Clinical features and prognosis of Reye's syndrome

Assessment of Reye's syndrome profile with data from the US Food and Drug Administration Adverse Event Reporting System and the Japanese Adverse Drug Event Report databases using the disproportionality analysis

Objectives:

Reye’s syndrome is a rare and potentially fatal illness that is defined as encephalopathy accompanied by liver failure. The aim of this study was to assess Reye’s syndrome profiles by analyzing data from the spontaneous reporting system database.

Methods:

We analyzed reports of Reye’s syndrome using the US Food and Drug Administration Adverse Event Reporting System and the Japanese Adverse Drug Event Report databases. The reporting odds ratio and proportional reporting rate were used to detect the pharmacovigilance signal.

Results:

The US Food and Drug Administration Adverse Event Reporting System contains 12,201,620 reports from January 2004 to June 2020, of which 186 are on Reye’s syndrome. The Japanese Adverse Drug Event Report contains 646,779 reports from April 2004 to September 2020, of which 30 are on Reye’s syndrome. In the US Food and Drug Administration Adverse Event Reporting System database, the reporting odds ratios (95% confidence interval, number of cases) of aspirin, diclofenac, ibuprofen, acetaminophen, and valproate sodium were 404.6 (302.6–541.0, n = 80), 15.1 (6.7–34.1, n = 6), 26.2 (16.1–42.6, n = 18), 10.7 (5.5–20.9, n = 9), and 47.1 (26.2–84.6, n = 12), respectively. In the Japanese Adverse Drug Event Report database, the reporting odds ratios (95% confidence interval, number of cases) of aspirin, diclofenac, ibuprofen, loxoprofen, acetaminophen, and valproate sodium were 14.1 (5.4–36.8, n = 5), 51.7 (22.2–120.5, n = 7), 135.0 (40.8–446.2, n = 3), 17.6 (6.7–46.0, n = 5), 24.0 (9.2–62.6, n = 5), and 13.8 (3.3–57.9, n = 2), respectively. The reported number of female patients aged 30–39 years was the highest in the Japanese Adverse Drug Event Report.

Conclusion:

Although the frequency of the occurrence of Reye’s syndrome is low, the possible risk of the disease occurring in adult females should be considered.

Intracranial Pressure and its Monitoring in Childhood: A Review

Failure to measure intracranial pressure (ICP) in the childhood encephalopathies has been likened to treating heart failure without measuring the blood pressure. Raised ICP adds considerably to the morbidity and mortality of cerebral disease, yet its routine measurement remains controversial. This paper reviews the causes, measurement and management of ICP and outlines the indications for monitoring.

Hypoglycemia in critically ill children

BACKGROUND

The practice of glycemic control with intravenous insulin in critically ill patients has brought clinical focus on understanding the effects of hypoglycemia, especially in children. Very little is published on the impact of hypoglycemia in this population. We aimed to review the existing literature on hypoglycemia in critically ill neonates and children.

METHODS

We performed a systematic review of the literature up to August 2011 using PubMed, Ovid MEDLINE and ISI Web of Science using the search terms "hypoglycemia or hypoglyc*" and "critical care or intensive care or critical illness". Articles were limited to "all child (0-18 years old)" and "English".

RESULTS

A total of 513 articles were identified and 132 were included for review. Hypoglycemia is a significant concern among pediatric and neonatal intensivists. Its definition is complicated by the use of a biochemical measure (i.e., blood glucose) for a pathophysiologic problem (i.e., neuroglycopenia). Based on associated outcomes, we suggest defining hypoglycemia as <40-45 mg/dl in neonates and <60-65 mg/dl in children. Below the suggested threshold values, hypoglycemia is associated with worse neurological outcomes, increased intensive care unit stay, and increased mortality. Disruptions in carbohydrate metabolism increase the risk of hypoglycemia incritically ill children. Prevention of hypoglycemia, especially in the setting of intravenous insulin use, will be best accomplished by the combination of accurate measuring techniques, frequent or continuous glucose monitoring, and computerized insulin titration protocols.

CONCLUSION

Studies on hypoglycemia in critically ill children have focused on spontaneous hypoglycemia. With the current practice of maintaining blood glucose within a narrow range with intravenous insulin, the risk factors and outcomes associated with insulin-induced hypoglycemia should be rigorously studied to prevent hypoglycemia and potentially improve outcomes of critically ill children.

