Association of EEG Background and Neurodevelopmental Outcome in Neonates With Hypoxic-Ischemic Encephalopathy Receiving Hypothermia

BACKGROUND AND OBJECTIVES

Predicting neurodevelopmental outcome for neonates with hypoxic-ischemic encephalopathy (HIE) is important for clinical decision-making, care planning, and parent communication. We examined the relationship between EEG background and neurodevelopmental outcome among children enrolled in a trial of erythropoietin or placebo for neonates with HIE treated with therapeutic hypothermia.

METHODS

Participants had EEG recorded throughout hypothermia. EEG background was classified as normal, discontinuous, or severely abnormal (defined as burst suppression, low voltage suppressed, or status epilepticus) at 5 1-hour epochs: onset of recording, 24, 36, 48, and 72 hours after birth. The predominant background pattern during the entire continuous video EEG monitoring recording was calculated using the arithmetic mean of the 5 EEG background ratings (normal = 0; discontinuous = 1; severely abnormal = 2) as follows: "predominantly normal" (mean = 0), "normal/discontinuous" (0 < mean<1), "predominantly discontinuous" (mean = 1), "discontinuous/severely abnormal" (1 < mean<2), or "predominantly severely abnormal" (mean = 2). Primary outcome was death or neurodevelopmental impairment (NDI) defined as cerebral palsy, Gross Motor Function Classification Score ≥1, or cognitive score <90 on Bayley Scales of Infant Toddler Development, third edition at age 2 years. Neurodevelopment was also categorized into a 5-level ordinal measure: no, mild, moderate, severe NDI, or death for secondary analysis. We used generalized linear regression models with robust standard errors to assess the relative risk of death or NDI by EEG background in both unadjusted and adjusted analyses controlling for the effects of treatment group, sex, HIE severity, and study recruitment site.

RESULTS

Among 142 neonates, the predominant background EEG pattern was predominantly normal in 35 (25%), normal/discontinuous in 68 (48%), predominantly discontinuous in 11 (7.7%), discontinuous/severely abnormal in 16 (11%), and predominantly severely abnormal in 12 (8.5%). Increasing severity of background across monitoring epochs was associated with increasingly worse clinical outcomes. Children with severe EEG background abnormality at any time point (n = 36, 25%) were significantly more likely to die or have severe NDI at 2 years (adjusted relative risk: 7.95, 95% CI 3.49-18.12).

DISCUSSION

EEG background is strongly associated with NDI at age 2 years. These results can be used to assist health care providers to plan follow-up care and counsel families for decision-making related to goals of care.

SCN1A gain-of-function mutation causing an early onset epileptic encephalopathy

OBJECTIVE

Loss-of-function variants in SCN1A cause Dravet syndrome, the most common genetic developmental and epileptic encephalopathy (DEE). However, emerging evidence suggests separate entities of SCN1A-related disorders due to gain-of-function variants. Here, we aim to refine the clinical, genetic, and functional electrophysiological features of a recurrent p.R1636Q gain-of-function variant, identified in four individuals at a single center.

METHODS

Individuals carrying the recurrent SCN1A p.R1636Q variant were identified through diagnostic testing. Whole cell voltage-clamp electrophysiological recording in HEK-293 T cells was performed to compare the properties of sodium channels containing wild-type Nav 1.1 or Nav 1.1-R1636Q along with both Nav β1 and Nav β2 subunits, including response to oxcarbazepine. To delineate differences from other SCN1A-related epilepsies, we analyzed electronic medical records.

RESULTS

All four individuals had an early onset DEE characterized by focal tonic seizures and additional seizure types starting in the first few weeks of life. Electrophysiological analysis showed a mixed gain-of-function effect with normal current density, a leftward (hyperpolarized) shift of steady-state inactivation, and slower inactivation kinetics leading to a prominent late sodium current. The observed functional changes closely paralleled effects of pathogenic variants in SCN3A and SCN8A at corresponding positions. Both wild type and variant exhibited sensitivity to block by oxcarbazepine, partially correcting electrophysiological abnormalities of the SCN1A p.R1636Q variant. Clinically, a single individual responded to treatment with oxcarbazepine. Across 51 individuals with SCN1A-related epilepsies, those with the recurrent p.R1636Q variants had the earliest ages at onset.

