Biomedical subjects

V Demarin

Publications and source records attributed to V Demarin.

32 records · Page 2Linked to original sources

PubMed1999

Influence of prolonged stress on cerebral hemodynamics.

The author has investigated the impact of psychological and socio-economic factors on cerebral hemodynamics and development of cerebrovascular disease (CVD). A group of 120 war sufferers with signs of post-traumatic stress disorder and adaptation disturbances, and 120 persons of the control group with no traumatic war experience have been studied. The blood flow velocity and various parameters of spectral frequency analysis have been measured, using the method of transcranial doppler sonography (TCD). A greater number of hemodynamical changes has been found in the group of subjects than in the control group (p < 0.05), in which increase of vasospasm is statistically significant probably as a result of predomination of the sympathetic system stimulation and nicotinic effect on the brain blood vessels. Flow disturbances are relatively more frequent in older subjects, which suggests the rapid development of the atherosclerotic process. The results suggest that exposure to prolonged stress and bad socio-economic factors, through different neurobiological mechanisms, increased the risk for stroke.

Adaptation, Psychological↗

PubMed1998

Role of vertebral artery hypoplasia in migraine.

The role of cerebral hypoperfusion in the posterior circulation has not been clearly established in migraine. The purpose of this study was to determine the role of vertebral artery (VA) hypoplasia in the pathogenesis of migraine. We studied the extracranial part of VA in 59 migraine patients (17 with and 42 without aura) using color Doppler. In migraine with aura, 29% of patients had hypoplastic VA, and in migraine without aura 7%. In migraine with aura, mean diameter of the right VA was 2.7+/-0.7 mm, and of the left 3.3+/-0.7 mm; in migraine without aura mean diameter was 3.1+/-0.5 mm on the right, and 3.3+/-0.6 on the left. In migraine with aura, mean systolic blood flow velocity was 55+/-16 cm/s on the right, 60+/-17 cm/s on the left, in migraine without aura 57+/-18 cm/s on the right, 57+/-18 cm/s on the left. We observed higher frequency of hypoplastic VA in migraine with aura, suggesting that hypoplasia of VA may be an additional factor which can lead to hypoperfusion in the posterior circulation during the aura phase.

Adult↗

PubMed1997

Maternal cerebral circulation in normal and abnormal pregnancies.

BACKGROUND: Abnormal pregnancies are usually associated with an impairment of maternal cerebral circulation which is mainly a consequence of generalized vasospasm and cerebral edema. The pathogenesis of vasospasm has still been a matter of controversy. The aim of this study was to evaluate maternal cerebral blood flow velocity (CBFV) changes in normal and abnormal pregnancies, and to correlate CBFV findings with the severity of symptoms in abnormal pregnancies. METHODS: A group of 40 gravidas (aged between 25 and 32 years) with pre-eclampsia were analyzed by Transcranial Doppler (TCD), Color Doppler Flow Imaging of carotid arteries and Transcranial Color Coded System once a week, starting from 32nd week of pregnancy and followed 2 months after delivery. The study was performed from the January 1996 to June 1996. RESULTS: The results showed 70% of abnormal pregnancies to have impaired TCD findings, mostly increased CBFV. The degree of toxemia measured by Goecke's index significantly correlated with abnormal CBFV Nine gravidas with increased CBFV on the first examination developed vasospasm during 34 to 36 weeks of gravidity. No statistically significant difference of the M1 segment of MCA diameters was found between normal (3.8 +/- 0.7 mm) and abnormal pregnancies (4.1 +/- 0.9 mm). CONCLUSIONS: The increase in the maternal CBFV was the most frequent observation in abnormal pregnancies. It was progressive during late pregnancy, when vasospasm may develop, although the presence of vasospasm is still the matter of controversy. The most important observation was that significant changes in CBFV preceded neurologic symptoms, emphasizing the predictive role of TCD in abnormal pregnancies.

Cerebrovascular Circulation↗

PubMed1997

Serotonin syndrome.

Serotonin syndrome usually occurs after treatment with monoamine oxydase inhibitors and drugs that enhance serotoninergic transmission. Serotonin agents, such as Proza, are commonly prescribed drugs; therefore, the serotonin syndrome appears more frequently than before. Clinicians must be able to prevent, recognize, and treat this syndrome in their practice. This review summarizes the literature of case reports of patients who developed the serotonin syndrome.

