Spontaneous degeneration of the posticus muscle

The intrinsic muscles of the larynx were prepared in 265 forensic postmortems (death by strangulation: 73; other violent deaths: 93, natural death: 79, others: 20) for a histological examination. Muscle-fiber alterations were found in the (macroscopically normal) PCA muscle in most cases where the persons were of middle age or older. There were abnormalities such as rows or clumps of nuclei (also inside muscle fibers), the accumulation of lipofuscin pigment, focal or total necrosis of muscle fibers with or without predominant histiocytic infiltration, atrophic muscle cells, and fibrosis. The changes were mostly mild (normal muscle cells predominated) but clearly visible. If there had been acute damage to the larynx (for instance, death some time after attempted strangulation), these preexistent alterations must be taken into consideration when interpreting the microscopical findings.     

Soft tissue hemorrhage within the larynx following strangulation

The inner soft tissues of the larynx (i.e., true vocal cord, false vocal cord, paralaryngeal space) were examined by special preparation of the larynx: thyroid cartilage was detached from the cricoid and the laryngeal cords, which could then be examined. Bleeding (not visible before) was found in 18 of 40 cases of persons killed by throttling or choking; bleeding occurred whenever blunt trauma of the throat had taken place (n = 8). Hemorrhage develops even in cases without damage to the laryngeal skeleton; this bleeding can result from direct compression of the larynx (large and not well defined bleeding) and can originate indirectly (small hemorrhages mostly in the vocal muscles). The finding of hemorrhages like this can help to demonstrate that the victim has undergone a violent attack on the throat.     

Instructions for the complete preparation of the larynx

A method of preparing the larynx in forensic cases is described especially when death occurs by strangulation (manually or using some form of ligature). After the usual dissection of the hyoid bone and the upper horns of the thyroid cartilage, the complete larynx is clipped and fixed in formaldehyde overnight. The first part of dissection after that is to cut away the thyroid gland and the remaining muscles in front of the larynx, except for the cricothyroid muscle and the esophagus and hypopharynx from the back of the larynx. The complete thyroid cartilage is dissected out, and then a horizontal cut is made through the cricoid cartilage. Median-sagittal halving of the remaining larynx completes the gross dissection. Arytenoid cartilages are exposed by dissection of the arytenoid muscles and opening the cricoarytenoid joints. Now all parts of the laryngeal skeleton and all articulations are examined, and all muscles and soft tissues are visible and can be clipped for histological examination.     

Morphologic findings for airway occlusion in strangulation

Report of two cases of strangulation by hand. There were large submucous bleedings of the larynx (both sides of conus elasticus) of symmetrical arrangement, near the vocal processes of the arytenoid cartilages. They are believed to be the result of the violent contact of the vocal folds during laryngeal compression; perhaps while the arytenoid cartilages were subluxated inwards and downwards. Bleedings like this indicate the closure of the airway. In one case (50-year old woman) the ossified cricoid was broken; in the other (21-year old woman) the elastic laryngeal skeleton was intact, but large bleedings of the deeper tissues of both vocal folds indicated the vehement compression too. The analysis of 110 cases of attack against the neck (strangulation by hand -n = 30- or ligature -n = 30- alone or together -n = 32-; blunt force: n = 8, other types: n = 10) showed in 7 additional cases less typical but similar bleedings, especially in strangulation by hand.     

Homicide by asphyxia--yes or no? On the use of muscle histology

In two cases of death autopsy revealed large hemorrhages in the muscles of the neck, which lead to the conclusion of a murder by strangulation, e.g. with a soft tool. Histologic examination of the injured muscles didn't show any sign of vital reaction, which means, that they had developed post mortem. There was no reason for further suspicion of a violent crime. Later it became obvious, that neck lesions resulted from inadequate recovery and transport of the corpses. "Vital" type of muscular alteration is characterized by segmental or disk-like fragmentation of muscle fibres, loss of sarcoplasmatic cross-striation and appearance of pathologic longitudinal fibrillar structures. These signs are missing in case of a postmortal injury, whereas the cross striation is intact. The slides should be stained with PTAH. With these two cases we would like to demonstrate the importance of histologic examination of injured muscles, when question for intravital or postmortal injury rises.     

Thyreoglobulin and violent asphyxia

The concentration of thyreoglobulin (tg) was determined for death caused by hanging, strangulation by ligature, and throttling. Cases of sudden death (traumatic aortic rupture, penetrating wounds of the heart) were used for comparison. The mean values in cases of hanging (149.9±202.3 ng/ml), strangulation by ligature (193.1±173.3), manual strangulation (561.6±173.9) are distinguishable from violent acute deaths (23.3±27.6) and living healthy individuals (17.3±16.1). By means of statistical comparisons, significant differences were found between throttling and strangulation by ligature and between throttling and hanging (adjusted P<0.001). In connection with examination of the bodies high tg values can be regarded as a vital reaction in obstructive asphyxia.     

