Biomedical subjects

P Traubner

Publications and source records attributed to P Traubner.

15 recordsLinked to original sources

PubMed1998

Stroke risk factors and development of collateral flow in carotid occlusive disease.

BACKGROUND AND PURPOSE: Blood flow through collateral vessels compensates for reduced blood flow through stenotic or occluded extracranial carotid arteries. Previous studies have shown that extent of collateral flow influences likelihood of stroke and its outcome. Here we analyzed the relationship between stroke risk factors (hypertension, coronary artery disease, diabetes mellitus, tobacco smoking and hypercholesterolemia) and number of patent intracranial collaterals detected by transcranial Doppler ultrasonography. SUBJECTS AND METHODS: We studied 182 patients with various degrees of angiography proven unilateral stenosis of the internal carotid artery. Contribution of the anterior and posterior communicating arteries to the perfusion of the cerebral hemisphere on the side of the stenosis or occlusion was evaluated by a series of compression tests performed during continuous insonation of the middle cerebral artery. The number of detected collateral vessels was correlated with analyzed stroke risk factors. RESULTS: Subjects with stenosis more than 75% or occlusion of the internal carotid artery had a higher frequency of two major intracranial collateral vessels (P< or =0.01 and P< or =0.001, respectively). Hypertensive patients with stenosis more than 75% or total carotid occlusion were more likely to have only a single collateral vessel than patients without hypertension (P< or =0.01 and P< or =0.05, respectively). Other risk factors did not influence the patency of preformed collateral vessels. CONCLUSIONS: Hypertension hindered the development of preformed intracranial collateral vessels in our patients with carotid occlusive disease.

Aged↗

PubMed1996

[The heart and the brain. Aspects of their interrelations].

The objective of the investigation was an attempt to analyze some aspects of the heart-brain relationship. The group was formed by 626 patients with the diagnosis of focal cerebral ischaemia (CI) and 191 patients with the diagnosis of subarachnoidal haemorrhage (SAH). It was revealed that the CI group comprised 77.3% patients with a pathological finding on the heart. Analysis revealed moreover that in the group of patients with "congestive heart failure" there was a significantly higher percentage of patients with a severe neurological deficit as compared to the group with a "normal" ECG (p < 0.001). Atrial fibrillation causes a fivefold increase of the risk of cerebral infarction. The incidence of ECG abnormalities of various types was significantly higher in the group of patients with CI during long-term ECG monitoring, as compared to the results of conventional ECG examination (p < 0.001). The value of long-term ECG monitoring was confirmed also in an investigation of these changes in a group of patients with arterial hypertension, quari potential candidates of cerebral infarction. The relationship between cardiac and cerebral function was tested also in an investigation focused on the incidence of ectopic activity and changes of the QT interval. It was revealed that while the percentage rate of ectopic activity assessed by conventional ECG examination was in the group of "improved" patients 18.0%, long-term monitoring revealed a rate as high as 48.0%, the difference being statistically significant. Similar significant differences were observed also on analysis of the QT interval: in the group of patients with neurological "improvement" the QT interval was significantly shorter, as compared with the group with neurological "deterioration". It was assumed that the prolonged QT interval could be the cause of sudden death. A cardio-cerebral relationship was found also on analysis of changes of the cerebral circulation (CBF) in different forms of cardiac insufficiency. It was revealed that isolated ventricular extrasystoles reduced the CBF by 8.0%, isolated atrial extrasystoles by 12% and in atrio-ventricular tachyarrhythmia the CBF is reduced by as much as 25.0%. The cerebro-cardiac relationship was tested in a group of patients with SAH. ECG abnormalities of a varying type were found in 30.7% of the patients with SAH. They are described in as many as 100% of patients and were detected also other in cerebral disorders, such as contusion of the brain, intraoerebral haemorrhage and cerebral tumours.

Arrhythmias, Cardiac↗

PubMed1996

[Imaging methods in the diagnosis of acute cerebrovascular stroke].

The authors emphasize the possibilities of some new imaging methods in the diagnosis of acute cerebrovascular attacks, i.e. methods used under local conditions: differentiation of intracranial haemorrhage in case of a haematoma in the area of a ruptured aneurysm, blood in the subarachnoidal space in subarachnoid haemorrhage. To differentiate a tumour decompensated by the vascular route. It is known that imaging by computed tomography. Imaging on the basis of magnetic resonance in the diagnosis of acute, subacute and chronic infarction has some specific features. It was revealed that also magnetic resonance angiography can be an asset, in particular when major vessels are affected. Classical intervention angiography still is useful in acute cerebrovascular attacks as well as in the diagnosis of cerebral death.

Cerebrovascular Disorders↗

PubMed1996

[Ultrasonic diagnosis in the area of the carotid and vertebrobasilar circulation].

At present the duplex ultrasonic method is the best non-invasive examination method of the carotid and vertebrobasilar circulation. It was developed by a combination of the Doppler method with two-dimensional imaging in real time. It makes it possible to evaluate all stages of the stenotic process, the size and surface of plaques, the lumen of the vessels, occlusions. It provides a comprehensive picture of the morphology and function of vessels. The introduction of transcranial Doppler ultrasonography by R. Aaslid in 1982 made it possible to examine also basal intracranial arteries. Examination by ultrasound makes it possible to diagnose vascular changes in still asymptomatic patients; it helps to establish the correct diagnosis, offers the possibility to evaluate the therapeutic effect as well as terminal conditions-cerebral death.

