Clinical Neuroscience

[Neuroprotection in brain ischemia - doubts and hopes]


MARCH 15, 2004

Clinical Neuroscience - 2004;57(03-04)

[In ischaemic stroke the two major potential therapeutic strategies are aimed at either improving cerebral blood flow or directly interacting with the cytotoxic cascade - a large body of evidence gained from animal studies is in support of them. In clinical trials direct neuroprotection by blocking the neurotoxic cascade remained ineffective, although there are several clinical trials still in progress. We summarize the experimental data and present the results of clinical trials and also discuss why so many drugs, which were effective in animal studies, failed in human trials. It is emphasized, that 1. in most animal studies the reduction of infarct size, i.e. the amount of saved penumbral tissue, was the outcome measure, whereas neurological function remained unassessed; 2. the recovery of intellectual performance and higher cortical functions are of major importance in the future quality of life in stroke victims; however, it is impossible to examine these parameters appropriately in animal studies; 3. in many clinical trials the patient population was rather heterogenous and low in number, the study protocol was not optimal and the critical analysis of the subacute and chronic phase was lacking or insufficient. We present the major experimental stroke models, discuss their similarities, differencies and limitations as compared to the human pathophysiological processes. The pitfalls of extrapolating data from animal studies to clinical practice are also summarized. The complex network of functional and morphological intercellular connections, the long timescale of neurotoxic and reparative events and the lessons learned from clinical trials suggest, that the use of drug combinations (therapeutic cocktails) targeting multiple steps of the neurotoxic cascade would hopefully result in more effective treatment of ischaemic stroke. Strategies to facilitate brain plasticity and regeneration is an additional promising tool to enhance recovery in brain ischaemia.]



Further articles in this publication

Clinical Neuroscience

[12th Annual Meeting of the Hungarian Society of Neuroradiology]

[12th Annual Meeting of the Hungarian Society of Neuroradiology 2004;57(03-04)]

Clinical Neuroscience

[Effect lesions of extrahypothalamic brain structures on testicular functions in rats with special emphasis on asymmetry]


[Introduction - The aim of our studies was to investigate the involvement of extrahypothalamic brain structures in the control of testicular functions with special emphasis on the effect of right- and left-sided structures. Material and method - We performed lesion of the insular cortex, the amygdala, interrupted part of nerve fibers to and from the insular cortex, and cut the major commissural pathway of the brain the corpus callosum in adult male rats and studied the effect of the interventions on testicular steroidogenesis, serum testosterone and gonadotrop hormone concentrations. Results - Following lesion of the insular cortex on the right side serum testosterone level and steroidogenesis of the testes decreased (in the case of the left testis the difference was significant). Similar lesion on the left side did not change the parameters studied. Both right- and left-sided lesion induced a significant increase in serum LH concentration. The effect was more pronounced after right-sided lesion. Interruption of nerve fibers above the amygdala by a paramedian sagittal knife cut on the right or on the left side resulted in opposite effect on testicular steroidogenesis: right-sided intervention increased while left-sided one reduced testosterone secretion. Only left-sided cut influenced (decreased) serum testosterone level. There was no changes in LH concentration. Both right- and left-sided lesion of the amygdala induced a significant decrease in basal testosterone secretion in vitro of both testes and in serum testosterone level. However, serum LH concentration decreased only after left-sided surgery. Interruption of the corpus callosum in animals with leftsided orchidectomy induced a significant rise in steroidogenesis of the remaining (right) testis. Both sham surgery and callosotomy combined with left orchidectomy resulted in a significant increase in serum FSH level. Conclusion - Results of our studies suggest that extrahypothalamic brain structures and interventions influence endocrine functions of the testis through the hypothalamohypophyseal- testicular axis and by a direct neural route.]

