Extra Nerve Fibers May Heighten Female Pain Perception

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Extra Nerve Fibers May Heighten Female Pain Perception



By Jeff Minerd, MedPage Today Staff Writer

Reviewed by Zalman S. Agus, MD; Emeritus Professor at the University

of Pennsylvania School of Medicine.

October 27, 2005



MedPage Today Action Points

Explain to patients who ask that these preliminary results need to be

confirmed by larger and less limited studies before any changes in

pain management for women can be considered.

Review

SPRINGFIELD, Ill., Oct. 27 - Women appear to have a greater density

of nerve receptors than men, suggesting that they are

constitutionally more sensitive to pain, researches here reported.

Women averaged double the number of receptors compared with men in a

certain area of facial skin, according to a study conducted by Bradon

J. Wilhelmi, M.D., and colleagues at the Plastic Surgery Institute of

the Southern Illinois University School of Medicine.

If the results of this study are confirmed, it could represent a

physiological explanation for previous reports that women have higher

pain perception and lower pain tolerance compared with men, the

researchers reported in the October issue of Plastic and

Reconstructive Surgery.

The basis of this phenomenon has not been understood, said the

authors. Some have suggested the reason could be psychosocial, while

others have offered biological explanations including differences in

receptor action potentials, integration of central nervous system

signals, and biochemical signaling properties.

To investigate whether a difference in nerve receptor density might

account for the phenomenon, Dr. Wilhelmi and colleagues tested the

skin of 20 cadavers, half men and half women. One centimeter square

skin samples directly overlying the infraorbital nerve foramen were

harvested, prepared with immunohistochemistry, and examined under a

high-powered microscope.

The nerve fibers in each sample were counted by a researcher who was

blinded to the gender. The average fiber density in female samples

was 34 ± 19 fibers per square centimeter. The average density in male

samples was 17 ± 8 fibers per square centimeter. (P=0.038.)

" Although preliminary and limited in scope, these findings favor a

physical (organic) rather than a psychosocial explanation for more

pronounced pain perception in female patients, " the study authors

concluded.

However, they acknowledged that the area of skin they tested may not

be representative, and they cautioned that " a larger sample size

would be desirable before drawing any definitive conclusions. "

If the results are confirmed, " This study has serious implications

about how we treat women after surgery as well as women who

experience chronic pain, " said Dr. Wilhelmi. " Because women have more

nerve receptors, they may experience pain more powerfully than men,

requiring different surgical techniques, treatments, or medicine

dosages to help manage their pain and make them feel comfortable. "

Primary source: Plastic and Reconstructive Surgery

Source reference:

Mowlavi A et al. Increased cutaneous nerve fibers in female

specimens. Plastic and Reconstructive Surgery. 2005; 116:1407-1410.

Click here for the abstract.

http://www.medpagetoday.com/Neurology/GeneralNeurology/tb/2017