Autonomic Afferents and Ascending Central Pathways
An important aspect of the autonomicnervoussystem is its sensory function (Dworkin, 2000). In fact, over 75% of the fibers in the largest autonomic nerve, the vagus, are afferents. Visceral afferents carry a range of information concerning the in- ternal state of the body, from baroreceptors, chemo- receptors, and other interoceptors. Some visceral afferents enter the spinal cord via the dorsal root (along with somatic afferents) and terminate in the dorsal horn, where second-and higher- order neurons may participate in local autonomic re- flexes, or relay visceral information to higher cen- tral structures. One such structure is the nucleus of the tractus solitarius (NTS), a major visceral relay station in the brainstem (Figure 1). Additional vis- ceral afferents, such as those carried by the vagus and other cranial nerves, terminate directly in the NTS. The NTS is a key structure in brainstem auto- nomic reflexes and serves as an important relay in ascending pathways to higher levels of the neuraxis where they can modulate the processing of rostral neural systems. Although the functional contribu- tions of this ascending visceral information have not been fully elucidated, it has been shown, for example, that baroreceptor activation can reduce cortical arousal, suppress spinal reflexes, and at- tenuate pain transmission (Dworkin, 2000). The impact of this ascending information on rostral neurobehavioral mechanisms, and its role in cogni- tive and behavioral processes, has become an active area of research.
Keywords: resistant hypertension, renal sympathetic ablation, autonomicnervoussystem, ambulatory blood pressure monitoring, blood pressure control
In the Paton Lecture for 2010, Murray Esler 1 of the Baker IDI Heart and Diabetes Institute, Melbourne, Australia, reviewed work from the von Euler lab at the Karolinska Institute in Solna, Sweden, which identified norepinephrine as the neurotransmitter of sympathetic nerves, 2 whose total body activity could be estimated by an assay from a 24-hour urine collection. 3 Esler referred to anatomical studies of Thomas Willis, published in 1664, in which a detailed dissection of the sympathetic nervoussystem appeared. 4 Esler also referred to studies from the Cannon Lab 5 at Harvard Medical School that gave insight into control of blood pressure and blood glucose in cats, dogs, and other species by measurements before and after surgical resections of major sym- pathetic ganglia above and below the diaphragm (Table 1). These observations would eventually have a role in proposed treatments for resistant hypertension.
Bone Marrow production is impaired during stress (drops platelets and hemoglobin)
In my daughter’s case, her Autonomic Dysfunction, which is consider moderate in
nature, requires multiple daily interventions. These include catheterizing her bladder, use of parenteral (IV) nutrition, constant monitoring of vital signs, extensive pain medication regimen, and lifestyle modifications to address temperature regulation problems, eye dilation, and similar problems. While not all of her issues can be solely attributed to Autonomic Dysfunction, they tend to be exacerbated by her AutonomicNervous System’s inability to work correctly.
Figure 3: Typical ECG recording revealing the waveform of one single heart beat marked with the different phases (P, Q, R, S and T). R-R interval is the time difference between two consecutive heartbeats.
The rhythm of the heart is controlled by the cardiac sinoatrial node located in the heart. The sinoatrial node receives nerve impulses from the autonomicnervoussystem, including both sympathetic and parasympathetic branches. This is why the outcome of the interrelationship between the sympathetic and parasympathetic nervoussystem can be “read” from HRV. Generally, increased HRV is linked to good health and decreased stress. By measuring HRV, the human body can be monitored much more efficiently and accurately than by just measuring traditional heart rate.
This is to certify that this Dissertation entitled,
“STUDY OF AUTONOMICNERVOUSSYSTEM DYSFUNCTION IN PARKINSON’S PATIENTS” is a bonafide record of work done by Dr.E.ARUN RAJ under our guidance and supervision in the Institute of Neurology, Rajiv Gandhi Government General Hospital, Madras Medical College, Chennai, submitted as partial fulfillment for the requirements of D.M. Degree examination Branch I NEUROLOGY, AUGUST 2013, under the Tamil Nadu Dr. M.G.R. Medical University, Chennai.
HRV analysis is a significant tool for assessing the functions of AutonomicNervousSystem(ANS). The cardiac and ANS activities significantly changes in diseased conditions. These changes can be easily assessed using HRV analysis. HRV analysis gives the linear and nonlinear parameters of the HRV. Linear parameters are broadly divided in to time-domain and frequency domain parameters. Nonlinear parameters includes correlation coefficient, detrended fluctuation analysis and poinecare plot. These are various softwares available for extracting HRV parameters like KARDIA, RHRV,aHRV,gHRV, kubios software etc, making HRV analysis to be simpler. This work reviews HRV analysis in different diseased conditions, like myocardial infarction, blood pressure, neurological ailments, renal failure, effects of drugs, in addictions like alcohol and smoking, sleeping stages, influence of age and gender on HR. The vital physiological signals required to obtain HRV are ECG and PPG. Both of these are contact methods and the challenges of obtaining these signals are discussed. The noncontact methods of measuring cardiac activity have wide applications in both clinical and commercial applications. The home-health care is emphasizing on measuring the physiological signals at home itself. Hence there is a growing interest in the field of easy and noncontact measuring of cardiac activities. Because of the potential benefits in various fields, many works is going on worldwide, in search for new sensors, novel methods of analysis and improving the already existed ones.
