Impact of COVID-19 on ischemic stroke care in Hungary.

Data about the coronavirus disease 2019 (COVID-19) pandemic's collateral damage on ischemic stroke (IS) care during the second epidemic wave in Central Europe are limited. We sought to evaluate the impact of the COVID-19 outbreak on Hungarian IS care during the two epidemic waves. This retrospective observational study was based on a nationwide reimbursement database that encompasses all IS admissions and all reperfusion interventions, i.e., intravenous thrombolysis (IVT) and endovascular therapy (EVT) from 2 January 2017 to 31 December 2020 in Hungary. COVID-19 pandemic's effect on the number of IS admissions and reperfusion interventions were analyzed using different statistics: means, medians, trends, relative rates, and linear relationships. The mean and median values of IS admissions and reperfusion interventions decreased only in some measure during the COVID-periods. However, trend analysis demonstrated a significant decline from the trends. The decline's dynamic and amplitude have differed for each variable. In contrast to IVT, the number of IS admissions and EVTs negatively correlated with the epidemic waves' amplitude. Besides, the decrease in the number of IS admissions was more pronounced than the decrease in the number of reperfusion interventions. Our study demonstrated a significant disruption in IS care during the COVID-19 epidemic in Hungary, in which multiple different factors might play a role. The disproportionate reduction of IS admission numbers could partially be explained by the effect of health emergency operative measures and changes in patients' social behavior. Further studies are needed to evaluate the causes of our observations.

[Relationship between patent foramen ovale and cryptogenic stroke in a retrospective hospital-based study]. / A foramen ovale apertum és a cryptogen stroke kapcsolata. Retrospektív kórházi vizsgálat.

BACKGROUND AND PURPOSE: After routine workup, 23-25% of ischemic strokes etiology remains unknown, i.e. cryptogenic. However, according to international results pathogenic patent foramen ovale (PFO) reveals in 25% of these cases. Aim of our retrospective study to prove the substantial etiological role of PFO-related stroke (PFO-RS) in cryptogenic strokes (CS), and to identify age related differences in stroke etiology. METHODS: All new ischemic strokes of 2014-2015 were classified by ASCOD (Atherosclerosis, Small-vessel disease, Cardiac pathology, Other, Dissection) phenotyping. CS was defined when the etiology was unknown. With the help of special ultrasound techniques and RoPE (Risk of Paradoxical Embolism) score the portion of PFO-RS were determined in the examined CS population. Moreover, etiological distribution and differences between age groups (<40, 40-60, >60 years) were described. RESULTS: During the examined period, 8.12% of 985 new ischemic strokes were categorized as CS. 41.38% of examined CS were found to be PFO-related. PFO-RS were considerably more frequent in the younger age groups than in the older age groups. The probability of appearance of PFO-RS were significantly higher in younger age than in case of age independency. Our results verify the substantial etiological role of PFO-RS in CS, and confirm the essential role of contrast enhanced functional transcranial Doppler in the routine diagnostic workup. Age related differences in stroke etiology were found to be statistically significant (p=0.000, df=14), in which small-vessel disease, cardiac pathology, dissection, other pathologies, CS and PFO-RS were contributed significantly. CONCLUSION: Based on our results, till in young age rare etiologies are typical, while in older age classical etiologies are mainly characteristic.

[Administration of idarucizumab in spontaneous intracerebral hemorrhage under dabigatran-therapy]. / Idarucizumab alkalmazása dabigatranterápia melletti spontán intracerebralis vérzésben.

Introduction - Among antidotes in development for reversal of novel oral anticoagulants, dabigatran-specific idarucizumab was the first one to reach the market. Case presentation - We present the first Hungarian case of intracerebral hemorrhage under treatment with dabigatran, where idarucizumab was administered to suspend anticoagulation. Discussion - Our report is concordant with prior publications, confirming the efficacy of the antidote in reversing the effect of dabigatran, and thus, preventing intracerebral hematoma progression in the acute phase. Conclusion - Since there is no proven alternative to idarucizumab, conducting randomized clinical trials would be unethical. Therefore, besides case reports, positive results of prospective studies could help us revise therapeutic guidelines, and thus, improve the prognosis of dabigatran-associated intracerebral hemorrhages.

