The effect of different doses and different routes of acetylsalicylic acid administration on platelet aggregation in healthy volunteers and ischemic stroke patients.

The purpose was to assess the effect of different doses and different routes of acetylsalicylic acid (ASA) administration on platelet aggregation and the comparison between platelet aggregation after the single and the repetitive administration of ASA in healthy individuals and in patients after ischemic stroke. The study group consists of 22 healthy individuals and 30 patients with documented ischemic stroke. Platelet aggregation was measured in healthy individuals: (a) twice before ASA and (b) 2 h after different single doses and different routes of ASA administration-(b1) 500 mg orally, (b2) 500 mg intravenously, and (b3) 100 mg orally. We measured aggregability in healthy individuals after five consecutive days of 100 mg of ASA q.d. and in patients on chronic ASA 100 mg q.d. The VerifyNow was used with results expressed in aspirin reaction units (ARU). In healthy individuals, the dose-(b1) 500 mg orally-reduced the aggregability to mean (SD) 392 (36) ARU (p < 0.001), (b2) 500 mg intravenously to 428 (46) (p < 0.001) and (b3) 100 mg orally to 460 (76) (p < 0.001). The suppression of aggregation after 500 mg was (p = 0.029) higher after the oral compared to intravenous administration, and the same is true for the suppression after single dose of 500 mg orally and 100 mg orally (p = 0.011). Oral dose 100 mg for 5 days in healthy individuals reduced aggregation to 405 (37) and in post-stroke patients to 433 (54). All doses of ASA, both orally and intravenously, have produced a significant reduction of platelet aggregation. Preference of the parenteral to oral application has not been established.

Non-invasive evaluation of proximal vertebral artery stenosis using color Doppler sonography and CT angiography.

BACKGROUND AND PURPOSE: A reliable and safe diagnostic procedure for vertebral artery (VA) stenosis is needed, but none is generally accepted yet. In our study, we evaluated symptomatic VA stenoses using color Doppler sonography (CDS). CT angiography (CTA) has been employed as a non-invasive reference method. Next, we tested the accuracy for medium to high degree stenoses by digital subtraction angiography (DSA). MATERIALS AND METHODS: Sixty-two symptomatic patients with a proximal VA stenosis were examined prospectively with CDS and CTA. The VA diameters by both methods were correlated. The stenotic peak systolic velocity (PSV1) and its ratio to the post-stenotic segment (PSVr) were analysed using receiver operating characteristic curve (ROC). Cut-off values for PSV1 and PSVr defining moderate and severe stenosis were assessed. In stenoses≥50%, an additional search for correlation with DSA was carried out. RESULTS: Mean VA diameter was 3.561mm (95% CI 3.361-3.760) by CDS and 4.180 (95% CI, 3.950-4.411) by CTA, accompanied with significant similarity in Pearson' correlation (0.847, P<0.001). The PSV1 and PSVr appeared to be equally accurate for VA stenoses of 50% or more (PSV 1-AUC 0.814, P<0.001, cut-off velocity≥1.35m/s, PSVr-AUC 0.819, P<0.001 with a cut-off value≥2.2). Final Spearman' correlation of CTA results vs DSA was highly significant (0.823, P<0.001). CONCLUSION: Our results endorse the non-invasive combination of CDS with CTA in the evaluation of VA stenosis as a reliable diagnostic algorithm, tightly correlating with DSA.

Stroke care in Central Eastern Europe: current problems and call for action.

Stroke is a major medical problem and one of the leading causes of mortality and disability all over in Europe. However, there are significant East-West differences in stroke care as well as in stroke mortality and morbidity rates. Central and Eastern European countries that formerly had centralized and socialist health care systems have serious and similar problems in organizing health and stroke care 20 years after the political transition. In Central and Eastern Europe, stroke is more frequent, the mortality rate is higher, and the victims are younger than in Western Europe. High-risk patients live in worse environmental conditions, and the socioeconomic consequences of stroke further weaken the economic development of these countries. To address these issues, a round table conference was organized. The main aim of this conference was to discuss problems to be solved related to acute and chronic stroke care in Central and Eastern European countries, and also, to exchange ideas on possible solutions. In this article, the discussed problems and possible solutions will be summarized, and introduce 'The Budapest Statement of Stroke Experts of Central and Eastern European countries'.