taining homeostasis against external conditions by control- ling the activities of the viscera, blood vessels, and secretory glands. 6 As the incidences of certain diseases such as diabe- tes, affecting the vascular system, are increasing, the aware- ness of their effects on the autonomicnervoussystem has been heightened. Various evaluation methods have been de- veloped to examine the function of the autonomicnervoussystem, including measuring cardiovascular parameters re- lated to posture and isometric exercises, measuring body sur- face temperature with infrared ray photography, evaluating the mobility of the gastrointestinal tract using certain iso- topes, analyzing blood levels of autonomic neurotransmit- ters, testing electrophysiological parameters, examining the autonomicnervoussystem response to medication, quantita- tively measuring sweating, and evaluating pupils and puden- dal nerve responses. 7-9 However, most of these evaluation methods have limited clinical applications because of diffi- culty in quantifying the results, lack of ability to reproduce the results, or they are very invasive. 10 Heart rate is constant- ly changing to maintain homeostasis, and is determined by autonomicnervoussystem stimulation of the S-A node and spontaneous excitation of the S-A node. 11,12 Since heart rate is controlled by the antagonistic work of sympathetic and parasympathetic nervous systems, the analysis of heart rate change can reflect the balance of each component of the au- tonomic nervoussystem. 6,13-18 This analysis yields three points on the power spectrum: an ultra low frequency com- ponent of less than 0.05 Hz related to thermoregulation and the renin-angiotensin system, a low frequency component at around 0.1 Hz, and a high frequency component at around 0.25 Hz. 10,12,17,19-24
Background: Fabry disease is an inherited, multisys- temic and progressive lysosomal storage disorder.
The first symptoms of Fabry neuropathy reflect pro- gressive loss of function of both peripheral somatic and autonomic nerve cells. We aimed to evaluate autonomicnervoussystem (ANS) activity in a cohort of patients with Fabry disease. Methods: ANS activity was evaluated by determining heart rate variability, spontaneous baroreflex sensitivity and ambulatory blood pressure in 9 patients with Fabry disease. Pos- sible correlations between ANS activity and clinical phenotype were investigated. Results: Indices of global activity were frequently high, while ANS bal- ance was disturbed only in a few patients. Sympa- thetic nervoussystem parameters were within normal ranges, but indices of parasympathetic parameters were highly variable. Baroreflex sensitivity was sig- nificantly correlated with glomerular filtration rate.
The autonomicnervoussystem is composed of sympa- thetic and parasympathetic divisions and is often divided by neural and endocrine regulatory components. The sympathetic nervoussystem (SNS) originates from the thoracolumbar region of the spinal cord (Fig. 1). Short preganglionic fibers from the T1-L2 segments synapse on paravertebral or prevertebral ganglia, enabling long post- ganglionic fibers to innervate target organs such as the heart and lungs. On the other hand, the parasympathetic nervoussystem originates from cranial nerves III, VII, IX, and X and the sacral nerves S2-S4. In general, parasympa- thetics cause vasodilation of blood vessels including the
throughout the body. Thus it could be speculated that cold exposure triggers a localized autonomicnervoussystem response that is quite different from other locales.
There were other limitations that may have potentially influenced the
experimental execution of this trial. These limitations have to do with positional shifts during moderate cold (4° C) exposure testing and from measuring RMR in two separate rooms. While the pre and post mild cold HRV measurement procedures were sound, the moderate cold exposure measurement could have been improved by decreasing participant movement when going from warm to cold environments and having
C onsider the following situations: You wake up at night after having eaten at a restaurant where the food did not taste quite right, and you find yourself waiting helplessly for your stomach to “decide” whether it can hold the food down. A few days later, you are driving to school after drinking too much coffee and wish in vain that your full bladder would stop its uncomfortable contractions. Later that day, your professor asks you a hard question in front of the class, and you try not to let them see you sweat—but the sweat runs down your face anyway. All of these are exam- ples of visceral motor functions that are not easily controlled by the conscious will and that sometimes seem to “have a mind of their own.” These functions are performed by the autonomicnervoussystem (ANS), a motor system that does indeed operate with a certain amount of independence ( autonomic = self-governing).