SIGNIFICANCE

The recurrent SCN1A p.R1636Q variant causes a clinical entity with a wider clinical spectrum than previously reported, characterized by neonatal onset epilepsy and absence of prominent movement disorder. Functional consequences of this variant lead to mixed loss and gain of function that is partially corrected by oxcarbazepine. The recurrent p.R1636Q variant represents one of the most common causes of early onset SCN1A-related epilepsies with separate treatment and prognosis implications.

Adverse Childhood Experiences Are Associated With Seizures in Children: A Cross-sectional Analysis

Background and Objective

To assess the relationship between adverse childhood experiences (ACE/ACEs) and epilepsy.

Methods

We performed a cross-sectional retrospective cohort analysis using population-based data from the 2018 and 2019 National Survey of Children's Health to examine caregiver-reported ACE exposures and their relationship to caregiver-reported physician diagnoses of epilepsy or seizure disorder in children. ACEs elicited in the survey included questions about experience of violence, household dysfunction, and food and housing insecurity. Adjusting for age, race, and income level, we used logistic regression to test the relationships between cumulative ACE score and current seizure disorder or epilepsy diagnosis and to examine which specific ACEs were individually associated with current seizure disorder or epilepsy diagnosis.

Results

The study population consisted of 59,963 participants; 52.2% were female, and 47.8% were male. Participant ages ranged from 0 to 17 years. A current diagnosis of epilepsy or seizure disorder was reported in 377 (0.63%) participants, and 22,749 (37.9%) participants had one or more ACE exposures. As the number of ACEs increased, odds of current epilepsy or seizure disorder diagnosis increased by 1.14 (95% confidence interval 1.07-1.22). Five ACE exposures demonstrated a high association with a current diagnosis of epilepsy or seizure disorder: food/housing insecurity, witnessing domestic violence, household mental illness, neighborhood violence, and parent/guardian incarceration.

Discussion

Multiple ACE exposures were individually associated with reporting a diagnosis of epilepsy or seizure disorder. An increase in cumulative ACE exposures increased odds of having current diagnosis of epilepsy or seizure disorder.

The incidence of dry chlorhexidine gluconate transfer from skin to surgical gloves: a simulation and in vitro study

BACKGROUND

To prevent alcohol-based chlorhexidine from reaching the cerebrospinal fluid, it is recommended that the antiseptic solution be allowed to dry before skin palpation or puncture. However, no guidelines specify a drying time interval. Manufacturers recommend 3 min of air drying, based upon the isopropyl alcohol component. Therefore, to fill this knowledge gap, we designed a simulation study to investigate the incidence of primary chlorhexidine transfer from skin to gloves following three drying time intervals. We also investigated the incidence of secondary chlorhexidine transfer from gloves to another surface following one drying time interval.

METHODS

An alcohol-based chlorhexidine antiseptic solution with dye, ChloraPrep®, was applied to the skin of the lumbar region of 20 volunteers. Cotton-tipped applicators wrapped in material from gloves were taken from the application area at 3, 4, 5, and 10 min following application. Transfer of chlorhexidine from skin to gloves, and gloves to another medium, was assessed through a chemical assay that produced a color change when chlorhexidine was present on the sample.

RESULTS

The incidence of primary chlorhexidine transfer from skin to gloves at 3, 4 and 10 min following application was 99.5%, 99.4%, and 99.6%, respectively. The incidence of secondary chlorhexidine transfer from gloves to another surface was 68.9%.

CONCLUSION

Gloves are routinely contaminated with chlorhexidine during central neuraxial blockade. The high incidence of secondary transfer in our simulation suggests a pathway by which chlorhexidine may gain access to the neuraxial space.

Development and Validation of a Seizure Prediction Model in Neonates After Cardiac Surgery

BACKGROUND

Electroencephalographic seizures (ESs) after neonatal cardiac surgery are often subclinical and have been associated with poor outcomes. An accurate ES prediction model could allow targeted continuous electroencephalographic monitoring (CEEG) for high-risk neonates.

METHODS

ES prediction models were developed and validated in a multicenter prospective cohort where all postoperative neonates who underwent cardiopulmonary bypass (CPB) also underwent CEEG.