Impact of aging on cerebral vasoregulation and parenchymal integrity.

UNLABELLED: Sufficient vasodilatory and vasoconstrictive reactivity of cerebral arterioles is an important prerequisite for adequate capillary perfusion. To appreciate its capacity during aging and to elucidate its impact on parenchymal integrity we undertook a correlation using ultrasonography and brain MRI. Sixty healthy persons with no stenoses in the carotid and vertebral arteries were examined by transcranial Doppler to assess middle cerebral artery mean flow velocities (MFV) at rest, after 30 s apnea and after 90 s hyperventilation. Young persons, N=20, with a mean age of 24.8 (20-32) were compared with the middle aged, N=20, 54.8 (40-63) and elderly, N=20, 76.2 (69-84). A different cohort of 40 elderly persons, with a mean age of 68.4 (57-85) were evaluated also by MRI using FLAIR and T2-weighted sequences. Their extent of leukoaraiosis measured by the Fazekas scale was correlated with their vasoregulatory capacity. RESULTS: The steady state MFV in young persons, 71 cm/sec, decreases to 48.1 and to 44.9 cm/sec in the middle and the old aged. The post-apnoic vasodilatation in young persons accelerates the MCA blood velocity by 41.7%, while in middle and old age only by 37.6 and 32.9% respectively. The MCA deceleration post-hyperventilation by 50.2% in young people decreases to 39.1% and to 29.7% respectively in the older categories. The correlation of periventricular hyperintensities and deep white matter lesions was found highest with the index of resistance (0.45, p<0.05) while with the apnoic acceleration and hyperventilatory deceleration it was minimal (0.01 and 0.08 respectively). CONCLUSION: The extent of vasoregulatory capacity during aging decreases along with the decreasing basic MFV. Its effect on the initial stages of leukoaraiosis is minimal.

History of dementia research in Bohemia and middle Europe.

UNLABELLED: The clinical aspects and histopathology of dementia are best understood when based on knowledge of the historical milestones associated with its development. We studied archive materials and visited some of the psychiatric asylums that were active in Prague during the 19th century. RESULTS: The gradual recognition of dementia and its histological correlates on the territory of the actual Czech Republic from the 1830s are described, together with its links to Austrian, German, and other foreign psychiatry and neurology. A stepwise differentiation between inborn mental incapacity and the acquired forms occurred between 1830 and 1890. This was followed by contributions from Emil Redlich, Arnold Pick, Karel Kuffner, Oskar Fischer and others between 1890 and 1930, elucidating features of senile plaques, and shedding light on behavioral-morphological correlations and on the role of inflammatory tissue changes. These discoveries allowed the distinction between neurodegenerative causes of dementia and other etiological categories. CONCLUSION: One hundred years ago, Prague was one of the cradles from which our modern understanding of neurodegenerative dementia emerged.

Cerebral blood supply with aging: normal, stenotic and recanalized.

