Changes in the lung connective tissue framework in sudden infant death (SIDS)

Light microscopy findings are reported on the interstitial connective tissue framework of 45 lungs from babies who died within the first 2 years of life. Thirty were confirmed cases of SIDS and 15 were controls of similar age who died of known causes. The stains applied were H & E, PAS, Prussian blue, Elastica van Gieson, Trichrom (Masson-Goldner), Gomori's silver methenamine and Picro-Sirius polarization (modified). Particular attention was paid to type I and type III collagen, reticulin fibers and ground substance. All investigated cases showed evidence of chronic recurrent interstitial edema in a highly significant frequency and intensity in contrast to the controls. Areas of recent and persistent lymphedema were observed, some of them with reactive fibroplastic activity, which tended towards gradual fibrosis. These changes were irregularly distributed and frequently involved the mural interstitium. Considering the effects of such changes on expansibility, ventilation and perfusion of the lungs, as well as the impairment of gas diffusion, the findings described could be significant in the forensic evaluation of the signs of asphyxia found in most cases of SIDS.     

Desquamative interstitial pneumonia in an infant. Mimicry of sudden infant death syndrome

A 15-week-old infant girl, without a prior history of overt illness, was found dead while sleeping between her two parents. The gross examination at autopsy showed only congested lungs, and the initial diagnosis was sudden infant death (SID). On microscopic examination, a desquamative interstitial pneumonia (DIP) was observed. The widespread, patchy intraalveolar histiocytic desquamation was associated with lymphocytic infiltration of bronchiolar and aveolar walls, which together provided convincing evidence that an interstitial pneumonitis was the cause of death. A viral etiology seems most likely in view of the accompanying chronic inflammation of bronchial submucosal glands.     

Histologic findings in the lung in sudden infant death

The lungs of 79 children who had died between the ages of 1 week and 2 years old were histologically examined. 59 of these children could be categorized as cases of Sudden Infant Death because of the history and postmortem findings. In the remaining 20 cases a definite cause of death could be established. This is the same collective on which the histological investigations of the lymphatic tissue has been carried out. Morphological changes which are typical for a virus pneumonia were found in a substantially higher frequency in the cases of Sudden Infant Death than in the control cases. The validity of these findings and their possible significance for the cause of death are discussed.     

Tissue distribution of components of the insulin-like growth factor system in sudden infant death and controls

Growth factors may be involved in sudden infant death (SID). Among these factors, the insulin-like growth factor (IGF) family is important in human fetal and perinatal organ growth and development. In order to detect probable differences in the occurrence and distribution of components of the IGF system, tissue samples from liver, lung, skin, parotid and thyroid gland, gut and cerebellum from SID children (n=9) and controls (n=6) aged between 14 and 258 days of life (mean 105 days) were stained immunohistochemically using antibodies against IGF-I, IGF-II and their specific IGF-I-receptor (IGF-IR). In contrast to controls in hepatocytes of SID children a reduction or an absence of immunoreactivity for IGF-I and IGF-IR and a weaker staining for IGF-II was detected. IGF-II in smooth muscle layers in the gut and IGF-I in epithelial cells in intestinal specimens also showed a reduced immunoreactivity in SID children and those who died traumatic deaths. In the other organs examined no significant differences in the distribution of the insulin-like growth factor system between the groups could be detected, indicating that in SID children no fundamental differences or alterations in the physiology of the IGF system occur. Because of the decreased immunostaining of IGFs in the liver and intestine of SID cases, a local dysregulation may be discussed.     

Toxicology and sudden infant death

One hundred thirty cases of sudden infant death occurring in Wayne County, Michigan, (population 2.7 million) were analyzed for possible drugs. The toxicological protocol has been outlined. Six cases were found to be positive, and in five of these the drugs found had been prescribed for a variety of illnesses. In one case methadone was found in the blood of an infant whose mother was undergoing methadone treatment for drug addiction, the drug being transmitted through breast milk. In none of the 102 cases of sudden infant death syndrome (SIDS) included in the study did the toxicological results affect the diagnosis. In our study, toxicological analyses never contradicted an initial diagnosis of SIDS, and, therefore, we feel that this diagnosis should be made promptly based on investigative and autopsy findings.     

Cardiac lesions in sudden infant death syndrome

Sequential morphological changes as found in the hearts of 250 sudden infant death syndrome (SIDS) infants are described. Detailed examination of macroscopic and microscopic lesions reveal that all SIDS infants had identifiable lesions at the time of their death. The lesions can best be described as selective focal anoxic muscle fibre necrosis at chronologically different developmental stages. The extent of these lesions vary markedly from case to case, from a minimal muscle fibre eosinophilia through contraction band formation, myocytolysis, stromal condensation to scar formation. The morphological variations in the lesions amongst individual cases can be interpreted as relating to the time interval of the development of the lesions. The intramural and coronary arteries in some cases are also affected showing intimal hyperplasia. Although these sequential morphological aberrations are not specific and typical to SIDS infants only, they were present in all SIDS infants in this series.     

