Proportion of single-chain recombinant tissue plasminogen activator and outcome after stroke

Low-density lipoprotein receptor-related protein-1 (LRP1) in the glial lineage modulates neuronal excitability

The low-density lipoprotein related protein receptor 1 (LRP1), also known as CD91 or α-Macroglobulin-receptor, is a transmembrane receptor that interacts with more than 40 known ligands. It plays an important biological role as receptor of morphogens, extracellular matrix molecules, cytokines, proteases, protease inhibitors and pathogens. In the CNS, it has primarily been studied as a receptor and clearance agent of pathogenic factors such as Aβ-peptide and, lately, Tau protein that is relevant for tissue homeostasis and protection against neurodegenerative processes. Recently, it was found that LRP1 expresses the Lewis-X (Lex) carbohydrate motif and is expressed in the neural stem cell compartment. The removal of Lrp1 from the cortical radial glia compartment generates a strong phenotype with severe motor deficits, seizures and a reduced life span. The present review discusses approaches that have been taken to address the neurodevelopmental significance of LRP1 by creating novel, lineage-specific constitutive or conditional knockout mouse lines. Deficits in the stem cell compartment may be at the root of severe CNS pathologies.

Impact of drug treatment and drug interactions in post-stroke epilepsy

Stroke is a huge burden on our society and this is expected to grow in the future due to the aging population and the associated co-morbidities. The improvement of acute stroke care has increased the survival rate of stroke patients, and many patients are left with permanent disability, which makes stroke the main cause of adult disability. Unfortunately, many patients face other severe complications such as post-stroke seizures and epilepsy. Acute seizures (ASS) occur within 1 week after the stroke while later occurring unprovoked seizures are diagnosed as post-stroke epilepsy (PSE). Both are associated with a poor prognosis of a functional recovery. The underlying neurobiological mechanisms are complex and poorly understood. There are no universal guidelines on the management of PSE. There is increasing evidence for several risk factors for ASS/PSE, however, the impacts of recanalization, drugs used for secondary prevention of stroke, treatment of stroke co-morbidities and antiseizure medication are currently poorly understood. This review focuses on the common medications that stroke patients are prescribed and potential drug interactions possibly complicating the management of ASS/PSE.

Assessment of the incidence and risk factors of early poststroke seizures in Lebanese patients

BACKGROUND

Early seizures have been recognized as serious complications of ischemic strokes where the data are limited among Lebanese patients. This study aimed to assess the incidence and risk factors of early seizures postischemic stroke and to determine the effect of early seizures on functional outcome among Lebanese stroke patients.

METHODS

This was a retrospective observational study conducted between January 2017 and March 2020 on patients with acute ischemic strokes at two tertiary hospitals in Lebanon. Data were collected from patients' medical records at each site through a well-designed data collection sheet. Early seizures were defined as seizures occurring within 7 days after acute stroke. Functional outcome was assessed at discharge, according to modified Rankin scale (mRS).

RESULTS

Of 140 enrolled patients, early seizure developed in 12 patients (8.6%) with mean age of 68.42 ± 9.89 years and 8 (67%) were females. Independent risk factors for early seizure development were female gender and cortical involvement. Moreover, early seizure development was not associated with higher disability and mortality at hospital discharge.

CONCLUSION

The findings of the study highlight that early seizures occurred more commonly in patients with cortical involvement and female gender. In addition, early seizures did not impair functional outcome in our study, however; further studies are needed to predict patients at risk of early seizure so that appropriate prevention and treatment strategies can be implemented promptly.

Single- and two- chain tissue type plasminogen activator treatments differentially influence cerebral recovery after stroke

Tissue type Plasminogen Activator (tPA), named alteplase (Actilyse®) under its commercial form, is currently the only pharmacological treatment approved during the acute phase of ischemic stroke, used either alone or combined with thrombectomy. Interestingly, the commercial recombinant tPA (rtPA) contains two physiological forms of rtPA: the single chain rtPA (sc-rtPA) and the two-chains rtPA (tc-rtPA), with differential properties demonstrated in vitro. Using a relevant mouse model of thromboembolic stroke, we have investigated the overall effects of these two forms of rtPA when infused early after stroke onset (i.e. 20 min) on recanalization, lesion volumes, alterations of the integrity of the blood brain barrier and functional recovery. Our data reveal that there is no difference in the capacity of sc-rtPA and tc-rtPA to promote fibrinolysis and reperfusion of the tissue. However, compared to sc-rtPA, tc-rtPA is less efficient to reduce lesion volumes and to improve functional recovery, and is associated with an increased opening of the blood brain barrier. These data indicate better understanding of differential effects of these tPA forms might be important to ultimately improve stroke treatment.

