cardiovascular (CV) comorbidities. However,...

Lumbar spinal stenosis associated with peripheral arterial disease: a prospective multicenter observational study

BackgroundIntermittent claudication is a common symptom of both lumbar spinal stenosis (LSS) and peripheral arterial disease (PAD) in middle-aged and elderly people. However, the prevalence and clinical characteristics of LSS with PAD (LSSPAD) have not been investigated in a multicenter study. The aim of this study was to investigate the prevalence and clinical characteristics of LSS associated with PAD. Methods570 patients diagnosed with LSS using a clinical diagnostic support tool and MRI at 64 facilities were enrolled. We evaluated each patient’s medical history, physical findings, ankle brachial index, Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) score, and the Short Form 36 (SF-36) score. Statistical analyses were performed to compare LSSPAD patients and LSS patients without PAD using the t test, Mann–Whitney’s U test, and multivariate recurrence analysis. p values of <0.05 were considered statistically significant. ResultsThe LSSPAD group comprised 38 patients (6.7 %); 20 (3.5 %) had pre-diagnosised PAD while 18 (3.2 %) had undetected PAD. The clinical characteristics of these patients were advanced age, diabetes, and a history of ischemic heart disease and cerebrovascular disorder. 570 patients enrolled, and 448 (78.6 %) of those patients were followed up at three - months after enrollment. Pain in buttocks and legs improved less in the LSSPAD group than in the LSS group (p < 0.05). Improvements in the “general health” score in SF-36 were lower in the LSSPAD group than in the LSS group (p < 0.05). ConclusionsAdvanced age, diabetes, and a history of cerebrovascular disorder and ischemic heart disease were associated with LSSPAD. Because LSSPAD patients show less improvement in QOL than patients with LSS but without PAD do, clinicians should consider the coexistence of PAD in LSS patients.

Novel MRI Approaches for Assessing Cerebral Hemodynamics in Ischemic Cerebrovascular Disease

Changes in cerebral hemodynamics underlie a broad spectrum of ischemic cerebrovascular disorders. An ability to accurately and quantitatively measure hemodynamic (cerebral blood flow and cerebral blood volume) and related metabolic (cerebral metabolic rate of oxygen) parameters is important for understanding healthy brain function and comparative dysfunction in ischemia. Although positron emission tomography, single-photon emission tomography, and gadolinium-MRI approaches are common, more recently MRI approaches that do not require exogenous contrast have been introduced with variable sensitivity for hemodynamic parameters. The ability to obtain hemodynamic measurements with these new approaches is particularly appealing in clinical and research scenarios in which follow-up and longitudinal studies are necessary. The purpose of this review is to outline current state-of-the-art MRI methods for measuring cerebral blood flow, cerebral blood volume, and cerebral metabolic rate of oxygen and provide practical tips to avoid imaging pitfalls. MRI studies of cerebrovascular disease performed without exogenous contrast are synopsized in the context of clinical relevance and methodological strengths and limitations.

Effects of Hyul-Bu-Chuke-Tang on Erythrocyte Deformability and Cerebrovascular CO2Reactivity in Normal Subjects

Aim. Hyul-bu-chuke-tang (HCEt) is a well-known traditional herbal medicine that is used for the treatment of ischemic cerebrovascular disorders. We investigated the acute effects of HCEt on erythrocyte deformability and cerebrovascular CO2 reactivity (CVR) in healthy male subjects. Materials and Methods. We examined erythrocyte deformability in an HCEt group (n = 14) and a control group (n = 10). CVR was measured using hyperventilation-induced CO2 reactivity of the middle cerebral artery and transcranial Doppler (TCD) in the HCEt group (n = 11). A historical control group (n = 10) of CVR measurements was also created from our previous study. All measurements were performed prior to and 1, 2, and 3 hours after HCEt administration. Results. HCEt significantly improved erythrocyte deformability 1 hour after administration compared to the control group (2.9 ± 1.1% versus −0.6 ± 1.0%, P = 0.034). HCEt significantly improved the CVR 2 hours after administration compared to the historical control group (9.1 ± 4.0% versus −8.1 ± 4.1%, P = 0.007). The mean blood pressure and pulse rate did not vary from baseline values in either group. Conclusions. We demonstrated that HCEt improved erythrocyte deformability and CVR. Our findings suggest that an improvement in erythrocyte deformability contributes to HCEt's effect on cerebral microcirculation.

Asymptomatic Carotid Rete Mirabile and Contralateral Carotid Agenesis: A Case Report

Carotid rete mirabile (CRM) is a physiological network between the external carotid artery (ECA) and internal carotid artery (ICA) in lower mammals. It is a transdural arterial network centered at the parasellar area, in anatomical localization of intracavernous or petrous segment of ICA, associated with hypoplasia or absence of the cervical or petrous segment of ICA. It clinically presents as hemorrhagic or ischemic cerebrovascular disorder. Carotid rete mirabile have an angiographic frequency of 0.01%. The authors present a new case of right ICA agenesis supported by primary collateral channels associated with left hypoplasic ICA and CRM. It is an unusual entity and we highlight the role of CRM in cerebral hemodynamic in this asymptomatic vascular patient. Our aim is detail the angiographic features and diagnosis criteria of CRM.

