{"title":"Large-scale genetic mapping for human brain asymmetry.","authors":"Zhiqiang Sha, Clyde Francks","doi":"10.1016/B978-0-443-15646-5.00029-4","DOIUrl":"https://doi.org/10.1016/B978-0-443-15646-5.00029-4","url":null,"abstract":"<p><p>Left-right asymmetry is an important aspect of human brain organization for functions including language and hand motor control, which can be altered in some psychiatric traits. The last 5 years have seen rapid advances in the identification of specific genes linked to variation in asymmetry of the human brain and/or handedness. These advances have been driven by a new generation of large-scale genome-wide association studies, carried out in samples ranging from roughly 16,000 to over 1.5 million participants. The implicated genes tend to be most active in the embryonic and fetal brain, consistent with early developmental patterning of brain asymmetry. Several of the genes encode components of microtubules or other microtubule-associated proteins. Microtubules are key elements of the internal cellular skeleton (cytoskeleton). A major challenge remains to understand how these genes affect, or even induce, the brain's left-right axis. Several of the implicated genes have also been associated with psychiatric or neurologic disorders, and polygenic dispositions to autism and schizophrenia have been associated with structural brain asymmetry. Knowledge of developmental mechanisms that lead to hemispheric specialization may ultimately help to define etiologic subtypes of brain disorders.</p>","PeriodicalId":12907,"journal":{"name":"Handbook of clinical neurology","volume":"208 ","pages":"241-254"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143614615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Sex/gender differences in hemispheric asymmetries.","authors":"Sophie Hodgetts, Markus Hausmann","doi":"10.1016/B978-0-443-15646-5.00014-2","DOIUrl":"https://doi.org/10.1016/B978-0-443-15646-5.00014-2","url":null,"abstract":"<p><p>This chapter will critically review evidence across 40 years of research, covering both early and contemporary studies that have investigated sex/gender differences in hemispheric asymmetries, including both structural and functional asymmetries. We argue that small sex/gender differences in hemispheric asymmetry reliably exist, but there is significant overlap between the sexes and considerable within-sex variation. Furthermore, we argue that research to date is limited in its consideration of sex/gender-related factors, such as sex hormones and gender roles. Moreover, we highlight a critical limitation stemming from the lack of universal agreement on the definitions of \"sex\" and \"gender,\" resulting in the majority of studies interested in sex/gender differences in hemispheric asymmetry involving the separation of participants into dichotomous male/female groups based solely on self-identified sex. Future research involving sex/gender should adopt a biopsychosocial approach whenever possible, to ensure that nonbinary psychologic, biologic, and environmental/social factors related to sex/gender, and their interactions, are routinely accounted for. Finally, we argue that while the human brain is not sexually dimorphic, sex/gender differences in the brain are not trivial and likely have several clinically relevant implications, including for the development of stratified treatment approaches for both neurologic and psychiatric patient populations.</p>","PeriodicalId":12907,"journal":{"name":"Handbook of clinical neurology","volume":"208 ","pages":"255-265"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143614668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Chronobiologic treatments for mood disorders.","authors":"Sara Dallaspezia, Francesco Benedetti","doi":"10.1016/B978-0-323-90918-1.00011-3","DOIUrl":"https://doi.org/10.1016/B978-0-323-90918-1.00011-3","url":null,"abstract":"<p><p>Chronotherapeutics are nonpharmacologic interventions whose development stems from investigations into sleep and circadian rhythm abnormalities associated with mood disorder. These therapies utilize controlled exposure to environmental cues (light, darkness) to regulate biologic rhythms. They encompass sleep-wake manipulations (partial/total sleep deprivation, sleep phase adjustment) and light therapy approaches. Growing evidence supports the safety and efficacy of chronotherapeutics in clinical settings. Indeed, they target core depressive symptoms, including suicidality and may represent a novel therapeutic approach for treatment-resistant depression. This makes them a viable treatment option, both as a monotherapy and in combination with existing psychopharmacologic medications and paves the way for their potential inclusion as first-line treatments for mood disorders.</p>","PeriodicalId":12907,"journal":{"name":"Handbook of clinical neurology","volume":"206 ","pages":"181-192"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143045818","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Stefanie Blain-Moraes, Aarti Sarwal, J Claude Hemphill
