Deep medullary vein engorgement and superficial medullary vein engorgement: two patterns of perinatal venous stroke.

Perinatal venous stroke has classically been attributed to cerebral sinovenous thrombosis with resultant congestion or thrombosis of the small veins draining the cerebrum. Advances in brain MRI, in particular susceptibility-weighted imaging, have enabled the visualization of the engorged small intracerebral veins, and the spectrum of perinatal venous stroke has expanded to include isolated congestion or thrombosis of the deep medullary veins and the superficial intracerebral veins. Congestion or thrombosis of the deep medullary veins or the superficial intracerebral veins can result in vasogenic edema, cytotoxic edema or hemorrhage in the territory of disrupted venous flow. Deep medullary vein engorgement and superficial medullary vein engorgement have characteristic findings on MRI and should be differentiated from neonatal hemorrhagic stroke.

MRI Vessel Wall Enhancement and Other Imaging Biomarkers in Pediatric Focal Cerebral Arteriopathy-Inflammatory Subtype.

Background and Purpose- Focal cerebral arteriopathy-inflammatory type (FCA-i) is a common cause of pediatric arterial ischemic stroke characterized angiographically by unifocal and unilateral stenosis/irregularity of the large anterior circulation arteries with a presumed inflammatory cause. Arterial vessel wall enhancement (VWE) on vessel wall magnetic resonance imaging is a potential biomarker of inflammation that may improve diagnosis, guide treatment, and predict outcomes in patients with FCA-i. We hypothesized that patients with FCA-i with more severe or extensive VWE would have worse arteriopathy, larger infarcts, worse clinical outcome, and increased risk for infarct progression/recurrence. Methods- Pediatric patients with arterial ischemic stroke, classified as FCA-i, and who underwent vessel wall imaging were retrospectively identified at our institution. Clinical data were reviewed and the Pediatric Stroke Outcome Measure at 1 year was determined as the primary clinical end point. Neuroimaging studies were assessed for infarct size, arteriopathy severity (Focal Cerebral Arteriopathy Severity Score), and VWE. Results- Nine cases of FCA-i with vessel wall imaging were evaluated, and there was a strong correlation between clinical outcome at 1-year with initial infarct volume (Spearman correlation coefficient rho=0.84; P<0.01) and arteriopathy severity (Focal Cerebral Arteriopathy Severity Score; rho=0.85; P<0.01). Patients with infarct progression/recurrence had worse Focal Cerebral Arteriopathy Severity Score at presentation compared with those without progression/recurrence (median [IQR]; 9.0 [8.0-11.8] and 5.0 [4.0-7.0], respectively; P<0.05). On the contrary, measures of VWE were not correlated with arteriopathy severity, infarct size, clinical outcome, or risk of infarct progression/recurrence. Moreover, not all patients with FCA-i demonstrated VWE. Conclusions- VWE may not be a reliable biomarker for the diagnosis or assessment of FCA-i, and future work is needed to assess the utility of vessel wall imaging in pediatric arterial ischemic stroke and FCA-i.

Acute Hospital Management of Pediatric Stroke.

The field of pediatric stroke has historically been hampered by limited evidence and small patient cohorts. However the landscape of childhood stroke is rapidly changing due in part to increasing awareness of the importance of pediatric stroke and the emergence of dedicated pediatric stroke centers, care pathways, and alert systems. Acute pediatric stroke management hinges on timely diagnosis confirmed by neuroimaging, appropriate consideration of recanalization therapies, implementation of neuroprotective measures, and attention to secondary prevention. Because pediatric stroke is highly heterogenous in etiology, management strategies must be individualized. Determining a child's underlying stroke etiology is essential to appropriately tailoring hyperacute stroke management and determining best approach to secondary prevention. Herein, we review the methods of recognition, diagnosis, management, current knowledge gaps and promising research for pediatric stroke.

Optimizing the concentration and bolus of a drug delivered by continuous infusion.

We consider treatment regimes in which an agent is administered continuously at a specified concentration until either a response is achieved or a predetermined maximum infusion time is reached. Response is an event defined to characterize therapeutic efficacy. A portion of the maximum planned total amount administered is given as an initial bolus. For such regimes, the amount of the agent received by the patient depends on the time to response. An additional complication when response is evaluated periodically rather than continuously is that the response time is interval censored. We address the problem of designing a clinical trial in which such response time data and a binary indicator of toxicity are used together to jointly optimize the concentration and the size of the bolus. We propose a sequentially adaptive Bayesian design that chooses the optimal treatment for successive patients by maximizing the posterior mean utility of the joint efficacy-toxicity outcome. The methodology is illustrated by a trial in which tissue plasminogen activator is infused intraarterially as rapid treatment for acute ischemic stroke.

Practical model-based dose finding in early-phase clinical trials: optimizing tissue plasminogen activator dose for treatment of ischemic stroke in children.