RESULTS

ESs occurred in 7.4% of neonates (78 of 1053). Model predictors included gestational age, head circumference, single-ventricle defect, deep hypothermic circulatory arrest duration, cardiac arrest, nitric oxide, extracorporeal membrane oxygenation, and delayed sternal closure. The model performed well in the derivation cohort (c-statistic, 0.77; Hosmer-Lemeshow, P = .56), with a net benefit (NB) over monitoring all and none over a threshold probability of 2% in decision curve analysis (DCA). The model had good calibration in the validation cohort (Hosmer-Lemeshow, P = .60); however, discrimination was poor (c-statistic, 0.61), and in DCA there was no NB of the prediction model between the threshold probabilities of 8% and 18%. By using a cut point that emphasized negative predictive value in the derivation cohort, 32% (236 of 737) of neonates would not undergo CEEG, including 3.5% (2 of 58) of neonates with ESs (negative predictive value, 99%; sensitivity, 97%).

CONCLUSIONS

In this large prospective cohort, a prediction model of ESs in neonates after CPB had good performance in the derivation cohort, with an NB in DCA. However, performance in the validation cohort was weak, with poor discrimination, poor calibration, and no NB in DCA. These findings support CEEG of all neonates after CPB.

Unplanned Readmissions of Children With Epilepsy in the United States

BACKGROUND

The burden and characteristics of unplanned readmission after epilepsy-related discharge in children in the United States is not known.

METHODS

We undertook a retrospective cohort study of children aged one to 17 years discharged after a nonelective hospitalization for epilepsy, sampled from the Healthcare Cost and Utilization Project's 2013 and 2014 Nationwide Readmissions Database. Descriptive statistics and logistic regression models were used to examine the characteristics of initial hospitalization and risk factors for readmission.

RESULTS

A total of 42,873 admissions for unique patients were identified, with 4470 (10.4%) leading to readmission within 30 days. The most common readmission diagnosis was epilepsy (24.9%). Neurodevelopmental diagnoses including cerebral palsy, intellectual disability, and developmental delay were associated with increased odds of readmission. Longer hospitalization, gastrostomy, and tracheostomy were also associated with readmission, but continuous electroencephalography use was not. Children insured by Medicare had a readmission rate of 34.4%, whereas there were no associations of readmission with other sociodemographic characteristics such as neighborhood, income, and sex.

CONCLUSIONS

Seizures are among the most frequent reasons for hospitalization in children. Establishing a benchmark readmission rate for pediatric epilepsy of 10.4% may be useful to health systems designing quality improvement efforts. Clinical factors were more strongly associated with readmission than demographic characteristics. Interventions to reduce pediatric epilepsy readmissions may have the highest yield when targeting children with neurodevelopmental comorbidities.

An effective CTL peptide vaccine for Ebola Zaire Based on Survivors' CD8+ targeting of a particular nucleocapsid protein epitope with potential implications for COVID-19 vaccine design

The 2013-2016 West Africa EBOV epidemic was the biggest EBOV outbreak to date. An analysis of virus-specific CD8+ T-cell immunity in 30 survivors showed that 26 of those individuals had a CD8+ response to at least one EBOV protein. The dominant response (25/26 subjects) was specific to the EBOV nucleocapsid protein (NP). It has been suggested that epitopes on the EBOV NP could form an important part of an effective T-cell vaccine for Ebola Zaire. We show that a 9-amino-acid peptide NP44-52 (YQVNNLEEI) located in a conserved region of EBOV NP provides protection against morbidity and mortality after mouse adapted EBOV challenge. A single vaccination in a C57BL/6 mouse using an adjuvanted microsphere peptide vaccine formulation containing NP44-52 is enough to confer immunity in mice. Our work suggests that a peptide vaccine based on CD8+ T-cell immunity in EBOV survivors is conceptually sound and feasible. Nucleocapsid proteins within SARS-CoV-2 contain multiple Class I epitopes with predicted HLA restrictions consistent with broad population coverage. A similar approach to a CTL vaccine design may be possible for that virus.

Immediate outcomes in early life epilepsy: A contemporary account

RATIONALE

Early-life epilepsies (ELEs) include some of the most challenging forms of epilepsy to manage. Given recent diagnostic and therapeutic advances, a contemporary assessment of the immediate short-term outcomes can provide a valuable framework for identifying priorities and benchmarks for evaluating quality improvement efforts.

