Post-sympathectomy pain and changes in sensory neuropeptides

Postsympathectomy limb pain, postsympathectomy parotid pain, and Raeder's paratrigeminal syndrome are pain states associated with the loss of sympathetic fibres and in particular with postganglionic sympathetic lesions. There is a characteristic interval of about 10 days between surgical sympathectomy and onset of pain. It is proposed that this pain in man is correlated with the delayed rise in sensory neuropeptides seen in rodents after sympathectomy. These chemical changes probably reflect the sprouting of sensory fibres and may result from the greater availability of nerve growth factor after sympathectomy. The balance between the sensory and sympathetic innervations of a peripheral organ may be determined by competition for a limited supply of nerve growth factor.
Lancet. 1985 Nov 23;2(8465):1158-60http://www.ncbi.nlm.nih.gov/pubmed/2414615?dopt=Abstract

sensory abnormalities, abnormal body sweating, and pathologic gustatory sweating

The aim of this study is to describe the incidence and characteristics of pain, sensory abnormalities, abnormal body sweating, and pathologic gustatory sweating in pain patients with persistent post-sympathectomy pain.
Results: Seventeen adults (13 females and 4 males) with a mean age of 37 years (range 25-52) at the time of sympathectomy met the inclusion criteria. Five of the 17 patients experienced temporary pain relief for an average of 4 months (range 2-12 months), 3/17 retained the same pain as before the surgery, 1 patient was cured of her original pain but experienced a new debilitating pain, and 8/17 patients continued to have the same or worse pain in addition to a new or expanded pain. Pathologic gustatory sweating was present in 7/11 patients asked, and abnormal sweating (known as compensatory hyperhidrosis) in 11/13 patients asked. Discussion: The present study does not allow for conclusions about the effectiveness of surgical sympathectomy for neuropathic pain. However, our findings indicate that if the pain persists after the procedure, the complications may be quite serious and at times worse than the problem for which the surgery was originally performed.
The Clinical journal of pain
2003, vol. 19, n^o3, pp. 192-199
http://cat.inist.fr/?aModele=afficheN&cpsidt=14775091

Recurrent sweating occurred in 17.6% of patients

J Neurosurg Spine. 2005 Feb;2(2):151-4.http://www.ncbi.nlm.nih.gov/pubmed/15739526

Post-sympathectomy neuralgia

Post-sympathectomy neuralgia is proposed here to be a complex neuropathic and central deafferentation/reafferentation syndrome dependent on: (a) the transection, during sympathectomy, of paraspinal somatic and visceral afferent axons within the sympathetic trunk; (b) the subsequent cell death of many of the axotomized afferent neurons, resulting in central deafferentation; and (c) the persistent sensitization of spinal nociceptive neurons by painful conditions present prior to sympathectomy. Viscerosomatic convergence, collateral sprouting of afferents, and mechanisms associated with sympathetically maintained pain are all proposed to be important to the development of the syndrome.

Pain. 1996 Jan;64(1):1-9
http://www.ncbi.nlm.nih.gov/pubmed/8867242?ordinalpos=2&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum

Neuroma following Sympathectomy

The authors conclude recomemnding the application of clips and if the syndrome nevertheless appears novocaine infiltration of the upper end of the sympathetic chain. The authors are convinced that the theory of Hermann and Cooley about neuroma formation at the ends of the sympathetic chain after resection of a segment is true.
http://www.revangiol.com/sec/resumen.php?or=web&i=e&id=227082.
Traumatic neuroma follows different forms of nerve injury (often as a result of surgery). They occur at the end of injured nerve fibres as a form of ineffective, unregulated nerve regeneration; it occurs most commonly near a scar, either superficially (skin, subcutaneous fat) or deep (e.g., after acholecystectomy). They are often very painful. It is also known as "pseudoneuroma".