Neil E. I. Langlois

A Prospective Study of Sudden Cardiac Death among Children and Young Adults

BACKGROUND Sudden cardiac death among children and young adults is a devastating event. We performed a prospective, population-based, clinical and genetic study of sudden cardiac death among children and young adults. METHODS We prospectively collected clinical, demographic, and autopsy information on all cases of sudden cardiac death among children and young adults 1 to 35 years of age in Australia and New Zealand from 2010 through 2012. In cases that had no cause identified after a comprehensive autopsy that included toxicologic and histologic studies (unexplained sudden cardiac death), at least 59 cardiac genes were analyzed for a clinically relevant cardiac gene mutation. RESULTS A total of 490 cases of sudden cardiac death were identified. The annual incidence was 1.3 cases per 100,000 persons 1 to 35 years of age; 72% of the cases involved boys or young men. Persons 31 to 35 years of age had the highest incidence of sudden cardiac death (3.2 cases per 100,000 persons per year), and persons 16 to 20 years of age had the highest incidence of unexplained sudden cardiac death (0.8 cases per 100,000 persons per year). The most common explained causes of sudden cardiac death were coronary artery disease (24% of cases) and inherited cardiomyopathies (16% of cases). Unexplained sudden cardiac death (40% of cases) was the predominant finding among persons in all age groups, except for those 31 to 35 years of age, for whom coronary artery disease was the most common finding. Younger age and death at night were independently associated with unexplained sudden cardiac death as compared with explained sudden cardiac death. A clinically relevant cardiac gene mutation was identified in 31 of 113 cases (27%) of unexplained sudden cardiac death in which genetic testing was performed. During follow-up, a clinical diagnosis of an inherited cardiovascular disease was identified in 13% of the families in which an unexplained sudden cardiac death occurred. CONCLUSIONS The addition of genetic testing to autopsy investigation substantially increased the identification of a possible cause of sudden cardiac death among children and young adults. (Funded by the National Health and Medical Research Council of Australia and others.).

Animal‐Related Fatalities—Part I: Characteristic Autopsy Findings and Variable Causes of Death Associated with Blunt and Sharp Trauma

Abstract:  Animals may be responsible for an array of potentially lethal injuries. Blunt force injuries characteristically involve larger animals such as cattle or horses that may kick, crush, or trample a victim causing head and facial injuries. Farm workers in particular are at high risk of lethal injuries involving the head and torso. Significant blunt trauma may be found in vehicle occupants after collisions with large animals such as camels or moose. Rarely, zookeepers may be crushed by particularly massive animals such as elephants. Sharp force injuries usually involve carnivore bites, most often from dogs with a “hole and tear” pattern of wounding. Injuries from animals such as alligators and sharks may have a significant component of crushing. Incised wounds may result in death from exsanguination and air embolism. On occasion, blunt or sharp trauma from animal activity may be confused with postmortem damage or with inflicted injury from an assault.

The practical application of reflectance spectrophotometry for the demonstration of haemoglobin and its degradation in bruises

Aims: To develop a non-invasive method to demonstrate the presence of haemoglobin and its degradation products in bruises in live human subjects for the purposes of objectively assisting in the determination of the age of a bruise. Methods: The cuvette holder unit of a Cary 100 Bio UV-Visible Spectrophotometer was replaced with the manufacture’s fibre optic cable and optical reflectance probe. The probe was placed on the skin surface. The absorption spectrum from 780 to 380 nm was collected and transformed into the first derivative. Calculation of the first derivative permits absorption attributed to haemoglobin degradation (primarily to bilirubin, but also haemosiderin) to be separated from absorption by haemoglobin. First derivative and colorimetry values, expressed as CIEL*a*b data, were derived from scans of 50 bruises. Results: The fibre optic cable and probe allowed the spectrophotometer to collect reproducible absorption spectra of bruises in the skin of living subjects. A bruise at three days has greater negative first derivative values at 480 and 490 nm than does a fresh bruise, indicating the local degradation of haemoglobin. Correlation between the first derivative and the CIEL*a*b “b” values in a series of bruises indicates that the yellow colour in a bruise is proportional to the amount of local haemoglobin breakdown. Conclusion: The ability to demonstrate the presence of haemoglobin and measure its degradation in bruises in living human subjects by a non-invasive method has not been described previously, and may be of use in the objective ageing of bruises for forensic purposes.

The Initial Changes of Fat Deposits During the Decomposition of Human and Pig Remains

Abstract:  The early stages of adipocere formation in both pig and human adipose tissue in aqueous environments have been investigated. The aims were to determine the short‐term changes occurring to fat deposits during decomposition and to ascertain the suitability of pigs as models for human decomposition. Subcutaneous adipose tissue from both species after immersion in distilled water for up to six months was compared using Fourier transform infrared spectroscopy, gas chromatography‐mass spectrometry and inductively coupled plasma‐mass spectrometry. Changes associated with decomposition were observed, but no adipocere was formed during the initial month of decomposition for either tissue type. Early‐stage adipocere formation in pig samples during later months was detected. The variable time courses for adipose tissue decomposition were attributed to differences in the distribution of total fatty acids between species. Variations in the amount of sodium, potassium, calcium, and magnesium were also detected between species. The study shows that differences in total fatty acid composition between species need to be considered when interpreting results from experimental decomposition studies using pigs as human body analogs.

