Thank you for the information, Barrett!
Isaac
-----Opprinnelig melding-----
Fra: Barrett Dorko [mailto:[log in to unmask]]
Sendt: 3. juli 2002 13:14
Til: [log in to unmask]
Emne: Re: Adverse Neural Tension (ANT)
Isaac,
You ask "What is ANT?"
Although I like the term "adverse neural tension" for its simplicity and I
feel that it accurately describes a common situation where within the nerve
there is tautness where slackness would ordinarily occur, the more recent
term in neurobiology is "abnormal neurodynamics." This encompasses
additional chemical processes that would produce symptoms without this
specific mechanical problem. Still, excessive and prolonged elongation of
the nervous tissue remains a compelling idea by itself.
Consider this passage from page 125 of Moving In On Pain
(Butterworth-Heinemann Australia 1995) edited by Michael O. Shacklock:
When nerves are elongated within physiologic (normal) limits, adequate
neural blood flow is maintained, but only up to the point where the normal
vascular protective mechanisms are preserved. Maintenance of intraneural
blood flow during neural elongation is accomplished by the blood vessels in
nerves containing undulations and coils. When nerves are loose, these
vascular convolutions are accentuated. However, if the nerve is lengthened,
the vascular coils follow the nerve elongation and are pulled taut.
Furthermore, the lumen of the vessels is reduced and occlusion can occur,
particularly when the nerve is stretched beyond the limit of protection
(Lundborg & Rydevik 1973). The blood vessels are then strangled, intraneural
blood flow is compromised and nerve function deteriorates (Ogata & Ngaito
1986). If the stretch is taken only slightly beyond the protective limits,
and for a brief period, nerve function is likely to return rapidly to normal
(Lundborg et at 1982). However, if the strain in the nerve is particularly
severe or sustained, the alterations in nerve function will be permanent.
The relevance of intraneural blood flow is that excessive mechanical stress
may cause anoxia and nerve damage, leading to heightened mechanosensitivity
and pain. In these circumstances, movements that mechanically stress the
neural tissues may evoke symptoms.
REFERENCES
Lundborg G, Rydevik B 1973 Effects of stretching the tibial nerve of the
rabbit. Journal of Bone and Joint Surgery 55B: 390-401
Ogata K, Ngaito M 1986 Blood flow of peripheral nerve effects of dissection,
stretching and compression. Journal of Hand Surgery 11B: 10-14
Lundborg G, Gelbermann R, Minteer-Convery M et al 1982 Median nerve
compression in the carpal tunnel - functional response to experimentally
induced controlled pressure. Journal of Hand Surgery 7: 252-259
This was copied from "Neuropathic Pathogenesis: The Case for Neural Tension"
on my web site <http://barrettdorko.com/> http://barrettdorko.com
I think the majority of the people I see for painful problems have this sort
of mechanosensitivity secondary to tautness in the system and I work to
resolve it by amplifying the ideomotor activity designed to reduce that.
Barrett L. Dorko, P.T.
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