Acute encephalopathy associated with influenza and other viral infections

Acute encephalopathy is the most serious complication of pediatric viral infections, such as influenza and exanthem subitum. It occurs worldwide, but is most prevalent in East Asia, and every year several hundreds of Japanese children are affected by influenza-associated encephalopathy. Mortality has recently declined, but is still high. Many survivors are left with motor and intellectual disabilities, and some with epilepsy. This article reviews various syndromes of acute encephalopathy by classifying them into three major categories. The first group caused by metabolic derangement consists of various inherited metabolic disorders and the classical Reye syndrome. Salicylate is a risk factor of the latter condition. The second group, characterized by a systemic cytokine storm and vasogenic brain edema, includes Reye-like syndrome, hemorrhagic shock and encephalopathy syndrome, and acute necrotizing encephalopathy. Non-steroidal anti-inflammatory drugs, such as diclofenac sodium and mephenamic acid, may aggravate these syndromes. Severe cases are complicated by multiple organ failure and disseminated intravascular coagulation. Mortality is high, although methylprednisolone pulse therapy may be beneficial in some cases. The third group, characterized by localized edema of the cerebral cortex, has recently been termed acute encephalopathy with febrile convulsive status epilepticus, and includes hemiconvulsion-hemiplegia syndrome and acute infantile encephalopathy predominantly affecting the frontal lobes. Theophylline is a risk factor of these syndromes. The pathogenesis is yet to be clarified, but an increasing body of evidence points to excitotoxicity and delayed neuronal death.

Reye's syndrome: the case for a causal link with aspirin

Reye's syndrome is a serious, acute encephalopathy that has been linked with aspirin (acetylsalicylic acid) use in children and teenagers <18 years of age. Although others may disagree, it is my belief that any objective analysis of published material in the last 20 years must conclude that there is a close link between the devastating encephalopathy Reye's syndrome and ingestion of aspirin during the febrile prodrome. The drug appears to act as a co-factor in susceptible individuals. Although some of the epidemiological data indicate an association between the two, the burden of evidence suggests actual causality and is both consistent and specific as well as strong and time related. Some of the evidence points to illness severity being dose related although it seems that in the presence of a viral infection, no dose of aspirin can be considered safe. No published work, using methodology that can be critically evaluated, has shown evidence to contradict these conclusions and they have been widely accepted. Since government health warnings were appended to aspirin-containing formulations, the decline in case numbers on both sides of the Atlantic has been nothing short of remarkable. Recent in vitro findings have pinpointed the site of action of the drug on the long chain hydroxyacyl-CoA dehydrogenase enzyme (a component of the mitochondrial trifunctional enzyme) and, even at therapeutic concentrations, oxidation is impaired in cultured fibroblasts from patients who have recovered from the disorder. This is quite unlike that seen in cells from normal controls. Even when major influenza outbreaks occur in the future, Reye's syndrome is preventable provided government health warnings are heeded and the cogent evidence set forth here is acted upon by the parents of feverish children and self-medicating teenagers.

Is aspirin a cause of Reye's syndrome? A case against

Reye's syndrome was a rare disease which appeared suddenly in the early 1950s and disappeared just as suddenly in the late 1980s. An association between Reye's syndrome and the ingestion of aspirin (acetylsalicylic acid) was claimed, although no proof of causation was ever established. The presence of salicylates in the blood or urine of Reye's syndrome patients has not been demonstrated, and no animal model of Reye's syndrome has been developed where aspirin causes the disease. It is clear from epidemiological data that the incidence of Reye's syndrome was decreasing well before warning labels were placed on aspirin products. Reye's syndrome disappeared from countries where aspirin was not used in children as well as from countries which continued to use aspirin in children. Reye's syndrome was probably either a viral mutation which spontaneously disappeared, or a conglomeration of metabolic disorders that had not been recognized or described at that time.

Rotavirus encephalopathy: pathogenesis reviewed

Two cases of rotavirus gastroenteritis associated with neurological involvement, one with encephalitis (defined by abnormal neurological signs, cerebrospinal fluid (CSF) pleocytosis and detection of rotavirus genomic nucleic acid in the CSF) and one with a non-inflammatory encephalopathy (defined by abnormal neurological signs, an entirely normal CSF and detection of rotavirus genomic nucleic acid in the CSF), are presented and used as a basis to review and explore potential pathogenetic mechanisms, including direct viral replication within neurons and indirect effects of the newly described rotavirus 'enterotoxin'.