METHODS

Children with newly diagnosed epilepsy and onset <3 years were prospectively recruited through 17 US hospitals, from 2012 to 2015 and followed for 1 year after diagnosis. Short-term outcome included mortality, drug resistance, evolution of nonsyndromic epilepsy to infantile spasms (IS) and from IS to other epilepsies, and developmental decline. Multivariable analyses assessed the risk of each outcome.

RESULTS

Seven hundred seventy-five children were recruited, including 408 (53%) boys. Median age at onset was 7.5 months (interquartile range (IQR): 4.2-16.5), and 509 (66%) had onset in the first year of life. Of 22 deaths that occurred within one year of epilepsy diagnosis, 21 were children with epilepsy onset in infancy (<12 months). Of 680 children followed ≥6 months, 239 (35%) developed drug-resistant seizures; 34/227 (15%) infants with nonsyndromic epilepsy developed IS, and 48/210 (23%) initially presenting with IS developed additional seizure types. One hundred of 435 (23%) with initially typical development or only mild/equivocal delays at seizure onset, had clear developmental impairment within one year after initial diagnosis. Each outcome had a different set of predictors; however, younger age and impaired development at seizure onset were broadly indicative of poorer outcomes. Type of epilepsy and early identification of underlying cause were not reliable predictors of these outcomes.

CONCLUSION

Early-life epilepsies carry a high risk of poor outcome which is evident shortly after epilepsy diagnosis. Onset in infancy and developmental delay is associated with an especially high risk, regardless of epilepsy type. The likelihood of poor outcomes is worrisome regardless of specific clinical profiles.

Neuroimaging of Early Life Epilepsy

OBJECTIVES

We assessed the adherence to neuroimaging guidelines and the diagnostically relevant yield of neuroimaging in newly presenting early life epilepsy (ELE).

METHODS

There were 775 children with a new diagnosis of epilepsy (<3 years old at onset) who were recruited through the ELE study at 17 US pediatric epilepsy centers (2012-2015) and managed prospectively for 1 year. The data were analyzed to assess the proportion of children who underwent neuroimaging, the type of neuroimaging, and abnormalities.

RESULTS

Of 725 children (93.5%) with neuroimaging, 714 had an MRI (87% with seizure protocols) and 11 had computed tomography or ultrasound only. Etiologically relevant abnormalities were present in 290 individuals (40%) and included: an acquired injury in 97 (13.4%), malformations of cortical development in 56 (7.7%), and other diffuse disorders of brain development in 51 (7.0%). Neuroimaging was abnormal in 160 of 262 (61%) children with abnormal development at diagnosis versus 113 of 463 (24%) children with typical development. Neuroimaging abnormalities were most common in association with focal seizure semiology (40%), spasms (47%), or unclear semiology (42%). In children without spasms or focal semiology with typical development, 29 of 185 (16%) had imaging abnormalities. Pathogenic genetic variants were identified in 53 of 121 (44%) children with abnormal neuroimaging in whom genetic testing was performed.

CONCLUSIONS

Structural abnormalities occur commonly in ELE, and adherence to neuroimaging guidelines is high at US pediatric epilepsy centers. These data support the universal adoption of imaging guidelines because the yield is substantially high, even in the lowest risk group.

Work-leave rotation pattern and incidence of offshore workplace injury

Background

Studies on work-leave rotation pattern and work place injuries among offshore oil and gas workers have been few and limited to a 2- or 3-week rotation schedule.

Aims

To examine incidence of workplace injury in relation to the duration of time into work rotation for extended work schedules up to 24 weeks.

Methods

Six-year injury data on four offshore installations were extracted. Data were analysed for incidence of injury over time and relative risk using linear trend lines and regression.

Results

In total, 311 injuries for 1302 workers were analysed, 39% with rotation schedule of 4 weeks work and 4 weeks rest, 27% 8 weeks work and 4 weeks rest, 23% 16 weeks work and 4 weeks rest and 10% 24 weeks work and 4 weeks rest. Incidence of injury decreased as duration of time into the work rotation increased, corrected for exposure, and this was statistically significant for all rotations in first 4 weeks (P < 0.01). Negative correlation between time offshore and injury was observed in all schedules and consistent for age groups, categories of work, shifts and severity of injury. There was no difference in relative risk of injuries between the four schedules, when corrected for exposure and occupational risk of injury.

