Explore the vast range of titles available.

Autonomic medicine is a rapidly evolving field focused on understanding diseases and processes that affect the autonomic nervous system (ANS). The ANS regulates essential involuntary physiologic processes such as heart rate, blood pressure, and digestion. This review introduces the key anatomical structures, physiological mechanisms, and biochemical processes underlying autonomic function. The anatomy section focuses on the peripheral components of the ANS, including the sympathetic and parasympathetic divisions. The physiological section explores the process of homeostasis and the intricate feedback systems that maintain this balance within the body. Finally, the biochemistry of autonomic signaling, focusing on the neurotransmitters acetylcholine, norepinephrine, and epinephrine, and their receptors, is reviewed. Pertinent clinical points are highlighted throughout, emphasizing the importance of the basic science to the clinical world. This review aims to provide a comprehensive basic science foundation for clinicians and researchers exploring the field of autonomic medicine.

There is now a wealth of evidence that anterior insular and anterior cingulate cortices have a close functional relationship, such that they may be considered together as input and output regions of a functional system. This system is typically engaged across cognitive, affective, and behavioural contexts, suggesting that it is of fundamental importance for mental life. Here, we review the literature and reinforce the case that these brain regions are crucial, firstly, for the production of subjective feelings and, secondly, for co-ordinating appropriate responses to internal and external events. This model seeks to integrate higher-order cortical functions with sensory representation and autonomic control: it is argued that feeling states emerge from the raw data of sensory (including interoceptive) inputs and are integrated through representations in conscious awareness. Correspondingly, autonomic nervous system reactivity is particularly important amongst the responses that accompany conscious experiences. Potential clinical implications are also discussed.

Historically, the creation of the parasympathetic division of the autonomic nervous system of the vertebrates is inextricably linked to the unification of the cranial and sacral autonomic outflows. There is an intriguing disproportion between the entrenchment of the notion of a ‘cranio-sacral’ pathway, which informs every textbook schematic of the autonomic nervous system since the early XX th century, and the wobbliness of its two roots: an anatomical detail overinterpreted by Walter Holbrook Gaskell (the ‘gap’ between the lumbar and sacral outflows), on which John Newport Langley grafted a piece of physiology (a supposed antagonism of these two outflows on external genitals), repeatedly questioned since, to little avail. I retrace the birth of a flawed scientific concept (the cranio-sacral outflow) and the way in which it ossified instead of dissipated. Then, I suggest that the critique of the ‘cranio-sacral outflow’ invites, in turn, a radical deconstruction of the very notion of a ‘parasympathetic’ outflow, and a more realistic description of the autonomic nervous system.

Several concepts developed in the nineteenth century have formed the basis of much of our neuroanatomical teaching today. Not all of these were based on solid evidence nor have withstood the test of time. Recent evidence on the evolution and development of the autonomic nervous system, combined with molecular insights into the development and diversification of motor neurons, challenges some of the ideas held for over 100 years about the organization of autonomic motor outflow. This review provides an overview of the original ideas and quality of supporting data and contrasts this with a more accurate and in depth insight provided by studies using modern techniques. Several lines of data demonstrate that branchial motor neurons are a distinct motor neuron population within the vertebrate brainstem, from which parasympathetic visceral motor neurons of the brainstem evolved. The lack of an autonomic nervous system in jawless vertebrates implies that spinal visceral motor neurons evolved out of spinal somatic motor neurons. Consistent with the evolutionary origin of brainstem parasympathetic motor neurons out of branchial motor neurons and spinal sympathetic motor neurons out of spinal motor neurons is the recent revision of the organization of the autonomic nervous system into a cranial parasympathetic and a spinal sympathetic division (e.g., there is no sacral parasympathetic division). We propose a new nomenclature that takes all of these new insights into account and avoids the conceptual misunderstandings and incorrect interpretation of limited and technically inferior data inherent in the old nomenclature.

