Christian Lund

Comparison of Cerebral Embolization During Off-Pump and On-Pump Coronary Artery Bypass Surgery

BACKGROUND Coronary artery bypass surgery with cardiopulmonary bypass carries a significant risk of perioperative brain injury. At least 1% to 5% will suffer a stroke, and at 3-months postoperatively approximately 30% are reported to have cognitive impairment assessed by neuropsychologic testing. In off-pump surgery cardiopulmonary bypass is not used and instrumentation on the ascending aorta is reduced. The main aim of this study was to assess if off-pump surgery reduces intraoperative cerebral embolization. METHODS This was a prospective and randomized study of two comparable groups with regard to age, sex, years of education, preoperative cognitive functioning, and surgical characteristics. Fifty-two patients (29 off-pump) were monitored by the use of transcranial Doppler ultrasound for cerebral microembolization during surgery. Preoperative and postoperative clinical, cerebral magnetic resonance imaging, and neuropsychologic examinations were also carried out. RESULTS There was a significant reduction in the number of cerebral microemboli during off-pump compared with on-pump surgery (16.3 [range 0 to 131] versus 90.0 [range 15 to 274], p < 0.0001). No significant difference with regard to the incidence of neuropsychologic performance (decline in 29% off-pump, 35% on-pump) or neuroradiologic findings at 3 months was found, and there was no association between the number of cerebral microemboli and cognitive outcome. CONCLUSIONS This study clearly demonstrates that off-pump surgery leads to a reduction in intraoperative cerebral microembolization. A significant reduction in the number of off-pump patients with cognitive decline or ischemic brain lesions on cerebral magnetic resonance imaging could not be demonstrated in this relatively small patient population.

European Stroke Initiative Recommendations for Stroke Management

This article summarises recommendations for acute management of stroke by the European Stroke Initiative (EUSI), on behalf of the European Stroke Council (ESC), the European Neurological Society (ENS), and the European Federation of Neurological Societies (EFNS).

Cerebral Microembolus Detection in an Unselected Acute Ischemic Stroke Population

Objective: The aims of this study were firstly to determine prevalence, frequency, and clinical significance of cerebral microemboli in an unselected acute ischemic stroke population and secondly to examine how this information may improve ischemic stroke subtype classification. Methods: We intended to perform transcranial Doppler (TCD) microembolus monitorings of the middle cerebral artery (MCA) in the symptomatic hemisphere for 45 min in 120 consecutive patients with internal carotid artery territory ischemia. The first examination was performed within 72 h from start of symptoms and the second 5 ± 1 days later. Platelet and coagulation system activation were measured following TCD monitoring in 38 patients. The strokes were subtyped using the TOAST classification criteria, and the patients’ clinical status was assessed at discharge using the Scandinavian Stroke Scale and the Barthel Index. Results: Microembolus monitoring was technically possible in 83 (69.2%) of the 120 patients. Thirty-two (26.6%) patients had an inadequate temporal bone acoustic window or were too restless to allow long-time monitoring. In 5 (4.2%) patients the relevant MCA was occluded. Twenty-two (26.5%) of the 83 patients had microemboli despite the fact that over 90% were receiving an antiplatelet or an anticoagulant treatment. The mean frequency of microemboli was 6.7 ± 13.6 per 45 min. Microemboli were more prevalent in assumed cardioembolic stroke than in other subtypes of ischemic stroke (p = 0.047). We found no association between the presence of cerebral microemboli and the clinical outcome or the parameters for platelet or coagulation system activation. The presence of microemboli was not associated with in-hospital deaths (p = 0.17), whereas MCA occlusion was (p = 0.01). Conclusions: Cerebral microemboli are frequent in unselected acute ischemic stroke patients despite antiplatelet or anticoagulant treatment. TCD detection of microemboli provides valuable pathophysiological information and may, therefore, improve current ischemic stroke subtype classification.

Tenecteplase versus alteplase for management of acute ischaemic stroke (NOR-TEST): a phase 3, randomised, open-label, blinded endpoint trial