BACKGROUND AND PURPOSE: A safe and effective tissue plasminogen activator (tPA) dose for childhood stroke has not been established. This article describes a Bayesian outcome-adaptive method for determining the best dose of an experimental agent and explains how this method was used to design a dose-finding trial for tPA in childhood. METHODS: The method assigns doses to successive cohorts of patients on the basis of each dose's desirability, quantified in terms of the tradeoff between efficacy and toxicity. The tradeoff function is constructed from several pairs of equally desirable (efficacy, toxicity) probabilities specified by the physicians planning the trial. Each cohort's dose is chosen adaptively, based on dose-outcome data from the patients treated previously in the trial, to optimize the efficacy-toxicity tradeoff. Application of the method to design the tPA trial is described, including a computer simulation study to establish design properties. A hypothetical cohort-by-cohort example is given to illustrate how the method works during trial conduct. RESULTS: Because only a dose that is both safe and efficacious may be selected and the method combines phase I and phase II by integrating efficacy and toxicity to choose doses, it avoids the more time-consuming and expensive conventional approach of conducting a phase I trial based on toxicity alone followed by a phase II trial based on efficacy alone. This is especially useful in settings with low accrual rates, such as trials of tPA for pediatric acute ischemic stroke.

Survival after treatment of rabies with induction of coma.

We report the survival of a 15-year-old girl in whom clinical rabies developed one month after she was bitten by a bat. Treatment included induction of coma while a native immune response matured; rabies vaccine was not administered. The patient was treated with ketamine, midazolam, ribavirin, and amantadine. Probable drug-related toxic effects included hemolysis, pancreatitis, acidosis, and hepatotoxicity. Lumbar puncture after eight days showed an increased level of rabies antibody, and sedation was tapered. Paresis and sensory denervation then resolved. The patient was removed from isolation after 31 days and discharged to her home after 76 days. At nearly five months after her initial hospitalization, she was alert and communicative, but with choreoathetosis, dysarthria, and an unsteady gait.

Fatal neonatal stroke from a prenatal cardiac thrombus.

Despite careful investigation, the etiology of many perinatal arterial strokes is unknown. We report on a 5-day-old boy with a cardiac thrombus of prenatal origin resulting in a fatal postnatal stroke. The thrombus was discovered only at autopsy, challenging the assumption of a placental source of embolus in perinatal strokes in the absence of macroscopic and microscopic examination of the heart.

Cone beam computed tomography-guided transpterygoidal aspiration of a carotid space abscess in Lemierre's syndrome.

Lemierre's syndrome results from anaerobic bacterial thrombophlebitis of the cervical venous vasculature, occasionally complicated by deep neck space abscesses, sepsis, septic emboli, vascular occlusions, or mycotic aneurysms. Fastidious organisms, such as Fusobacterium necrophorum, may be slow to respond to intravenous antibiotic therapy, prompting a need for more aggressive source control. Concomitant vascular occlusions and mycotic aneurysms present difficult decisions regarding anticoagulation, and the anatomy involved implies important technical considerations for intervention. A case of Lemierre's syndrome complicated by a carotid space abscess and mycotic internal carotid artery pseudoaneurysm progressed despite intravenous antibiosis. Transpterygoidal aspiration using cone beam computed tomography guidance provided both technical and clinical success.

Localized purpura associated with lamotrigine.

Antiepileptic drug hypersensitivity syndrome consists of fever, rash, and internal organ involvement and usually occurs within the first 2 months of initiation of therapy. This report describes a 13-year-old female with a right frontal high-grade glioma and complex partial seizures who developed localized purpura after 23 months of lamotrigine monotherapy. This case study is the second report of localized purpura after prolonged lamotrigine treatment suggesting this may be an atypical lamotrigine-induced drug reaction.

Clinical trial design for endovascular ischemic stroke intervention.

BACKGROUND: Randomized, double-blinded, placebo-controlled trials have significant impact on clinical practice. The ultimate goal of a clinical trial of therapy for acute ischemic stroke (AIS) is to compare 2 interventions. Challenges may include interventional therapy standardization, enrollment rate, patient selection, biases, data and safety monitoring, reporting, and financial and logistical support. METHOD: Selected randomized and single-arm prospective AIS trial designs. Clinical trial elements and their challenges are reviewed. Innovative designs and proposed recommendations to overcome some of the specific challenges and limitations are discussed. RESULTS: AIS therapy trials have specific challenges related to ethical issues, enrollment rate, outcome measures, limited time to treatment, efficacy, safety, and limited or variable operator experience with complex technology in a delicate end organ. Proposed suggestions for improving trial design include the following: incorporation of a lead-in phase; careful patient and outcome measure selection; historical, concurrent, or hybrid controls; open data access; and a Bayesian approach. An open data paradigm may facilitate creation of computerized prediction models for future trials (minimizing cost by decreasing sample size or providing futility analyses and directing resources to other trials). Collaborative, consortium, and network infrastructures may allow more effective and efficient study completion. Self-learning, self-correcting trials with intrinsic flexibility to adapt may help future clinical trial design in AIS. CONCLUSION: The randomized clinical trial design in AIS endovascular therapy is challenging. Lead-in phases, careful patient selection, use of innovative outcome measures, control groups, and newer clinical trial design may enhance conduct of future trials, their validity, and their results.