Brainstem nuclei (Bn) in humans play a crucial role in vital functions, such as arousal, autonomic homeostasis, sensory and motor relay, nociception, sleep, and cranial nerve function, and they have been implicated in a vast array of brain pathologies. However, an in vivo delineation of most human Bn has been elusive because of limited sensitivity and contrast for detecting these small regions using standard neuroimaging methods. To precisely identify several human Bn in vivo, we employed a 7 Tesla scanner equipped with multi-channel receive-coil array, which provided high magnetic resonance imaging sensitivity, and a multi-contrast (diffusion fractional anisotropy and T2-weighted) echo-planar-imaging approach, which provided complementary contrasts for Bn anatomy with matched geometric distortions and resolution. Through a combined examination of 1.3 mm3 multi-contrast anatomical images acquired in healthy human adults, we semi-automatically generated in vivo probabilistic Bn labels of the ascending arousal (median and dorsal raphe), autonomic (raphe magnus, periaqueductal gray), and motor (inferior olivary nuclei, two subregions of the substantia nigra compatible with pars compacta and pars reticulata, two subregions of the red nucleus, and, in the diencephalon, two subregions of the subthalamic nucleus) systems. These labels constitute a first step toward the development of an in vivo neuroimaging template of Bn in standard space to facilitate future clinical and research investigations of human brainstem function and pathology. Proof-of-concept clinical use of this template is demonstrated in a minimally conscious patient with traumatic brainstem hemorrhages precisely localized to the raphe Bn involved in arousal.

Skilled spoken language production requires fast and accurate coordination of up to 100 muscles. A long-standing concept—tracing ultimately back to Paul Broca—assumes posterior parts of the inferior frontal gyrus to support the orchestration of the respective movement sequences prior to innervation of the vocal tract. At variance with this tradition, the insula has more recently been declared the relevant “region for coordinating speech articulation”, based upon clinico-neuroradiological correlation studies. However, these findings have been criticized on methodological grounds. A survey of the clinical literature (cerebrovascular disorders, brain tumours, stimulation mapping) yields a still inconclusive picture. By contrast, functional imaging studies report more consistently hemodynamic insular responses in association with motor aspects of spoken language. Most noteworthy, a relatively small area at the junction of insular and opercular cortex was found sensitive to the phonetic-linguistic structure of verbal utterances, a strong argument for its engagement in articulatory control processes. Nevertheless, intrasylvian hemodynamic activation does not appear restricted to articulatory processes and might also be engaged in the adjustment of the autonomic system to ventilatory needs during speech production: Whereas the posterior insula could be involved in the cortical representation of respiration-related metabolic (interoceptive) states, the more rostral components, acting upon autonomic functions, might serve as a corollary pathway to “voluntary control of breathing” bound to corticospinal and -bulbar fiber tracts. For example, the insula could participate in the implementation of task-specific autonomic settings such as the maintenance of a state of relative hyperventilation during speech production.

Deep brain stimulation (DBS) is currently used as an effective treatment to reduce symptoms in chronic pain and movement disorders. An inadvertent and positive side effect of this therapy is the autonomic response to DBS in terms of changes to respiratory indices, lung function, and urinary and bladder function. This Review discusses the circuitry of the autonomic nervous system and its higher control centres, and the potential for DBS as a therapy for patients with dysautonomias. Deep brain stimulation (DBS) is an expanding field in neurosurgery and has already provided important insights into the fundamental mechanisms underlying brain function. One of the most exciting emerging applications of DBS is modulation of blood pressure, respiration and micturition through its effects on the autonomic nervous system. DBS stimulation at various sites in the central autonomic network produces rapid changes in the functioning of specific organs and physiological systems that are distinct from its therapeutic effects on central nervous motor and sensory systems. For example, DBS modulates several parameters of cardiovascular function, including heart rate, blood pressure, heart rate variability, baroreceptor sensitivity and blood pressure variability. The beneficial effects of DBS also extend to improvements in lung function. This article includes an overview of the anatomy of the central autonomic network, which consists of autonomic nervous system components in the cortex, diencephalon and brainstem that project to the spinal cord or cranial nerves. The effects of DBS on physiological functioning (particularly of the cardiovascular and respiratory systems) are discussed, and the potential for these findings to be translated into therapies for patients with autonomic diseases is examined. Key Points Discrete structures within all levels of the CNS, from the cortex to the medulla, comprise the central autonomic network The central autonomic network coordinates information from the CNS and PNS, which enables it to mediate autonomic responses rapidly Deep brain stimulation (DBS) produces autonomic sequelae in some patients during the electrode implantation procedure, and at subsequent testing DBS of the posterior hypothalamus, subthalamic nucleus (STN) and periaqueductal grey (PAG) can cause changes in cardiovascular indices at rest and during postural challenge In patients with chronic pain or movement disorders, lung function improvements seemingly unrelated to amelioration of the underlying syndrome can occur with DBS of the STN or PAG DBS could in the future provide a therapeutic option for patients with dysautonomias that affect a variety of body systems