Early epileptic seizures in ischaemic stroke treated by mechanical thrombectomy: influence of rt-PA

BACKGROUND

The epileptogenicity of recombinant tissue-plasminogen activator (rt-PA) has been suggested, but seizures were not evaluated in randomised controlled trials.

OBJECTIVE

To evaluate whether rt-PA was associated with early seizures in a cohort of consecutive patients with cerebral ischaemia.

METHOD

We included consecutive adults with ischaemic stroke due to large-vessel occlusion from the North-of-France stroke network selected for a mechanical thrombectomy (MT). Patients without contraindication received i.v. rt-PA. We evaluated stroke severity with the National Institutes of Health Stroke Scale (NIHSS), and functional status with the modified Rankin scale (mRS), and recorded epileptic seizures occurring between the end of imaging and day 7. We performed statistics using propensity analyses.

RESULTS

We included 1638 patients (783 men, 47.8%; median age 71 years; median NIHSS score 16; 1007 treated by rt-PA, 61.5%), in whom 60 (3.7%) developed early epileptic seizures. After adjustment on propensity scores, early seizures were associated with infections [adjusted odds ratio (_adjOR) 2.86; 95% confidence interval (CI) 1.37-5.95] and delay between stroke recognition and end of MT (_adjOR 1.04 for 10 min more; 95% CI 1.01-1.08), but not with rt-PA (_adjOR 1.35; 95% CI 0.55-3.33). The propensity-matched analysis of 343 pairs of patients found no difference in the occurrence of early seizures between those with and without rt-PA (p = 0.386).

CONCLUSION

We found no significant association between rt-PA and early epileptic seizures. If rt-PA has the potential for epileptogenicity, the magnitude of the effect should be modest compared to its favourable effect on functional outcome.

Incidence and Association of Reperfusion Therapies With Poststroke Seizures: A Systematic Review and Meta-Analysis

BACKGROUND AND PURPOSE

We performed a systematic review and meta-analysis to assess the incidence and risk of seizures following acute stroke reperfusion therapy (intravenous thrombolysis [IVT] with r-tPA [recombinant tissue-type plasminogen activator], mechanical thrombectomy or both).

METHODS

We searched major databases (MEDLINE, SCOPUS, and Cochrane Library) for articles published between 1995 and October 28, 2019. The primary outcome was the overall and treatment specific pooled incidence of poststroke seizures (PSS) following acute reperfusion therapy. We also computed the pooled incidence of early poststroke seizures and late poststroke seizures separately for all studies. We derived the risk of PSS associated with IVT in the pooled cohort of patients who received only IVT. The small number of studies (<3) that reported on the risk of PSS associated with mechanical thrombectomy alone or in combination with IVT did not allow us to compute an estimate of the risk of seizures associated with this therapy.

RESULTS

We identified 13 753 patients with stroke, of which 592 had seizures. The pooled incidence of PSS was 5.9 % (95% CI, 4.2%-8.2%). PSS incidence rates among patients with stroke treated with IVT, mechanical thrombectomy, and both were respectively 6.1% (95% CI, 3.6%-10.2%), 5.9% (95% CI, 4.1%-8.4%), and 5.8 % (95% CI, 3.0%-10.9%). The incidence of late PSS was 6.7% (95% CI, 4.01%-11.02%) and that of early PSS was 3.14% (95% CI, 2.05%-4.76%). The pooled odds ratio for the association between IVT and PSS was 1.24 (95% CI, 0.75-2.05).