Artifactual injuries of the larynx produced by resuscitative intubation

Over a period of 9 months we examined a series of 50 deaths due to natural and unnatural causes in which there had been endotracheal intubation and chest compression during resuscitation at the scene or in the emergency department shortly before death. In 37 of 50 cases (74%) there were airway injuries directly resulting from the intubation procedure which we documented using a standardized protocol and photography. Specific airway injuries, ranging from petechiae to contusions, included oral injury (28%), posterior pharyngeal injury (16%), epiglottic injury (22%), piriform recess injury (12%), laryngeal and tracheal mucosa injury (64%), strap muscle hemorrhage (14%), and cutaneous injury of the neck (4%). In addition, we recorded the presence of facial (6%) and conjunctival petechiae (21%) and attributed these changes to resuscitative chest compression. No cases had associated fractures of the hyoid or thyroid cartilage. Based on our findings, we conclude that resuscitative intubation can cause artifactual injury that may mimic inflicted injuries caused by neck compression, including strangulation and neck holds.     

A triad of laryngeal hemorrhages in strangulation: a report of eight cases

The results of histological studies on larynges from eight cases of manual strangulation, all that had intracartilaginous laryngeal hemorrhages, a recently described and under-recognized lesion associated with strangulation, are reported. Formalin-fixed larynges were examined in serial section using a standardized protocol. In all cases, intracartilaginous laryngeal hemorrhages were associated with subepithelial laryngeal hemorrhages, and intralaryngeal muscular hemorrhages forming a "triad of hemorrhages." In five cases, the triad was found in the presence of laryngeal cartilage microfractures. Since cartilage microfractures can be causally related to mechanical injury to the neck, it is likely that the triad of hemorrhages has diagnostic value as an independent morphological criterion for the postmortem diagnosis of strangulation. Since a proportion of cases of strangulation lack characteristics that are self-evidently due to violent application of pressure on the neck, recognition of the triad may have important implications for the postmortem diagnosis of strangulation.     

Intra-cartilaginous laryngeal haemorrhages and strangulation

A previously unrecognized laryngeal injury in young female victims of manual strangulation is described. Twelve larynges that were retrospectively and prospectively collected at the Office of the Chief Coroner for Ontario (1982–1997) were used for this study. In all instances, the larynges were from cases of strangulation (mean age 27±10 years, range 20–46) with classical postmortem findings of asphyxia and either manual or combined manual and ligature strangulation. None of the larynges had fractures of the lamina of the thyroid cartilage, superior cornua, or cricoid cartilages. However, in 9 of the 12 cases (75%), sagittal sections revealed multifocal acute haemorrhages into the base of the superior cornua of the thyroid cartilage at the point of origin from the laminae. The presence of acute intra-cartilaginous haemorrhage into the larynx likely represents the disruption of small blood vessels due to elastic deformation of the flexible larynx during strangulation. The recognition of this form of laryngeal injuries broadens the pathological findings in cases of asphyxia associated with pressure on the neck.     

2633例机械性窒息法医尸检资料回顾性研究

本文根据湖北省部分地区1957～1986年间尸检记录,收集并分析了2633例机械性窒息死的出现率、案情性质、城市与乡村的差别等问题,为法医学实践提供了可供参考的资料。     

Homicidal and suicidal ligature strangulation--a comparison of the post-mortem findings

Suicides by ligature strangulation are rare events. In Berlin (3.5 million inhabitants; ca. 500 suicides per year) approximately one case per year occurs. Here, we present the main findings of 19 cases investigated between 1978 and 1998, compared to 47 cases of homicidal ligature strangulation. Two of the 19 suicidal victims had single fractures of the upper thyroid horns and one victim a fracture of a lower thyroid horn; other types of laryngohyoid injuries were not observed. In the homicidal series, the laryngohyoid structures were unaffected in 26 cases (12 of these victims were children or adolescents), single thyroid horn fractures were present in three cases and more significant injuries in 18 cases. Macroscopic bleedings of the laryngeal muscles were found in 12 victims of the homicidal group and in none of the suicidal. Bleedings in the neck muscles seldom occurred in suicides. According to these findings, the laryngohyoid injuries can be helpful in the differentiation of suicide from homicide, if more than a single thyroid horn fracture or a laryngeal soft tissue trauma is present.     