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.

Neuroprotective effects of estrogen treatment on ischemia-induced behavioural deficits in ovariectomized gerbils at different ages.

Although much is known about the protective effect of acute estrogen therapy in cerebral ischemia, relatively little is known about its effect on functional outcome at different ages. The impact of age is, however, important on the efficacy of steroids in the central nervous system. We investigated whether a single dose of estradiol pre-treatment would be neuroprotective in young (4 months), middle-aged (9 months) and old (18 months) female gerbils following 10min global brain ischemia. Apoptotic and necrotic cells were labelled and quantified in the affected hippocampus; exploratory activity, attention and memory functions were tested using open field, spontaneous alternation, novel object recognition and hole-board test. Age effect and treatment effect were analysed. High single dose (4mg/kg b.w.) of estradiol pre-treatment exposed a marked neuroprotective effect against hippocampal cell loss in all age groups. In behavioural tests, however, age-related differences could be observed. In middle-aged and old animals the worsening in memory function following ischemia was more prominent compared to that in the young ones. In the Y-maze and the novel object recognition tests the middle-aged, in the hole-board test (investigating working memory and total time) the old gerbils had the worst functional outcome. Only reference memory in hole-board test did not change by age. Estrogen improved memory performances in all the tests at every age. We can conclude that age of experimental animals is a factor worsening the outcome following brain ischemia. A single-dose estrogen therapy prevents the lesion-induced behavioural dysfunctions and the hippocampal cell loss.

(-)Deprenyl-N-oxide, a (-)deprenyl metabolite, is cytoprotective after hypoxic injury in PC12 cells, or after transient brain ischemia in gerbils.

BACKGROUND AND AIMS: (-)-Deprenyl (selegiline) possesses cyto-protective effect in a much lower concentration, than it is needed to inhibit MAO-B activity. In permanent MCA occlusion stroke model in rats, the infarct volume and the number of apoptotic neurons in the penumbra region were decreased by low concentration (-)deprenyl treatment. Augmented Bcl-2 protein expression was documented as the responsible factor of this effect. The stabilization of mitochondrial membrane and diminished ROS production are the further possible consequences of (-)deprenyl treatment. It is not clear however that (-)deprenyl, or its metabolites are the acting neuroprotective molecules in the hypoxic/ischemic conditions. We report here the possible cyto-protective effect of deprenyl-N-oxide (DNO), a recently synthesized (-)deprenyl metabolite. METHODS: DNO in a very low dose (10(-5,-8,-12) M) was tested in PC12 cell culture after hypoxia and in gerbils after transient occlusion of bilateral common carotid artery. In PC12 culture the cell death was visualized by PI staining. The level of reactive oxygen species was measured by the Cerium method, and the mitochondrial membrane integrity was labeled by JC1 staining. Apoptotic neurons were counted on formaldehyde fixed gerbil brain slices after TUNEL and caspase-3 immune-staining - NIKON/BIORAD confocal microscopy was used for the quantitative analysis. RESULTS: DNO treatment significantly decreased the frequency of cell death in PC12 cultures after hypoxia, increased the mitochondrial transmembrane potential (DeltaY(m)) and decreased the ROS production. In the CA2 regions of gerbil hippocampus, we found significantly less apoptotic neurons than in the untreated controls. CONCLUSION: Transient hypoxia or ischemia induced cell damage could be diminished by DNO. This (-)deprenyl metabolite is an active cell protective molecule.

Adopted cognitive tests for gerbils: validation by studying ageing and ischemia.