Conclusions

These results are at variance with previous studies, although no prior study has looked beyond 3-week rotation schedule. Longer offshore schedules are safely possible and this could help decrease manpower and logistics costs for oil and gas companies coping with unprecedented low oil prices.

Initial Treatment for Nonsyndromic Early-Life Epilepsy: An Unexpected Consensus

OBJECTIVE

There are no evidence-based guidelines on the preferred approach to treating early-life epilepsy. We examined initial therapy selection in a contemporary US cohort of children with newly diagnosed, nonsyndromic, early-life epilepsy (onset before age three years).

METHODS

Seventeen pediatric epilepsy centers participated in a prospective cohort study of children with newly diagnosed epilepsy with onset under 36 months of age. Details regarding demographics, seizure types, and initial medication selections were obtained from medical records.

RESULTS

About half of the 495 enrolled children with new-onset, nonsyndromic epilepsy were less than 12 months old at the time of diagnosis (n = 263, 53%) and about half (n = 260, 52%) had epilepsy with focal features. Of 464 who were treated with monotherapy, 95% received one of five drugs: levetiracetam (n = 291, 63%), oxcarbazepine (n = 67, 14%), phenobarbital (n = 57, 12%), topiramate (n = 16, 3.4%), and zonisamide (n = 13, 2.8%). Phenobarbital was prescribed first for 50 of 163 (31%) infants less than six months old versus seven of 300 (2.3%) of children six months or older (P < 0.0001). Although the first treatment varied across study centers (P < 0.0001), levetiracetam was the most commonly prescribed medication regardless of epilepsy presentation (focal, generalized, mixed/uncertain). Between the first and second treatment choices, 367 (74%) of children received levetiracetam within the first year after diagnosis.

CONCLUSIONS

Without any specific effort, the pediatric epilepsy community has developed an unexpectedly consistent approach to initial treatment selection for early-life epilepsy. This suggests that a standard practice is emerging and could be utilized as a widely acceptable basis of comparison in future drug studies.

Contemporary Profile of Seizures in Neonates: A Prospective Cohort Study

OBJECTIVE

To determine the contemporary etiology, burden, and short-term outcomes of seizures in neonates monitored with continuous video-electroencephalogram (cEEG).

STUDY DESIGN

We prospectively collected data from 426 consecutive neonates (56% male, 88% term) ≤44 weeks' postmenstrual age with clinically suspected seizures and/or electrographic seizures. Subjects were assessed between January 2013 and April 2015 at 7 US tertiary care pediatric centers following the guidelines of the American Clinical Neurophysiology Society for cEEG for at-risk neonates. Seizure etiology, burden, management, and outcome were determined by chart review by the use of a case report form designed at study onset.

RESULTS

The most common seizure etiologies were hypoxic-ischemic encephalopathy (38%), ischemic stroke (18%), and intracranial hemorrhage (11%). Seizure burden was high, with 59% having ≥7 electrographic seizures and 16% having status epilepticus; 52% received ≥2 antiseizure medications. During the neonatal admission, 17% died; 49% of survivors had abnormal neurologic examination at hospital discharge. In an adjusted analysis, high seizure burden was a significant risk factor for mortality, length of hospital stay, and abnormal neurological examination at discharge.

CONCLUSIONS

In this large contemporary profile of consecutively enrolled newborns with seizures treated at centers that use cEEG per the guidelines of the American Clinical Neurophysiology Society, about one-half had high seizure burden, received ≥2 antiseizure medications, and/or died or had abnormal examination at discharge. Greater seizure burden was associated with increased morbidity and mortality. These findings underscore the importance of accurate determination of neonatal seizure frequency and etiology and a potential for improved outcome if seizure burden is reduced.

Do all epistaxis patients with a nasal pack need admission? A retrospective study of 116 patients managed in accident and emergency according to a peer reviewed protocol

Introduction: Epistaxis is the most common nasal emergency and if nasal packing is required this commonly results in admission.

Methods: A literature search could find no published (UK) protocols for the management of this common condition in accident and emergency (A&E) departments. This paper presents a retrospective review of 116 patients with epistaxis, following implementation of the new peer reviewed protocol in June 2004.