Oronasal blood in sudden infant death.

Oronasal secretions are observed frequently in sudden infant death syndrome (SIDS), but overt blood is uncommonly reported. The literature on oronasal blood in sudden infant death is limited. The goal of this study was to determine the frequency of oronasal blood in sudden infant deaths and to examine possible causative factors. Oronasal blood was described in 28 (7%) of 406 cases of sudden infant death. Oronasal blood could not be attributed to cardiopulmonary resuscitation in 14 cases, including 10 (3%) of 300 cases of SIDS, 2 (14%) of 14 accidental suffocation cases, and 2 (15%) of 13 undetermined cases. Eight of the 10 infants in cases of sudden infant death were bedsharing: 5 with both parents, 2 between both parents. The infant in 1 SIDS case was from a family that had had three referrals to Child Protective Services. Oronasal blood not attributable to cardiopulmonary resuscitation occurs rarely in SIDS when the infant is sleeping supine in a safe environment. Bedsharing may place infants at risk of suffocation from overlaying. Oronasal blood observed before cardiopulmonary resuscitation is given is probably of oronasal skin or mucous membrane origin and may be a sign of accidental or inflicted suffocation. Sanguineous secretions that are mucoid or frothy are likely of remote origin, such as lung alveoli. The use of an otoscope to establish the origin of oronasal blood in cases of sudden infant death is recommended.     

婴儿猝死综合征的研究现状及其法医学检验

婴儿猝死综合征(dudden infant death s yndrome,SIDS)一直是法医学和儿科学领域的研究热点。相对于北美、欧洲、澳洲以及日本等地对SIDS广泛深入的研究,来自中国的报道相对较少。本文通过总结文献,介绍SIDS的发展历史、研究现状和新的发展趋势,并结合2004年各国学者在美国圣地亚哥公布的SIDS分型,讨论实际检案中需注意的问题以及推进其调查研究的可行性。     

Melatonin concentrations in the sudden infant death syndrome

To examine a possible relationship between pineal function and the sudden infant death syndrome (SIDS), samples of whole blood, ventricular cerebrospinal fluid (CSF) and/or vitreous humor (VH) were obtained at autopsy from 68 infants (45 male, 23 female) whose deaths were attributed to either SIDS (n = 32, 0.5-5.0 months of age; mean +/- S.E.M., 2.6 +/- 0.2 months) or other causes (non-SIDS, n = 36, 0.3-8.0 months of age 4.3 +/- 0.3 months). The melatonin concentrations were measured by radioimmunoassay. A significant correlation was observed for melatonin levels in different body fluids from the same individual. After adjusting for age differences, CSF melatonin levels were significantly lower among the SIDS infants (91 +/- 29 pmol/l; n = 32) than among those dying of other causes (180 +/- 27; n = 35, P less than 0.05). A similar, but non-significant trend was also noted in blood (97 +/- 23, n = 30 vs. 144 +/- 22 pmol/l, n = 33) and vitreous humor (68 +/- 21, n = 10 vs. 81 +/- 17 pmol/l, n = 15). These differences do not appear to be explainable in terms of the interval between death and autopsy, gender, premortem infection or therapeutic measures instituted prior to death. Diminished melatonin production may be characteristic of SIDS and could represent an impairment in the maturation of physiologic circadian organization.     

Changing trends in the diagnosis of sudden infant death

A study of 114 consecutive cases of unexpected infant death that occurred in South Australia over a 5-year period from January 1994 to December 1998 was undertaken. There were 45 deaths attributed to sudden infant death syndrome (SIDS), 19 to natural causes, 21 to accidents. and 5 to homicides; 24 cases were listed as "undetermined." Although there has been a genuine and continued decline in SIDS numbers in this population, there has also been an increase in the diagnosis of cases of accidental asphyxia due to unsafe sleeping environments and of cases in which the family background and autopsy findings suggested more complex mechanisms. The change in diagnostic profile has followed the introduction of more rigorous clinical history review, death scene examination, and autopsy testing. Thus, although diagnostic outcomes have altered in this population, it is more likely the result of more careful interpretation of the extensive investigations that are now undertaken rather than arbitrary reclassification.     