Transient occlusion of common carotid arteries in gerbils is a simple and widely used model for assessing histological and functional consequences of transient forebrain ischemia and neuroprotective action of pharmaceuticals. In the present study we aimed to introduce additional behavioural tests as novel object recognition and food-motivated hole-board learning in order to measure attention and learning capacity in gerbils. For validating these cognitive tests the effects of ageing (4, 9 and 18 months) and those of transient forebrain ischemia induced by bilateral carotid occlusion at 9 months of age were investigated. Neuronal cell death was estimated in the hippocampus using TUNEL and caspase-3 double fluorescence labelling and confocal microscopy. Ageing within the selected range although influenced ambulatory activity, did not considerably change attention and memory functions of gerbils. As a result of transient ischemia a selective neuronal damage in CA1 and CA2 regions of the hippocampus has been observed and tested 4 days after the insult. Ischemic gerbils became hyperactive, but showed decreased attention and impaired spatial memory functions as compared to sham-operated controls. According to our results the novel object recognition paradigm and the hole-board spatial learning test could reliably be added to the battery of conventional behavioural tests applied previously in this species. The novel tests can be performed within a wide interval of adult age and provide useful additional methods for assessing ischemia-induced cognitive impairment in gerbils.

Bcl-2 or Bcl-XL gene therapy reduces apoptosis and increases plasticity protein GAP-43 in PC12 cells.

The anti-apoptotic gene replacement could be an option in preventing hypoxia induced neuronal loss-necrosis and/or apoptosis. This intervention is however still controversial. In this paper, we tested the bcl-2 or bcl-XL anti-apoptotic gene transfers using an adenovirus vector in PC12 cells after hypoxia and re-oxygenation. Gene delivery results in a significant increase in both Bcl-2 and Bcl-XL proteins expression. Hypoxia (1h)/re-oxygenation (4-48 h) have a detrimental effect upon cultured cells by inducing increased apoptosis by 30% compared to the controls. After hypoxia the compromised mitochondrial membrane function was detected by decreased tetramethyl-rhodamine-ethylester (TMRE) staining. Anti-apoptotic genes transferred 1h after hypoxia, prevent the cell damage; the number of apoptotic cells has been reduced significantly and the gene transfers prevent mitochondrial membrane damage. Under normoxic conditions or following hypoxia the expression of plasticity protein, growth associated protein 43 (GAP-43) increased significantly by the gene treatment. We can conclude that anti-apoptotic gene transfers are not only cytoprotective as it is already documented before but these genes activate GAP-43 as well. This link on apoptotic signals and cell plasticity is a new finding.

Cytoprotective effect of two synthetic enhancer substances, (-)-BPAP and (-)-deprenyl, on human brain capillary endothelial cells and rat PC12 cells.

Enhancer regulation is a new control mechanism in the brain [Knoll, J., 2003. Enhancer regulation/endogenous and synthetic enhancer compounds: a neurochemical concept of the innate and acquired drives. Neurochemical Research 28(8), 1275-1297]. Enhancer substances exert their effect in bi-modal form with a highly characteristic dose-dependency. Two bell-shaped concentration curves have been published. The one in ultra low concentration range (fM) specific form of enhancer regulation and the other at high concentration (100 microM) non-specific form of enhancer regulation. Catecholaminergic neurons proved to be enhancer-sensitive cells. Since rat PC12 cells and human brain endothelial cells (HBEC) work under catecholaminergic influence, it was reasonable to expect that both the specific and non-specific form of the enhancer regulation might be detectable in these cells. We tested this possibility on these cultured cells under normoxia and hypoxia-reoxygenation. After 1 h hypoxia produced by Argon gas and 0, 2, 4, and 20 h reoxygenation the cell loss was calculated by propidiumiodide assay and the cell activity was investigated by Alamar Blue assay colorimetric measurement. The percentages of living and necrotic cells were expressed after propidiumiodide staining. Broad scale concentrations of the two compounds (1 fM-100 microM) were added to the culture strait after the oxygen deprivation. (-)-BPAP and (-)-deprenyl, due to their enhancer effect, exerted a significant cytoprotective effect on both HBECs and PC12 cells. In harmony with Knoll's publications we were able to demonstrate by the aid of (-)-BPAP and (-)-deprenyl that both HBEC and PC12 are enhancer-sensitive cells. We detected the specific form of the enhancer regulation in the ultra low concentration range (fM-pM) and also the non-specific form of the enhancer regulation was visible (mM-microM).

Visualization of mitochondrial membrane potential and reactive oxygen species via double staining.