A submacroscopic anatomical investigation of the entire autonomic cardiac nervous system, from origin to peripheral distribution, was performed by examining 36 sides of 18 adult human cadavers under a stereomicroscope. The following new results and points of discussion were obtained: (1) The superior cervical, the middle cervical, the vertebral, and the cervicothoracic (stellate) ganglia, composed of the inferior cervical and 1st thoracic ganglia, were mostly consistent among the specimens. (2) The superior, middle, and inferior cardiac nerves innervated the heart by simply following the descent of the great arteries. In contrast, the thoracic cardiac nerve in the posterior mediastinum followed a complex course because of the long distance to the middle mediastinum. (3) The actual course of the right thoracic cardiac nerve differed from that of the previous descriptions in that it ascended obliquely or ran transversely to the vertebrae, regardless of the intercostal vessels. Regarding the right thoracic cardiac nerve, two descending courses were observed: the descent of the right thoracic cardiac nerve via the azygos vein and right venous porta, and the descent of the recurrent right thoracic cardiac nerve via the aorta. (4) The cranial cardiac nerve and branch tended to distribute into the heart medially, and the caudal cardiac nerve and branch tended to distribute into the heart laterally. (5) The mixing positions (cardiac plexus) of the sympathetic cardiac nerve and the vagal cardiac branch, as well as the definitive morphology of brachial arteries with the recurrent laryngeal nerves, tended to differ on both sides. These new and detailed anatomical descriptions of the human autonomic cardiac nervous system may provide important clues regarding the morphogenesis of autonomic cardiac nerves in addition to contributing to the improvement of cardiac surgery.

Objective To analyse pelvic autonomous innervation with magnetic resonance imaging (MRI) in comparison with anatomical macroscopic dissection on cadavers. Material and methods Pelvic MRI was performed in eight adult human cadavers (five men and three women) using a total of four sequences each: T1, T1 fat saturation, T2, diffusion weighed. Images were analysed with segmentation software in order to extract nervous tissue. Key height points of the pelvis autonomous innervation were located in every specimen. Standardised pelvis dissections were then performed. Distances between the same key points and the three anatomical references forming a coordinate system were measured on MRIs and dissections. Concordance (Lin’s concordance correlation coefficient) between MRI and dissection was calculated. Results MRI acquisition allowed an adequate visualization of the autonomous innervation. Comparison between 3D MRI images and dissection showed concordant pictures. The statistical analysis showed a mean difference of less than 1 cm between MRI and dissection measures and a correct concordance correlation coefficient on at least two coordinates for each point. Conclusion Our acquisition and post-processing method demonstrated that MRI is suitable for detection of autonomous pelvic innervations and can offer a preoperative nerve cartography. Key Points • Nerve preservation is a hot topic in pelvic surgery • High resolution MRI can show distal peripheral nerves • Anatomo - radiological comparison shows good correlation between MRI and dissection • 3D reconstructions of pelvic innervation were obtained with an original method • This is a first step towards image - guided pelvic surgery

Objective To present the distribution of neurovascular and lymphatic vessels in uterine ligaments using 3D models based on the pathological staining of serial 2D sections of postoperative specimens. Methods Serial transverse sections of fresh uterine ligaments from a patient with stage IB1 cervical squamous cell carcinoma were studied using the computer-assisted anatomic dissection (CAAD) technique. The sections were stained with hematoxylin and eosin, Weigert elastic fibers, D2-40 and immunostainings (sheep anti-tyrosine hydroxylase and rabbit anti-vasoactive intestinal peptide). The sections were then digitalized, registered and reconstructed three-dimensionally. Then, the 3D models were analyzed and measured. Results The 3D models of the neurovascular and lymphatic vessels in uterine ligaments were created, depicting their precise location and distribution. The vessels were primarily located in the upper part of the ligaments model, while the pelvic autonomic nerves were primarily in the lower part; the lymphatic vessels were scattered in the uterine ligaments, without obvious regularity. Conclusion CAAD is an effective anatomical method to study the precise distribution of neurovascular and lymphatic vessels in uterine ligaments. It can present detailed anatomical information about female pelvic autonomic innervation and the spatial relationship between nerves and vessels and may provide a better understanding of nerve-sparing radical hysterectomy.