MRI in the Evaluation of Cryptogenic Stroke and Embolic Stroke of Undetermined Source.

Cryptogenic stroke refers to a stroke of undetermined etiology. It accounts for approximately one-fifth of ischemic strokes and has a higher prevalence in younger patients. Embolic stroke of undetermined source (ESUS) refers to a subgroup of patients with nonlacunar cryptogenic strokes in whom embolism is the suspected stroke mechanism. Under the classifications of cryptogenic stroke or ESUS, there is wide heterogeneity in possible stroke mechanisms. In the absence of a confirmed stroke etiology, there is no established treatment for secondary prevention of stroke in patients experiencing cryptogenic stroke or ESUS, despite several clinical trials, leaving physicians with a clinical dilemma. Both conventional and advanced MRI techniques are available in clinical practice to identify differentiating features and stroke patterns and to determine or infer the underlying etiologic cause, such as atherosclerotic plaques and cardiogenic or paradoxical embolism due to occult pelvic venous thrombi. The aim of this review is to highlight the diagnostic utility of various MRI techniques in patients with cryptogenic stroke or ESUS. Future trends in technological advancement for promoting the adoption of MRI in such a special clinical application are also discussed.

Immunonutrition with Omega-3 Fatty Acid Supplementation in Severe TBI: Retrospective Analysis of Patient Characteristics and Outcomes.

Background: Early evidence-based medical interventions to improve patient outcomes after traumatic brain injury (TBI) are lacking. In patients admitted to the ICU after TBI, optimization of nutrition is an emerging field of interest. Specialized enteral nutrition (EN) formulas that include immunonutrition containing omega-3 polyunsaturated fatty acids (n-3 PUFAs) have been developed and are used for their proposed anti-inflammatory and pro-immune properties; however, their use has not been rigorously studied in human TBI populations. Methods: A single-center, retrospective, descriptive observational study was conducted at LAC + USC Medical Center. Patients with severe TBI (sTBI, Glasgow Coma Scale score ≤ 8) who remained in the ICU for ≥ 2 weeks and received EN were identified between 2017 and 2022 using the institutional trauma registry. Those who received immunonutrition formulas containing n-3 PUFAs were compared to those who received standard, polymeric EN in regard to baseline characteristics, clinical markers of inflammation and immune function, and short-term clinical outcomes. Results: A total of 151 patients with sTBI were analyzed. Those who received immunonutrition with n-3 PUFA supplementation were more likely to be male, younger, Hispanic/Latinx, and have polytrauma needing non-central nervous system surgery. No differences in clinical markers of inflammation or infection rate were found. In multivariate regression analysis, immunonutrition was associated with reduced hospital length of stay (LOS). ICU LOS was also reduced in the subgroup of patients with polytrauma and TBI. Conclusion: This study identifies important differences in patient characteristics and outcomes associated with the EN formula prescribed. Study results can directly inform a prospective pragmatic study of immunonutrition with n-3 PUFA supplementation aimed to confirm the biomechanistic and clinical benefits of the intervention.

Association Between Glycemic Gap and In-hospital Outcomes in Aneurysmal Subarachnoid Hemorrhage.

Introduction: Glycemic gap (GG), as determined by the difference between glucose and the hemoglobin A1c (HbA1c)-derived estimated average glucose (eAG), is associated with poor outcomes in various clinical settings. There is a paucity of data describing GG and outcomes after aneurysmal subarachnoid hemorrhage (aSAH). Our main objectives were to evaluate the association of admission glycemic gap (aGG) with in-hospital mortality and with poor composite outcome and to compare aGG's predictive value to admission serum glucose. Secondary outcomes were the associations between aGG and neurologic complications including vasospasm and delayed cerebral ischemia following aSAH. Methods: We retrospectively reviewed 119 adult patients with aSAH admitted to a single tertiary care neuroscience ICU. Spearman method was used for correlation for non-normality of data. Area under the curve (AUC) for Receiver Operating Characteristic (ROC) curve was used to estimate prediction accuracy of aGG and admission glucose on outcome measures. Multivariable analyses were conducted to assess the value of aGG in predicting in-hospital poor composite outcome and death. Results: Elevated aGG at or above 30 mg/dL was identified in 79 (66.4%) of patients. Vasospasm was not associated with the elevated aGG. Admission GG correlated with admission serum glucose (r = 0.94, p < 0.01), lactate (r = 0.41, p < 0.01), procalcitonin (r = 0.38, p < 0.01), and Hunt and Hess score (r = 0.51, p < 0.01), but not with HbA1c (r = 0.02, p = 0.82). Compared to admission glucose, aGG had a statistically significantly improved accuracy in predicting inpatient mortality (AUC mean ± SEM: 0.77 ± 0.05 vs. 0.72 ± 0.06, p = 0.03) and trended toward statistically improved accuracy in predicting poor composite outcome (AUC: 0.69 ± 0.05 vs. 0.66 ± 0.05, p = 0.07). When controlling for aSAH severity, aGG was not independently associated with delayed cerebral ischemia, poor composite outcome, and in-hospital mortality. Conclusion: Admission GG was not independently associated with in-hospital mortality or poor outcome in a population of aSAH. An aGG ≥30 mg/dL was common in our population, and further study is needed to fully understand the clinical importance of this biomarker.