Fluoxetine↗

PubMed1992

Transvaginal color Doppler study of middle cerebral artery blood flow in early normal and abnormal pregnancy.

Transvaginal color and pulsed Doppler sonography was performed on 106 singleton pregnant women; 75 had clinically normal pregnancies, and the remaining 31 patients had complicated pregnancies with vaginal bleeding. The gestational ages ranged from the 7th to 18th menstrual weeks. The aim of the study was to establish the earliest gestational age at which intracranial blood flow could be detected, in particular in the middle cerebral artery. The intracranial circulation becomes visible at the 8th week of gestation (7 weeks and 3 days). The end-diastolic component of blood flow is inconstantly present from the 11th to the 13th gestational week, and is always detected thereafter. A significant decrease in the pulsatility index (p < 0.05) and peripheral flow impedance index (p < 0.001) was observed during the early weeks of pregnancy in both the normal and complicated pregnancies. There was no significant difference between the groups (p > 0.05). Results suggest that Doppler studies of middle cerebral arteries in early pregnancy are unlikely to be of value in identifying fetal hemodynamic disorders in the early stages of spontaneous abortion.

Journal Article↗

PubMed1991

Transcranial Doppler diagnostic criteria in the evaluations of arteriovenous malformations.

In order to get a better insight in hemodynamic occurrence of intracranial arteriovenous malformations (AVM), 31 patients with AVM, documented by CT and angiography, were investigated by Transcranial Doppler (TDC). Although the angiography provides definite diagnosis of AVM, its size, position, type feeders and involvement of various vascular segments, TCD provides more information about collateral circulation, intracerebral shunts or functional stenosis due to high blood velocities within the blood vessels involved by AVM. The parameters obtained by TCD: mean cerebral blood flow velocities (MCBFV) in middle and internal carotid artery (MCA, ICA), pulsatility index (PI), MCA/ICA ratio and (S-D)/S ratio were introduced. Results have shown that TCD findings in non-feeding arteries were normal in all patients. TCD finding of MCBFV in MCA and ICA, PI and MCA/ICA ratio in feeding arteries has shown a significant difference from normal arteries (p less than 0.01). These parameters are shown to be AVM size dependent. MCBFV in MCA on the feeder side was statistically significant higher in those patients with large AVM (greater than 4 cm) size (p less than 0.01). For assessment of AVM and its improved and advanced analysis the potential advantages of parameters: (S-D)/S ratio and 3D hemodynamic mapping has been emphasised.

Adolescent↗

PubMed1991

Development of carotid stenosis.

A group of 29 patients with carotid artery stenosis was analyzed with the purpose of following-up the development of stenosis, and performing duplex scanner of carotid arteries. The follow-up was performed on the very first day of the study and six months later. There were 49 stenoses of internal carotid arteries in 29 patients. Carotid stenoses were classified into six categories. Most carotid stenoses were unchanged during the six month period (57.2%), or progressed (36.7%), but spontaneous regression was found in 6.1%. The ultrasonic characterization of carotid plaques was made in four types. Regression was noticed mainly in ulcerative plaques, while hard and fibrous plaques remained unchanged or progressed. Soft plaques progressed in all cases. Intraplaque hemorrhage was found in 2 patients. The most common risk factors for carotid atherosclerosis were hypertension, hyperlipidemia and cigarette smoking.

Aged↗

PubMed1991

Prevention of stroke--a report from collaboration project between Zagreb and Barcelona.