白血病死亡的法医学鉴定

材料和方法回顾性研究我所2003～2005年间检案实践中4例白血病死亡的法医学鉴定案件。结果4例死者生前均无明显的血液病症状,其中1例死亡前经临床确诊为急性颗粒增多型早幼粒细胞性白血病（M3）,另外3例均无血液病相应的临床资料。尸体解剖主要所见：（1）多器官（尤其是脑）白血病细胞浸润;（2）肝、脾肿大;（3）凝血功能障碍引起的出血倾向,如：皮肤紫癜、创口渗血或迁延不愈等;（4）可排除暴力死亡。结论白血病细胞脑浸润引起的脑内血肿和血液病的并发症弥漫性血管内凝血（DIC）是导致死亡的常见原因;在白血病患者突发死亡的案例中,死者生前往往缺乏典型的血液病症状,或仅有轻微的症状未引起注意;此类案件的法医学鉴定应注意收集临床资料,必须进行系统的尸体解剖检验,在有检验条件的情况下应进行骨髓细胞学病理检验。     

Homicidal asphyxia

Homicides due to asphyxia are relatively uncommon. To better understand the presentation of such cases, the files of the Bexar County Medical Examiner's Office were reviewed from January 1, 1985, through December 31, 1998, for all such homicides. A total of 133 cases were found. The largest category was ligature strangulation with 48 deaths (21 male, 27 female). Petechiae were present in the conjunctivae and/or sclerae in 86% of the cases; fractures of the hyoid and/or thyroid cartilage were present in 12.5%. There were a total of 41 deaths from manual strangulation (27 female, 14 male). Petechiae were present in 89% of the cases. In cases of manual strangulation, fractures of the hyoid, thyroid, or cricoid cartilage were found in all the male victims and slightly more than one half of the female victims. Twenty-six cases of suffocation were found; 20 of the victims were < or =2 years of age. Only 1 of these children had petechiae and/or scleral hemorrhage. Five deaths were due to choking. Three of the deaths involved adults who were gagged; 2 deaths involved infants with foreign material pushed into the mouth. Other categories of asphyxia were as follows: 9 deaths due to more than one form of asphyxia; 1 death due to hanging, and 3 deaths due to drowning. Rape was the motive in 66% of the female victims of ligature strangulation and 52% of those due to manual strangulation.     

Forensic assessment of survived strangulation

By a retrospective analysis of all survived strangulation cases examined at the Institute of Forensic Medicine of Berne, Switzerland between 1987 and 2002, the authors tried to find out, if findings and symptoms of victims could be related to the fierceness of the assault and the mode of strangulation and if general evaluation criteria could be established on the basis of objective findings. One hundred and thirty-four survived strangulation cases were analysed on the basis of written reports, photographies and schematical sketches. Findings and symptoms reflected the fierceness of the assault in 71% of all cases by displaying a continuum of findings from minor injuries to severe traumatisation. This applied especially for cases of manual strangulation while other modes of strangulation resulted in different constellations of findings. As a result of this study, the authors deem the following classification of three degrees of severity as practical on condition that a complete forensic medical examination was performed upon the surviving victim shortly after the incident of strangulation: Light strangulation, confined to skin abrasions and/or reddening of the skin of the neck. Moderate strangulation, defined as bruising to, and/or bleeding from the neck, and/or damage to deeper soft tissues or the larynx, as exhibited by the symptoms of sore throat, difficulty in swallowing, and hoarseness. Severe, life-threatening strangulation if the victim presents petechial bleedings as a result of venous congestion with or without accompanying loss of consciousness.     

Toxicological findings in victims of traumatic deaths.

The toxicological findings from 6037 analyses of viscera obtained from victims of traumatic death are used to correlate the relative incidence of carbon monoxide, ethyl alcohol, narcotics, hypnotics, analgesics, and tranquilizers-antidepressants in deaths occurring under the following circumstances: fire related, asphyxia by hanging, by use of plastic bags, from physical obstruction of trachae, and by drowning; traumatic injury from impact of moving train, fall from height, and occupational accident; traumatic injury to pedestrian, driver, and passenger from vehicular accidents; and from violent death by shooting, stabbing, strangulation, and beating. The influence of alcohol, narcotic drugs, and tranquilizers on carbon monoxide can be seen in some of these traumatic deaths. Ethanol alone and in combination with other drugs was present in 42.3% and 19.5% of driver and pedestrian victims, respectively, of vehicular accidents in the year 1974. Comparative analysis is presented for the toxicological data obtained on victims of homicide (shooting, stabbing, strangulation, and beating) in New York City and similar data reported for victims of homicide in Detroit. In New York City 45.9% of such victims died while under the influence of alcohol or narcotic drugs, or both, with methadone predominating in the latter category. Tissue concentrations of drugs found in victims of traumatic death are presented. Diphenylhydantoin, diazepam, meperidine, and slow-acting barbiturates were found in normal therapeutic levels. Higher concentrations of amitriptyline, chlorpromazine, propoxyphene, short-acting barbiturates, and methadone were observed. The concentration of methadone in blood and brain (0.13 +/- 0.14 mg/100 ml) and in liver (0.53 +/- 0.42 mg/100 ml) in cases of traumatic death are not different from those observed in deaths classified as due to methadone overdose.     