This study examined the stress-reducing effect on the endocrine system and the autonomicnervoussystem of music with a frequency of 528 Hz, which has recently attracted attention as a “healing” type of music. Nine healthy participants (one man and eight women, aged 26 - 37 years) listened to 528 Hz and standard 440 Hz music on separate days. We measured salivary bio- markers of stress (cortisol, chromogranin A, and oxytocin) before and after exposure to music, and continuously recorded the activity of the autonomicnervoussystem. The Profile of Mood State, 2 nd edition, was also administered as a subjective indicator of stress. In the 528 Hz condition, mean levels of cor- tisol significantly decreased, chromogranin A tended to decrease, and oxyto- cin significantly increased after music exposure. However, no significant change was observed in any salivary biomarkers in the 440 Hz condition. The ratio of low frequency to high frequency autonomicnervoussystem activity significantly decreased after exposure to both types of music, and the coeffi- cient of variation of R-R intervals also significantly decreased, but only after exposure to 528 Hz music. Tension-anxiety and Total Mood Disturbance scores were significantly reduced after exposure to 528 Hz music, while there was no significant difference following 440 Hz music. These results suggest that the influence of music on the autonomicnervoussystem and endocrine system varies depending on the frequency of the music, and furthermore, that 528 Hz music has an especially strong stress-reducing effect, even following only five minutes of exposure.
The autonomicnervoussystem is the normally involuntary or uncon scious division of the peripheral nervoussystem. Irs efferent stimulation of all smooth muscles from blood vessels, lymphatic vessels, organs and glands as well as the resting muscle tone that allows us to sit up is a func tion of this autonomicnervoussystem. The autonomicnervoussystem has two divisions, the sympathetic and the parasympathetic. The parasympa thetic system regulates the funcrions necessary for long term survival. Everything from salivation and digestion to heart rate, respiratory rate, pancreatic function, liver and gallbladder function, and urine excretion through the kidneys, ureters and bladder, are only a few of the things that fall under autonomic control. The sympathetic system meets all crises; it spares no expense. The parasympathetics pick up after the sympathetics, replenishing, restoring and replacing, preparing for a rainy day. And when the parasympathetics can no longer "keep up" all life becomes a crisis and the overload escalates more and more with less and less provocation.
The response by anti-stress hormones is intended to protect the living body, but canal so have a neurotoxic effect; data indicate it can promote neuronal death in the hippocampus . Therefore, excessive secretion of anti-stress hormone due to chronic stress may not only cause BPSD but also exacerbate cognitive dysfunc- tion in dementia. Accordingly, it is necessary to monitor stress levels and treat po- tential chronic stress conditions as soon as possible. Autonomicnervoussystem measurement by heart rate variability analysis, which has a low level of invasive- ness and is convenient, may be a useful method. In addition, this study shows that it is necessary to pay attention to not only sympathetic nervoussystem activity, but also parasympathetic nervous activity when measuring autonomicnervoussystem activity for stress in dementia. However, such a strategy is viable when brain function is in the normal or near-normal range; if brain function has declined sig- nificantly, such a strategy may not be effective.
Bioelectronic medicine (BM) is an emerging new approach for developing novel neuromodulation therapies for pathologies that have been previously treated with pharmacological approaches. In this review, we will focus on the neuromodulation of autonomicnervoussystem (ANS) activity with implantable devices, a field of BM that has already demonstrated the ability to treat a variety of conditions, from inflammation to metabolic and cognitive disorders. Recent discoveries about immune responses to ANS stimulation are the laying foundation for a new field holding great potential for medical advancement and therapies and involving an increasing number of research groups around the world, with funding from international public agencies and private investors. Here, we summarize the current achievements and future perspectives for clinical applications of neural decoding and stimulation of the ANS. First, we present the main clinical results achieved so far by different BM approaches and discuss the challenges encountered in fully exploiting the potential of neuromodulatory strategies. Then, we present current preclinical studies aimed at overcoming the present limitations by looking for optimal anatomical targets, developing novel neural interface technology, and conceiving more efficient signal processing strategies. Finally, we explore the prospects for translating these advancements into clinical practice.
There will usually be an immediate lowering of the BP. However, if it was very high, it may take an hour or more to return completely to the usual resting BP.
Caution: Autonomic dysreflexia is a potentially fatal condition when it is not correctly diagnosed and treated. Most General Practitioners
4- Map out the various plexuses in head and neck, thorax, abdomen and pelvis.
5- Make a list of the components of the system.
6- Review the basic structure of sympathetic trunk.
7- Describe the source of sympathetic system in the neck and make a list of target organs.
MOST FREQUENTLY USED DRUG CATEGORIES FOR AUTONOMICSYSTEM THERAPY
Beta 1 Adrenergic Blockers (Anatgonists) - Work on the Heart
Beta 1 Adrenergic receptors are typically found on the heart and is a means for the sympathetic (adrenergic) nervoussystem to control heart rate. Therefore, Beta 1 Adrenergic Blockers block these receptors and limit heart rate. From an autonomic perspective, there are two classes of these drugs: peripherally acting (e.g., Metaprolol, Toprol, Atenolol, and Propanolol), and centrally acting (e.g., Acebutolol and Coreg). (Actually, Acebutolol and Coreg are known as cocktails, they contain more than one agent, and only one of their agents actually crosses into the brain.) The centrally acting Beta-Blockers, have a component that works in the brain stem and one or more components that work on the connection between the sympathetic nerves and the heart.