The science behind the quest to determine the age of bruises—a review of the English language literature

Bruises are common injuries that can have medicolegal significance. There are those that maintain it is not possible to estimate the age of bruises. However, appreciation of the biological processes related to the resolution of a bruise suggests that these may provide information regarding the age of a bruise. Potential methods for determining the age of bruises—visual observation, colorimetry, spectrophotometry and histology—are reviewed. The observation of yellow (not orange or brown) indicates a bruise is not recent, but the abilities of visual observation are limited by the physiology of the human eye. Analysis of spectrophotometric data may provide more useful and objective information. Histological examination may be appropriate only in the postmortem situation. The lack of published information limits this as a tool for estimating the age of bruises. It is not known how the wide range of factors that can influence bruise formation and resolution could affect estimation of bruise age.

Applying visible hyperspectral (chemical) imaging to estimate the age of bruises

Hyperspectral (chemical) imaging collects spectroscopic data in a two-dimensional spatial format. The potential application for the determination of the age of bruises is demonstrated and compared to reflectance probe spectrophotometry as well as photography. Blood was deposited on white cotton cloth or injected subcutaneously into pig skin to simulate a ‘fresh bruise’. A mixture of blood and bile was used to simulate ‘old’ bruises. On the cloth background all the photographic methods clearly separated the two groups of samples (i.e. ‘blood only’ from ‘blood plus bile’). However, on the pig skin the two groups could be separated by one of the photographic methods only. Separation of blood from blood and bile mixtures was obtained on the cloth and skin backgrounds using spectrophotometry and hyperspectral imaging. In a test using serial dilutions of blood and bile mixtures, the hyperspectral system performed slightly better than the spectrophotometer. The former also had the advantage of imaging a wider area and providing spatial data. Hyperspectral (chemical) imaging and spectrophotometry are superior to photography for the detection of bilirubin on a background of skin (due to the presence of yellow chromophores); this technology combined with mathematical analysis of the spectral data warrants further investigation.

Injuries associated with resuscitation - An overview.

External cardiopulmonary resuscitation is a potentially lifesaving intervention aimed at preserving the cerebral function of a person in cardiac arrest. However, certain injuries can be caused by the various techniques employed. Although these are seldom consequential, they may complicate the forensic evaluation of cases. Fractures of the ribs and sternum are the most common internal injuries and are frequently acknowledged as a consequence of resuscitation. Nonethlesss, the recognition that less common fractures such as of the larynx or injuries involving the stomach, spleen, heart and liver can occur due to resuscitation will assist the forensic examiner assess the significance of these findings when they present in cases of sudden death.

Using the Excess Heat Factor (EHF) to predict the risk of heat related deaths

Extremes of climate are not uncommon in Australia and heatwaves are not infrequent. Periods of high ambient temperature may result in clusters of heat related deaths, which may place strain on forensic facilities. This paper describes the formulation of the Excess Heat Factor using meteorological data to provide a means of predicting death resulting from periods of extreme heat stress. The 2009 South Australian heatwave had the highest ranked Excess Heat Factor in Adelaides records. There were 58 heat related deaths, with the bulk of the heat related deaths following the peak Excess Heat Factor value (144 °C(2)). The 2008 heatwave had a lower peak Excess Heat Factor value (36 °C(2)); there was only one heat related death, which followed the peak in the Excess Heat Factor. It is proposed that calculation of the Excess Heat Factor from meteorological data could provide a means to predict and identify heat related deaths resulting from extreme weather conditions.

Animal-Related Fatalities—Part II: Characteristic Autopsy Findings and Variable Causes of Death Associated with Envenomation, Poisoning, Anaphylaxis, Asphyxiation, and Sepsis

Abstract:  In addition to blunt and sharp trauma, animal‐related fatalities may result from envenomation, poisoning, anaphylaxis, asphyxiation, and sepsis. Although the majority of envenomation deaths are caused by hornets, bees, and wasps, the mechanism of death is most often anaphylaxis. Envenomation resulting from the injection of a poison or toxin into a victim occurs with snakes, spiders, and scorpions on land. Marine animal envenomation may result from stings and bites from jellyfish, octopus, stonefish, cone fish, stingrays, and sea snakes. At autopsy, the findings may be extremely subtle, and so a history of exposure is required. Poisoning may also occur from ingesting certain fish, with three main forms of neurotoxin poisoning involving ciguatera, tetrodotoxin ingestion, and paralytic shellfish poisoning. Asphyxiation may follow upper airway occlusion or neck/chest compression by animals, and sepsis may follow bites. Autopsy analysis of cases requires extensive toxinological, toxicological, and biochemical analyses of body fluids.

Sudden adult death

In the investigation of sudden death in adults, channelopathies, such as long QT syndrome, have risen to the fore in the minds of forensic pathologists in recent years. Examples of these disorders are touched upon in this review as an absence of abnormal findings at postmortem examination is characteristic and the importance of considering the diagnosis lies in the heritable nature of these conditions. Typically, a diagnosis of a possible channelopathy is evoked as an explanation for a ‘negative autopsy’ in a case of apparent sudden natural death. However, the one potential adverse effect of this approach is that subtle causes of sudden death may be overlooked. The intention of this article is to review and discuss potential causes of sudden adult death (mostly natural) that should be considered before resorting to a diagnosis of possible channelopathy. Nonetheless, it becomes apparent that many of the potential causes of sudden death can have a genetic basis. Thus, it becomes an important consideration that there may be a genetic basis to sudden death that extends beyond the negative autopsy.