Airway obstruction by laryngeal masses in sudden and homicidal deaths

We present two cases of autopsy detection of laryngeal masses with medico-legal implications. The first is a 56-year-old man who died suddenly of asphyxia due to upper airway obstruction caused by a large glosso-epiglottic retention cyst and glottic oedema. Hypothesis of medical liability was raised, due to delayed tracheotomy as the result of repeated failed attempts at oral intubation by various physicians. Difficult oral intubation due to the presence of a laryngeal mass in an asphyxiating subject requires rapid tracheotomy. The second case deals with a 43-year-old woman who died of asphyxia due to airway obstruction, as a result of injury of a cavernous laryngeal haemangioma after homicidal manual strangulation, with severe haemorrhagic infiltration of the surrounding soft tissues. Damage to laryngeal/hypopharyngeal masses should be considered as a possible sign of manual strangulation, as well as neck skin bruises/abrasions and laryngeal haemorrhages.     

Injuries to laryngeal articulations in strangulation and throttling

During the consecutive examination of the larynges of (81) deceased persons (strangulation by hand and/or ligature, blunt force against the neck, from other persons), the cricothyroid and cricoarytenoid-articulations were prepared and opened, and capsular or articular cavity hemorrhaging was found in 30% of all cases; a clear distinction being found between effect of manual strangulation (43%) or blunt trauma (44%) on the one hand and strangulation by ligature alone (9%) on the other. The greater the extent of injury to the cartilages the more articular lesions are found as an expression of the mechanical load on the entire laryngohyoid structure.     

Comparative histologic studies of the origin of petechial thymus hemorrhage

Systematic histological investigations were carried out on the thymus with regard to the incidence and genesis of petechial thymus hemorrhages in 145 cases of death (fetuses from pregnancy terminations and stillbirth, mature and immature neonates, SIDS cases, other baby deaths, deaths during infancy and childhood). Petechial thymus hemorrhages were most frequently found in SIDS cases (87%). Even though distinguishable, a distribution pattern similar to that of thymus hemorrhages in SIDS cases (including hemorrhages mainly in the cortical zone of the lobes) could be detected in the group of fetuses from pregnancy terminations and stillbirth, as well as in mature and immature neonates. Histologically, deaths in babies and infants without extrinsic suffocation showed a different histological bleeding pattern (irregular hemorrhages of varying size in the cortex and medulla of the lobes). In violent extrinsic suffocation of babies and infants, thymus hemorrhages were much rarer and less pronounced in quantitative terms. Acute and subacute or chronic forms of asphyxia, the cause of death and the duration of the death struggle are discussed as pathogenetic factors to explain the different patterns of the findings.     

How extensive can injury of the larynx in self-choking be?]

Is it possible to distinguish between suicidal and homicidal strangulation by the extent of the injuries of the larynx if the results of the police investigations are uncertain? Therefore evaluation of the German publications (115 reported cases of suicidal strangulation) and our own cases (17 cases). Hereafter more intensive injuries of the neck are extremely rare in cases of self-strangulation. Casuistic: Body of a 40 years old woman with signs of strangulation. The husband declared his wife strangulated herself in the bathtub with the belt of a bathrobe. Autopsy: Typical findings of drowning, intensive injuries of the neck tissues and the larynx. Kind and extent of the findings are speaking well for an assault mainly by manual strangulation. Undepending of the medical findings the police investigations are almost excluding a suicide. Condemnation of the husband.     

Intrapulmonary aquaporin-5 expression as a possible biomarker for discriminating smothering and choking from sudden cardiac death: a pilot study

The diagnosis of mechanical asphyxia as a cause of death, especially smothering and choking lacking evident injury, is one of the most difficult tasks in forensic pathology. The present study investigated the intrapulmonary expressions of aquaporins (AQPs; AQP-1 and AQP-5), as markers of water homeostasis, in forensic autopsy cases (total n=64, within 48 h postmortem) of mechanical asphyxiation due to neck compression (strangulation, n=24), including manual/ligature strangulation (n=12) and atypical hanging (n=12), smothering (n=7) and choking (n=8), compared with sudden cardiac death (n=14) and acute brain injury (n=11). Quantification of mRNA using a Taqman real-time PCR assay system demonstrated suppressed expression of AQP-5, but not AQP-1, in smothering and choking, compared with that in strangulation as well as sudden cardiac death and acute brain injury death. Immunostaining of AQP-5 was weakly detected in a linear pattern in the type I alveolar epithelial cells in smothering and choking cases, while cardiac and brain injury death showed marked positivity, and most strangulation cases had AQP-5-positive granular aggregates and fragments in intra-alveolar spaces. These observations indicate a partial difference in pulmonary molecular pathology among these causes of death, suggesting a procedure for possible discrimination of smothering and choking from sudden cardiac death.