Humans are born too soon: impact on pediatric otolaryngology

Evolutionary game model of migraine based on the human brain hypersensitivity

Based on all studies published up to 2020, the prevalence of migraine worldwide is approximately 14%, although it varies regionally. Despite being one of the most disabling diseases, migraine still exists through natural selection and is prevalent today. This raises the question of what evolutionary advantages have led to the survival of migraine. The ultimate answer to this question should be found in evolution; however, there is no clear explanation yet. Notably, all the genes that cause migraine make the sensory organs and cortex of the migraine sufferer hypersensitive. In a state of hypersensitivity, the brain could recognize external threats easily. Game theory is a useful tool for explaining evolution in terms of genes. Just as the Hawk–Dove game, which has two strategies (aggressive and passive) and four fitness values, an evolutionary game between a migraineur and a non-migraineur, which shows two phenotypes (more sensitive and less sensitive) and four fitness values, can be played if a migraineur quickly recognizes a predator and informs a non-migraineur of its appearance and the non-migraineur later helps the migraineur escape from danger. This study aimed to explore the evolutionary mechanics of migraine that can be modeled. Furthermore, it tried to define why the human brain's hypersensitivity is a prerequisite for developing this evolutionary game model.

Clinical perspectives on nasopharyngeal morphology in humans

The nasopharynx is an integral component of the upper aerodigestive tract, whose morphologic features share an intimate relationship with a vast array of clinical, functional, and quality of life conditions related to contemporary humans. Its composite architecture and central location amidst the nasal cavity, pharyngotympanic tube, palate, and skull base bears implications for basic physiologic functions including breathing, vocalization, and alimentation. Over the course of evolution, morphological modifications of nasopharyngeal anatomy have occurred in genus Homo which serve to distinguish the human upper aerodigestive tract from that of other mammals. Understanding of these adaptive changes from both a comparative anatomy and clinical perspective offers insight into the unique blueprint which underpins many clinical pathologies currently encountered by anthropologists, scientists, and otorhinolaryngologists alike. This discussion intends to familiarize readers with the fundamental role that nasopharyngeal morphology plays in upper aerodigestive tract conditions, with consideration of its newfound clinical relevance in the era of the COVID-19 pandemic.

Identification of critical windows in early development of human upper respiratory tract and middle ear disease

Otitis media (OM) or middle ear disease is a prevalent pediatric condition generally related to early growth of the cartilaginous Eustachian tube (CET). This study used a developmental series of dry crania to reconstruct CET and dilator tubae (DT, the muscle opening the CET) morphology. Timing and directionality of CET and upper respiratory tract (URT) growth were investigated. Traditional and 3D geometric morphometrics (GM) were used to assess bony landmarks on the crania. The series was divided using dental eruption into seven growth stages ranging from before eruption of deciduous dentition (approximately the first 6 postnatal months) to eruption of the first permanent maxillary molar (after approximately 6 years). Bony endpoints of the CET and DT were used to calculate their morphology. GM analysis showed substantial shape differences between newborns, early infants, and all later developmental stages. Univariate measures showed the largest growth change between birth and 6 months. Subsequently, CET morphology changed little in the latter half of year 1, instead maturing gradually until approximately 3 years whereas DT relative length and orientation finish growth by the end of year 1. Incongruence in slower CET growth and faster DT growth could impact CET function between 6 and 12 months and be a contributing factor of OM. Tubal aeration may improve after this time when both CET and DT morphology mature, coinciding with clinically reported drop-off in ear infections.