Arterial Occlusive Diseases↗

PubMed1995

Effect of collateral flow patterns on outcome of carotid occlusion.

The relationship between anatomical configuration of collateral flow and the outcome of the internal carotid artery (ICA) occlusion was analyzed. Sixty-one patients with occlusion of ICA were studied with transcranial Doppler ultrasonography. The authors monitored blood flow velocities in the middle cerebral artery (MCA) ipsilateral to the ICA occlusion during a series of carotid compressions. Blood flow through three major collateral arteries (anterior and posterior communicating arteries and ophthalmic artery) was determined as a residual flow in MCA after each compression. Twelve subjects had asymptomatic occlusion and 46 had stroke; patients with stroke were divided into mild, moderate, and severe stroke groups. Subjects with asymptomatic occlusion had a higher number of patent collateral vessels than severe stroke patients (p < or = 0.001). The same relationship was found between mild and severe stroke patients (p < or = 0.001) and between moderate and severe stroke (p < or = 0.01). Patients with watershed ischemia had a lower number of patent collateral arteries than patients with thromboembolic ischemia as revealed by CT examination (p < or = 0.02). This study demonstrates the crucial role of collateral flow in the stroke pathogenesis and stroke outcome in subjects with extracranial ICA occlusions.

Adult↗

PubMed1994

Compressions of carotid and vertebral arteries in assessment of intracranial collateral flow: correlation between angiography and transcranial Doppler ultrasonography.

The authors examined 61 subjects with carotid angiography and 50 with vertebral angiography. Angiograms were evaluated for collateral flow through the ophthalmic, anterior communicating, and posterior communicating arteries. The authors evaluated the patency of collateral vessels directly using transcranial Doppler ultrasonography; they made indirect detection after the compression of carotid and vertebral arteries while monitoring flow velocities in the middle cerebral artery. They established criteria for the hemodynamic significance of tested collateral vessels. A combination of carotid compressions and transcranial Doppler ultrasonography detected the patency of the ophthalmic and anterior communicating arteries with a specificity and sensitivity of 1.00. Examination of the posterior communicating artery had a sensitivity of 0.97 and specificity of 0.98. Indirect evaluation of collateral vessels can not only detect their presence but also establish their hemodynamic significance with high accuracy.

Adult↗

PubMed1993

Blood flow velocities in basilar artery during rotation of the head.

The authors measured blood flow velocities with transcranial Doppler ultrasonography in the basilar artery after extreme rotations of the head. Studied subjects were divided in two groups according to the degree of asymmetry of the vertebral artery lumens. Rotation of the head caused significant reduction of the mean flow velocity in the basilar artery in the subjects with asymmetry of the vertebral arteries of more than 75%. The decline occurred only after the rotation ipsilaterally to the hypoplastic vertebral artery. This study confirms the importance of the collateral flow in the compensation of dynamic compression of the vertebral artery.

Adult↗

PubMed1992

Short-term prognosis of stroke due to occlusion of internal carotid artery based on transcranial Doppler ultrasonography.

BACKGROUND AND PURPOSE: The clinical course of stroke due to occlusion of the internal carotid artery is influenced by amount of collateral flow. We measured mean frequency shifts in the middle cerebral artery by transcranial Doppler ultrasonography to determine its prognostic value. METHODS: Patients with proven extracranial occlusion of the internal carotid artery and ipsilateral hemispheral stroke were enrolled in our study. We performed transcranial Doppler ultrasonography on 31 patients within 48 hours after the stroke onset and followed up 25 patients in 28 days. At the same time, neurological examination with quantification of neurological deficit was done. We correlated values of flow frequency shifts on the side of stroke with degree of neurological deficit at the onset and at 28 days as well as the degree of clinical improvement and the value of frequency shifts. RESULTS: We found a negative correlation between blood flow frequency shifts in the middle cerebral artery and degree of neurological deficit at the onset (Spearman rank correlation coefficient, -0.567; p less than 0.001). We also found a positive correlation between the change of the neurological deficit during follow-up and frequency shifts at the onset (Spearman rank coefficient, 0.548; p less than 0.05). CONCLUSIONS: Diminished blood flow velocity (mean frequency shift) in the area of stroke is a negative prognostic factor for the degree of neurological deficit at the onset and a negative prognostic factor for possible improvement. Knowledge of hemodynamic conditions in the stroke area may help to improve therapeutic decisions.

Adult↗

PubMed1989

[Vascular headache: circulatory, hemorrheologic, electrophysiologic and psychological aspects].

The aim of the work was to analyze circulatory, rheological, electrophysiological and psychological characteristics of patients with vascular headache, mostly migraine and vasomotor cephalea. The group was formed by 69 patients, mean age 40.4 +/- 9.0 years. It was revealed that: 1. there were no significant changes in rheological properties of blood in the following six parameters: coagulation, viscosity of plasma and blood, platelzo aggregation, of circulating aggregates, 2. there were no significant changes in rCBF (FF,SF,AF and ISI) parameters in the group of patients with bilateral headache but a rising rCBF in unilateral headache, 3. there was a significant reduction of the "peak frequency" in supratrochlear arteries and a significant increase of the flow rate in the intracerebral arteries (a.cerebralis media, a.cerebralis anterior), 42.4% of the patients displayed abnormal but non-specific EEg changes, 5. there was a significant increase of the amplitude of P1 and N2 waves of visual evoked potentials and a non-significant shortening of the latency of wave N1, 6. significant changes were recorded in some psychological parameters, in particular an increase of the score of depressivity, anxiety and neuroticism.

Adult↗

PubMed1988