Severe neural tube defect syndrome from the Early Archaic of Florida

Spina bifida, the normal, the pathological and the in-between: first evidence from a forensic osteological collection

Spina bifida (SB), a rare congenital disorder, is often mentioned as an individualizing factor in Forensic Anthropology. A lack of empirical data regarding SB is noticed in the scientific literature. Moreover, within the scope of anthropological research on SB disparities in terminology, classification systems, and methodological approaches result in incomparable results. The wide range (1,2%-50%) of "spina bifida occulta" reported prevalences is a good example. This research aims to analyze and debate the standard diagnostic criteria of SB on human skeletal remains, and attempts to elaborate on an universal system, premised on the distinction between SB as a pathology, and cleft neural arch (CNA) as an anatomical variant, according to Barnes (1994, p. 360 [1). A study-base of 209 individuals (88 males; 121 females; 44-99 years old) from the 21st Century Identified Skeletal Collection from the University of Coimbra (CEI/XXI) was macroscopically analyzed, focusing on the sacrum and remaining vertebrae. Four individuals presented complete posterior opening of the sacral canal (2,6%[4/156]). The observed bone changes, combined with the analysis of the entire skeleton, indicate that CNA, rather than SB linked to a neural tube defect, is the most reliable explanation for these cases. Overall, CNA was observed on 11 skeletons (7.05% of 156). The viability and applicability of the developed methodology for the identification of SB/CNA in forensic and/or osteological contexts are discussed, as well as the possibility of a lower prevalence of SB occulta, in the general population, than speculated before. HIGHLIGHTS: • Spina bifida has been studied so far under different methodologies, classification systems and nomenclature, leading to unstandardized and incomparable data. • Spina bifida as a pathological manifestation of a neural tube defect, as opposed to cleft neural arch as a simple form of skeletal variation. • Both spina bifida and complete sacral cleft fit the criteria of an individualizing trait in Forensic Anthropology.

Sacral Spina Bifida Occulta: A Frequency Analysis of Secular Change

Substantial relaxation of natural selection beginning around 1900 changed the mutation/selec­tion balance of modern genetic material, producing an increase in variable anatomical structures. While multiple structures have been affected, the temporal increase in variations of the sacrum, specifically, ‘Sa­cral Spina Bifida Occulta,’ have been reliably demonstrated on a localised scale. Calculation of largescale frequency has been hindered by the localised nature of these publications, the morphological variability of this variation, and potential pathological associations, which have produced divergent classifications, and conflicting reported rates of occurrence. A systematic review of the reported literature was conducted to provide an objective analysis of Sacral Spina Bifida Occulta frequency from 2500 BCE to the present. This review was designed to compensate for observed inconsistencies in reporting and to ascertain, for the first time, the temporal trajectory of this secular trend. A systematic review of Sacral Spina Bifida Occulta lit­erature was conducted through the strict use of clinical meta-analysis criteria. Publications were retrieved from four databases: PubMed, Embase, the Adelaide University Library database, and Google Scholar. Data were separated into three historical groups, (1 = <1900, 2 = 1900 to 1980 and 3 = >1980), and frequency outcomes compared, to determine temporal rates of occurrence. A total of 39/409 publications were included in the final analysis, representing data for 16,167 sacra, spanning a period of 4,500 years. Statistically significant results were obtained, with total open S1 frequen­cy increasing from 2.34%, (79 to 1900CE), to 4.80%, (1900 to 1980CE) and to 5.43% (>1980CE). These increases were significant at p<0.0001, with Chi-squared analysis. A clear secular increase in the global frequency of Sacral Spina Bifida Occulta has been demonstrated from 1900 to the present. This research provides a novel and adaptable framework for the future assessment of variation distribution, with impor­tant implications for the fields of biological anthropology and bioarchaeology.

Thundering hoofbeats and dazzling zebras: A model integrating current rare disease perspectives in paleopathology

OBJECTIVE

The article reviews the study of rare diseases and their nomenclature, emerging government policies and initiatives, and the concerns voiced by the modern rare disease communities. An interpretive model is then presented for the bioarchaeological interpretations of individuals with paleopathological evidence of rare diseases.