Admission glycemic gap in the assessment of patients with intracerebral hemorrhage.

BACKGROUND: Intracerebral hemorrhage (ICH) is the most common type of hemorrhagic stroke. Glycemic gap, determined by the difference between glucose and the HbA1c-derived average glucose, predicts poor outcomes in various clinical settings. Our main objective was to evaluate association of some admission factors and outcomes in relation to admission glycemic gap (AGG) in patients with ICH. METHODS: We retrospectively analyzed 506 adult patients with ICH between 2014 and 2019. AGG was defined as A1c-derived average glucose (28.7×HbA1c-46.7) subtracted from admission glucose. Admission factors and hospital outcomes indicative of poor outcome (i.e. death, gastrostomy tube, tracheostomy, and discharge status) were compared between patients with elevated (greater than 80 mg/dL) vs. non-elevated (less than or equal-to 80 mg/dL) AGG. Pearson chi-square test was used for independence, and multivariate analysis was used for association. SPSS and excel were used for all data analysis. RESULTS: We found that 67 of 506 (13%) ICH patients had elevated AGG with a mean of 137.3 mg/dL compared to 439 (87%) non-elevated AGG with a mean of 12.6 mg/dL. While mean and standard deviation values for age, weight,and body mass index were comparable between groups, the elevated AGG group had significantly higher admission glucose (286.1 ± 84.3 vs. 140.1 ± 42.5, p < 0.001), higher lactic acid (3.26 ± 2.04 mmol/L vs. 1.99 ± 1.33 mmol/L, p < 0.001), lower Glasgow Coma Scale (GCS) scores (7.70 ± 4.28 vs. 11.24 ± 4.14, p < 0.001), and higher ICH score (median 3, IQR 2-4 vs. median 1, IQR 0-3, p < 0.001). Higher AGG was associated with an increased likelihood of mechanical ventilation, and in-hospital mortality (74.6% vs. 38.3% and 47.8% vs. 15.0% respectively, p < 0.001). Placements of tracheostomy and gastrostomy were similar between the two groups (13.4% vs. 11.8%, p = 0.69% and 1.5% and 4.6%, p = 0.34 respectively). The higher AGG group had a more common poor discharge outcome to either long-term acute care, skilled nursing facility, and/or hospice (65.7% vs. 42.6%, p < 0.001). Hospital cost and length of hospitalization did not differ significantly. Although AGG was not an independent predictor of poor outcome, multivariate analysis showed it was significantly associated with poor outcome while admission glucose was not (p < 0.001 vs. p = 0.167). CONCLUSION: Elevated AGG was associated with worse GCS and ICH scores on admission, as well as need for mechanical ventilation, in hospital mortality and poor discharge status. Elevated AGG has value in prediction of outcome, but existing understanding is limited.

The Continued Role and Value of Imaging for Acute Ischemic Stroke.

Advances in neuroimaging in the last 2 decades have revolutionized the management of acute ischemic stroke (AIS). Here we review the development of computed tomography (CT) and magnetic resonance imaging (MRI) modalities used to guide treatment of patients with AIS characterized by large vessel occlusion. In particular, we highlight recent randomized trials and their patient selection methodologies to detail the progression of these selection paradigms. With advanced imaging, distinction between at-risk penumbra and ischemic core in AIS may be performed using either CT or MRI. While limitations exist for methodologies to quantify core and penumbra, commercially available fully automated software packages provide useful information to guide treatment decisions. Randomized controlled trials implementing perfusion imaging to patient selection algorithms have demonstrated marked success in improving functional outcomes in patients with large vessel occlusions. As such, imaging has become a vital aspect of AIS treatment in selecting patients who may benefit from mechanical thrombectomy.

Corrigendum: Targeted Temperature Management and Multimodality Monitoring of Comatose Patients After Cardiac Arrest.

