Re: Relationshipsrhinitis, fibromyalgia, and chronic fatigue
Posted by Deborah on 6/23/10
Okay, have to have my handy dandy medical and research science
terminology dictionary handy for this one "visceral nociception";
Visceral Nociception: Peripheral and Central Aspects of Visceral
Philosophical Transactions of the Royal Society of London.
Series B, Biological Sciences, Volume 308, Issue 1136, pp. 325-337
Discomfort and pain are the sensations most commonly evoked
from viscera. Most nociceptive signals that originate from
visceral organs reach the central nervous system (c.n.s.) via
afferent fibres in sympathetic nerves, whereas parasympathetic
nerves contain mainly those visceral afferent fibres concerned
with the non-sensory aspects of visceral afferent function.
Noxious stimulation of viscera activates a variety of specific
and non-specific receptors, the vast majority of which are
connected to unmyelinated afferent fibres. Studies on the
mechanisms of visceral sensation can thus provide information on
the more general functions of unmyelinated afferent fibres.
Specific visceral nociceptors have been found in the heart,
lungs, testes and biliary system, whereas noxious stimulation of
the gastro-intestinal tract appears to be detected mainly by
non-specific visceral receptors that use an intensity-encoding
mechanism. Visceral nociceptive messages are conveyed to the
spinal cord by relatively few visceral afferent fibres which
activate many central neurons by extensive functional divergence
through polysynaptic pathways. Impulses in visceral afferent
fibres excite spinal cord neurons also driven by somatic inputs
from the corresponding dermatome (viscero-somatic neurons).
Noxious intensities of visceral stimulation are needed to
activate viscero-somatic neurons, most of which can also be
excited by noxious stimulation of their somatic receptive
fields. The visceral input to some viscero-somatic neurons in
the spinal cord can be mediated via long supraspinal loops.
Pathways of projection of viscero-somatic neurons include the
spino-reticular and spino-thalamic tracts. All these findings
give experimental support to the `convergence-projection' theory
of referred visceral pain. Visceral pain is the consequence of
the diffuse activation of somato-sensory nociceptive systems in
a manner that prevents accurate spatial discrimination or
localization of the stimuli. Noxious stimulation of visceral
receptors triggers general reactions of alertness and arousal
and evokes unpleasant and poorly localized sensory experiences.
This type of response may be a feature of sensory systems
dominated by unmyelinated afferent inputs.
And, from what little I've read so far, there can be permanent
damage to these nociceptors from either chronic or acute
exposures to noxious stimulants.
On 6/23/10, Deborah wrote:
> Good one. Thanks, Sharon.
> On 6/21/10, Sharon wrote:
>> Relationships among rhinitis, fibromyalgia, and chronic
>> Authors: Baraniuk, James N.; Zheng, Yin
>> Source: Allergy and Asthma Proceedings, Volume 31, Number
>> 3, May/June 2010 , pp. 169-178(10)
>> Publisher: OceanSide Publications, Inc
>> Allergy and Asthma Proceedings is a peer reviewed
>> publication dedicated to distributing timely scientific
>> research regarding advancements in the knowledge and
>> practice of allergy, asthma and immunology. Its primary
>> readership consists of allergists and pulmonologists.
>> The goal of the Proceedings is to publish articles with a
>> predominantly clinical focus which directly impact quality
>> of care for patients with allergic disease and asthma.
>> Featured topics include asthma, rhinitis, sinusitis, food
>> allergies, allergic skin diseases, diagnostic techniques,
>> allergens, and treatment modalities. Published material
>> includes peer-reviewed original research, clinical trials
>> and review articles.
>> New information about the pathophysiology of idiopathic
>> nonallergic rhinopathy indicates a high prevalence in
>> chronic fatigue syndrome (CFS). This article shows the
>> relevance of CFS and allied disorders to allergy practice.
>> CFS has significant overlap with systemic hyperalgesia
>> (fibromyalgia), autonomic dysfunction (irritable bowel
>> syndrome and migraine headaches), sensory hypersensitivity
>> (dyspnea; congestion; rhinorrhea; and appreciation of
>> visceral nociception in the esophagus, gastrointestinal
>> tract, bladder, and other organs), and central nervous
>> system maladaptations (central sensitization) recorded by
>> functional magnetic resonance imaging (fMRI). Neurological
>> dysfunction may account for the overlap of CFS with
>> idiopathic nonallergic rhinopathy. Scientific advances are
>> in fMRI, nociceptive sensor expression, and, potentially,
>> infection with xenotropic murine leukemia-related virus
>> provide additional insights to novel pathophysiological
>> mechanisms of the “functional” complaints of these patients
>> that are mistakenly interpreted as allergic syndromes. As
>> allergists, we must accept the clinical challenges posed by
>> these complex patients and provide proper diagnoses,
>> assurance, and optimum care even though current treatment
>> algorithms are lacking.
>> Keywords: Central sensitization; CFS; chronic fatigue
>> syndrome; dysautonomia; fatigue; fibromyalgia; idiopathic
>> nonallergic rhinitis; pain; xenotropic murine leukemia-
>> related virus; XMRV
>> Document Type: Research article
>> DOI: 10.2500/aap.2010.31.3311
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