Clinical Neuroscience

[Report from the UEMS/European Board of Neurology Meeting]


Clinical Neuroscience

[Neurological aspects of some sleep disorders]


[My aim is to examine the relation between some sleep disorders and neurological diseases; to analyse their mutual interactions in order to achieve new practical data for clinical use. In the theoretical part I summarise some main points of sleep physiology concentrating on the associations of sleep regulation and neurological diseases. In my examinations, besides clinical methods, the most important tools used are sleep analyses performed by polysomnography and MESAM IV as well as brain imaging methods. To assess clinical state of my stroke patients I utilised NIH Stroke Scale. I found pathological sleep apnoea frequency in more than half of the patients in any type (bleeding/infarction) of acute stroke. In a prospective study, sleep apnoea parameters remain permanent during 3 months in the ischaemic group; on the other hand, sleep apnoea improves during follow up after brain haemorrhages. I showed pathological sleep apnoea frequency in myasthenia gravis among male patients without daytime respiration complaint. I looked for the link between the mechanism of the sleep disorder and the underlying organic lesion in two cases. In this analyses I took into account the function of the affected structure in sleep regulation. I found a basal forebrain tumour, affecting sleep regulating centres underlying severe insomnia and I suggest a neurovascular compression of the lateral preoptic area of the hypothalamus being the reason of sleep related painful erection, a parasomnia of unknown origin.]

Clinical Neuroscience

[Newer approaches in self-theories]


All articles in the issue

Related contents

Clinical Neuroscience

The applications of transcranial Doppler in ischemic stroke


Background: This overview provides a summary of the applications of transcranial Doppler (TCD) in ischemic stroke. Results: A fast-track neurovascular ultrasound protocol has been developed for detecting occlusion or stenosis. The technique is more reliable in the carotid area than in the posterior circulation. By monitoring the pulsatility index the in­crea­sed intracranial pressure can be diagnosed. TIBI score was developed for grading residual flow. TCD has been shown to accurately predict complete or any recanalization. Regarding recanalization, TCD has a sensitivity of 92%, a specificity of 88%, a positive predictive value of 96%, a negative predictive value of 78% and an overall accuracy of 91%, respectively. Sonothrombolysis seemed to be a promising application but randomized controlled trials have shown that it does not improve clinical outcome. TCD examination can detect microembolic signals (MES) which are associated with an increased risk of stroke. Micro­em­boli were detected in symptomatic and asymptomatic carotid artery stenosis and during carotid endarterectomy. The number of microemboli can be decreased by antithrombotic therapy. Contrast en­chan­ced examination and Valsalva maneuver with continuous TCD monitoring can accurately screen for right-to-left shunt.

Clinical Neuroscience

[Systemic thrombolysis and endovascular intervention in postpartum stroke]


[Introduction - There are no previously published cases about intravenously applied recombinant tissue plasminogen activator in acute ischemic stroke during puerperium. Case presentation - We report a 40-year-old woman with postpartum acute ischemic stroke caused by multiple cervical artery dissections treated by systemic thrombolysis and endovascular intervention. Discussion - There are only limited data regarding thrombolytic treatment in acute stroke during pregnancy and puerperium. Current acute stroke treatment guidelines - while considering pregnancy as a relative exclusion criterion - do not deal with the postpartum state. Conclusion - As the condition is rare, randomized controlled trials are not feasible, therefore further reports on similar cases could eventually help us suggest guidelines or at least propose recommendations for the acute thrombolytic treatment of strokes occurring in pregnancy and puerperium.]

Clinical Neuroscience

Comparison of hospitalized acute stroke patients’ characteristics using two large central-eastern european databases

ORBÁN-KIS Károly, SZŐCS Ildikó, FEKETE Klára, MIHÁLKA László, CSIBA László, BERECZKI Dániel, SZATMÁRI Szabolcs