MATERIALS

In demonstration of the application of the proposed framework, we evaluate the skeletal remains of an adult female (EZ 3-7-1) excavated in the 1980s from the Middle Woodland (50BCE-CE400) context of the Elizabeth site (11PK512) in the lower Illinois Valley, USA.

METHODS

We use macroscopic examination methods, as well as cementochronology, to put forth the osteobiographical profile.

RESULTS

The skeletal manifestations observed suggests limitations of major life activities, which would have increased in severity throughout the life course of EZ 3-7-1.

CONCLUSIONS

The study of EZ 3-7-1 demonstrates how an osteobiography, centering on the lived experiences and limitations throughout a life course, can allow for a deeper appreciation for life in the past.

SIGNIFICANCE

By considering the perspectives of the modern rare disease community in the bioarchaeological methodology, research can include the nuanced impacts of the disease on life experiences and varying societal perceptions and attitudes, as well as raising awareness and advancing contemporary perspectives on impairment and disability.

LIMITATIONS

Without ample contextual evidence, there are limitations in making conclusions regarding social identity and disability.

SUGGESTIONS FOR FURTHER RESEARCH

This framework should be applied to other rare diseases in a variety of contexts to further test its functionality.

Carrying human infants - An evolutionary heritage

We propose that infant carrying is a biological norm for human caregiving, given that human infants have evolved a capacity to cling onto an upright caregiver whose body co-evolved to enable offspring carrying. The origins of this mutual adaptation may date back 4 million years, with the emergence of bipedalism, which precluded the infant horizontal and gravity-supported position on the back of a quadrupedal caregiver. We describe infant cooperative reflexes and behaviors, including the carrying-induced calming response and discuss hypotheses for the invention of infant carrier tools. Carrying involves several physiological and behavioral parent-infant co-adaptations that imply it is an evolutionarily conserved strategy. Epigenetic transmission of reproductive behavior through generations affects the development of the offspring, as well as the mental health of the parent. Carrying might have contributed to the evolution of Hominidae, potentially aiding dexterity, handedness, language acquisition, and social interactions. We review the evolutionary milestones and time points where the infant-caregiver interactions might have changed, exploring infant carrying as it intersects with biological and cultural evolution. We briefly summarize the effects of infant carrying on physiological, epigenetic, and socio-emotional outcomes.

An Age Old Problem? Estimating the Impact of Dementia on Past Human Populations

OBJECTIVE

To model the impact of dementia on past societies.

METHOD

We consider multiple lines of evidence indicating elderly individuals to have been more common throughout the past than is frequently accepted. We then apply known dementia incidence/prevalence rates to plausible assumptions of past population structures to suggest prevalence in the past.

RESULTS

Dementia prevalence in premodern societies is likely to have been around 5% of the rate seen in modern, developed countries but with a total past incidence running into billions.

DISCUSSION

Dementia is often seen as a "modern" challenge that humans have not had to contend with before. We argue that this condition has had considerably greater effects than previously envisaged and is a challenge that humans have already withstood successfully, on one hand at a lower incidence but on the other without the considerable clinical, technological, and social advances that have been made in recent times.

Anencephaly: do the pregnancy and maternal characteristics impact the pregnancy outcome?

Objective. To describe the characteristics of obstetric and perinatal outcome of a group of pregnancies complicated by an anencephalic fetus. Methods. Observational study including anencephalic fetuses, divided into groups according to the evolution of pregnancy: elective termination of pregnancy ETP; stillbirths (SBs); live births (LBs), and loss of follow-up. After a univariate description of the sample, some variables were compared using statistical tests. Results. 180 anencephalic fetuses were included. The mean maternal age was 25.3 years. In 71 fetuses (39%) were found additional anomalies. Comparing the groups, no statistical differences in maternal age (P = 0.5315), parity (P = 0.6070), number of previous abortion (P = 0.7464), fetal sex (P = 0.0502) and additional anomalies (P = 0.186) were found. Among those fetuses whose parents opted for continuation of pregnancy (n = 53), 20 spontaneous intrauterine deaths occurred (38%) and 33 were live births (62%). The average postnatal survival time was 51 minutes. There was no association between survival time and gestational age (P = 0.6125) or the presence of additional malformations (P = 0.1948). Conclusion. Results presented here could contribute to a better understanding of the natural history of this malformation, allowing obstetricians a more detailed discussion with the families.