Psoriasis and cardiovascular disease

Current epidemiological data support the association between psoriasis and cardiovascular (CV) risk, in apparent correlation with psoriasis severity. Although less unanimously, evidence of an increased prevalence of CV diseases among psoriasis patients has been reported, including ischemic heart disease, cerebrovascular, peripheral vascular and heart structural disorders. In particular, various studies showed a correlation between psoriasis and major CV events (i.e., myocardial infarction, stroke), while others investigated subclinical changes of blood vessels, such as intima-media thickness increase, arterial stiffness and coronary artery calcification. A series of different mechanisms, like traditional CV risk or iatrogenic risk factors, inflammation, hemostasis dysregulation, hyperhomocysteinemia, and shared genetic susceptibility, are thought to underlie this epidemiological association. Among these elements, inflammation and its related cytokine milieu, including Th1-mediated response and Th17/Treg imbalance, C reactive protein and the newly implicated osteopontin are considered to play a primary role, even if yet to be fully understood.

Tendência da mortalidade relacionada à doença de Chagas, Estado de São Paulo, Brasil, 1985 a 2006: estudo usando causas múltiplas de morte

To study mortality trends related to Chagas disease taking into account all mentions of this cause listed on any line or part of the death certificate. Mortality data for 1985-2006 were obtained from the multiple cause-of-death database maintained by the São Paulo State Data Analysis System (SEADE). Chagas disease was classified as the underlying cause-of-death or as an associated cause-of-death (non-underlying). The total number of times Chagas disease was mentioned on the death certificates was also considered. During this 22-year period, there were 40 002 deaths related to Chagas disease: 34 917 (87.29%) classified as the underlying cause-of-death and 5 085 (12.71%) as an associated cause-of-death. The results show a 56.07% decline in the death rate due to Chagas disease as the underlying cause and a stabilized rate as associated cause. The number of deaths was 44.5% higher among men. The fact that 83.5% of the deaths occurred after 45 years of age reflects a cohort effect. The main causes associated with Chagas disease as the underlying cause-of-death were direct complications due to cardiac involvement, such as conduction disorders, arrhythmias and heart failure. Ischemic heart disease, cerebrovascular disorders and neoplasms were the main underlying causes when Chagas was an associated cause-of-death. For the total mentions to Chagas disease, a 51.34% decline in the death rate was observed, whereas the decline in the number of deaths was only 5.91%, being lower among women and showing a shift of deaths to older age brackets. Using the multiple cause-of-death method contributed to the understanding of the natural history of Chagas disease.

Effect of parenteral or oral vinpocetine on the hemorheological parameters of patients with chronic cerebrovascular diseases

Hemorheological factors play an important role in the pathomechanism of ischemic cerebrovascular disorders. Abnormal rheological conditions in patients with chronic cerebrovascular disease predispose for recurrent strokes. Vinpocetine (VP), a synthetic ethyl esther of apovincamine, has successfully been used in the treatment of cerebrovascular diseases, in part because of its favourable rheological effects. The study investigates the hemorheological changes in 40 patients in the chronic stage of ischemic cardiovascular disease after administration of vinpocetine. All patients received a high dose of intravenous VP in doses gradually increased to l mg/kg/day. In addition, 20 patients (mean age: 61+/-8 years) received 30 mg VP orally for 3 months. The other 20 patients (mean age: 59+/-6 years), who received placebo tablets, served as controls. Hemorheological parameters (hematocrit, plasma fibrinogen, whole blood viscosity, red blood cell aggregation and deformability) were evaluated at 1 and 3 months. The high-dose parenteral VP significantly decreased red blood cell aggregation, plasma and whole blood viscosity (p < 0.05) compared to the initial values. In patients with additional oral treatment, plasma and whole blood viscosities were significantly lower compared to the placebo patients at 3 months (p < 0.05). Our results confirmed the beneficial rheological effects of high-dose parenteral VP (partially caused by hemodilution) observed previously, and also warrant its long-term oral admission to maintain the beneficial rheological changes.

Circulating platelet aggregates in patients with acute ischemic and so-called chronic cerebrovascular disorders

A modified platelet function test was assessed as a routine method in 71 normal subjects and 96 patients. In patients with cerebral infarction (33) and those with transitory ischaemic attacks (30) definite changes in platelet function were demonstrated. In patients with cerebrovascular insufficiency (33) there was significantly increased platelet aggregation, but in only 46% of these patients were the values over 3 standard deviations above the mean of the control group (71).