Structural and functional development in airways throughout childhood: Children are not small adults

Children are not small adults and this fact is particularly true when we consider the respiratory tract. The anatomic peculiarities of the upper airway make infants preferential nasal breathers between 2 and 6 months of life. The pediatric larynx has a more complex shape than previously believed, with the narrowest point located anatomically at the subglottic level and functionally at the cricoid cartilage. Alveolarization of the distal airways starts conventionally at 36-37 weeks of gestation, but occurs mainly after birth, continuing until adolescence. The pediatric chest wall has unique features that are particularly pronounced in infants. Neonates, infants, and toddlers have a higher metabolic rate, and consequently, their oxygen consumption at rest is more than double that of adults. The main anatomical and functional differences between pediatric and adult airways contribute to the understanding of various respiratory symptoms and disease conditions in childhood. Knowing the peculiarities of pediatric airways is helpful in the prevention, management, and treatment of acute and chronic diseases of the respiratory tract. Developmental modifications in the structure of the respiratory tract, in addition to immunological and neurological maturation, should be taken into consideration during childhood.

Human accelerated genome regions with value in medical genetics and drug discovery

Accumulated evolutionary knowledge not only benefits our understanding of the pathogenesis of diseases, but also help in the search for new drug targets. This is further supported by the recent finding that human accelerated regions (HARs) identified by comparative genomic studies are linked to human neural system evolution and are also associated with neurological disorders. Here, we analyze the associations between HARs and diseases and drugs. We found that 32.42% of approved drugs target at least one HAR gene, which is higher than the ratio of in-research drugs. More interestingly, HAR gene-targeted drugs are most significantly enriched with agents treating neurological disorders. Thus, HAR genes have important implications in medical genetics and drug discovery.

What does tympanostomy tube placement in children teach us about the association between atopic conditions and otitis media?

Otitis media is the most common infection second only to viral upper respiratory infection in the outpatient setting. Tympanostomy tube insertion (TTI) is the most common ambulatory surgical procedure in the USA. While many risk factors for otitis media have been identified, atopic conditions have been underrecognized as risk factors for recurrent and persistent otitis media. Given that asthma and other atopic conditions are the most common chronic conditions during childhood, it is worth examining the association between atopic conditions and risk of otitis media, which can provide insight into how atopic conditions influence the risk of microbial infections. This paper focuses its discussion on otitis media; however, it is important that the association between atopic conditions and risk of otitis media be interpreted in the context of the association of atopic conditions with increased risks of various microbial infections.

Disease consequences of human adaptation

Adaptive evolution has provided us with a unique set of characteristics that define us as humans, including morphological, physiological and cellular changes. Yet, natural selection provides no assurances that adaptation is without human health consequences; advantageous mutations will increase in frequency so long as there is a net gain in fitness. As such, the current incidence of human disease can depend on previous adaptations. Here, I review genome-wide and gene-specific studies in which adaptive evolution has played a role in shaping human genetic disease. In addition to the disease consequences of adaptive phenotypes, such as bipedal locomotion and resistance to certain pathogens, I review evidence that adaptive mutations have influenced the frequency of linked disease alleles through genetic hitchhiking. Taken together, the links between human adaptation and disease highlight the importance of their combined influence on functional variation within the human genome and offer opportunities to discover and characterize such variation.

Consequences of evolution: is rhinosinusitis, like otitis media, a unique disease of humans?

We hypothesize that if otitis media is most likely primarily a human disease due to consequences of evolution, rhinosinusitis may also be limited to humans for similar reasons. If otitis media, with its associated hearing loss, occurred in animals in the wild, they probably would have been culled out by predation. Similarly, if rhinosinusitis occurred regularly in animals, they likely would have suffered from severely decreased olfactory abilities, crucial for predator avoidance, and presumably would likewise have been selected against evolutionarily. Thus, both otitis media and rhinosinusitis-common conditions particularly in infants and young children-appear to be essentially human conditions. Their manifestation in our species is likely due to our unique evolutionary trajectory and may be a consequence of adaptations, including adaptations to bipedalism and speech, loss of prognathism, and immunologic and environmental factors.

A new age for child protection--General Comment 13: why it is important, how it was constructed, and what it intends?