Spina bifida: a diagnostic dilemma in paleopathology

This article provides information regarding the etiology, pathogenesis, and skeletal manifestation of spina bifida or spinal dysraphisms. On the basis of a review of the medical literature, it addresses discrepancies in documentation and interpretation of spina bifida in paleopathology. Furthermore, it offers suggestions for use of universal terminology and highlights the difficulties in the specific diagnosis of dysraphisms in skeletal remains. In addition, the necessity of examining the entire skeleton for abnormalities to distinguish simple delay/failure of fusion of the posterior neural arches from other occult spinal dysraphisms is emphasized, as it is the need for stratification of the sample by age and sex when reporting frequencies of sacral spina bifida occulta.

Qualitative and quantitative diagnosis of lethal cranial neural tube defects from the fetal and neonatal human skeleton, with a case study involving taphonomically altered remains

Cranial neural tube defect, or anencephaly, is the absence of normal brain development because of severe developmental defect in the fetus. While the current incidence of human anencephaly ranges between 1 to 5 per 1000 births, and was higher prior to folic acid supplementation, there is no discussion of anencephaly diagnosis in the forensic literature and only one published example from the archeological record. This article presents both qualitative observations of abnormal cranial elements and an osteometric method to quantitatively determine anencephaly from forensic recovery contexts where taphonomic variables may otherwise mask diagnostic characteristics. Evidence is presented for only the second case of anencephaly diagnosed from a burial context, and the first not involving soft tissue mummification. The initial recognition and accurate prediction of anencephaly is a significant contribution to investigators recovering found human fetal remains.

A sequential developmental field defect of the vertebrae, ribs, and sternum, in a young woman of the 12th century AD

Changes in the vertebral column are often noted in skeletal material. Descriptions of these anomalies are often lacking, and their developmental origins are not often discussed. The skeleton of a young woman from the medieval cemetery of Tirup, in Denmark, has multiple defects of the axial skeleton, including extra thoracic and lumbar vertebrae, border shifting, extra ribs, block vertebra, and deformed sternum. This case study is particularly interesting because of the number and diversity of anomalies seen; the rarity of these defects, even in living populations; and her survival to adult age. Careful analysis of the bones and use of the morphogenetic method of determining development stages has led to the conclusion that the initial defect probably occurred very early in development, during blastogenesis, with the initial development of at least two extra somitomeres in the paraxial mesoderm. These extra elements in turn led to problems in union and differentiation, and later chondrification and ossification of the vertebra. The malformations of the vertebrae also induced changes in the ribs and sternum. The initial error of segmentation is identified as a developmental field defect, and the cascade of anomalies seen is a developmental sequence caused by the initial field defect. The genetic and environmental causes of developmental field defects are reviewed.

Registries of birth defects and genetic diseases

Registries can be very useful scorecards for tracking the occurrence of birth defects and genetic diseases and for monitoring the effectiveness of prevention programs. They can also help us to identify causes and risk factors and develop new prevention approaches. For registries to be useful, however, their data must be precise and focus on time, place, person, and diagnosis.

Can paleopathology provide evidence for "compassion"?

Paleopathological analyses of skeletal remains have provided significant information about diet and health in prehistoric populations. A number of individuals have been recovered whose remains show evidence of impairments that would have precluded "normal" functioning, resulting in a disability. The most famous example is Shanidar I; more recent discoveries include the Romito 2 dwarf from Italy and a boy with spina bifida from the Windover site in Florida. These finds have been interpreted by some writers as evidence for compassion and "moral decency" among the other members of the community, who would have had to support these nonproductive individuals. However, these interpretations are based on a number of implicit assumptions: about the number of nonproductive members normally present in any population, about the abilities of disabled individuals to contribute to society, about the treatment of disabled individuals by other members of the group, and about the "moral rightness" of facilitating the survival of a disabled individual under all circumstances. These assumptions are not justified by the evidence from the archeological record or by reference to ethnographic analogy. A tendency to focus on physical traits as the sole measure of productive ability, images of Rousseau's "noble savage" transported to the past, and unexamined beliefs about the disabled in modern societies have influenced these archeological interpretations. We are not justified in drawing conclusions either about the quality of life for disabled individuals in the past or about the motives or attitudes of the rest of the community from skeletal evidence of physical impairment.