BACKGROUND Tenecteplase is a newer thrombolytic agent with some pharmacological advantages over alteplase. Previous phase 2 trials of tenecteplase in acute ischaemic stroke have shown promising results. We aimed to investigate the safety and efficacy of tenecteplase versus alteplase in patients with acute stroke who were eligible for intravenous thrombolysis. METHODS This phase 3, randomised, open-label, blinded endpoint, superiority trial was done in 13 stroke units in Norway. We enrolled adults with suspected acute ischaemic stroke who were eligible for thrombolysis and admitted within 4·5 h of symptom onset or within 4·5 h of awakening with symptoms, or who were eligible for bridging therapy before thrombectomy. Patients were randomly assigned (1:1) to receive intravenous tenecteplase 0·4 mg/kg (to a maximum of 40 mg) or alteplase 0·9 mg/kg (to a maximum of 90 mg), via a block randomisation schedule stratified by centre of inclusion. Patients were not informed of treatment allocation; treating physicians were aware of treatment allocation but those assessing the primary and secondary endpoints were not. The primary outcome was excellent functional outcome defined as modified Rankin Scale (mRS) score 0-1 at 3 months. The primary analysis was an unadjusted and non-stratified intention-to-treat analysis with last observation carried forward for imputation of missing data. This study is registered with ClinicalTrials.gov, number NCT01949948. FINDINGS Between Sept 1, 2012, and Sept 30, 2016, 1107 patients met the inclusion criteria and seven patients were excluded because informed consent was withdrawn or eligibility for thrombolytic treatment was reconsidered. 1100 patients were randomly assigned to the tenecteplase (n=549) or alteplase (n=551) groups. The median age of participants was 77 years (IQR 64-79) and the median National Institutes of Health Stroke Scale score at baseline was 4 points (IQR 2-8). A final diagnosis other than ischaemic stroke or transient ischaemic attack was found in 99 (18%) patients in the tenecteplase group and 91 (17%) patients in the alteplase group. The primary outcome was achieved by 354 (64%) patients in the tenecteplase group and 345 (63%) patients in the alteplase group (odds ratio 1·08, 95% CI 0·84-1·38; p=0·52). By 3 months, 29 (5%) patients had died in the tenecteplase group compared with 26 (5%) in the alteplase group. The frequency of serious adverse events was similar between groups (145 [26%] in the tenecteplase group vs 141 [26%] in the alteplase group; p=0·74). INTERPRETATION Tenecteplase was not superior to alteplase and showed a similar safety profile. Most patients enrolled in this study had mild stroke. Further trials are needed to establish the safety and efficacy in patients with severe stroke and whether tenecteplase is non-inferior to alteplase. FUNDING Research Council of Norway.

Stoppers and non-starters of disease- modifying treatment in multiple sclerosis

To explore the frequency of non‐starters and stoppers of disease‐modifying therapy (DMT) in a cohort of people recently diagnosed with multiple sclerosis (MS) and to identify reasons for non‐starting or stopping DMT measured by demographic variables, social support [The Interpersonal Support Evaluation List (ISEL)] and disease‐related stress [The Impact of Event Scale (IES)].

Assessment of acute stroke cerebral CT examinations by anaesthesiologists

It is essential to diagnose ischaemic stroke as soon as possible after symptom onset, so that thrombolytic treatment can be initiated as quickly as possible. This might be greatly facilitated if cerebral CT could be carried out in a pre‐hospital setting. The aim of this study was to evaluate if anaesthesiologists, who in Norway provide pre‐hospital medical care, could be trained to assess cerebral CT scans to exclude radiological contraindications for thrombolytic stroke treatment.

Multiple sclerosis and seizures: incidence and prevalence over 40 years

The prevalence of multiple sclerosis (MS) is increasing worldwide. Epileptic seizures are more common in MS patients than in the general population. The aim of this study was to investigate changes in the prevalence and incidence of MS in a well‐defined population over several decades and estimate the occurrence of epilepsy in the same cohort.

Cerebral microemboli detection and differentiation during transcatheter closure of atrial septal defect in a paediatric population.

INTRODUCTION The aim of this prospective study was to determine the frequency and composition of cerebral microemboli in a paediatric population during transcatheter atrial septal defect closure. METHODS Multi-frequency transcranial Doppler was used to detect microembolic signals in the middle cerebral artery of 24 patients. Embolic signals were automatically identified and differentiated according to their composition, gaseous or solid. The procedure was divided into five periods: right cardiac catheterisation; left cardiac catheterisation; pulmonary angiography; balloon sizing; and device placement. RESULTS Microemboli were detected in all patients. The median number of signals was 63 and over 95% gaseous. The total number of microembolic signals detected during two periods - balloon sizing and sheath placement and device placement - was not significantly different (median: 18 and 25, respectively) but was significantly higher than each of the other three periods (p<0.001). In eight patients, the device was opened more than once and the number of embolic signals decreased with each successive device deployment. There was no correlation between the number of microembolic signals and fluoroscopic time, duration of procedure, age, or device size. CONCLUSION This is the first study to investigate the timing and composition of cerebral microemboli in a paediatric population during cardiac catheterisation. Microembolic signals were related to specific catheter manipulations but were not associated with fluoroscopic time or duration of procedure.

Ventricular Fibrillation during Off-Pump Coronary Artery Bypass Grafting: Transcranial Doppler and Clinical Findings

A 73-year-old male developed ventricular fibrillation which lasted for 2 min and 24 s, during off-pump coronary artery bypass grafting. Cerebral hemodynamics were assessed by continuous transcranial Doppler monitoring. Ventricular fibrillation resulted in an immediate fall in cerebral blood flow velocities to almost zero with only slight fluctuations. This was then followed by a pronounced reactive hyperperfusion. Cerebral magnetic resonance imaging examinations and detailed neurological and neuropsychological evaluations were performed before and at 3 and 12 months after surgery. No evidence of cerebral damage was found.

Interpretation of Brain CT Scans in the Field by Critical Care Physicians in a Mobile Stroke Unit

In acute stroke, thromboembolism or spontaneous hemorrhage abruptly reduces blood flow to a part of the brain. To limit necrosis, rapid radiological identification of the pathological mechanism must be conducted to allow the initiation of targeted treatment. The aim of the Norwegian Acute Stroke Prehospital Project is to determine if anesthesiologists, trained in prehospital critical care, may accurately assess cerebral computed tomography (CT) scans in a mobile stroke unit (MSU).