Children continue to be subjected to high levels of violence (i.e., physical, psychological and sexual maltreatment) throughout the world. International concern about violence against children has increased significantly during the last decade. A Study on Violence Against Children, encouraged by the UN Committee on the Rights of the Child, conducted under the auspices of the United Nations Secretary General and reported in 2006, has become a rallying call to improve child protection. Child protection practices and systems have been judged to be generally inadequate and, in some cases, destructive. It is widely recognized that business as usual-more of the same-will not do. A General Comment (guide to fulfilling obligations) for Article 19, the central conceptualization of child protection of the UN Convention on the Rights of the Child, has the potential to promote a worldwide reformulation of child protection priorities, policies, and practices by virtue of the infusion of a child rights approach. It can be a mechanism for framing and promoting the transformational change needed - for a genuine paradigm shift. Here, explication is given for the historical context, rationale, centrality of child rights, process of development, holistic nature, and primary elements of General Comment 13 (GC13): The child's right to freedom from all forms of violence. GC13 embodies and champions a child rights approach to child protection entailing strong support for proactive primary prevention, promotion of good child care, and a commitment to secure the rights and well-being of all children. A child rights-based, comprehensive coordinating framework is recommended for the implementation of GC13.

Risk factors for supraglottoplasty failure

OBJECTIVE

To review outcomes after supraglottoplasty for laryngomalacia and identify risk factors for supraglottoplasty failure.

STUDY DESIGN

Case series with chart review.

SETTING

Tertiary care children's hospital.

SUBJECTS AND METHODS

Retrospective case series evaluating patient outcomes after supraglottoplasty at an academic medical center between 2004 and 2010. Surgical failure was defined as need for revision surgery, tracheostomy tube placement, or gastrostomy tube insertion. Multivariable logistic regression was performed to identify risk factors for failure.

RESULTS

The authors identified 95 children who underwent supraglottoplasty. After excluding patients with inadequate follow-up data, 74 patients were included. On the basis of chart review, 12 (16%) of those patients were defined as failures according to the criteria above. Age, history of prematurity (<34 weeks' gestational age), weight, growth curve percentile, neurologic/developmental problems, genetic syndrome, cardiac abnormality, synchronous airway lesions, and surgical technique were considered in risk factor analysis. Multivariable logistic regression was performed, revealing history of prematurity to be the only independent risk factor for failure (odds ratio = 4.85; 95% confidence interval, 1.07-22.1; P = .041).

CONCLUSIONS

Outcomes after supraglottoplasty were comparable to previous reports in the literature. History of prematurity should be considered a risk factor for surgical failure.

Human evolutionary history: consequences for the pathogenesis of otitis media

The pathogenesis of otitis media is multifactorial, but the role of evolution on its development has not been addressed. We posit that the high prevalence of middle-ear disease is most likely restricted to humans, in contrast to other wild species, because the associated hearing loss would have reduced the fitness of affected individuals as a result of predation. We present here the possible consequences of two human adaptations that may have resulted in ubiquitous otitis media: the interaction of bipedalism and increased brain size, and the loss of facial prognathism resulting from speech or cooking. As a consequence of our adaptation for bipedalism, the female pelvic outlet is constricted, which, in the context of a rapidly enlarging brain, results in humans being born 12 months too soon. Significantly, immature eustachian tube structure and function, in conjunction with an immature immune system, helps to explain the high incidence of otitis media in the first year of life. But the persistence of middle-ear disease beyond this stage is not explained by "immaturity." The morphology of the palate changed with the adaptations that produced facial flattening, with concomitant effects on eustachian tube function. These changes resulted in relatively poor human physiologic tubal function in comparison to the nonhuman primate.

Type A esophageal atresia: a critical review of management strategies at a single center

PURPOSE

The purpose of was to study the short- and long-term outcomes in the management of isolated esophageal atresia with different operative strategies.

METHODS

All patients undergoing type A atresia repair over a 15-year period were included. Demographic data, birth weight, gestational age, incidence of associated anomalies, management, and long-term outcomes were studied.

