Featured Research

from universities, journals, and other organizations

Congenital blindness results in lower thermal pain thresholds

Date:
November 1, 2013
Source:
Elsevier
Summary:
Absence of vision from birth leads to a permanent state of pain hypersensitivity, reports a new study.

Compared with sighted subjects, congenitally blind subjects appear to have lower heat pain thresholds, rate heat pain stimuli as more painful than the normal-sighted reported, and have increased sensitivity to cold pain stimuli.
Credit: Superingo / Fotolia

Absence of vision from birth leads to a permanent state of pain hypersensitivity, reports an article in the jounral PAIN.

An international team of scientists investigated whether congenitally blind subjects experience pain differently than sighted individuals. Their results, published in the current issue of PAIN, reveal compelling evidence that congenitally blind individuals are hypersensitive to pain caused by thermal stimuli.

The findings are important because a key biological function of acute pain is to prevent bodily injury. Vision plays a critical role, as it allows a person to immediately detect and avoid potentially hazardous situations. Previous studies conducted in normal-sighted individuals had already demonstrated the link between vision and pain perception. The research team hypothesized that the absence of visual cues may therefore lead to heightened vigilance for painful stimuli.

Investigators recruited one group of 11 congenitally blind and 15 normal-sighted participants from Italy and a second group of 18 congenitally blind and 18 normal-sighted participants from Denmark. They conducted three experiments. The first compared pain thresholds and responses to suprathreshold pain (pain of sufficient intensity to produce a physiologic effect) stimuli among members of both groups. The second measured detection thresholds for warmth and cold perceptions. The third tested whether study results could be reproduced in an independent study population with culturally distinct ways of responding to pain.

Researchers used thermal probes on the medial forearm to measure thresholds of pain. The congenitally blind participants were allowed to touch the equipment beforehand and received verbal descriptions to reduce any anxiety. Sighted subjects were blindfolded during the actual testing. All subjects reported feelings of heat or cold pain through use of a response button. To assess suprathreshold pain, the researchers used a laser stimulation device. All participants completed a pain vigilance and awareness questionnaire, which allowed researchers to gather information on attitudes toward pain in daily life.

The study team found that compared with sighted subjects, congenitally blind subjects have lower heat pain thresholds, rate suprathreshold heat pain stimuli as more painful than the normal-sighted reported, and have increased sensitivity to cold pain stimuli.

In addition, interesting cultural differences emerged. "There is evidence that, compared to people from northern countries (e.g., Denmark), people in southern countries (e.g., Italy) are more emotionally expressive and responsive to pain," says lead investigator Ron Kupers, PhD, Director of the BRAINlab, Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences -- Panum Institute, University of Copenhagen, Denmark.

The results of the pain questionnaires further demonstrated that blind subjects are more attentive to external threat signals. Dr. Kupers concludes, "We have shown that the absence of vision from birth induces a hypersensitivity to painful stimuli, lending new support to a model of sensory integration of vision and pain processing."

In a commentary accompanying the article, Flavia Mancini, PhD, Institute of Cognitive Neuroscience, University College London, United Kingdom, says, "The novel finding of pain hypersensitivity in blindness has several important implications for both basic and clinical science. This study is noteworthy for research on multisensory interactions and plasticity, because it shows a strong link between vision and pain. The next step is to understand the nature of the interaction between visual loss and pain sensitivity. Which aspect of pain processing is involved in the interplay with vision, and what is its neural basis? The hope is that this work will open the door to pain investigations into the world of sensory loss, left unexplained for too long."


Story Source:

The above story is based on materials provided by Elsevier. Note: Materials may be edited for content and length.


Journal Reference:

  1. Hocine Slimani, Sabrina Danti, Emiliano Ricciardi, Pietro Pietrini, Maurice Ptito, Ron Kupers. Hypersensitivity to pain in congenital blindness. PAIN, 2013; 154 (10): 1973 DOI: 10.1016/j.pain.2013.05.036

Cite This Page:

Elsevier. "Congenital blindness results in lower thermal pain thresholds." ScienceDaily. ScienceDaily, 1 November 2013. <www.sciencedaily.com/releases/2013/11/131101125413.htm>.
Elsevier. (2013, November 1). Congenital blindness results in lower thermal pain thresholds. ScienceDaily. Retrieved August 21, 2014 from www.sciencedaily.com/releases/2013/11/131101125413.htm
Elsevier. "Congenital blindness results in lower thermal pain thresholds." ScienceDaily. www.sciencedaily.com/releases/2013/11/131101125413.htm (accessed August 21, 2014).

Share This




More Health & Medicine News

Thursday, August 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Drug Used To Treat 'Ebola's Cousin' Shows Promise

Drug Used To Treat 'Ebola's Cousin' Shows Promise

Newsy (Aug. 21, 2014) An experimental drug used to treat Marburg virus in rhesus monkeys could give new insight into a similar treatment for Ebola. Video provided by Newsy
Powered by NewsLook.com
Cadavers, a Teen, and a Medical School Dream

Cadavers, a Teen, and a Medical School Dream

AP (Aug. 21, 2014) Contains graphic content. He's only 17. But Johntrell Bowles has wanted to be a doctor from a young age, despite the odds against him. He was recently the youngest participant in a cadaver program at the Indiana University NW medical school. (Aug. 21) Video provided by AP
Powered by NewsLook.com
Possible Ebola Patient in Isolation at California Hospital

Possible Ebola Patient in Isolation at California Hospital

Reuters - US Online Video (Aug. 20, 2014) A patient who may have been exposed to the Ebola virus is in isolation at the Kaiser Permanente South Sacramento Medical Center. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Reasons Why Teen Birth Rates Are At An All-Time Low

Reasons Why Teen Birth Rates Are At An All-Time Low

Newsy (Aug. 20, 2014) A CDC report says birth rates among teenagers have been declining for decades, reaching a new low in 2013. We look at several popular explanations. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins