Factors associated with delayed revascularization in patients with ischemic stroke: a prospective study in one French region.

BACKGROUND AND IMPORTANCE: Optimizing the care pathway of stroke is crucial for the revascularization of ischemic stroke. OBJECTIVES: to identify factors associated with (1) a time interval over 4 h between the symptom onset and cerebral imaging in suspected stroke patients and (2) the absence of revascularization in patients with ischemic stroke. DESIGN, SETTINGS AND PARTICIPANTS: Patients over 18 years old with a suspected stroke admitted in 22 emergency rooms or stroke units in one French region between 1 March 2019 and 30 April 2019 were prospectively included by filling a dedicated form. OUTCOME MEASURES AND ANALYSIS: Factors associated with the previously mentioned outcome measures were identified using logistic regression models. MAIN RESULTS: In total 991 patients were included; 537 patients (64% of 845 with available time intervals) were admitted more than 4 h after symptom onset. Three predictors were identified: not calling emergency medical services (EMS) [odds-ratio (OR) 5.2; 95% confidence interval (3.4-8.1)], a preexisting autonomy loss [2.0 (1.3-2.9)] and atypical clinical presentation [2.0 (1.3-3.1)]. A total of 385 patients had an ischemic stroke of whom 93 underwent a revascularization procedure (24%). The same three predictors were associated with the absence of revascularization procedure, added to an initial admission in a hospital without stroke unit [3.1 (1.1-8.6)]. CONCLUSION: This study shows that efforts to organize the care chain for stroke need to be intensified in the region to reduce treatment time intervals, which could include information campaigns focused on the impact of EMS call and the clinical presentation recognition.

Diagnostic and therapeutic value of echocardiography during the acute phase of ischemic stroke.

BACKGROUND: Echocardiography is routinely used to identify potential cardiac sources of embolism (CSE) in the acute phase of ischemic stroke (IS). We know that transoesophageal echography (TEE) is superior to detect CSE than transthoracic echography (TTE). However, the indications of each technique remain controversial. We aimed to evaluate the diagnostic yield (DY) and the therapeutic impact (TI) of echocardiography (both techniques combined) in IS and to analyze impact of clinical factors on these values. METHODS: We included consecutive IS patients over a period of 22 months. All patients underwent TTE, and selected patients (young or with a high suspicion of cardioembolic origin) then underwent TEE. DY (detection of CSE) and TI (introduction of oral anticoagulant, closure of patent foramen ovale and targeted cardiologic consultation) were systematically evaluated. RESULTS: We analyzed 300 patients (mean age 61 years). All patients underwent TTE and 127 patients underwent TTE and TEE. Echocardiography overall detected CSE in 22% of patients with a TI in 11% of all cases. The TI was higher in patients less than or equal to 55 years of age. In contrast to other studies, the DY and TI of echocardiography were not associated with vascular risk factors. CONCLUSIONS: Echocardiography, as currently practiced in our stroke unit, allows detection of CSE in one patient in five, and leads to change in therapy in half of these cases. Our results suggest that TTE should be used for all patients admitted for IS, and to limit the use of TEE to younger patients.

Could (18) F-DPA-714 PET imaging be interesting to use in the early post-stroke period?

BACKGROUND: Cerebral stroke is a severe and frequent condition that requires rapid and reliable diagnosis. If administered shortly after the first symptoms manifest themselves, IV thrombolysis has been shown to increase the functional prognosis by restoring brain reperfusion. However, a better understanding of the pathophysiology of stroke should help to identify potential new therapeutic targets. Stroke is known to induce an inflammatory brain reaction that involves overexpression of the 18-kDa translocator protein (TSPO) in glial cells and infiltrated leukocytes, which can be visualised by positron emission tomography (PET). We aimed to evaluate post-stroke neuroinflammation using the PET TSPO radioligand (18) F-DPA-714. METHODS: Nine patients underwent (18) F-DPA-714 PET and magnetic resonance imaging (MRI) between 8 and 18 days after the ictus. Co-registration of MRI and PET images was used to define three volumes of interest (VOIs): core infarction, contralateral region, and cerebellum ipsilateral to the stroke lesion. Time activity curves were obtained from each VOI, and ratios of mean and maximum activities between the VOIs were calculated. RESULTS: We observed an increased uptake of (18) F-DPA-714 co-localised with the infarct tissue and extension beyond the region corresponding to the damage in the blood brain barrier. No correlation was identified between (18) F-DPA-714 uptake and infarct volume. (18) F-DPA-714 uptake in ischemic lesion (mainly associated with TSPO expression in the infarct area and in the surrounding neighbourhood) slowly decreased from 10 min pi to the end of the PET acquisition, remaining higher than that in both contralateral region and ipsilateral cerebellum. CONCLUSION: Our results show that (18) F-DPA-714 uptake after acute ischemia is mainly associated with TSPO expression in the infarct area and in the surrounding neighbourhood. We also demonstrated that the kinetics of (18) F-DPA-714 differs in injured tissue compared to normal tissue. Therefore, (18) F-DPA-714 may be useful in assessing the extent of neuroinflammation associated with acute stroke and could also help to predict clinical outcomes and functional recovery, as well as to assess therapeutic strategies, such as the use of neuroprotective/anti-inflammatory drugs.

Unexpected low prevalence of atrial fibrillation in cryptogenic ischemic stroke: a prospective study.

PURPOSE: Ischemic stroke is a frequent pathology with high rate of recurrence and significant morbidity and mortality. There are several causes of stroke, affecting prognosis, outcomes, and management, but in many cases, the etiology remains undetermined. We hypothesized that atrial fibrillation was involved in this pathology but underdiagnosed by standard methods. The aim of the study was to determine the incidence of atrial fibrillation in cryptogenic ischemic stroke by using continuous monitoring of the heart rate over several months. The secondary objective was to test the value of atrial vulnerability assessment in predicting spontaneous atrial fibrillation. METHODS AND RESULTS: We prospectively enrolled 24 patients under 75 years of age, 15 men and 9 women of mean age 49 years, who within the last 4 months had experienced cryptogenic stroke diagnosed by clinical presentation and brain imaging and presumed to be of cardioembolic mechanism. All causes of stroke were excluded by normal 12-lead ECG, 24-h Holter monitoring, echocardiography, cervical Doppler, hematological, and inflammatory tests. All patients underwent electrophysiological study. Of the patients, 37.5% had latent atrial vulnerability, and 33.3% had inducible sustained arrhythmia. Patients were secondarily implanted with an implantable loop recorder to look for spontaneous atrial fibrillation over a mean follow-up interval of 14.5 months. No sustained arrhythmia was found. Only one patient had non-significant episodes of atrial fibrillation. CONCLUSION: In this study, symptomatic atrial fibrillation or AF with fast ventricular rate has not been demonstrated by the implantable loop recorder in patients under 75 years with unexplained cerebral ischemia. The use of this device should not be generalized in the systematic evaluation of these patients. In addition, this study attests that the assessment of atrial vulnerability is poor at predicting spontaneous arrhythmia in such patients.

Fibrinolytic effects of transparietal ultrasound associated with intravenous infusion of an ultrasound contrast agent: study of a rat model of acute cerebral stroke.

The aim of this study was to evaluate the thrombolytic effect of focused transparietal ultrasound in combination with a specific contrast agent (microbubbles) in acute cerebral ischemia. Acute cerebral ischemia was induced in 10 rats by intra-arterial clots injection. Five rats (group 1) were treated with a combination of transparietal ultrasound (probe 2 MHz, acoustic power 500 mW/cm(2)) and intravenous injection of 0.6 mL of the ultrasound contrast agent (UCA) sulfur hexafluoride. Five rats (group 2) were treated by fibrinolytic intravenous infusion (recombinant tissue plasminogen activator). Cerebral cellular energy production was determined by measuring the cellular phosphorylation using phosphorus magnetic spectroscopy before and during ischemia induction and after treatment. Measures were performed on a dedicated 2.35T magnet. The ratio phosphocreatine (P(Cr)) on inorganic phosphate (P(i)), P(Cr)/P(i), estimation of the oxidative phosphorylation metabolism and the intracellular pH (pHi) were measured in the two groups. Compared with the ischemia induction period, both treatments were associated with an increase of P(Cr)/P(i) and pHi values, respectively, +80% and +100% in group 1 (p=0.07) and +100% and +80% in group 2 (p=0.04). There was no significant difference between the two groups for the response treatment. To conclude, treatment with intravenous fibrinolytic infusion and treatment with focused ultrasound in combination with UCA seems to be equally effective in treating acute cerebral ischemia in rats. (E-mail: j.p.tasu@chu-poitiers.fr).

Abrupt onset of disturbed vigilance, bilateral third nerve palsy and masturbating behaviour: a rare presentation of stroke.

The clinical presentation of stroke usually includes sensory-motor impairment, cranial nerve palsies, or cognitive dysfunction. Disorders in behaviour are less frequently seen. The case of a patient with a very disturbing presentation, which included a disturbance in vigilance, bilateral third nerve palsy and masturbating behaviour, is presented. The topography of the lesions and its implications on the deficits observed are discussed.