RESULTS

Fifteen patients with type A atresia (9 male) were treated in the study period. The mean gestational age was 35.5 weeks (range, 27-39 weeks), and the mean birth weight was 2179 g (range, 670-3520 g). Eight babies had associated anomalies. Thirteen patients underwent gastrostomy as the initial procedure, and 2 underwent the Foker procedure. In the delayed management group, 9 patients underwent primary anastomosis, with 2 patients needing proximal pouch myotomy. Two patients underwent a Collis gastroplasty. Two patients underwent a cervical esophagostomy and a gastric tube replacement at 4 months and 1 year, respectively. Eight patients (60%) in this group had anastomotic leaks. All patients are currently on prokinetics and proton pump inhibitors. Seven required antireflux surgery. The median length of hospital admission was 4 months (range, 3-19 months). The native esophagus was preserved in 13 (85%) of 15 babies. All patients are alive, and 14 of 15 are capable of feeding orally.

CONCLUSIONS

Type A esophageal atresia continues to be associated with significant morbidity despite advances in surgical technique and intensive care.

Galapagos: Darwin, evolution, and ENT

This year is especially important in the history of the theory of evolution; 2009 is the bicentennial anniversary of the birth of Charles Darwin and the sesquicentennial anniversary of his publication, The Origin of Species. Darwin visited the Galapagos Islands as a young man, which greatly influenced his thinking. My son Jim and I had the good fortune to visit these islands in January 2009 and see firsthand what led Darwin to arrive at his monumental insights into the origins of life on this planet. I have described my observations and related some of this experience to the ear, nose, and throat, albeit with whimsy in several instances. Nonetheless, some of the adaptations in the animals on these unique islands may have bearing on my hypotheses related to the incidence and pathogenesis of otitis media in humans. It is hoped the reader will share my enthusiasm for the experience we had on these fantastic islands and tour them in the future.

Evolution of genomic imprinting in humans: does bipedalism have a role?

Recent studies have indicated that genomic imprinting is less conserved in human placenta and fetuses than in mice. Studies in mice confirm evolutionary predictions that imprinted genes have an important role in fetal growth via their effects on placental function, nutrient demand and transfer. Here, I argue that the development of bipedalism in humans might have contributed to a reduced role for imprinted genes in fetal growth. As a consequence of bipedalism, the shape of the human pelvis has changed, leading to a reduced gestation period and smaller 'premature' babies. This overarching selective pressure could, in turn, lead to a relaxation of the silencing of those imprinted genes that reduce fetal growth, a prediction borne out by current data.

Impact of evolution on the eustachian tube

I posit that humans appear to be the only species that develops otitis media. If animals in the wild had developed middle-ear disease to any significant degree, they would have been selected out during evolution because they would not have survived their predators given the associated hearing loss. Why do humans have otitis media? Evolution has had a significant impact. It is well known that humans are born 12 months too early, which is the result of adaptations to bipedalism and our big brain that, over time, resulted in a relatively small female pelvic outlet compared with nonhuman primates. As a consequence of too early a birth, not only is our immune system immature, but the eustachian tube is too short and floppy in the first year of life. But why is otitis media still common in older individuals? What other adaptation is uniquely human? We developed speech that was associated with descent of the larynx and hyoid bone, which, along with a decrease in prognathism (i.e., facial flattening), resulted in a change in palatal morphology as compared with other primates. Comparative anatomic and physiologic studies have demonstrated significant differences between humans and monkeys, especially in the muscles of the eustachian tube. Paradoxic constriction, as apposed to dilation, on swallowing is a common tubal dysfunction in humans and certain monkey models with chronic middle-ear effusion. My hypothesis is that chronic otitis media with effusion in patients with tubal constriction is a consequence of adaptation for speech and that, most likely, the levator veli palatini muscle is the cause.

Early acute otitis media: predictor for AOM and respiratory infections in schoolchildren?