Quantitative and qualitative analysis of both generated reactive oxygen species (ROS) and mitochondrial membrane potential cannot be detected simultaneously. We here introduce a simple, new double staining method. We have successfully used this for several years utilizing cerium for ROS detection and JC-1 staining to assess the mitochondrial membrane potential. The resultant signals on laser confocal images can be localized in the same cells and can easily quantify them. We used a confocal microscope along with our new, combined staining method to both visualize mitochondrial membrane potential (DeltaPsim) and imaged ROS. These were quantified by JC-1 staining and by cerium ions with reflectance in a method modified in our laboratory. To test this double labeling technique we used PC 12 cells subjected to 1 h hypoxia and 24h re-oxygenization. We are able to produce a quantitative analysis of red/green signals of JC-1 that reflected the energy state of the cells. Cerium reflectance correlates with the amount of ROS release in the same cells. Significant differences have been calculated after hypoxia and re-oxygenation in both modality of the cell staining. The red/green ratio was 18.2+/-9.3 (n=30) in normoxic cells versus 1.65+/-0.9 (n=30) in the hypoxia/re-oxygenation group (p<0.05). In the same randomly selected cells the average cerium reflectance signal intensity was 2.5+/-1.2 (n=30) in the control group while 5.8+/-3.1 (n=30) in the hypoxia/re-oxygenation group (p<0.05). This assay, by characterizing hypoxic injury and re-oxygenization induced ROS production, offers a qualitative and quantitative method to detect the consequences of oxidative stress in experimental conditions and to detect different cell protective strategies.

[New methods in the investigation of brain hypoxia]. / Uj módszerek az agyi hypoxia kutatásában.

The main challenge is the investigation of mechanism for apoptosis research and the drug development. Mitochondria have a key position in the production of reactive oxygen species and in the evolution of apoptosis. More possible pathway will be known with the apoptosis investigation. For development of neuroprotective molecules could give strategies the investigation of apoptosis. Exact knowledge of apoptosis provides the possibility to screen new neuroprotective molecules. We developed a research assay, that could provide quantitative and qualitative data about the free radical production and the mitochondrial transmembrane potential using confocal microscopy. Thus, we could screen drug candidate, neuroprotective molecules.

[11C]vinpocetine: a prospective peripheral benzodiazepine receptor ligand for primate PET studies.

Vinpocetine, a synthetic derivative of the Vinca minor alkaloid vincamine, is a widely used drug in neurological practice. We tested the hypothesis that vinpocetine binds to peripheral benzodiazepine binding sites (PBBS) and is therefore a potential ligand of PBBS. Positron emission tomography (PET) measurements in two cynomolgous monkeys showed that pretreatment with vinpocetine markedly reduced the brain uptake of [11C]PK11195, a known PBBS radioligand. On the other hand, whereas pretreatment with PK11195 increased the brain uptake of [11C]vinpocetine due to the blockade of PBBS in the periphery, it significantly reduced the binding potential (BP) values of [11C]vinpocetine in the whole brain and in individual brain structures to PK11195. These findings indicate that, whereas the two ligands have different affinities to PBBS, vinpocetine is a potent ligand of PBBS, which in turn suggests that the pharmacological activity of vinpocetine may involve the regulation of glial functions.

Effects of vinpocetine on the redistribution of cerebral blood flow and glucose metabolism in chronic ischemic stroke patients: a PET study.

The pharmacological effects of the neuroprotective drug vinpocetine, administered intravenously in a 14-day long treatment regime, on the cerebral blood flow and cerebral glucose metabolism in chronic ischemic stroke patients (n=13) were studied with positron emission tomography in a double-blind design. The regional and global cerebral metabolic rates of glucose (CMRglc) and cerebral blood flow (CBF) as well as vital physiological parameters, clinical performance scales, and transcranial Doppler parameters were measured before and after the treatment period in patient groups treated with daily intravenous infusion with or without vinpocetine. While the global CMRglc values did not change markedly as a result of the infusion treatment with (n=6) or without (n=7) vinpocetine, the global CBF increased and regional CMRglc and CBF values showed marked changes in several brain structures in both cases, with more accentuated changes when the infusion contained vinpocetine. In the latter case the highest rCBF changes were observed in those structures in which the highest regional uptake of labelled vinpocetine was measured in other PET studies (thalamus and caudate nucleus: increases amounting to 36% and 37%, respectively). The findings indicate that a 2-week long intravenous vinpocetine treatment can contribute effectively to the redistribution of rCBF in chronic ischemic stroke patients. The effects are most pronounced in those brain regions with the highest uptake of the drug.