Results: Apart from cautery, 62 had nasal packing inserted. Only 17 required admission. Forty-six patients were discharged with nasal packing in situ and only seven (16 per cent) returned due to bleeding. The overall return rate was 11 per cent.

Discussion: We feel this is a safe and logical protocol. Compared to mandatory admission after nasal pack insertion, we saved 39 admissions in five months. There were also the added benefits to patients of being able to recuperate at home rather than in hospital and avoidance of the risk of hospital acquired infection.

Das Konservieren von Baudenkmalen: eine neue Methode, um die Wirksamkeit einer stein festigenden Massnahme nachzuweisen / The conservation of monuments: A new method to evaluate consolidating treatments

The degradation of monumental stones is the result of the interaction between the material and environmental factors, such as water, heat, atmospheric pollutants and living organisms. This interaction starts at the stone surface, progresses inwards and may reach several millimetres in depth. The common decay processes may lead to significant losses of the strength properties of the outermost layer of some stone materials which results in erosion, cohesionless appearance and disintegration. At present there is no method to measure stone hardness, both at the superficial surface and at larger depths (few centimetres), with the same sensitivity and reliability, which can be used both in laboratory and in situ. The aim of this paper is to present the application of a new methodology for measuring the Drilling Resistance (DR) of natural stones, by the use of the new portable system (DFMS) that can operate in the laboratory and in situ. The results obtained so far show that this new method is highly promising for in situ evaluation of the mechanical properties in order to assess the consolidating treatment applied for the conservation of monuments.

Determinants of enrollment among applicants to PACE

During the 1970s and 1980s, a new approach to the integration of acute and long-term care (LTC) services was conceived and refined at On Lok, an organization in the Chinese community of San Francisco. Since then, On Lok and 10 Federal demonstration sites have tested this model which is today called the Program of All-Inclusive Care for the Elderly (PACE). This program has gained considerable political support and as a result, the 1997 Balanced Budget Agreement establishes PACE as a permanent provider under Medicare. The Federal demonstration of PACE was designed as a voluntary program. By exploiting its voluntary enrollment design, this study analyzes the determinants of program participation within a group of screened applicants. Findings of this study support the theory that the capitated payment structure of PACE creates incentives for program staff to avoid costly individuals. However, home ownership and provider attachment also act as important and significant barriers to enrollment.

Continuous ascitic recirculation in severe ovarian hyperstimulation syndrome

Massive ascites, hydrothorax, acute renal failure and thromboembolism are clinical manifestations of severe ovarian hyperstimulation syndrome (OHSS) which may complicate the induction of ovulation with exogenous gonadotrophins. We report a case of severe OHSS with ascites formation in excess of five litres per day. Massive ascites and bilateral pleural effusions resulted in respiratory failure. Continuous ascitic recirculation (AR) was commenced after repeated paracentesis and i.v. fluid therapy failed to improve the patient's condition. The procedure was undertaken for a total of 15 days and rapidly resulted in marked improvement of impaired respiratory function. Febrile episodes occurred on 3 occasions, but we did not observe coagulation disturbances or adverse haemodynamic effects. Continuous AR is a safe and effective treatment of complicated severe OHSS.

Pilot randomized trial of tissue plasminogen activator in acute ischemic stroke. The TPA Bridging Study Group

BACKGROUND AND PURPOSE

Early thrombolytic therapy with recombinant tissue-type plasminogen activator is a theoretically attractive approach to the treatment of acute focal cerebral ischemia. In preparation for a larger multicenter trial, three centers piloted a protocol for a randomized, double-blind, placebo-controlled trial of intravenous recombinant tissue-type plasminogen activator begun within 3 hours of the onset of symptoms of acute stroke to test its feasibility and to explore trends.

METHODS

Eligible patients had pretreatment computed tomographic scanning, gave informed consent, and began treatment with either 0.85 mg/kg recombinant tissue-type plasminogen activator or placebo as soon as possible, but no later than 180 minutes after stroke onset. Patients were stratified by whether treatment was begun within 90 minutes or 91 to 180 minutes from onset. The primary end point was the proportion of patients in each group who improved by 4 or more points on the National Institutes of Health Stroke Scale at 24 hours, as determined by a separate blinded evaluator.