Histologic thyroid gland findings in the newborn infant and infant, with special reference to sudden infant death

The morphological picture of the thyroid gland, the only endocrine organ with a follicle structure, allows a limited conclusion to be drawn with respect to the functional state in spite of any physiological variability. The thyroid of the newborn shows total colloid release and collapse of the follicles. The regular structure of the thyroid will be rebuilt within several weeks after birth. Total colloid absorption can be found in cases of stress-activated thyroids as well as in cases of death due to freezing. A histological examination was done on 88 thyroids of fetuses, newborns and infants. About 70% of the results on 27 cases of sudden infant death syndrome (SIDS) may be interpreted as a morphological correlate of a premortal chronic or recurrent stress reaction. The value of these results is discussed.     

A functional approach to sudden unexplained infant deaths

There is a great deal of variation in the methods and wording used by medical examiners in the medicolegal investigation and certification of infant deaths. This paper was created by the NAME Ad Hoc Committee on Sudden Unexplained Infant Death to address several specific issues, namely: * To establish a functional approach to the investigation of sudden unexplained infant deaths; * To outline a "bare minimum" set of recommendations to define the scope of investigation required; * To recommend methods and wording to be used when certifying infant deaths; * To develop a list of potential stressors or possible external causes of death that should be identified and reported on the death certificate and/or within a medical examiner/coroner office database. This paper was electronically posted for NAME member review and comment for a period of 30 days. The paper was further revised based on member comments and then submitted to the NAME board of directors in the fall of 2005 prior to the annual meeting. This text of this paper was officially approved and endorsed by the NAME board of directors on October 14, 2005, at the annual meeting in Los Angeles, CA.     

Cardiac rhabdomyoma presenting as sudden infant death syndrome

A case of cardiac rhabdomyoma presenting as sudden infant death in a four-and-one-half month-old infant is reported. The child was the product of an essentially uncomplicated pregnancy and enjoyed good health before his unexpected, sudden death. Autopsy examination revealed the presence of multiple cardiac lesions which histologically were diagnosed as rhabdomyomas. Death was attributed to fatal cardiac arrhythmia caused by the tumor. To the authors' knowledge this represents the first reported case in the forensic science literature of death as a result of cardiac rhabdomyoma presenting as sudden infant death syndrome (SIDS).     

Acallosal brain in sudden infant death syndrome (SIDS).

A definitive explanation of "crib" or "cot" death remains unknown. An unusual incidental autopsy finding of agenesis of the corpus callosum in a case presenting as "near miss" sudden infant death syndrome (SIDS) is discussed. Hitherto, only a single case associated with SIDS has been reported in the literature. The condition may be easily missed outside the interest in neuropathology.     

Toxic environmental factors in sudden infant death (SIDS)

The increasing number of discussions on the influence of toxic environmental factors, including SIDS, prompted systematic postmortem chemical-toxicological investigations to be carried out on 54 SIDS cases and 2 control cases of the same age group. Tissue levels of arsenic, lead, cadmium, mercury, and pentachlorphenol, as well as other organic noxious agents, were measured in several organs. In addition, the COHb concentrations were determined. In spite of the widely scattered values, the extreme levels measured and the arithmetic means and median averages of As, Pb, Cd, Hg, PCP, and COHb had no more range in concentrations than can be expected for toxic effects - according to present knowledge anyway. It was observed that infants from an urban environment showed no greater concentration of noxious agents than did infants from rural regions. There were also no differences between SIDS cases and the controls, nor was there a correlation between infections of the respiratory system that are often morphologically detected - including laryngitis - and higher concentrations of these agents in the organs of SIDS cases.     

Resuscitation measures and petechial thymus hemorrhages in sudden infant death

In 45 cases of sudden infant death syndrome (SIDS) in which unsuccessful attempts at resuscitation had been made and in 21 cases without attempted resuscitation, systematic histological investigations were carried out on the thymus. In these investigations, petechial hemorrhages were detected in 82% of the cases with attempted resuscitation and in 76% of the cases without attempted resuscitation. The histological distribution pattern of the petechial thymus hemorrhages did not differ notably between the two groups. The pattern of findings indicates that the hemorrhages had already developed during the death agony and that the typical histological distribution pattern with an increased occurrence of petechial in the cortical zone was altered by massive attempts at resuscitation in individual cases.     

婴幼儿猝死综合征神经病理学的研究进展

婴幼儿猝死综合征(SIDS)是指发生于1岁以内婴儿无明显病因的突然死亡,其死亡原因及鉴别诊断标准迄今仍不明确。本文参考了近年来采用免疫组化方法对SIDS神经系统病理变化的研究文献,提出SIDS致命的病理生理机制是与睡眠相关的呼吸循环失控或衰竭,即SIDS的主要病因存在于中枢神经系统,但不是单一病因。