{"title":"The Curing Coma Campaign: A platform for advancing science and clinical care worldwide.","authors":"Stefanie Blain-Moraes, Aarti Sarwal, J Claude Hemphill","doi":"10.1016/B978-0-443-13408-1.00005-1","DOIUrl":"10.1016/B978-0-443-13408-1.00005-1","url":null,"abstract":"<p><p>Recovery from coma or impaired consciousness is often the central issue in acute neurologic conditions such as traumatic brain injury, hypoxic-ischemic brain injury, stroke, and central nervous system infections. Recent advances in the science underpinning acute disorders of consciousness (DoC) have also served to highlight further scientific gaps and the lack of a coordinated approach to improving care for these patients. The Curing Coma Campaign (CCC) was initiated by the Neurocritical Care Society in 2019 as a platform to bring together the scientific, clinical, and public communities to cohesively address this issue. Comprised of various modules and working groups focused on aspects including fundamental science, prospective clinical studies, ethics, care of the coma patient, and engagement and community, initial efforts of the CCC have ranged from developing strategies for biomarker development to creating World Coma Day as an opportunity for widespread interaction. To achieve the goal of relevance across different geographic and resourced environments, the CCC implemented specific considerations to ensure equity and generalizability. These include international representation of patients in research studies, attention to assessments and interventions that can be implemented in resource-limited settings, and recognition of the impact of culture on the care of DoC patients.</p>","PeriodicalId":12907,"journal":{"name":"Handbook of clinical neurology","volume":"207 ","pages":"265-280"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143476475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Foreword.","authors":"Michael J Aminoff, François Boller, Dick F Swaab","doi":"10.1016/B978-0-443-15646-5.09997-8","DOIUrl":"https://doi.org/10.1016/B978-0-443-15646-5.09997-8","url":null,"abstract":"","PeriodicalId":12907,"journal":{"name":"Handbook of clinical neurology","volume":"208 ","pages":"xi"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143614371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Patrick C Trettenbrein, Emiliano Zaccarella, Angela D Friederici
{"title":"Functional and structural brain asymmetries in sign language processing.","authors":"Patrick C Trettenbrein, Emiliano Zaccarella, Angela D Friederici","doi":"10.1016/B978-0-443-15646-5.00021-X","DOIUrl":"https://doi.org/10.1016/B978-0-443-15646-5.00021-X","url":null,"abstract":"<p><p>The capacity for language constitutes a cornerstone of human cognition and distinguishes our species from other animals. Research in the cognitive sciences has demonstrated that this capacity is not bound to speech but can also be externalized in the form of sign language. Sign languages are the naturally occurring languages of the deaf and rely on movements and configurations of hands, arms, face, and torso in space. This chapter reviews the functional and structural organization of the neural substrates of sign language, as identified by neuroimaging research over the past decades. Most aspects of sign language processing in adult deaf signers markedly mirror the well-known, functional left-lateralization of spoken and written language. However, both hemispheres exhibit a certain equipotentiality for processing linguistic information and the right hemisphere seems to specifically support processing of some constructions unique to the signed modality. Crucially, the so-called \"core language network\" in the left hemisphere constitutes a functional and structural asymmetry in typically developed deaf and hearing populations alike: This network is (i) pivotal for processing complex syntax independent of the modality of language use, (ii) matures in accordance with a genetically determined biologic matrix, and (iii) may have constituted an evolutionary prerequisite for the emergence of the human capacity for language.</p>","PeriodicalId":12907,"journal":{"name":"Handbook of clinical neurology","volume":"208 ","pages":"327-350"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143614376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Handedness and brain asymmetries in nonhuman primates.","authors":"William D Hopkins, Adrien Meguerditchian","doi":"10.1016/B978-0-443-15646-5.00007-5","DOIUrl":"https://doi.org/10.1016/B978-0-443-15646-5.00007-5","url":null,"abstract":"<p><p>A majority of humans are right-handed and exhibit left hemisphere specialization for the comprehension and production of language. To what extent population-level behavioral and brain asymmetries are unique to humans remains a topic of interest across a wide range of scientific disciplines. In this chapter, we present current findings on the expression of population-level behavioral and brain asymmetries in nonhuman primates. We further present data on the association between communication functions, and especially gestures and individual variation in neuroanatomic asymmetries in nonhuman primates, with an emphasis on data from chimpanzees and baboons. The collective data are interpreted within the context of different theories on the evolution of language lateralization.