Corrigendum: How often is occult atrial fibrillation in cryptogenic stroke causal vs. incidental? A meta-analysis

[This corrects the article DOI: 10.3389/fneur.2023.1103664.].

How often is occult atrial fibrillation in cryptogenic stroke causal vs. incidental? A meta-analysis

Introduction

Long-term cardiac monitoring studies have unveiled low-burden, occult atrial fibrillation (AF) in some patients with otherwise cryptogenic stroke (CS), but occult AF is also found in some individuals without a stroke history and in patients with stroke of a known cause (KS). Clinical management would be aided by estimates of how often occult AF in a patient with CS is causal vs. incidental.

Methods

Through a systematic search, we identified all case–control and cohort studies applying identical long-term monitoring techniques to both patients with CS and KS. We performed a random-effects meta-analysis across these studies to determine the best estimate of the differential frequency of occult AF in CS and KS among all patients and across age subgroups. We then applied Bayes' theorem to determine the probability that occult AF is causal or incidental.

Results

The systematic search identified three case–control and cohort studies enrolling 560 patients (315 CS, 245 KS). Methods of long-term monitoring were implantable loop recorder in 31.0%, extended external monitoring in 67.9%, and both in 1.2%. Crude cumulative rates of AF detection were CS 47/315 (14.9%) vs. KS 23/246 (9.3%). In the formal meta-analysis, the summary odds ratio for occult AF in CS vs. KS in all patients was 1.80 (95% CI, 1.05–3.07), p = 0.03. With the application of Bayes' theorem, the corresponding probabilities indicated that, when present, occult AF in patients with CS is causal in 38.2% (95% CI, 0–63.6%) of patients. Analyses stratified by age suggested that detected occult AF in patients with CS was causal in 62.3% (95 CI, 0–87.1%) of patients under the age of 65 years and 28.5% (95 CI, 0–63.7%) of patients aged 65 years and older but estimates had limited precision.

Conclusion

Current evidence is preliminary, but it indicates that in cryptogenic stroke when occult AF is found, it is causal in about 38.2% of patients. These findings suggest that anticoagulation therapy may be beneficial to prevent recurrent stroke in a substantial proportion of patients with CS found to have occult AF.

Mycotic aneurysm

Angioinvasive fungal infections of the cerebral vasculature often lead to significant morbidity and mortality. High clinical suspicion and early antifungal therapy could improve outcomes. We describe the fatal case of a patient with a rapidly enlarging cavernous carotid aneurysm due to angioinvasive fungus. This case highlights the challenges in diagnosis and management of this condition.

Incidence and Predictive Factors Associated with Beta-Lactam Neurotoxicity in the Critically Ill: A Retrospective Cohort Study

BACKGROUND

Beta-lactam neurotoxicity is a relatively uncommon yet clinically significant adverse effect in critically ill patients. This study sought to define the incidence of neurotoxicity, derive a prediction model for beta-lactam neurotoxicity, and then validate the model in an independent cohort of critically ill adults.

METHODS

This retrospective cohort study evaluated critically ill patients treated with ≥ 48 h of cefepime, piperacillin/tazobactam, or meropenem. Two separate cohorts were created: a derivation cohort and a validation cohort. Patients were screened for beta-lactam neurotoxicity by using search terms and diagnosis codes, followed by clinical adjudication using a standardized adverse event scoring tool. Multivariable regression models and least absolute shrinkage and selection operator were used to identify surrogates for neurotoxicity and develop a multivariable prediction model.

RESULTS

The overall incidence of beta-lactam neurotoxicity was 2.6% (n/N = 34/1323) in the derivation cohort and 2.1% in the validation cohort (n/N = 16/767). The final multivariable neurotoxicity assessment tool included weight, Charlson comorbidity score, age, and estimated creatinine clearance as predictors of neurotoxicity. Incidence of neurotoxicity reached 4% in those with a body mass index more than 30 kg/m². Use of the candidate variables in the neurotoxicity assessment tool suggested that a score more than 35 would identify a patient at high risk for neurotoxicity with 75% sensitivity and 54% specificity.

CONCLUSIONS

In this single center cohort of critically ill patients, beta-lactam neurotoxicity was demonstrated less frequently than previously reported. We identified obesity as a novel risk factor for the development of neurotoxicity. The prediction model needs to be further refined before it can be used in clinical practice as a tool to avoid drug-related harm.