CONCLUSIONS

The findings of this meta-analysis suggest that about one in 15 ischemic stroke patients treated with IVT, mechanical thrombectomy, or both develop seizures independently of the specific reperfusion treatment that they received.

Early seizures after ischemic stroke: focus on thrombolysis

INTRODUCTION

Stroke is a significant underlying cause of epilepsy. Seizures due to ischemic stroke (IS) are generally categorized into early seizures (ESs) and late seizures (LSs). Seizures in thrombolysis situations may raise the possibility of other etiology than IS.

AIM

We overtook a systematic review focusing on the pathogenesis, prevalence, risk factors, detection, management, and clinical outcome of ESs in IS and in stroke/thrombolysis situations. We also collected articles focusing on the association of recombinant tissue-type plasminogen activator (rt-PA) treatment and epileptic seizures.

RESULTS

We have identified 37 studies with 36,775 participants. ES rate was 3.8% overall in patients with IS with geographical differences. Cortical involvement, severe stroke, hemorrhagic transformation, age (<65 years), large lesion, and atrial fibrillation were the most important risk factors. Sixty-one percent of ESs were partial and 39% were general. Status epilepticus (SE) occurred in 16.3%. 73.6% had an onset within 24 h and 40% may present at the onset of stroke syndrome. Based on EEG findings seizure-like activity could be detected only in approximately 18% of ES patients. MRI diffusion-weighted imaging and multimodal brain imaging may help in the differentiation of ischemia vs. seizure. There are no specific recommendations with regard to the treatment of ES.

CONCLUSION

ESs are rare complications of acute stroke with substantial burden. A significant proportion can be presented at the onset of stroke requiring an extensive diagnostic workup.

Cerebral ischaemia with unknown onset: Outcome after recanalization procedure

BACKGROUND

Stroke of unknown time of onset (UTOS) accounts for one-third of contra-indications for revascularization procedures. With modern neuroimaging techniques it is possible to differentiate the core infarcts and the presence of penumbra.

OBJECTIVE

To evaluate outcomes in patients with UTOS, treated with intravenous (i.v.) recombinant tissue-plasminogen activator (rt-PA), mechanical thrombectomy (MT), or both.

METHOD

We conducted this observational study in patients treated by i.v. rt-PA, MT, or both, selected by a diffusion-weighted image/fluid-attenuated inversion recovery mismatch. We evaluated outcomes with the modified Rankin scale (mRS) at 3 months.

RESULTS

Of 992 consecutive patients (522 women, 52.6%; median age 76 years; median baseline national institutes of health stroke scale [NIHSS] 10), 153 (15.4%) had UTOS, including 101 with wake-up strokes. Compared to other patients, they were more likely to have pre-existing mRS scores >2 (P=0.022), multiple infarcts (P<0.001), middle cerebral artery occlusions (P=0.023), and to undergo MT (P=0.003), and less likely to receive i.v. rt-PA (P<0.001). They had higher NIHSS scores (P<0.001) and longer discovery to treatment initiation times (P<0.001). They were more likely to develop pulmonary (P=0.001) and urinary (P=0.006) infections, and pulmonary embolism (P=0.019), and tended to have a higher mortality rate (P=0.052) within 7 days. After adjustment, there was no association of UTOS with any of these outcome measures anymore.

CONCLUSION

Patients with UTOS have more severe strokes and more comorbidities, but after adjustment, their outcomes did not differ from those of other patients.

The role of plasminogen activators in stroke treatment: fibrinolysis and beyond

Although recent technical advances in thrombectomy have revolutionised acute stroke treatment, prevalence of disability and death related to stroke remain high. Therefore, plasminogen activators-eukaryotic, bacterial, or engineered forms that can promote fibrinolysis by converting plasminogen into active plasmin and facilitate clot breakdown-are still commonly used in the acute treatment of ischaemic stroke. Hence, plasminogen activators have become a crucial area for clinical investigation for their ability to recanalise occluded arteries in ischaemic stroke and to accelerate haematoma clearance in haemorrhagic stroke. However, inconsistent results, insufficient evidence of efficacy, or reports of side-effects in trial settings might reduce the use of plasminogen activators in clinical practice. Additionally, the mechanism of action for plasminogen activators could extend beyond the vessel lumen and involve plasminogen-independent processes, which would suggest that plasminogen activators have also non-fibrinolytic roles. Understanding the complex mechanisms of action of plasminogen activators can guide future directions for therapeutic interventions in patients with stroke.

