Recent Japanese article hilights spinal sensitization in neuropathic pain suggesting lidocaine and ketamine maybe should play bigger role
Nihon Hansenbyo Gakkai Zasshi. 2008 Sep;77(3):215-8.
[Mechanisms of the development of neuropathic pain and its treatment] Yamamoto T. abstract
Author discusses spinal mechanisms under following:
1) sprouting of A beta fibers to the superficial layer of the dorsal horn,
2) ectopic discharge in the dorsal root ganglion and/or in neuroma at the nerve stump,
3) spinal sensitization.
Under treatment he discusses differing chemical pathways:
1) Na+channels – blocked by lidocaine and anti-convulsants
as far as I can tell Na+ channel anticonvulsant blockers are Dilantin, carbamazepine, and perhaps valproic acid which are not major pain helps except in tics or headaches.
2) NMDA circuits blocked by Ketamine
3) Alpha2delta subunit Ca2+ channels – blocked by gabapentin and pregabalin (lyrica).
A protocol which causes significant relief of pain for up to one month was devised by Dr.Ellen Thompson (Pain Research and Management 2005 abstracts Nova Scotia)
This can give unprecedented help but results in almost a general anesthetic effect while in progress. It would require in hospital administration which is just not going to happen with our present healthcare setting. Dr. Thompson’s outlook however, is Shame on you for pushing toxic NSAID’s when this should be readily available and as or more effective. I have not been able to work around that allegation except to say my enquiries on doing it here were negative.
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