Cerebrovascular disease (CVD) is the main killer in the modern society and the most frequent cause of death and disability. According to the experiences of highly developed Western countries, especially of the U.S.A., the incidence of stroke can be reduced by the development and introduction of preventive actions and change of life style. Incidence of cerebrovascular disease is high in Croatia as well as in Spain (46% in the 46-59 age range) with an increasing tendency in younger population. As prevention is the only way of CVD incidence reduction, it is indispensable to organize an integral preventive neurologic network. Within the W.H.O. project "Health for All by the Year 2000 and the project "Zagreb"--Healthy City" a preventive action under the slogan 'With perfect brain and veins--enjoy the healthy days', has been organized with the aim to reduce the incidence of stroke for 20% during the following 10-year period. A standardized work of preventive network in Zagreb has also been established in Barcelona as a joint work. Using the interdisciplinary counselling approach, medical teams are still making examinations. In Zagreb Center for Neurological Sciences and Brain Research, data of risk factor distributions and trends of stroke incidence changes have been collected and the results have been analyzed. The Zagreb Center has also become a center for continuous evaluation and further planning. In this article functions of preventive centers, the preventive standardized protocol and structural and functional preventive network are introduced. The results of preventive action in Zagreb are also briefly presented.

Aged↗

PubMed1991

Measurement of blood flow through AV-fistulae by means of Doppler sonography in regularly haemodialysed patients.

In regularly dialyzed patients a variety of pathological events can negatively influence haemodynamics and blood flow through arterio-venous fistula, leading to inadequate blood flow through the dialyzer or disturbances in hemodynamics of the whole body. It therefore appears important to quantify flow velocity and volume flow through the arteriovenous fistula in such cases. We used a Vasoview computer controlled system for noninvasive vascular diagnostics based on B-scan "real-time" ultrasound for imaging the structure of tissue, combined with pulsed Doppler ultrasound for determination of hemodynamics. Thirty patients (16 males and 14 females, aged 45 +/- 10 years; range 23 to 61 years), with different periods spent on hemodialysis (5.5 +/- 3.1 years, range 1 to 11 years) were included in this study. The average systolic, diastolic and mean blood volume flows were 2131.8 +/- 565.8, 972.0 +/- 309.6 and 728.4 +/- 287.4 ml/min, respectively. The mean blood volume flow was calculated by integration of the area under curve of blood flow in one heart cycle on the Doppler signal. It is calculated by the apparatus and displayed on the screen during measurement. The average blood vessel diameter was 9.1 +/- 1.3 mm (mu +/- omega). The results revealed a marked inter-individual variation in volume flow through arteriovenous fistulae of dialyzed uremics (range 240.0 to 1200.0 ml/min). Doppler ultrasound thus appears to be a valuable method for determination of blood flow through arteriovenous fistula of dialyzed uremics as well as for detection of hemodynamics disturbances of interest, such as turbulent blood flow.

Adult↗

PubMed1990

Intra- and extracranial circulatory changes in cigarette smokers assessed by ultrasound: transcranial Doppler (TCD) and duplex scanning investigation.

The group of 98 "healthy smokers" was analyzed in order to evaluate potential influence of cigarette smoking on intracranial blood flow disturbances and extracranial carotid intimal changes, performing transcranial Doppler (TCD) and Duplex scanning of the carotid arteries. Almost 70% of smokers analyzed in our study had some intracranial circulatory changes, predominantly in the vertebral arteries (35%). Half of smokers analyzed had some pathological intimal changes in the carotid arteries. The most frequent finding was wall thickening (23%) and then calcified (13%) and soft plaques (10%). Dose response relationship between smoking and atherosclerosis is also introduced. More than 30 cigarettes smoked per day can significantly influence plaque development and already 20 cigarettes smoked per day can cause significant intracranial blood flow disturbances. The majority of our investigated smokers were in high risk category for development of cerebrovascular disease and 5% were in a very high risk category. Cessation of cigarette smoking will eliminate it as a risk factor. A low dose-response relation and the development of tolerance produced by exposure to nicotine were also introduced.

Adult↗

PubMed1989

[Perioperative complications in carotid endarterectomy with respect to the stage of the cerebrovascular disease].