UNLABELLED: The prosperity of brain parenchyma during aging depends on the preservation of cerebral blood flow (CBF) parameters. We have analysed ultrasonographic measurements of peak systolic (PSV) and end diastolic velocities (EDV) along with pulsatility (PI) and resistance indexes (RI) in common (CCA), internal (ICA) and external carotid artery (ECA) (N=199) and in vertebral arteries (VA) (N=200) in patients without any signs of stenosis. In two other cohorts patients with internal carotid artery stenosis (N=231) and patients prior to and after therapeutic recanalization (N=81) were evaluated in the same parameters. RESULTS: in the range of 21-92 years PSV in CCA decreases by 7 mm/s/year, while in ICA only by 2.31 mm/s/year. The decrease of EDV in carotid arteries occurs between 1.72 and 2.28 mm/s/year. PSV in VA drops down by 0.91 mm/s/year, EDV by 0.86 mm/s/year. PI and RI increase with age in all vessels, but not significantly. Stenotic ICAs are associated with increased PSV in the range of 0.7-2.9 m/s, but also with an increasing PSV variability along the growing stenosis in individual patients. In all degrees of stenoses some patients preserve normal velocities. In average the increment for each 10% of the stenosis below 50% makes 8 cm/s, while above 50% it makes already 50 cm/s. In persons with bilateral stenoses the increment with growing stenosis is steeper. The restoration of normal ICA lumen by means of carotid endarterectomy or by angioplasty with stenting results in an average drop by 1.23 m/s in PSV and by 0.4 m/s in EDV. We have investigated the ophthalmic artery and other substitution supplies and deduce, that the remarkable differences in blood flow velocity reactions to a compromised carotid lumen depend on the formation of collaterals in mutual interplay with peripheral resistance.

Mastoiditis complicated with Gradenigo syndrome and a hypertrophic pachymeningitis with consequent communicating hydrocephalus.

We present the clinical, radiological and pathological features of a case of a cranial hypertrophic pachymeningitis that developed in the course of mastoiditis and petrous apex inflammation and responded to immunosuppressive therapy only. Documented by the development of clinical findings, magnetic resonance imaging, cerebrospinal fluid changes, histopathology findings, by otosurgical intervention and finally by the insertion of a ventriculo-peritoneal shunt, the case illustrates a gradual development of pachymeningitis with consequent hydrocephalus and intracranial hypertension. We consider this disease development an example of immune-induced proliferative fibrotic changes in meninges.

Cerebral microangiopathy in the mosaic of new discoveries.

After a short historical note on the diversion of the vascular concept of dementia from that of primary degeneration, this review describes cerebral deterioration on vascular grounds in three levels. Occlusions of big vessels with a single major infarct, middle calibre vasculopathy with multiple lacunes and finally microangiopathy causing leukoaraiosis--all these three entities produce cognitive disorders. Changes in the vessel wall, in cerebral blood flow velocity, the territorial and interterritorial rules for the location of malacia or lacunes are reviewed using neuroradiologic aspects revealed by ultrasound, by CT and MRI. Alterations in diffusion and their measurements by MRI are discussed in regard to ultrastructural reactions to ischaemia. Thresholds for tissue deterioration are shown in association with ATP depletion and with pathologic compounds in the interstitium.

The current availability of neurological in-patient services in post-communist central and eastern European countries.

BACKGROUND AND PURPOSE: Limited information can be obtained as to the availability of neurological in-patient services in the former communist countries of Eastern and Central Europe. The objective was to analyse data received directly from representatives of the particular countries. METHODS: The data were collected under the auspices of the 'First European Cooperation Neurology Workshop' held in April 2000, in Trest, Czech Republic. Neurologists from 15 post-communist countries provided information from their respective countries. Linear trends in graphs including the reliability value R(2) were used in the analysis of correlations. RESULTS: Data from 14 countries were assembled and trends were analysed. CONCLUSIONS: Direct relationships were found between: (1) the average department size and the average catchment area (R(2) = 0.1015); (2) the percentage of districts with a neurological in-patient department and the gross national product (GNP) per capita (R(2) = 0.1359); (3) the average neurological department size and the GNP per capita (R(2) = 0.1135), and (4) the average length of treatment and the number of neurological beds/100,000 inhabitants (R(2) = 0.1745). Inverse relationships were found between: (1) the number of neurological beds/100,000 inhabitants and the average hospital catchment area (R(2) = 0.2105), and (2) the number of neurological beds/100,000 inhabitants and the GNP per capita (R(2) = 0.1144).