The mechanism of inhibition of beta-oxidation by aspirin metabolites in skin fibroblasts from Reye's syndrome patients and controls

The effects of aspirin metabolites on beta-oxidation were studied in skin fibroblasts from eight typical Reye's syndrome (RS) patients and controls. RS patients' cells did not differ from controls in rates of palmitate oxidation or in the three component activities of the mitochondrial trifunctional enzyme (MTE), indicating no inherited beta-oxidation defect. Aspirin metabolites salicylate, hydroxyhippurate and gentisate, but not aspirin, directly inhibited palmitate oxidation in control and RS cells. RS cells were significantly more sensitive to inhibition than controls at 0.5 to 5 mM salicylate. Inhibition was concentration-dependent and reversible. Inhibition did not occur in fibroblasts lacking activity of the long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) activity of MTE. Salicylate was therefore inhibiting beta-oxidation at this step. Hydroxyhippurate and salicylate reversibly inhibited HAD activities in extracts of control and RS cells. Studies with pure short-chain HAD and LCHAD (MTE) showed hydroxyhippurate and salicylate were competitive inhibitors of the former but mixed (not competitive) inhibitors of the latter. Both compounds inhibited the combined, three-step, MTE reaction measured in the physiological direction. We conclude that (1) salicylate and hydroxyhippurate decrease beta-oxidation in intact cells by reversible inhibition of LCHAD activity of the MTE, and (2) beta-oxidation in RS cells is inherently more sensitive to inhibition by low concentrations of salicylate than controls.

A sibling-controlled study of intelligence and academic performance following Reye syndrome

The authors compared the intellectual, cognitive and academic abilities of 22 survivors of Reye syndrome attending normal schools with the sibling nearest in age as control. The British Ability Scales, visual and verbal IQ, short-term memory scales and attainment tests were administered to all children. Reye syndrome children as a group differed significantly from the controls only on the basic number skills test. However, children with severe encephalopathy and those whose illness occurred in infancy had significant deficits on many of the tests. 18 children recovered without requiring 'additional educational provision'; the mean IQ of the 22 Reye syndrome children was 101. Nonetheless, these children's poor performance on the basic number skills test has important implications for teachers, and careful monitoring of future educational performance is essential.

Reye and Reye-like syndromes: results of a pilot study in Peninsular Malaya, 1986

A pilot epidemiologic study of all cases of Reye and Reye-like syndromes was undertaken at 8 representative major hospitals in Peninsular Malaya from January 1st to December 31st 1986. The cases were classified as definitive Reye's syndrome, clinical Reye's syndrome and encephalo-hepatopathies. Less than 50% of cases reviewed fulfilled the National Center for Disease Control criteria for clinical Reye's syndrome. Causes of Reye-like syndromes/encephalo-hepatopathies included fulminant hepatitis, Japanese B encephalitis, dengue, septicaemia, and complex febrile fits. It was not possible to differentiate clinical Reye's syndrome from the other encephalo-hepatopathies by either the clinical features (except for jaundice) or biochemical parameters. Liver biopsy is necessary for a definitive diagnosis of Reye's syndrome in Malaysia, because of the high prevalence of Reye-like diseases. The mortality rate in the 2 groups of patients is similar. Ingestion of salicylates was not found to be significantly associated with Reye and Reye-like syndromes in this study.

Development of West syndrome in a patient with Reye syndrome: a case study

We report the case of a 3 month old female with a diagnosis of Reye Syndrome, confirmed with laboratory exams. Three months after apparently recovering from the acute clinical picture, the patient developed massive spasms and psychomotor delay with an EEG tracing typical of hypsarrythmia, the classic triade which suggests West Syndrome.

Preadmission antipyretics in Reye's syndrome

The parents of 106 children who had had Reye's syndrome and those of 185 comparison children who had febrile illnesses were interviewed in order to compare preadmission medication exposure rates in the two groups. Although comparable proportions of case and comparison patients had taken antipyretics in the three weeks before admission, a significant excess of cases (59% compared with 26% in the comparisons) had been given aspirin, whereas significantly more comparison children (49% compared with 25% in the cases) had taken paracetamol. There was an excess exposure to aspirin in children under 5 years of age; the excess observed in older patients just failed to reach significance. Separate analyses within Northern Ireland and England also showed a case-comparison difference. A significant correlation was shown between aspirin (but not paracetamol) exposure and the closeness with which cases conformed to the diagnostic criteria of Reye's syndrome, measured by an artibrary score. The many difficulties of conducting and interpreting the findings of an epidemiological risk factor study of an association between aspirin and Reye's syndrome are reviewed and emphasised. Inherent biases were present in this as in previous studies and it did not conform to the classical case-control design. Nevertheless the findings suggested that an association between Reye's syndrome and preadmission aspirin may exist in some children.