[Effectiveness and safety of intraventricular fibrinolysis in secondary intraventricular hemorrhages (a prospective, randomized study)]. / Az agykamrába töro vérzések lokális fibrinolízisének biztonságossága és hatékonysága (prospektív, randomizált vizsgálat).

BACKGROUND AND PURPOSE: Intraventricular clot secondary to brain hemorrhage has still one of the worst prognosis among all stroke subtypes, regardless of conservative therapy or surgical interventions. The rapid clot resolution with thrombolytic agents could improve the outcome by restoring the impaired cerebrospinal fluid circulation, for this reason, the authors examined the safety and efficacy of Urokinase therapy in a randomized, controlled study. METHODS: They enrolled 27 patients with severe intraventricular hemorrhage between 1998 and 2002. All patients had supratentorial intracerebral hemorrhage caused by hypertension, with IVH, moreover clinically worsening course due to the obstructive hydrocephalus confirmed by CT. Eleven persons were treated with ventriculostomy alone and 16 received adjunctive intraventricular urokinase. The authors examined the early, 30-day and 1-year mortality, furthermore the neurological (Scandinavian Stroke Scale) and functional outcome (Barthel Scale). The mean age was 60 +/- 9.5. The initial Scandinavian Stroke Scale was 7.51 +/- 8.64, Glasgow Coma Scale was 6.85 +/- 2.52, intracerebral hemorrhage volume was 22.44 +/- 18.14 ml. RESULTS: The 1 year survival rate was significant higher in the urokinase treated group (p = 0.014), This tendency in the mortality (31.3% vs. 54.5%) and in the neurological/functional condition (SSS, p = 0.078/Barthel, p = 0.119) at 30th day have been also documented. No hemorrhagic complications due to urokinase were observed. Two meningitis (7.4%) and two intraparenchymal hemorrhages (7.4%) related to drain insertion were detected (p = 0.009). The probability of pulmonary infection was roughly two times higher in the group without clot lysis (RR = 1.870; 95% CI: 1.004-3.482). CONCLUSIONS: In the authors experience, urokinase treatment reveals to be safe in the intraventricular clot lysis. This therapy allows earlier mobilization and rehabilitation, and decreases the number of infections, which are favorable to the long-term survival rate.

[Thyrotropin-secreting pituitary adenomas--diagnosis and treatment in five case]. / Thyreotrop hormont szekretáló hypophysis adenomák diagnosztikája és kezelése öt eset kapcsán.

The authors report five cases of thyrotropin secreting pituitary adenomas (4 males and 1 female) in whom the diagnosis was established by a combined occurrence of elevated serum free thyroid hormone levels and measurable serum thyrotropin concentration, as well as by visualisation of the pituitary adenomas using magnetic resonance imaging (pituitary microadenoma in two and macroadenoma in three cases). Other tests were less diagnostic: only two out of 4 patients proved to be non-responders during testing with thyrotropin releasing hormone, and serum alpha subunit was elevated in only 2 out of 3 cases. There was a significant decrease of serum thyrotropin concentration in all of the four patients tested by 100 micrograms octreotide (Sandostatin, Novartis). Somatostatin-analogue treatment (slow release preparation in two cases) restored euthyroidism in all three cases treated prior to surgery. In one case the hyperthyroidism persisted after surgery of the macroadenoma, but irradiation of the pituitary area and subsequent somatostatin-analogue treatment resulted finally in a complete cure (euthyroidism and no tumor remnant). In the three other operated patients surgery resulted in euthyroidism. These cases demonstrate the variety of diagnostic and therapeutical modalities in the management of thyrotropin secreting pituitary adenomas.