Acute Epstein-Barr virus infection presenting as Guillain-Barre syndrome

An 18-year-old man presented with 5-days of a lower extremity rash, sore throat, rapidly progressive bilateral facial numbness and paresthesias in his distal extremities. His neurological examination acutely deteriorated to include moderate bilateral facial weakness in a lower motor neuron pattern, mild flaccid dysarthria, mild bilateral interossei weakness, and diffuse hyporeflexia. In addition to neurological examination, EMG results of acute demyelinating polyradiculoneuropathy were suggestive of Guillain-Barre Syndrome (GBS). Infectious laboratory testing demonstrated acute infection of Epstein-Barr Virus (EBV) with relatively low EBV DNA quantitative values. The patient subsequently developed fever and cervical lymphadenopathy during his hospital course. Contrasting typical GBS, which presents weeks after an acute infection, the patient's presenting symptom of EBV infection was GBS. GBS as a presenting symptom of EBV has not previously been described. This case may represent a unique mechanism for the pathogenesis of GBS in acute infections as opposed to the traditional post-infectious antibody-mediated process.

Medulla Oblongata Hemorrhage and Reverse Takotsubo Cardiomyopathy

BACKGROUND

Acute brain injury with strong surges of adrenergic outflow has resulted in takotsubo cardiomyopathy, but there are surprisingly few reports of takotsubo cardiomyopathy after intracranial hemorrhage, and none have been described from hemorrhage within the brainstem.

RESULTS

We describe a patient with reverse and reversible cardiomyopathy following a hemorrhage in the lateral medulla oblongata. While it is limited in size, the location of the hemorrhage caused acute systolic failure with left ventricular ejection fraction of 27% and vasopressor requirement for cardiogenic shock and pulmonary edema. There was full recovery after 7 days.

METHODS

Detailed case report.

CONCLUSION

Hemorrhage into medulla oblongata pressor centers may result in acute, reversible, stress-induced cardiomyopathy, affirming the adrenergic origin of this condition.

Ventriculostomy and Risk of Upward Herniation in Patients with Obstructive Hydrocephalus from Posterior Fossa Mass Lesions

BACKGROUND

Patients with posterior fossa lesions causing obstructive hydrocephalus present a unique clinical challenge, as relief of hydrocephalus can improve symptoms, but the perceived risk of upward herniation must also be weighed against the risk of worsening or continued hydrocephalus and its consequences. The aim of our study was to evaluate for clinically relevant upward herniation following external ventricular drainage (EVD) in patients with obstructive hydrocephalus due to posterior fossa lesions.

METHODS

We performed a retrospective review of patients undergoing urgent/emergent EVD placement at our institution between 2007 and 2014, evaluating the radiographic and clinical changes following treatment of obstructive hydrocephalus.

RESULTS

Even prior to EVD placement, radiographic upward herniation was present in 22 of 25 (88%) patients. The average Glasgow Coma Scale of patients before and after EVD placement was 10 and 11, respectively. Radiographic worsening of upward herniation occurred in two patients, and upward herniation in general persisted in 21 patients. Clinical worsening occurred in two patients (8%), though in all others the clinical examination remained stable (44%) or improved (48%) following EVD placement. Of the patients who had a worsening clinical exam, other variables likely also contributed to their decline, and cerebrospinal fluid diversion was likely not the main factor that prompted the clinical change.

CONCLUSIONS

Radiographic presence of upward herniation was often present prior to EVD placement. Clinically relevant upward herniation was rare, with only two patients worsening after the procedure, in the presence of other clinical confounders that likely contributed as well.

Variable Significance of Brain MRI Findings in Infective Endocarditis and Its Effect on Surgical Decisions

OBJECTIVE

To determine how brain magnetic resonance imaging (MRI) findings impact clinical outcomes in patients with infective endocarditis (IE) and to propose a management algorithm for patients with neurologic symptoms who are candidates for valve surgery (VS).

PATIENTS AND METHODS

Data from our center were retrospectively reviewed for patients hospitalized with IE between January 1, 2007, and December 31, 2014. Outcomes were postoperative intracerebral hemorrhage (ICH), 6-month mortality, and functional outcome at last follow-up as described by the modified Rankin Scale (mRS) score. Good outcome was defined as an mRS score of 2 or less.

RESULTS

A total of 361 patients with IE were identified, including 127 patients (35%) who had MRI. One hundred twenty-six of 361 patients (35%) had neurologic symptoms, which prompted MRI in 79 of 127 patients (62%); 74 of 79 (94%) had acute or subacute MRI abnormalities. One patient with subarachnoid and multifocal ICH on MRI developed postoperative ICH. Patients with VS despite MRI abnormalities had lower 6-month mortality (odds ratio [OR], 0.17; 95% CI, 0.06-0.48; P<.001) and better functional outcome (OR, 4.43; 95% CI, 1.51-13.00; P=.005). Irrespective of VS, lobar or posterior fossa ICH on MRI was associated with 6-month mortality (OR, 3.58; 95% CI, 1.22-10.50; P=.02) and territorial ischemic stroke was inversely associated with good mRS (OR, 0.29; 95% CI, 0.13-0.66; P=.002). In neurologically asymptomatic patients who had VS, MRI findings did not impact 6-month mortality or functional outcomes.