[This corrects the article DOI: 10.3389/fneur.2018.00768.].

Targeted Temperature Management and Multimodality Monitoring of Comatose Patients After Cardiac Arrest.

Out-of-hospital cardiac arrest (CA) remains a leading cause of sudden morbidity and mortality; however, outcomes have continued to improve in the era of targeted temperature management (TTM). In this review, we highlight the clinical use of TTM, and provide an updated summary of multimodality monitoring possible in a modern ICU. TTM is neuroprotective for survivors of CA by inhibiting multiple pathophysiologic processes caused by anoxic brain injury, with a final common pathway of neuronal death. Current guidelines recommend the use of TTM for out-of-hospital CA survivors who present with a shockable rhythm. Further studies are being completed to determine the optimal timing, depth and duration of hypothermia to optimize patient outcomes. Although a multidisciplinary approach is necessary in the CA population, neurologists and neurointensivists are central in selecting TTM candidates and guiding patient care and prognostic evaluation. Established prognostic tools include clinal exam, SSEP, EEG and MR imaging, while functional MRI and invasive monitoring is not validated to improve outcomes in CA or aid in prognosis. We recommend that an evidence-based TTM and prognostication algorithm be locally implemented, based on each institution's resources and limitations. Given the high incidence of CA and difficulty in predicting outcomes, further study is urgently needed to determine the utility of more recent multimodality devices and studies.

Basilar artery territory stroke secondary to invasive fungal sphenoid sinusitis: a case report and review of the literature.

BACKGROUND: Mucormycosis is a fungal infection with the following 5 classic forms: cutaneous, pulmonary, gastrointestinal, disseminated, and rhinocerebral. The rhinocerebral form can be rapidly progressive and invasive with a high mortality rate. We present a case of a 38-year-old man with invasive mucormycosis that led to a basilar artery territory stroke. Rhinocerebral mucormycosis is an unusual cause of stroke. CASE REPORT: A 38-year-old man with a past medical history of diabetes mellitus presented with altered mental status. A lumbar puncture revealed eosinophilic pleocytosis with a mildly elevated total protein and borderline low glucose level. CT revealed a left medullary and cerebellar infarct confirmed by MRI. MRI also displayed a diffuse marrow signal abnormality in the clivus with contiguous sinus disease. Endoscopic sinus surgery confirmed that the fungal sinusitis was mucormycosis of the Rhizopus genus, which had affected the left sphenoid sinus, invaded through the skull base, and involved the basilar artery. He was given liposomal amphotericin (500 mg i.v.) with posaconazole (400 mg i.v. twice daily). Due to the severity of the invasion and poor prognosis, the patient was discharged with comfort care measures. DISCUSSION: Clinicians should be aware of invasive sinusitis as a rare cause of stroke in diabetics. Once the subarachnoid space and basal arteries of the brain have been invaded, the prognosis is very poor. The key to improvement of outcomes is early recognition and treatment, and examination of the sinuses on neuroimaging in all cases of stroke is vital.

Stroke Mimics and Acute Stroke Evaluation: Clinical Differentiation and Complications after Intravenous Tissue Plasminogen Activator.

BACKGROUND: Intravenous tissue-plasminogen activator remains the only U.S. Food and Drug Administration-approved treatment for acute ischemic stroke. Timely administration of fibrinolysis is balanced with the need for accurate diagnosis. Stroke mimics represent a heterogeneous group of patients presenting with acute-onset focal neurological deficits. If these patients arrive within the extended time window for acute stroke treatment, these stroke mimics may erroneously receive fibrinolytics. OBJECTIVE: This review explores the literature and presents strategies for differentiating stroke mimics. DISCUSSION: Clinical outcome in stroke mimics receiving fibrinolytics is overwhelmingly better than their stroke counterparts. However, the risk of symptomatic intracranial hemorrhage remains a real but rare possibility. Certain presenting complaints and epidemiological risk factors may help differentiate strokes from stroke mimics; however, detection of stroke often depends on presence of posterior vs. anterior circulation strokes. Availability of imaging modalities also assists in diagnosing stroke mimics, with magnetic resonance imaging offering the most sensitivity and specificity. CONCLUSION: Stroke mimics remain a heterogeneous entity that is difficult to identify. All studies in the literature report that stroke mimics treated with intravenous fibrinolysis have better clinical outcome than their stroke counterparts. Although symptomatic intracranial hemorrhage remains a real threat, literature searches have identified only two cases of symptomatic intracranial hemorrhage in stroke mimics treated with fibrinolytics.