Sudden Death in an Infant with Central Nervous System Abnormalities

Some deaths during the first year of life are classified as sudden infant death syndrome (SIDS), the diagnosis of which requires a complete autopsy without adequate explanation for the death. We report a 1-month-old infant whose clinical history was fairly typical for SIDS. Postmortem examination was remarkable in revealing clinically unsuspected central nervous system (CNS) abnormalities, including lobar holoprosencephaly, absence of the olfactory tracts and grooves (arhinencephaly), subependymal gray matter heterotopias, and delayed myelination. Although the CNS findings do not adequately explain the patient's sudden death, this case illustrates the need for a complete autopsy to include careful CNS evaluation, especially in any presumed SIDS death.     

Tumors Associated with Sudden Infant and Childhood Death

Tumors are rare causes of sudden death in infancy and early childhood. The goals of this study were to determine the types and frequency of the tumors associated with sudden death occurring in cases between birth and age 3 years. The San Diego Sudden Infant Death Syndrome/sudden unexplained death in childhool (SUDC) Research Project database and the literature were reviewed retrospectively. Sixty-eight cases, with the most (84%) affecting the heart and brain, were identified. Tumors are a rare but significant cause of sudden death in infancy and early childhood, and their diagnosis may have significant genetic implications for planning future pregnancies. The diagnosis of these lesions can be established only after thorough postmortem examination.     

Cardiac Myxoma as the Cause of Death in an Infant

ABSTRACT. Cardiac myxoma is a rare disease most frequently encountered in adults, usually localized in the left atrium. It rarely occurs in infants. We report a 3 1/2 month old girl whose sudden death was caused by a huge atrial myxoma, completely occluding the tricuspidal orifice. The importance of possible prodromal symptoms suggesting a cardiac disease is stated, and the role of echocardiography as an excellent examination technique is discussed.     

Dermatoglyphics in Sudden Infant Death Syndrome

An analysis of digital and palmar dermatoglyphic patterns was conducted in 173 victims of the sudden infant death syndrome (SIDS). The results expose four dermaloglyphic regions with pattern frequencies differing from those in a control population. These are an excess of Sydney creases, hypothenar patterns, open fields (with fewer vestiges) in interdigital region IV, and arches on all digits (females only). These findings indicate a genetic or early intrauterine environmental influence in SIDS infants. An increased incidence of dysmorphism and anomalies including recognition of specific syndromes support this contention. One could speculate that these dermatoglyphic deviations reflect specific genotypes and/or phenotypes particularly vulnerable to postnatal challenges. Differences in multiple dermatoglyphic categories support the concept of heterogeneity of the SIDS population and multicausality of SIDS.     

Gastroesophageal Reflux and Sudden Infant Death Syndrome

The possible role of gastroesophageal reflux in the pathogenesis of the sudden infant death syndrome (SIDS) has not yet been clearly defined, although it does appear that infants with significant reflux are at greater risk of respiratory complications. A study was undertaken to characterize more precisely the histological features of esophageal mucosa taken from a series of infants who died of SIDS to determine the range of changes present. Full-length strips of mucosa were examined microscopically for reflux-related changes of basal layer hyperplasia, papillary elongation, and intraepithelial eosinophilia. Eight infants (21 %) showed changes considered diagnostic of reflux esophagitis, 17 infants (45%) showed minor nondiagnostic changes, and 13 infants (34 %) showed no histologic abnormalities. These findings demonstrate considerable morphological heterogeneity in a group of infants presenting with sudden and unexpected death. The absence of, or presence of only very minor, pathological alterations within the esophageal mucosae of 79% of infants suggests that reflux of a degree sufficient to cause diagnostic histologic changes is found in only a minority of infants presenting with SIDS.     

Enlargement of the Tongue in Sudden Infant Death Syndrome

Anatomic details of the infantile oropharynx and relationships to possible airway obstruction in sudden infant death syndrome (SIDS) are understood incompletely. Tonkin recognized this in 1975, suggesting that enlargement of the tongue might be important in SIDS, within the context of other anatomic and physiologic factors unique to early life. We therefore conducted a morphometric study of the tongue in 100 victims of SIDS and 36 control infants; the latter group consisted of infants with the same range in age and body size who had grown normally and died acutely. Highly significant differences in tongue weight, width, and thickness were demonstrated between the two groups by linear regression and analysis of covariance. Two multivariate techniques, stepwise discriminant analysis and factor analysis, identified marked discordance between somatic and lingual size in SIDS and a statistical uniqueness in tongue thickness. Certain explanations for lingual enlargement in SIDS were ruled out: redistribution of fluid and other effects of death, postmortem interval, duration and mode of feeding, and smallness of control tongues. At present, the functional significance of these observations is unclear. The effects of both normal and increased tongue size on airway patency are, however, widely recognized. Further studies of the enlarged tongue, addressing such topics as in situ anatomy and developmental mechanisms, are necessary to establish the potential for pathophysiologic consequences in SIDS.     

