Thrombolysis beyond 4.5 h in Acute Ischemic Stroke.

PURPOSE OF REVIEW: The purpose of this article is to review the current approaches using neuroimaging techniques to expand eligibility for intravenous thrombolytic therapy in acute ischemic stroke patients with stroke of unknown symptom onset. RECENT FINDINGS: In recent years, several randomized, placebo-controlled trials have shown neuroimaging-guided approaches to be feasible in determining eligibility for alteplase beyond 4.5 h from last known well, and efficacious for reducing disability. DWI-FLAIR mismatch on MRI is an effective tool to identify stroke lesions less than 4.5 h in onset in patients with stroke of unknown symptom onset. Additionally, an automated perfusion-based approach, assessing for a disproportionate amount of salvageable tissue, is effective in identifying patients likely to benefit from late window alteplase treatment. In patients with stroke of unknown symptom onset, an individualized approach using neuroimaging to determine time of stroke onset or presence of salvageable brain tissue is feasible in the acute setting and associated with improved long-term outcomes.

Neuroimaging in Sports-Related Concussion.

Mild traumatic brain injuries, or concussions, often result in transient brain abnormalities not readily detected by conventional imaging methods. Several advanced imaging studies have been evaluated in the past couple decades to improve understanding of microstructural and functional abnormalities in the brain in patients suffering concussions. The thought remains a functional or pathophysiologic change rather than a structural one. The mechanism of injury, whether direct, indirect, or rotational, may drive specific clinical and radiological presentations. This remains a dynamic and constantly evolving area of research. This article focuses on the current status of imaging and future directions in concussion-related research.

Incidence, predictors, and outcomes of post-thrombectomy seizures in the extended time window.

Mechanical thrombectomy 6-24 h after the last time where a patient was known to be without signs or symptoms of a stroke is the standard of care for patients with a stroke due to large vessel occlusion. This is referred to as thrombectomy within an extended time window. There have been very few studies looking at patients who had seizures within the first week (early post-stroke seizures) following mechanical thrombectomy in this extended time window. Our study suggests that this group of patients does not have a higher incidence of early post stroke seizures. Our findings do reveal however, that patients who do have early post-stroke seizures may have a less favorable functional outcome at 90 days than those who did not develop early seizures. Hence, rapid identification and subsequent treatment of seizures in these patients is important.

Antithrombotic Management After Intracranial Hemorrhage.

PURPOSE OF REVIEW: Intracranial hemorrhage remains one of the most feared acute neurological emergencies. However, apart from the acute management, secondary risk factor management and prevention of ischemic events remains ambiguous. We present a thorough review of the current data available regarding management of antithrombotics after intracranial hemorrhage. RECENT FINDINGS: The most robust evidence comes from the investigators of the RESTART trial which reassured the safety of resuming antiplatelet therapy after ICH, namely in patients with prior indication and treatment with antithrombotics. We conclude that based on available data, the risk of recurrent ICH is probably too small to exceed the found benefits of antiplatelet therapy in the secondary prevention of ischemic vascular disease.

MTHFR Gene Mutations Correlate with White Matter Disease Burden and Predict Cerebrovascular Disease and Dementia.

The incidence of dementia is on the rise and expected to continue to increase in the foreseeable future. Two of the most common subtypes of dementia are Alzheimer's subtype and vascular dementia. Hyperhomocysteinemia has been shown to serve as a risk factor for dementia due to an associated blood-brain barrier dysfunction and subsequent small-vessel disease pathology. There are varying causes for hyperhomocysteinemia, including genetic and dietary, among others. We highlight the importance of identifying hyperhomocysteinemia as a potential etiologic and therapeutic target for the most common subtypes of dementia.

Patent Foramen Ovale in Cryptogenic Stroke and Migraine with Aura: Does Size Matter?

INTRODUCTION: There is an association between cryptogenic strokes and patent foramen ovale (PFO), as well as between migraines with aura and PFO. The purpose of the current study was to compare shunt characteristics in the stroke and migraine populations. METHODS: We retrospectively evaluated the degree of the shunt in 68 consecutive patients with cryptogenic stroke (n=33) or migraines with aura (n=35) evaluated in a single transcranial Doppler laboratory. All patients underwent an intravenous injection of agitated saline, followed by the insonation of the middle cerebral artery to determine the degree of the right-to-left shunt. We graded the shunt size according to the number of emboli: Grade I, none; Grade II, 1-10; Grade III, 11-100; and Grade IV, >100. Grades I and II were considered low-grade shunts, and Grades III and IV were considered high-grade. RESULTS: In the 14-month study period, we found 31 high-grade shunts and 37 low-grade shunts. Among migraines with aura patients, 27 (77%) had high-grade shunts, whereas only 4 patients (12%) with cryptogenic stroke had high-grade shunts. These percentages were significantly different between groups (Fisher's exact test, p<0.0001). CONCLUSIONS: In a standardized laboratory using uniform methods, we found a significant difference in shunt size associated with PFO between cryptogenic stroke and migraine with aura patients. We hypothesize that in migraines with aura, venous admixture with arterial blood is the main mechanism by which PFO contributes to the condition. In contrast, cryptogenic strokes associated with PFO are more likely to arise from an atrial septal clot within the PFO space.

Changes in Transcranial Sonographic Measurement of the Optic Nerve Sheath Diameter in Non-concussed Collegiate Soccer Players Across a Single Season.

Introduction Bedside ultrasound measurement of the optic nerve sheath diameter (ONSD) is emerging as a non-invasive technique to evaluate and predict raised intracranial pressure (ICP) in both children and adults. The prognostic value of increased ONSD on brain computed tomography (CT) scan has previously been correlated with increased intensive care unit (ICU) mortality in patients with severe traumatic brain injury (TBI). Previous studies have also evaluated the association between high-contact sports, such as soccer, and TBI; however, the related changes in ONSD are still unknown. The aim of this study was to evaluate for the natural evolution of changes in ONSD in athletes who participate in high-contact sports. Methods In this prospective observational study, volunteers from a collegiate women's soccer team underwent the measurement of ONSD with transcranial Doppler (TCD). ONSDs were measured during the initial visit during the pre-season period and again at the three-month follow-up. A single experienced neuro-sonographer performed all measurements to eliminate any operator bias. Results Twenty-four female college soccer players between the ages of 18 and 23 were included in this analysis. Mean ONSD during the initial pre-season clinic visit and the three-month follow-up were 4.14±0.6 mm and 5.02±0.72 mm, respectively (P < 0.0001). A two-tailed t-test analysis was performed, which resulted in a t-value of 4.76 and P < 0.00001. The average ONSD measured during the post-season follow-up showed a 21.3% increase compared to the baseline. Conclusion The evaluation of high-contact sports athletes is limited due to the lack of objective radiologic and diagnostic tools. Moreover, in an athlete suffering a concussion, return-to-play decisions are heavily dependent on the symptoms reported by the athletes. In our analysis of collegiate women's soccer players, active participation in soccer competitions and practice may be associated with an increase in ONSD, independent of concussions. Further studies are underway to evaluate the clinical significance of these findings as well as possible correlations between concussions and changes in ONSD.