RESULTS

Twenty-seven patients were randomized: 20 (10 recombinant tissue-type plasminogen activator, 10 placebo) within 90 minutes, and 7 (4 recombinant tissue-type plasminogen activator, 3 placebo) from 91 to 180 minutes. Median baseline Stroke Scale scores were 16 (minimum = 5, maximum = 26) for the recombinant tissue-type plasminogen activator-treated group and 11 (minimum = 3, maximum = 21) for the control subjects in the group treated within 90 minutes. Six patients treated with recombinant tissue-type plasminogen activator within 90 minutes improved by 4 or more points at 24 hours compared with 1 patient in the placebo group (P < .05, Fisher's Exact Test). Two patients in each group in the 91- to 180-minute arm improved. One fatal intracerebral hemorrhage occurred in the placebo group.

CONCLUSIONS

A randomized, double-blind, placebo-controlled trial of recombinant tissue-type plasminogen activator very early in acute stroke is feasible. Preliminary observations suggest that recombinant tissue-type plasminogen activator treatment within 90 minutes may be associated with early neurological improvement. Larger studies are needed so that the potentially serious short-term risks of this treatment can be assessed in relation to meaningful long-term benefit.

Urgent therapy for stroke. Part I. Pilot study of tissue plasminogen activator administered within 90 minutes

BACKGROUND AND PURPOSE

Thrombolytic agents hold theoretical promise as therapy for cerebral infarction. This study was designed to evaluate the safety of tissue plasminogen activator, to accomplish urgent patient treatment, and to estimate potential efficacy of tissue plasminogen activator.

METHODS

Following neurological evaluation and computed tomography of the brain, patients with acute ischemic stroke were evaluated and treated with intravenous tissue plasminogen activator under an open-label, dose-escalation design within 90 minutes from symptom onset. End points examined included symptomatic and asymptomatic intracranial hematoma, systemic hemorrhage, and neurological outcome at 2 hours, 24 hours, and 3 months.

RESULTS

Seventy-four patients were treated within 90 minutes of symptom onset over seven dose tiers of tissue plasminogen activator, ranging from 0.35 mg/kg to 1.08 mg/kg. Intracranial hematoma with associated neurological deterioration occurred in three patients and was related to increasing doses of tissue plasminogen activator (p = 0.045). Intracranial hematoma did not occur in any of the 58 patients treated with less than or equal to 0.85 mg/kg. Major neurological improvement occurred in 22 patients (30%) at 2 hours from the initiation of tissue plasminogen activator and in a total of 34 patients (46%) at 24 hours, but major neurological improvement was not related to increasing doses of tissue plasminogen activator or to stroke type.

CONCLUSIONS

Patients with acute stroke can be evaluated and treated within 90 minutes. Tissue plasminogen activator for acute ischemic infarction is not without risk, but the potential for clinical benefit justifies a randomized clinical trial. To date, differences in hemorrhagic risk or neurological benefit of tissue plasminogen activator for particular ischemic stroke types are not apparent.

Polyamine metabolism in potassium-deficient bacteria

The metabolism of polyamines was studied in K(+)-dependent strains of Escherichia coli. When these stringent organisms were in a medium containing Na(+) instead of K(+), protein synthesis was arrested, but synthesis of ribonucleic acid continued as it would in a relaxed organism. The Na(+) medium inhibited synthesis of spermidine and S-adenosylmethionine. However, the synthesis of putrescine was accelerated at least five- to eightfold. Exogenous ornithine doubled even this rate of putrescine synthesis but did not increase the low level of putrescine synthesis in the K(+) medium. In K(+) or Na(+) media, with or without 0.3 mm arginine, putrescine was derived almost entirely from ornithine via ornithine decarboxylase. Addition of spermidine (5 mm) to a Na(+) culture markedly inhibited putrescine synthesis. The ornithine decarboxylase of an extract of a K(-)-dependent strain prepared at low ionic strength was separated from ribosomes, deoxyribonucleic acid, and associated polyamines by centrifugation, and from many ions by ultrafiltration and fractionation on Sephadex G-100. Addition of Na(+) and K(+) salts to 200 mm was markedly inhibitory. The combined reductions both in synthesis of the inhibitor spermidine and in intracellular ionic strength may explain the in vivo activation of this enzyme.