Records of perioperative complications following 407 consecutive carotid endarterectomies performed in 366 patients in the 18-year period have been presented. The complications are categorized according to the clinical stage of vascular disease, that is, according to the indications for the surgery. Out of the total number, 46 (11.3%) operations were done in the 1st, asymptomatic stage of disease, for the haemodinamically significant stenoses and ulcerated plaques; 173 (42.5%) in the 2nd clinical stage for hemispheral and nonhemispheral transient ishemic attacks (TIA) and reversible neurologic deficits (RIND); 3 (0.7%) in the 3rd stage which is a progressive cerebrovascular stroke and 185 (45.5%) in the 4th clinical stage of the disease, in patients with previous cerebral infarction and a permanent neurologic deficit. The rate of a temporary and permanent neurologic deficit, as well as mortality in the first stage of the disease equals zero. In the second stage of the disease, the rate of a temporary neurologic postoperative morbidity increases to 1.7%, of a permanent neurologic morbidity to 1.2%, while the rate of mortality is 1.2%. In the 3rd and 4th stage, those rates amount to 66.7%, 0% and 33.3%, and 1.1%, 3.8% and 1.6%, respectively. The rates of perioperative morbidity and mortality are in proportion to the scope of preoperative brain dysfunction. Results of this work suggest the necessity of categorization of patients, candidates for carotid endarterectomy, according to the clinical stage of the disease, which will enable a better comparison with other authors' results, give a more reliable view on the efficacy of the surgical treatment and justify the surgeons' attitude towards indications.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1989

Duplex scanner versus conventional arteriography for carotid artery disease evaluation.

In order to evaluate extracranial circulation, Duplex scanning and conventional angiography were performed. The group of 41 patients (mean age 53.8 +/- 11.8, 71% male) were examined. Results were analyzed for extracranial disease presence such as presence of vessel stenosis (mild, moderate, severe), occlusion and presence of plaques. Data from Duplex scanning and carotid arteriography were correlated within the patients in the term of sensitivity and specificity of the methods used. The sensitivity of Duplex scanning for disease presence was 93% and specificity was 83%. For the presence of stenosis, sensitivity was 79% and specificity was 62%. For mild and moderate stenosis (less than 50% of lumen narrowing) sensitivity was 63%, whereas for severe, high-grade stenosis (greater than 50%) and occlusion the sensitivity was 100%. For the plaque presence the sensitivity was 52% and specificity was 73%. A good accordance of plaque findings with both methods was found only in 24% of patients. By Duplex scanner the plaques were discovered in 92% of patients while by arteriography they were found only in 32%. Duplex scanning and conventional arteriography are both accurate methods for determination of the reduction in diameter of carotid arteries (especially in stenosis greater than 50%), whereas Duplex scanning is more accurate for plaque detection and plaque characterisation.

Blood Flow Velocity↗

PubMedDate not supplied

A correlation of 5-hydroxytriptamine and cerebral vasoreactivity in patients with migraine.

Cerebral haemodynamics and the level of serum 5-hydroxytriptamine (5-HT) were analysed in 21 migraine patients (8 with and 13 without aura) during the headache-free period as well as the attack. Cerebral vasoreactivity was evaluated by acetazolamide test and Transcranial Doppler ultrasonography (TCD). TCD findings were within normal ranges in the majority of migraine patients. Patients with migraine without aura had higher blood flow velocities (BFV) than patients with aura. Comparison of BVF and pulsatility index (PI) data patterns in migraine with and in migraine without aura during the attack revealed differences indicating cerebral hypoperfusion. It was noticed that systolic BFV decreased in migraine with aura on the headache side while PI increased. In migraine without aura, both systolic BFV and PI increased. 5-HT findings were heterogeneous. Reduction of cerebral vasoreactivity was observed especially in migraine with aura. Our results suggest different pathogenic mechanisms between migraine with and without aura, supporting the neurogenic inflammation theory.

Acetazolamide↗

PubMedDate not supplied

[Importance of the evaluation of cerebral vasoreactive capacity in the indication for carotid endarterectomy].

In order to evaluate the outcome of endarterectomy, we estimated the cerebral vasoreactive capacity in 3 main patient groups with carotid artery disease: A. occlusion, B. high-grade, and C. low-grade carotid stenosis. The results showed that certain proportion of patients with reduced CVC can be distinguished in the each investigated groups, indicating thus, those patients in whom endarterectomy can benefit. Our study provides evidence that acetazolamide test with TCD measuring may be used to assess the CVC before and after endarterectomy. Carotid endarterectomy improves CVC in patients who had compromised cerebral perfusion reserve before operation. We suggest that the endarterectomy can also benefit in the patients with carotid occlusion and low grade stenosis if CVC is estimated.

Acetazolamide↗