Infant sleep position, head shape concerns, and sleep positioning devices

AIM: The Back To Sleep campaign has successfully promoted the use of the supine sleep position for infants, with a corresponding decrease in sudden infant death syndrome death rates around the world. The aim of this study was to survey current infant sleep position practices, concerns about plagiocephaly, and the use of sleep positioning devices. METHODS: A postal survey of 400 mothers of infants aged 6 weeks to 4 months was carried out in Auckland, New Zealand. RESULTS: Of the 278 (69.5%) respondents, the supine position was usually used in 64.8%, the prone position in 2.9%, with 32.3% using the side position or a combination of side and back positions. Approximately one-third had a concern about their infant's head shape, and 80% described practices to help prevent head deformation. Thirty per cent reported they had changed their infant's sleep position because of head shape concerns. A third of the mothers used some sort of positioning system to maintain the infant's sleep position. CONCLUSIONS: Anxieties about plagiocephaly, aspiration of vomit, and poor quality sleep are the main concerns that parents have about sleeping their infants on their backs. Further education is needed to inform mothers about these issues and to alleviate their fears.     

How Useful is Postmortem Examination in Sudden Infant Death Syndrome?

There exists great variability in the literature as to the percentage of cases of sudden and unexpected infant death in which definable causes can be identified. Review was undertaken of the clinical and family histories, death scene features including parental interviews, and pathological and microbiological features of 361 consecutive cases presenting as sudden and unexpected infant death with minimal preceding symptoms and signs to the Adelaide Children's Hospital over a 10-year period from 1983 to 1992. Three hundred and twenty-nine cases of SIDS were identified. Nine cases (2.5%) were attributed to accidental asphyxia based partly on death scene examination. This left only 23 cases (6.4%), which were due to a variety of other diverse entities including sepsis, volvulus with sepsis, congenital cardiac disease, probable metabolic disorders, heat stroke, and unclassifiable disorders. This relatively low figure lends support to definitions of SIDS that emphasize the importance of death scene investigation and clinical history review prior to postmortem examination.     

Sudden Infant Death in Stockholm

ABSTRACT. During a ten year period, March 1976-February 1986, 83 non-selected consecutive cases of sudden unexpected death in infants, between one week and one year of age, were examined at the Department of Forensic Medicine in Stockholm. Forty-three deaths (52%) were classified as typical or possible cases of Sudden Infant Death Syndrome (SIDS), 35 (42%) as non-violent non-SIDS cases and 5 (6%) as non-natural deaths. Cardiovascular disease, including myocarditis, was found in 21 (25%) instances, infections with inflammatory manifestations in various organs outside the heart in 12 (14%) and miscellaneous, non-violent causes of death in 2 (2%) cases. The male: female ratio was 1.15:1 for SIDS and 1.30:1 for non-SIDS cases. A peak of incidence was found for SIDS cases in infants between two and four months of age, while non-SIDS victims tended to be somewhat older. Ninety-five percent of the SIDS fatalities occurred during the winter months (October-April) as compared to 71% of the non-SIDS cases. Outdoor temperature below the annual mean of 5.9°C in combination with a sudden decrease in temperature was associated with sudden deaths, particularly SIDS. Thirty-three percent of the SIDS victims died in their cribs compared to 51% of the non-SIDS cases. Corresponding figures for deaths outdoors in a pram were 33% and 11%, respectively. Fourteen percent of the infants in both groups died while in bed with one of the parents. Ninety-five percent of the SIDS victims were previously healthy, but in 9% one or more periods of abnormal breathing had been noted. The corresponding figures for non-SIDS were 70% and 3%, respectively. Among the cases of non-natural deaths was one infant who died of heroin poisoning and one of hypothermia.     