</p>","PeriodicalId":12907,"journal":{"name":"Handbook of clinical neurology","volume":"208 ","pages":"197-210"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143614379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Handedness.","authors":"Sebastian Ocklenburg, Onur Güntürkün","doi":"10.1016/B978-0-443-15646-5.00016-6","DOIUrl":"https://doi.org/10.1016/B978-0-443-15646-5.00016-6","url":null,"abstract":"<p><p>This chapter offers an overview of the literature on human handedness and its assessment in clinical neurologic practice and research. There are two major forms of handedness: hand preference, which describes a subjective preference to use one hand over the other for skilled motor activities like writing, and hand skill, which describes objectively measured mother skill. This chapter gives an overview of widely used questionnaires and tests to assess hand preference and hand skill, as well as suggestions on how to determine handedness categories such as left-handed, right-handed, and mixed-handed based on the results of these questionnaires and tests. Handedness is just one form of hemispheric asymmetry in the human motor system, and the chapter also provides an overview of its association with other motor asymmetries such as footedness. Moreover, the associations of handedness with functional brain activation as well as with structural markers on the cortical, subcortical, cerebellar, and spinal levels are discussed. Furthermore, the potential relevance of handedness retraining for clinical neurologic research and the association of handedness and cognitive abilities are discussed. The chapter concludes with an outlook on the critical importance of including handedness in clinical neurologic research and practice.</p>","PeriodicalId":12907,"journal":{"name":"Handbook of clinical neurology","volume":"208 ","pages":"379-391"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143614382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Hemispheric asymmetries, paleoneurology, and the evolution of the human genus.","authors":"Emiliano Bruner","doi":"10.1016/B978-0-443-15646-5.00026-9","DOIUrl":"https://doi.org/10.1016/B978-0-443-15646-5.00026-9","url":null,"abstract":"<p><p>Brain asymmetries are a distinctive feature of Homo sapiens and are associated with key evolutionary functions including language and handedness. Nonetheless, differences between humans and apes could be just a matter of degree and size and not the expression of unique traits of our species. In this chapter, I introduce paleoneurology and the study of brain morphology in fossil hominids, reviewing the anatomic factors that can influence the main asymmetries of the endocranial cavity (cortical volumes, sulcal patterns, and craniovascular features). The paleoneurological evidence suggests that most extinct human species displayed a pattern of gross endocranial asymmetries similar to modern humans. In addition, the behavioral information on handedness also points to a similar degree of laterality in archaic species of the human genus and in Neandertals. At present, there is therefore no evidence suggesting that the brain asymmetries in H. sapiens are part of a derived set of features. Of course, even a simple proportional change due to brain size increase can anyway prompt crucial cognitive changes, mostly if threshold effects are considered. Nonetheless, we still lack much information in basic anatomy to support consistent hypotheses on the biologic factors involved in endocranial asymmetries in fossil hominids. This missing information concerns endocranial morphogenesis and topology, spatial conflicts and constraints, the biomechanical balance between cerebral tissues, and the actual histologic changes associated with encephalization.</p>","PeriodicalId":12907,"journal":{"name":"Handbook of clinical neurology","volume":"208 ","pages":"231-240"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143614434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
George F Michel, Iryna Babik, Eliza L Nelson, Claudio L Ferre, Julie M Campbell, Emily C Marcinowski
{"title":"Development of handedness and other lateralized functions during infancy and early childhood.","authors":"George F Michel, Iryna Babik, Eliza L Nelson, Claudio L Ferre, Julie M Campbell, Emily C Marcinowski","doi":"10.1016/B978-0-443-15646-5.00003-8","DOIUrl":"https://doi.org/10.1016/B978-0-443-15646-5.00003-8","url":null,"abstract":"<p><p>Using a historical or \"development from\" approach to study the development of hand-use preferences in infants and children, we show how various sensorimotor experiential events shape the cascade from initial to subsequent hand-use preferences. That cascade represents, creates, and shapes the lateralized asymmetry of neural circuits in the cerebral hemispheres. The control of the preferred hand requires neural circuits in the contralateral hemisphere that are capable of processing the organization of finely timed, sequentially organized movements and detecting haptic information derived from high-frequency transitions in the stimulus. We propose that the lateralized differences in these neural circuits underlie processes contributing to the development of other forms of hemispheric specialization of function. We show how the development of hand-use preferences contributes to the development of language skills, tool use, spatial skills, and other cognitive abilities during infancy and early childhood. Such evidence supports the proposal of Michael Corballis that the phylogeny of human language emerged during the evolution of hominins from the co-option of those neural circuits employed in the expression of manual skills involved in tool use, tool manufacture, and communication. Finally, we summarize evidence from children with cerebral palsy, which shows that their difficulties with sensorimotor processing, visuomotor coordination, anticipatory motor planning, and other cognitive abilities may stem from disturbances in the development of their hand-use preferences and hence the functional specialization of their hemispheres.</p>","PeriodicalId":12907,"journal":{"name":"Handbook of clinical neurology","volume":"208 ","pages":"181-194"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143614610","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}