OBJECTIVE

It has been reported that acute otitis media (AOM) and respiratory infectious morbidity still are common in schoolchildren. However, the significance of early initiation of AOM on later respiratory infections is not known. The aim of the study was to assess whether early initiation of AOM is a predictor for AOM and other respiratory infections in schoolchildren, and if environmental exposures and host factors in early life predict later AOM.

METHODS

A population-based, prospective study of 3754 children born in Oslo in 1992/93, of which 2549 children were followed from birth to 10 years. Main outcome measures were questionnaire-based information on AOM and other respiratory infections at ages 6 months, 1 year and 10 years.

RESULTS

Of the 190 (5.3%) children with one or more episodes of AOM before 6 months, 97 (51.1%) remained susceptible the next 6 months. The total number of children with one or more episodes of AOM from 6 to 12 months was 812 (25.1%). Of the 336 (13.2%) with AOM at 10, 95 (28.3%) also had AOM the first year of life. One or more episodes of tonsillopharyngitis or lower respiratory infections were experienced in 624 (24.4%) of the children at 10 years. There was a predominance of boys with AOM the first year of life, while girls were more prone to AOM at age 10. AOM the first year of life was not strongly associated with AOM at age 10 with crude and adjusted odds ratios 1.3 (95% CI 1.0-1.6) and 1.2 (95% CI 0.9-1.5), respectively. A corresponding tendency was found for other respiratory infections (tonsillopharyngitis or lower respiratory infections) at age 10. Tobacco smoke exposure at birth, early life atopic eczema and otitis media surgery increased the risk of AOM at age 10.

CONCLUSIONS

We found no strong association between early AOM and AOM and other respiratory infections in schoolchildren. Parental smoking at birth, early life atopic eczema and female gender were only weakly associated with AOM in 10-year olds while otitis media surgery was strongly associated with AOM in schoolchildren.

Pediatric Laryngotracheal Obstruction: Current Perspectives on Stridor

OBJECTIVES/HYPOTHESIS

To assess how medical advances have impacted the diagnosis, management, and outcomes of pediatric laryngotracheal obstruction, and to describe the advantages of audio-video documentation of stridorous children.

STUDY DESIGN AND METHODS

Retrospective.

METHODS AND MATERIALS

268 patients were referred for suspected laryngotracheal obstruction during the 30 months between September 1, 1995 and March 1, 1998: 173 had 206 flexible fiberoptic laryngoscopies, and 160 had 273 direct laryngoscopies. One hundred and forty-one children were identified with laryngotracheal obstruction, yielding 40 different diagnoses that could be classified into 9 major categories. Thirty-six children (25.5%) had multiple sites of upper airway obstruction.

RESULTS

138 children had follow-up >1 month. Twelve children died (8.7%), leaving 126 survivors (mean follow-up=21.1 months). Outcomes were classified as resolved (44.2%), improved (37.0%), stable (9.4%), failed (0.7%), or death (8.7%). Better outcomes were seen in more readily treated diagnostic categories, such as tracheobronchial foreign body, chronic laryngitis, and suprastomal granulation tissue; laryngeal stenosis, tracheomalacia, and recurrent respiratory papillomatosis, had less favorable outcomes (P<.001). The former group also showed superior outcome compared to laryngomalacia (P<.001) and vocal cord mobility disorders (P=.004). Ninety-four patients (68.1%) had comorbidities complicating their management. Comorbid conditions were universal among deceased patients and least common in the resolved outcomes category (56.7%), supporting the premise that patients with poor outcomes are more likely to have comorbidities than patients with resolution of laryngotracheal symptoms (P=.034).

CONCLUSIONS

Audio-video recording of pediatric laryngotracheal obstruction offers numerous advantages. Children classified into an array of diagnostic categories usually have favorable outcomes, but opportunities for continued advances exist, particularly regarding management of comorbidity and chronic obstruction.