Advances in the application of biochemical tests to diseases of the liver and biliary tract: their role in diagnosis, prognosis, and the elucidation of pathogenetic mechanisms

Despite the biochemical complexity of the liver, few laboratory tests provide discriminatory diagnostic information in patients with hepatobiliary disease. Recent efforts have concentrated upon tests which assess the function of the liver, the severity of the disease state, and underlying pathological processes. Bile Acids: The emergence of facile technology and widespread application has brought the realization that these assays are not as sensitive in detecting liver disease as previously believed, although the cholate/chenate ratio may be useful in distinguishing cholestasis from chronic liver disease. The presence of unusual bile acids in serum or urine may be helpful in some cases. Drug Metabolism: A number of tests provide good evidence about liver function, hepatic blood flow and portal shunting, but the aminopyrine breath tests is the most useful, giving prognostic information in acetaminophen overdose and alcoholic liver disease. The antipyrine half-life identifies surgical cases at risk from poor hepatic function. Proteins and Immunochemical Tests: Interest has developed in plasma proteins such as prealbumin and retinol-binding protein to monitor hepatic protein synthetic function. Secretory IgA is more elevated in biliary tract disease, unlike the native protein which is increased principally in cirrhosis. Type III procollagen can be measured in serum, and correlates with the activity of collagen synthesis and the degree of fibrosis in biopsy samples. Reye's Syndrome: Biochemical tests play an essential role in diagnosis of this recently discovered disease. These will be presented and discussed.

Reye's syndrome: assessment of intracranial monitoring

Direct measurements of arterial blood pressure and intracranial pressure were recorded in 39 patients aged 3.6 months to 5 years 11 months with Reye's syndrome judged to be stage 2 or beyond. Of 33 patients who survived, 27 made a full recovery and six were severely handicapped. Measurement of cerebral perfusion pressure, which is greatly reduced in the more severe forms of Reye's syndrome, was a better guide to prognosis and management than intracranial pressure alone. The findings emphasise that maintenance of cerebral perfusion pressure is essential if mortality and morbidity are to be reduced. Intracranial monitoring is mandatory in all but the mildest cases of Reye's syndrome.

Recognition and early management of Reye's syndrome

Reye's syndrome continues to be associated with a high mortality. Out of 12 cases treated on our intensive care unit over a four year period, seven died, one suffered minimal cerebral damage, and four were normal. Rapid progression through coma stages and high peak ammonia concentrations worsened prognosis. Reye's syndrome was suspected in only 50% of cases at the referring hospital and resulted in prompt referral to the intensive care unit in only one case. Late referral to the unit was associated with a poor outcome. Sudden neurological deterioration followed diagnostic lumbar puncture in six children. Papilloedema was an unreliable sign of raised intracranial pressure and was absent in all cases. While computed tomography of the brain was useful in providing additional evidence of raised intracranial pressure, this could only be confirmed by direct measurement. Lumbar puncture in the presence of rapidly progressive coma should be deferred until raised intracranial pressure has been excluded. To this end, early admission to a paediatric intensive care unit with facilities for computed tomography and monitoring of intracranial pressure is recommended.

Reye's syndrome in Denmark. A retrospective study

We tried to determine the incidence of Reye's syndrome (RS) in Denmark in a retrospective study. As RS is often preceded by influenza B, we chose the year 1979, where an epidemic of influenza B was registered in Denmark. All children aged 1 month to 18 years, who died, were identified, excluding children who died from accidents or malignant diseases. Two hundred and forty-two children died in hospital. Review of the records revealed one case of RS. One hundred and five died outside hospital. Reviewing death certificates and autopsy reports, none of these fulfilled the criteria for RS. All paediatric departments were asked if they had made a diagnosis of RS. None had. In 1979 approximately 1.1 mill. children aged 1 month to 14 years lived in Denmark. This gives an incidence of 0.09 per 100 000 for 1979. Although this is a minimum figure, the incidence of RS in Denmark, for unknown reasons, seems very low.

Life-threatening intracranial hypertension in Reye's syndrome treated with intravenous thiopentone

A patient with Reye syndrome is described in whom cerebral perfusion pressure was reduced to less than 5 mmHg with loss of EEG activity. The intravenous administration of thiopentone reduced intracranial pressure and improved cerebral perfusion pressure with restoration of EEG and full recovery.

Follow-up of subjects in prospective studies based in general practice

In prospective studies of ischaemic heart disease, data on the incidence of morbidity as well as mortality are critical to the understanding of the natural history of disease. In the Regional Heart Study, 7,735 middle-aged men recruited from general practices in 24 towns in England, Wales and Scotland have been examined, and are being followed for morbidity and mortality for at least five years. This paper explains the methods used and the difficulties encountered in maintaining the flow of information on these subjects and, in particular, discusses the problems of removal and tracing. A network of enquiries, using Family Practitioner Committees, the NHS Central Register and the additional 500 doctors (to date) to whom subjects have transferred, has enabled contact to be maintained. In the first seven towns reviewed at five years from the initial examination, replies have been received from 98 per cent of the original sample still alive and living in Great Britain.