The Value of Serum IgE Assay in Milk Aspiration and the Sudden Infant Death Syndrome

ABSTRACT. Global serum levels of IgE (PRIST, Phadebas®) and specific anti-cow's milk IgE (RAST) were measured in populations of infants with a history of one or more episodes of milk aspiration ( n =12), victims of the sudden infant death syndrome (SIDS) ( n = 18), "near miss" SIDS infants ( n =23), siblings of a SIDS victim ( n =21) and control infants ( n =38). Only the infants with a past history of milk aspiration had significantly raised global and specific IgE. The absence of raised specific IgE in the subjects who died from SIDS argues against the hypothesis of sensitisation to cow's milk proteins during a previous episode of aspiration. Nasopharyngeal reflux is frequently seen in near-miss infants. This reflux is more often responsible for reflex apnoea due to stimulation of the laryngeal chemo-receptors than to a fatal aspiration.     

Early Neonatal Sudden Infant Death and Near Death of Fullterm Infants in Maternity Wards

ABSTRACT. In a large Swedish 2 1/2-year population of fullterm infants the incidence of early neonatal sudden death (ENSD) was 0.12 per 1000 newborn infants considered healthy at birth but presenting with sudden cardiovascular collapse between 6 and 100 hours after birth. In the total neonatal mortality the rate of ENSD was 11 %. Well-known risk infants, e.g. prematurity, perinatal asphyxia, difficult delivery or congenital malformations were not included. In an inborn population of 20123 fullterm newborns the rate of ENSD was 0.15 per 1000. In the same population near-missed ENSD occurred in 0.35 per 1000 liveborn infants. Possible causative factors were infections in 4 and anaemia in 2 cases. But in 7 of 13 infants thorough epidemiological examinations and postmortem sterile autopsies did not reveal the cause of death or near death. These are probably cases of sudden infant death syndrome hitherto unrecognized in the first days of life.     

Vocal Cord Basement Membrane in Non-Sudden Infant Death Syndrome Cases

Vocal cord basement membrane thickening (VCBMT) has been observed in children with sudden infant death syndrome (SIDS). It has been proposed that this lesion could be used as a positive indicator of this syndrome in autopsies of children who have died unexpectedly. The present investigation aimed to analyze vocal cord basement membranes from autopsies of children 0 to 365 days old. A total of 134 larynges were analyzed. Histological sections of paraffin-embedded larynges stained with H&E and submitted to histochemical staining with periodic acid–Schiff (PAS), Masson's trichrome, syrius red, and Carstairs were used for light microscopy analysis. Immunohistochemistry with monoclonal anti-collagen IV antibody was used to determine the nature of VCBMT. The study was completed with morphometry of H&E– and PAS-stained sections and revision of the clinical information contained in the hospital files. VCBMT was found in 25 cases (18.7%) and showed characteristics of normal basement membrane, including immunoreactivity to collagen IV. Our data support the conclusions that VCBMT is frequently seen in pediatric autopsies, is seen in children in all age-groups studied whose deaths were due to causes other than SIDS, and is commonly associated with infectious diseases. Like SIDS, VCBMT occurs in the first year of life. Received June 19, 1998; accepted November 16, 1998.     

Medium-Chain Acyl-Coa Dehydrogenase Deficiency: Postmortem Diagnosis in a Case of Sudden Infant Death and Neonatal Diagnosis of an Affected Sibling

Medium-chain acyl-CoA dehydrogenase (MCAD) deficiency is an inherited disorder of fatty acid oxidation associated with sudden death in infants and, in its fulminant form(s), a Reye-like syndrome. In an 18-month-old female who died suddenly and unexpectedly, the postmortem diagnosis of MCAD deficiency was made by analysis of organic acids, acylglycines, and acylcarnitines and by analysis of the most common mutation causing MCAD deficiency (A985G) in a sample of heart blood obtained at autopsy and frozen at—20° C for 8 months. The patient was homozygous for A985G and metabolites characteristic of MCAD deficiency were identified. Parents and an older sibling were heterozygous for A985G. The mother was 6 months pregnant when the results were known. At the birth of her male infant, blood spot cards and urine were obtained. The infant was homozygous for A985G by analysis of DNA extracted from blood spots and he excreted metabolites characteristic of MCAD deficiency. These results demonstrate the use of novel molecular and metabolite analysis in making the postmortem diagnosis of MCAD deficiency. The neonatal diagnosis of an affected sib permits the institution of appropriate dietary measures to prevent potentially fatal episodes of illness.     

