> Todd, > > Infants do not have a fully developed nervous system. For instance, > mylinization, how the major nerves and nerve pathways become electrically > insulated, isn't complete until after 18 on the average.
"Lack of myelination has been proposed as an index of the lack of maturity in the neonatal nervous system30 and is used frequently to support the argument that premature or full-term neonates are not capable of pain perception.9-19 However, even in the peripheral nerves of adults, nociceptive impulses are carried through unmyelinate (C-polymodal) and thinly myelinated (A-delta) fibers.31 Incomplete myelination merely implies a slower conduction velocity in the nerves or central nerve tracts of neonates, which is offset completely by the shorter interneuron and neuromuscular distances traveled by the impulse.32 Moreover, quantitative neuroanatomical data have shown that nociceptive nerve tracts in the spinal cord and central nervous system undergo complete myelination during the second and third trimesters of gestation. Pain pathways to the brain stem and thalamus are completely myelinated by 30 weeks; whereas the thalamocortical pain fibers in the posterior limb of the internal capsule and corona radiata are myelinated by 37 weeks.33" > Moreover pain > perception is also a matter of experience and interpretation. so if you > don't have the mechanism for the pain, its very difficult to define it as > such. The persistence of specific behavioral changes after circumcision in neonates implies the presence of memory. In the short term, these behavioral changes may disrupt the adaptation of newborn infants to their postnatal environment,174-176 the development of parent-infant bonding, and feeding schedules.182,182 In the long term, painful experiences in neonates could possibly lead to psychological sequelae,22 since several workers have shown that newborns may have a much greater capacity for memory than was previously thought.183-186 "Other responses in newborn infants are suggestive of integrated emotional and behavioral responses to pain and are retained in memory long enough to modify subsequent behavior patterns." These are from: PAIN AND ITS EFFECTS IN THE HUMAN NEONATE AND FETUS K.J.S. ANAND, M.B.B.S., D.PHIL., AND P.R. HICKEY, M.D >From the Department of Anesthesia, Harvard Medical School, and Children's Hospital, Boston. As printed in: NEW ENGLAND JOURNAL OF MEDICINE. Vol. 317 No 21: Pages 1321-1329, 19 November 1987. ______________________________________________________________________ Your ad could be here. Monies from ads go to support these lists and provide more resources for the community. http://www.fusionauthority.com/ads.cfm Archives: http://www.mail-archive.com/cf-community@houseoffusion.com/ Unsubscribe: http://www.houseoffusion.com/index.cfm?sidebar=lists