Objectives – Stroke is the third leading cause of death in the European region. In spite of a decreasing trend, stroke related mortality remains higher in Hungary and Romania when compared to the EU average. This might be due to higher incidence, increased severity or even less effective care. Methods – In this study we used two large, hospital based databases from Targu Mures (Romania) and Debrecen (Hungary) to compare not only the demographic characteristics of stroke patients from these countries but also the risk factors, as well as stroke severity and short term outcome. Results – The gender related distribution of patients was similar to those found in the European Survey, whereas the mean age of patients at stroke onset was similar in the two countries but lower by four years. Although the length of hospital stay was significantly different in the two countries it was still much shorter (about half) than in most reports from western European countries. The overall fatality rate in both databases, regardless of gender was comparable to averages from Europe and other countries. In both countries we found a high number of risk factors, frequently overlapping. The prevalence of risk factors (hypertension, smoking, hyperlipidaemia) was higher than those reported in other countries, which can explain the high ratio of recurring stroke. Discussion – In summary, the comparatively analyzed data from the two large databases showed several similarities, especially regarding the high number of modifiable risk factors, and as such further effort is needed regarding primary prevention.

Hypertension and nephrology

[Cerebrovascular diseases in patients with chronic kidney disease]

KISS István, NAGY Judit

[The reason of the unfavourable life expectancy of patients with chronic kidney disease (CKD) is not only the development of end-stage renal failure but the frequent appearance of cardiovascular diseases (CVD). Chronic kidney damage itself is a cardiovascular risk state and the occurrence of CVD/associated diseases is significantly higher in chronic kidney failure. Beside risk stratification and valid treatment of CVD (hypertension, diabetes mellitus, ischemic heart disease e.g.) we and the international nephrological community have left the cerebrovascular diseases of CKD patients out of consideration. However, up to 50% of patients suffering a stroke will die immediately, only 10% of stroke survivors can continue his/her profession, but the others will be permanently disabled. High blood pressure is a strong predictor of stroke and of other CVD in most of the patients. In stroke risk reduction it is particularly important to reach the target blood pressure values. The main object of the “Live under 140/90 mmHg” programme of the Hungarian Society of Hypertension is to familiarize with target blood pressure itself and how to reach target blood pressure. In 2010, prevention, early diagnosis and management of stroke are the most important challenges of this programme (The Brain Control Programme). We think it is advisable to prepare and publish a clinical practice guideline in collaboration with stroke societies which is similar to the guidelines of international societies and of the Hungarian Society of Stroke but specific for CKD patients. This guideline would help to give a uniform, up-to-date treatment for the cerebrovascular diseases of CKD patients.]

Clinical Neuroscience

Utilization of acute vascular imaging and neurointervention for acute ischaemic stroke patients in 20 Hungarian stroke centers

POZSEGOVITS Krisztián, SZABÓ Géza, SZUPERA Zoltán, NAGY Péter, NÉMETH László, KONDÁKOR István, TUSA Csaba, BERENTE László, SALACZ Pál, VÉCSEI László, SAS Katalin, SEMJÉN Judit, NIKL János, SZAPÁRY László, KAKUK Anikó, RÓZSA Csilla, HORVÁTH Melinda, IMRE Piroska, KÖVES Ágnes, BALOGH István, MOLNÁR Sándor, FOLYOVICH András, AL-MUHANNA Nadim, BÉRES-MOLNÁR Katalin Anna, HAHN Katalin, KRISTÓF Piroska, SZÁSZ Attila Sándor, SZŰCS Anna, BERECZKI Dániel

Background - Acute mortality rate of stroke in Hungary is significantly higher than in Western Europe, which is likely to be partially attributable to suboptimal treatment. Subjects and methods - We examined the use of acute vascular imaging and mechanical thrombectomy for acute ischaemic stroke patients. We collected data on 20 consecutive patients from Hungarian stroke centres before 31st August 2016. Results - Out of the reported 410 patients, 166 (40.4%) underwent CT angiography and 44 (10.7%) had mechanical thrombectomy. Conclusion - Only about 1/3 of acute ischaemic stroke patients eligible for thrombectomy actually had it. The underlying reasons include long onset-to-door time, low utilization of acute vessel imaging and a limited neuro­intervention capacity needing improvement.