Influence of on-going treatment with angiotensin-converting enzyme inhibitor or angiotensin receptor blocker on the outcome of patients treated with intravenous rt-PA for ischemic stroke

BACKGROUND

Many patients who receive intravenous (i.v.) recombinant tissue-plasminogen activator (rt-PA) for acute cerebral ischemia were under angiotensin-converting enzyme inhibitors (ACE-Is) or angiotensin receptor blockers (ARBs) at stroke onset. ACE-Is and ARBs have neuroprotective properties in animal models.

OBJECTIVE

To evaluate whether the 3-month outcome of patients treated with i.v. rt-PA for cerebral ischemia was influenced by on-going therapy with ACE-Is or ARBs.

METHOD

This study was observational, conducted in two prospective registries of stroke patients treated with i.v. rt-PA. We evaluated outcomes with the modified Rankin scale and symptomatic intracranial hemorrhages (s-ICH) according to the ECASS2 criteria. We compared outcomes between patients with and without ACE-Is/ARBs according to the modified Rankin scale (mRS) at month 3, using logistic regression analyses adjusted on propensity scores, and propensity-matched analyses.

RESULTS

Of 1803 patients, 455 (25.2%) were under ACE-Is (259), ARBs (188) or both (8). At 3 months, patients under ACE-Is or ARBs were more likely to have an mRS 0-1, but did not differ for mRS 0-2, s-ICH and death. After adjustment on propensity scores, the association between ACE-Is/ARBs and mRS 0-1 disappeared. The propensity-matched analysis, performed in 397 pairs of patients, found no difference in outcomes between patients with and without ACE-Is or ARBs.

CONCLUSION

In patients treated by intravenous thrombolytic therapy for ischemic stroke, on-going treatment with ACE-Is or ARBs does not influence on outcomes after adjustment on baseline characteristics and propensity scores.

Worse Outcome in Stroke Patients Treated with rt-PA Without Early Reperfusion: Associated Factors

Based on preclinical studies suggesting that recombinant tissue plasminogen activator (rt-PA) may promote ischemic brain injuries, we investigated in patients the possible risk of worse clinical outcome after rt-PA treatment as a result of its inability to resolve cerebral ischemia. Here, we designed a cohort study using a retrospective analysis of patients who received treatment with intravenous (4.5-h window) or intraarterial rt-PA, without or with thrombectomy. Controls were consecutive patients who did not receive recanalization treatment, who met all inclusion criteria. As a marker of reperfusion, we defined the variable of early neurological improvement as the difference between the score of the National Institute of Health Stroke Scale (NIHSS) (at admission and 24 h). The main variable was worsening of the patient’s functional situation in the first 3 months. To compare quantitative variables, we used Student’s t test or the Mann-Whitney test. To estimate the odds ratios of each independent variable in the patient’s worsening in the first 3 months, we used a logistic regression model. We included 1154 patients; 577 received rt-PA, and 577 served as controls. In the group of patients treated with rt-PA, 39.4% who did not present clinical reperfusion data developed worsening within 3 months after stroke compared with 3.5% of patients with reperfusion (P < 0.0001). These differences were not significant in the control group. In summary, administration of rt-PA intravenously or intraarterially without reperfusion within the first 24 h may be associated with a higher risk of functional deterioration in the first 3 months.

Can the benefits of rtPA treatment for stroke be improved?

Tissue-type plasminogen activator (tPA) is a serine protease well known to promote fibrinolysis. This is why: its recombinant form (rtPA) can be used, either alone or combined with thrombectomy, to promote recanalization/reperfusion following ischemic stroke. However, its overall benefits are counteracted by some of its side-effects, including incomplete lysis of clots, an increased risk of hemorrhagic transformation and the possibility of neurotoxicity. Nevertheless, better understanding of the mechanisms by which tPA influences brain function and promotes its alteration may help in the design of new strategies to improve stroke therapy.