Epidemiology of Intrathoracic Petechial Hemorrhages in Sudden Infant Death Syndrome

The possible effects of a wide range of sociodemographic and environmental factors on the incidence and distribution of petechiae were investigated in 485 sudden infant death syndrome (SIDS) cases from the New Zealand Cot Death Study. The number (nil, few, many) of macroscopic petechial hemorrhages in the visceral pleura, capsule of thymus, and epicardium was recorded in 458 of 474 autopsied SIDS cases. Other information was obtained from parental interview and obstetric records. Univariate analysis showed highly significant relationships (P ≤ 0.005) between the frequency of petechiae at one or more sites and socioeconomic status, parity, breast feeding, age at death, time of death, sleep position, and head covering at death and lesser but significant relationships (P ≤ 0.05) with Maori ethnicity, birth weight, gestation, pacifier use, and bed sharing. After multivariate analysis, significant associations remained between increased frequencies of thymic petechiae and parity (P = 0.0001), age at death (P = 0.0003), Maori ethnicity (P = 0.0019), pacifier use (P = 0.0001), and head covering at death (P = 0.0032); between increased frequencies of epicardial petechiae and head covering at death (P = 0.008) and an estimated time of death between 00:00 and 05:59 h (P = 0.056); and between increased frequencies of pleural petechiae and maternal smoking (P = 0.058) and parity (P = 0.022). There was a decreased frequency of pleural petechiae in infants placed prone for their final sleep (P = 0.058). The distribution and frequency of petechiae are affected by environmental factors, including known risk factors for SIDS, but these factors occur inconsistently across the three sites. The findings imply differences in the pathogenesis at each site but do not provide consistent support for previous theories of causation of petechiae. Received June 4, 1997; accepted September 9, 1997.     

Secular Trends of Sudden Infant Death Syndrome and Other Causes of Post Perinatal Mortality in Norwegian Birth Cohorts 1967–1984

ABSTRACT. Lack of positive diagnostic criteria and increasing professional concern, probably causing increasing ascertainment, have rendered reported increases in SIDS-rates controversial. However, these problems related to cause specific mortality do not apply to the total mortality. Due to the exceptional age-at-death distribution of SIDS cases, the SIDS fraction of all deaths increases during the first year of life to reach a maximum, in the present study of 56%, from the 105th through the 125th day of life. During these days, the total mortality rate in Norway increased from 0.24 per 1000 in 1971–72 to 0.46 in 1983–84. Thus, the observed trend, with an increase in the SIDS rate from 1.02 per 1000 in 1971–72 to 2.34 in 1983–84, is considered true. Observed in a country where perinatal and neonatal mortality have decreased for a long period of time and still remain very low in a global perspective, the increasing SIDS rate is a matter of great concern.     

Norepinephrine-Induced Pulmonary Petechiae in the Rat: An Experimental Model with Potential Implications for Sudden Infant Death Syndrome

Autonomic nervous system abnormalities have been implicated in infants dying of or considered at high risk of sudden infant death syndrome (SZDS). Zn a rat model, norepinephrine (0.02 mg/kg) caused systemic hypertension and numerous pulmonary petechiae, the latter a common finding in SIDS. Petechiae were not seen below the diaphragm. The animals were killed by tracheal occlusion 5 min after the intravenous administration of norepinephrine. The number of pulmonary petechiae was greatly reduced by alpha-adrenergic blockade (phentolamine) and dopaminergic blockade (haloperidol) but not by beta-adrenergic blockade (timolol). A significantly greater reduction of peak mean systemic arterial pressure occurred after alpha-adrenergic blockade than with other blocking agents. It is conceivable that hypoxia-induced endogenous catecholamine release contributes to the pathogenesis of pulmonary petechiae found at necropsy of SZDS victims.     

Cytomegalovirus and Human Herpesvirus-6 in Sudden Infant Death Syndrome: An in situ Hybridization Study

Thirty lung, spleen, and thymus sections and four lymph node sections from 40 sudden infant death syndrome (SIDS) cases were probed with biotinylated DNA probes specific for human herpesvirus-6 (HHV-6) and cytomegalovirus (CMV). Control material gave a strong, distinct signal with little or no background staining and no cross-reactivity. No staining was found with the SIDS material. We find no evidence to implicate an overwhelming infection by either virus in SIDS.     

Near miss sudden death in an infant with Wolff-Parkinson-White syndrome

A 6 month old infant with known Wolff-Parkinson-White syndrome presented with an out of hospital cardiac arrest. An electrocardiogram in the emergency department demonstrated atrial fibrillation with rapid ventricular response. The child subsequently was resuscitated and underwent successful interruption of an accessory connection after failing medical therapy. This case underlines the need to reassess the indications for invasive electrophysiologic testing in young children.