CONCLUSION

Magnetic resonance imaging detects a large number of abnormalities in patients with IE. Preoperative lobar hematoma and large territorial stroke determine outcome irrespective of VS. When indicated, VS increases the odds of a good outcome despite MRI abnormalities.

Lacosamide Pharmacokinetics in a Critically Ill Patient During Continuous Renal Replacement Therapy

The objective of this study is to describe the pharmacokinetics of lacosamide in a critically ill adult during continuous venovenous hemofiltration (CVVH). A 78-year-old male developed sepsis and acute kidney injury following cardiac surgery. He was initially treated with intermittent hemodialysis but developed nonconvulsive status epilepticus at the end of the first session and was subsequently initiated on CVVH. In addition to lorazepam boluses, levetiracetam, and midazolam infusion, he was loaded with lacosamide 400 mg intravenously and started on 200 mg intravenously twice daily as maintenance therapy. Noncompartmental modeling of lacosamide pharmacokinetics revealed significant extracorporeal removal, a volume of distribution of 0.69 L/kg, elimination half-life of 13.6 hours, and peak and trough concentrations of 7.4 and 3.7 mg/L, respectively (goal trough, 5-10 mg/L). We found significant extracorporeal removal of serum lacosamide during CVVH, which was higher than previously reported. This led to subtherapeutic concentrations and decreased overall antiepileptic drug exposure. The relationship between serum lacosamide concentrations and clinical efficacy is not well understood; thus, therapeutic drug monitoring is not routinely recommended. Yet, we demonstrated that measuring serum lacosamide concentrations in the critically ill population during continuous renal replacement therapy may be useful to individualize dosing programs. Further pharmacokinetic studies of lacosamide may be necessary to generate widespread dosing recommendations.

Utility of Brain Magnetic Resonance Imaging in the Surgical Management of Infective Endocarditis

BACKGROUND

Brain magnetic resonance imaging (MRI) is frequently obtained in patients with infective endocarditis, yet its utility in predicting outcomes for valve replacement surgery in patients is unknown. The objective of this study was to determine how brain MRI findings impact clinical management and outcomes.

METHODS

Demographic and clinical data from electronic medical records at Mayo Clinic were retrospectively reviewed for patients hospitalized with definite or possible infective endocarditis according to the modified Duke criteria between January 1, 2007 and December 31, 2014. There were 364 patients included in the study.

RESULTS

Cardiac valve replacement surgery was performed in 195 of 364 (53.6%) patients, and 95 (48.7%) of the surgical patients underwent preoperative MRI, which was associated with preoperative neurologic symptoms in 56 of 95 (58.9%) patients (odds ratio = 12.92; 95% confidence interval, 5.98-27.93; P <.001). Postoperative neurologic complications occurred in 24 of 195 (12.3%) patients, including new ischemic stroke in 4 of 195 (2.1%) and new intracerebral hemorrhage in 3 of 195 (1.5%). No patients with microhemorrhages developed postoperative hemorrhage. No significant differences existed in rates of postoperative complications between patients with and those without preoperative MRI. There were no substantial associations between preoperative MRI findings and postoperative neurologic complications, functional outcomes as described by the modified Rankin Scale score, or 6-month mortality.

CONCLUSIONS

In patients undergoing valve replacement surgery, preoperative MRI findings were not associated with differences in postoperative outcomes, irrespective of finding or timing of valve replacement surgery.

SSRI/SNRI Use is Not Associated with Increased Risk of Delayed Cerebral Ischemia After aSAH

BACKGROUND

To determine the effect of selective serotonin reuptake inhibitor (SSRI)/selective norepinephrine reuptake inhibitor (SNRI) use on the risk of symptomatic vasospasm and delayed cerebral ischemia (DCI) in patients hospitalized with aneurysmal subarachnoid hemorrhage (aSAH).

METHODS

Retrospective review of consecutive patients with aSAH at Mayo Clinic, Rochester from January 2001 to December 2013. The variables collected and analyzed included age, sex, SSRI/SNRI use, active smoking, transfusion, modified Fisher score, WFNS grade, and outcome at discharge. Multivariate logistic regression analysis was used to evaluate factors associated with DCI, symptomatic vasospasm, and poor outcome (modified Rankin score 3-6) within 1 year.

