Journal of Nippon Medical School: Vol.69 No.1 page.019

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ArticleTitle Current Perception Threshold Increases During Pregnancy but does not Change Across Menstrual Cycle

AuthorList Masayuki Oshima¹, Ryo Ogawa² and Daniel Londyn Menkes³

Affiliation ¹Department of Anesthesiology, Second Hospital, Nippon Medical School, ²Department of Anesthesiology, Nippon Medical School, ³Department of Neurology, University of Tennessee, Memphis, USA

Language EN

Volume 69

Issue 1

Year 2002

Page 19-23

Received March 26, 2001

Accepted July 3, 2001

Keywords current perception threshold, pregnancy, progesterone, menstrual cycle

Abstract It is well known that pregnancy reduces anesthetic requirements in response to various noxious stimuli. However, there have been no detailed reports concerning functional changes in nerve fibers during pregnancy. Using a Neurometer^®, a recently available commercial quantitative sensory monitor, we measured current perception threshold (CPT) values for three frequencies corresponding to the stimulation of A-beta, A-delta and C fibers on the median nerve in women at several stages: late pregnancy, the follicular phase and the luteal phase. A significant difference in CPT values on A fibers was noted between the gravid and the nongravid women, but, no significant difference in CPT values was noted in any of the nongravid women in the follicular or luteal phases. Our results support the current theory that pregnancy changes nerve fiber conduction, as indicated by an increase in CPT values especially on myelinated fibers, but does not cause changes in CPT values across the menstrual cycle.

Correspondence to Masayuki Oshima, MD, Department of Anesthesiology, Second Hospital, Nippon Medical School, 1-396 Kosugi-cho, Nakahara-ku, Kawasaki-shi, Kanagawa 211-8533, Japan
oshimasayuki@hotmail.com

ArticleTitle	Current Perception Threshold Increases During Pregnancy but does not Change Across Menstrual Cycle
AuthorList	Masayuki Oshima¹, Ryo Ogawa² and Daniel Londyn Menkes³
Affiliation	¹Department of Anesthesiology, Second Hospital, Nippon Medical School, ²Department of Anesthesiology, Nippon Medical School, ³Department of Neurology, University of Tennessee, Memphis, USA
Language	EN
Volume	69
Issue	1
Year	2002
Page	19-23
Received	March 26, 2001
Accepted	July 3, 2001
Keywords	current perception threshold, pregnancy, progesterone, menstrual cycle
Abstract	It is well known that pregnancy reduces anesthetic requirements in response to various noxious stimuli. However, there have been no detailed reports concerning functional changes in nerve fibers during pregnancy. Using a Neurometer^®, a recently available commercial quantitative sensory monitor, we measured current perception threshold (CPT) values for three frequencies corresponding to the stimulation of A-beta, A-delta and C fibers on the median nerve in women at several stages: late pregnancy, the follicular phase and the luteal phase. A significant difference in CPT values on A fibers was noted between the gravid and the nongravid women, but, no significant difference in CPT values was noted in any of the nongravid women in the follicular or luteal phases. Our results support the current theory that pregnancy changes nerve fiber conduction, as indicated by an increase in CPT values especially on myelinated fibers, but does not cause changes in CPT values across the menstrual cycle.
Correspondence to	Masayuki Oshima, MD, Department of Anesthesiology, Second Hospital, Nippon Medical School, 1-396 Kosugi-cho, Nakahara-ku, Kawasaki-shi, Kanagawa 211-8533, Japan oshimasayuki@hotmail.com