RESULTS

579 [females 363 (62.7%)] patients with a median age of 55 (IQR 47-65) years were admitted with aSAH during the study period. WFNS at nadir was IV-V in 240 (41.5%), and modified Fisher score was 3-4 in 434 (75.0%). 81 (13.9%) patients had been prescribed an SSRI or SNRI prior to admission and all continued to receive these medications during hospitalization. Symptomatic vasospasm was present in 154 (26.4%), radiological infarction in 172 (29.5%), and DCI in 250 (42.9%) patients. SSRI/SNRI use was not associated with the occurrence of DCI (p = 0.458), symptomatic vasospasm (p = 0.097), radiological infarction (p = 0.972), or poor functional outcome at 3 months (p = 0.376).

CONCLUSIONS

The use of SSRI/SNRI prior to and during hospitalization is not associated with DCI or functional outcome in patients with aSAH.

Posterior reversible encephalopathy in the intensive care unit

Posterior reversible encephalopathy syndrome (PRES) is increasingly diagnosed in the emergency department, and medical and surgical intensive care units. PRES is characterized by acute onset of neurologic symptoms in the setting of blood pressure fluctuations, eclampsia, autoimmune disease, transplantation, renal failure, or exposure to immunosuppressive or cytotoxic drugs, triggers known to admit patients to the intensive care unit (ICU). Although the exact pathophysiology remains unknown, there is growing consensus that PRES results from endothelial dysfunction. Because of the heterogeneous nature of the disorder, it is probable that different mechanisms of endothelial injury are etiologically important in different clinical situations. The presence of bilateral vasogenic edema on brain imaging, particularly in parieto-occipital regions, is of great diagnostic utility but PRES remains a clinical diagnosis. Although largely reversible, PRES can result in irreversible neurologic injury and even death. The range of clinical and radiographic manifestations of the syndrome is probably broader than previously thought, and it is imperative that clinicians become familiar with the full spectrum of the disorder, as prompt recognition and elimination of an inciting factor improve outcome. PRES may be the most frequent toxic-metabolic encephalopathy seen in the ICU.

Extensive Mobile Thrombus of the Internal Carotid Discovered After Intravenous Thrombolysis: What Do I Do Now?

This case report describes a rare presentation of ischemic stroke secondary to an extensive internal carotid artery thrombus, subsequent therapeutic dilemma, and clinical management. A 58-year-old man was administered intravenous (IV) thrombolysis for right middle cerebral artery territory ischemic stroke symptoms. A computed tomography angiogram of the head and neck following thrombolysis showed a longitudinally extensive internal carotid artery thrombus originating at the region of high-grade calcific stenosis. Mechanical embolectomy was deferred because of risk of clot dislodgement and mild neurological symptoms. Recumbency and hemodynamic augmentation were used acutely to support cerebral perfusion. Anticoagulation was started 24 hours after thrombolysis. Carotid endarterectomy was completed successfully within 1 week of presentation. Clinical outcome was satisfactory with discharge modified Rankin Scale score 0. A longitudinally extensive carotid artery thrombus poses a risk of dislodgement and hemispheric stroke. Optimal management in these cases is not known with certainty. In our case, IV thrombolysis, hemodynamic augmentation, delayed anticoagulation, and carotid endarterectomy resulted in a favorable clinical outcome.

Complications of Neurosurgery

PURPOSE OF REVIEW

This article provides an overview of the major neurologic complications of common neurosurgical and endovascular procedures.

RECENT FINDINGS

Brain edema, seizures, postoperative hemorrhage, and cerebral ischemia can complicate neurosurgical procedures and produce neurologic decline. The high variability of reporting, types of operations, patient characteristics, and acuity of cases make estimating the incidence and severity of complications difficult. Overall, the complication rate of neurosurgical procedures is approximately 14%, but these are commonly systemic complications (eg, bleeding requiring transfusion, need for mechanical ventilation). In addition to intracranial hemorrhage, ischemia, and seizures after craniotomies, additional characteristic complications include hyperperfusion syndrome and cranial nerve palsies after carotid endarterectomy, cerebrospinal fluid leaks and aseptic meningitis after posterior fossa surgery, and arterial dissections or groin hematomas after endovascular procedures.

SUMMARY

Neurologic decline can be caused by a variety of causes in the postoperative period. The indication for surgery, type of surgery, and time of decline is helpful in narrowing the differential diagnosis. Brain edema, elevated intracranial pressure (ICP), seizures, intracranial hemorrhage, ischemic infarction, and cranial nerve palsies are some of the more common complications in patients that neurologists may be asked to evaluate or comanage in the postoperative setting.