Pain Research

Publication Analysis 2009-2015
by Kathleen Gransalke, Labtimes 05/2017

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Especially Northern Europe, with several specialised research centres, is strong in pain research. Neuropathic pain and migraines are the discipline’s hottest topics.


It’s not an exaggeration to claim that almost everyone has made their own experience with pain – the occasional headache or migraine, stomach ache or the stabbing pain after accidentally stepping onto tiny toys, scattered in a child’s room. Unless you are one of the very few people (there are about 20 cases in the literature), who suffer from congenital analgesia. These people are not able to perceive any form of physical pain.

At first thought, this insensitivity to pain may sound like something good but one should not forget that pain has an important function in our body: it tells us to stop doing the things that could potentially harm us. “Internal injuries are the ones I fear the most. Appendicitis is what really scares me. Usually, whenever I have any type of stomach issues or a fever, I go to the hospital just to get it checked out,” a congenital analgesia sufferer told the BBC in 2012.

Scientists studying the condition showed that a mutated SCN9A gene is responsible. This gene normally codes for the NaV1.7 sodium channel, expressed in nociceptive neurons at the dorsal root ganglion in the spine. The mutated gene, however, generates only non-functional alpha subunits, preventing the ion channel from forming properly. “The thing is, with our condition, a lot of people see us and they might assume that we’re healthy. But they have no idea that my body could give out at any time that I ache all over.”

For the majority of humankind, however, pain – in its different forms – is a more or less constant companion and thus, it’s no surprise that many scientists are devoted to this area of research. Before we reveal, who are the most-cited pain researchers in Europe, we first have a look at the nations’ performance. For this part of the analysis, we solely relied on ‘specialist’ journals as selected by the Web of Science database. The reason being that the database cannot reliably fish out pain-related research papers from multi-disciplinary journals, such as Nature or Science. This restriction to specialist journals did, however, not apply to the most-cited authors list.

As usual, the top spots of the nations’ performance ranking go to Germany and England. The two nations are very close, with regard to total number of citations – Germany has just 1,000-odd citations more than England. But there is a huge difference between the two nations, when focussing on the citation-per-article ratio (11.2 vs 19.3). England, thus, should be named the true top performer in pain research – also, because only Scotland (21.0) managed to obtain more citations per article on average. The top 5 is completed by Italy, The Netherlands and France. Portugal in 19th spot deserves a special mention. Six years ago, when we did the last ranking round in pain research (LT 4-2011), the South European country had only 45 papers and 222 citations to its name. Now, they have multiplied their total citation result tenfold.

Globally, it’s the same picture again and again. European researchers write more papers and gather more citations but, on average, publications by their US peers are cited more often.

Neuropathic pain in the research spotlight

This brings us straight to the discipline’s most-cited papers. This time, the hottest topic is pretty clear. Four of the five top papers are about neuropathic pain – pain caused by injured nerves. Interestingly, not just one but many conditions can lead to neuronal damage, such as diabetes, lupus, rheumatoid arthritis or alcoholism. The two papers in spots 1 and 2 explore pharmacological options for the treatment of neuropathic pain, in general. And the other two papers are about diagnosis, assessment and/or pathophysiological mechanisms. Only the fourth-most-cited paper does not revolve around neuropathic pain, in particular. Here, scientists compared different methods to assess pain intensity – from number to verbal and visual scales.

Who are these authors, writing highly-cited papers in pain research? Our top 30 most-cited pain researchers in Europe might give us a hint. In contrast to many other publication analyses, identifying pain researchers was not so hard. Wherever we read “pain”, “headache” or “migraine” in the title or abstract of an article, we considered the associated authors to be suitable for our ranking.

Our top 30 showed that one can approach pain from many different scientific angles: psychologically, physiologically, neurologically or pharmacologically. And also from many different geographical locations – although Northern Europe turned out to be a top destination for pain researchers. Three of our most-cited scientists have their home institution in Norway, six in Denmark and one in Finland. When it comes to female top researchers, we again have good news. Among our top 30 are not less than six women – a comparatively good quota.

The top two places are firmly in the hands of Norwegian pain researchers, Lars Stovner (1st) and Timothy Steiner (2nd), both from the Norwegian University of Science and Technology, NTNU, in Trondheim. The duo gathered many of their citations with large, population-based studies, such as the Global Burden of Disease studies, which found, amongst other things, that “migraine is the third cause of disability in under 50s”. Stovner has also established the Norwegian Advisory Unit on headaches in Trondheim, while Steiner is the founder and director of the Global Campaign Against Headache.

Stovner and Steiner are not the only scientists fighting headaches and migraines. Among our top 30 are quite a few more. For instance, Jes Olesen (4th) from the University of Copenhagen and the Danish Headache Center. In a 2010 article in The Lancet, Olesen complains about the undervaluing of migraine research. “There is a tendency to disregard it because people think, well my wife has migraines, too, but she takes care of everything and she does her job, so it’s not a bad disease. They don’t grasp that it’s an extremely common disorder and you have it in all kinds of severities. (…) We still haven’t got through to the general decision-makers that they could actually get a lot out of their money, if they invested in headache research.” Little funding didn’t deter Peter Goadsby (7th), Tobias Kurth (8th), Michel Ferrari (18th), Arn van den Maagdenberg (20th) and Arne May (27th) from pursuing research on migraine and headache, either.

Other pain researchers are dedicated to finding relief for sufferers of neuropathic pain. Ralf Baron (3rd) and Claudia Sommer (9th) are two of them. Troels Jensen (13th), who’s interested in the pathophysiology of diabetic neuropathy, founded the Danish Pain Research Center, located in the “beautiful surroundings at Aarhus University Hospital”, in 1994. Also interested in neuropathic pain are Rolf-Detlef Treede (14th), Maija Haanpää (26th), Andrew Rice (28th) and last but not least, Nanna Finnerup (30th), who’s also associated with the Danish Pain Research Center.

Cancer pain, back pain, gastrointestinal pain

There are also many other types of pain: surgery-associated pain, for instance. Henrik Kehlet (5th) is “the most well-known surgeon among anaesthesiologists”. Stein Kaasa (11th) studies cancer pain, while Asbjørn Drewes (23rd) focusses on gastrointestinal pain. A rather common type of pain, back pain, is addressed by Bart Koes (10th) and Maurits van Tulder (15th). In a Cochrane Review, van Tulder scanned published research for herbal remedies against low back pain. Harpagophytum procumbens (devil’s claw), Salix alba (white willow) and Capsicum frutescens (e.g. piri piri) seemed to have some effect but as van Tulder must attest, “the quality of reporting in these trials was generally poor”.

A fourth group of highly-cited pain researchers studies pain from a more pharmacological or neurological perspective. Pain medication is the topic of interest for Andrew Moore (12th), Gerd Geisslinger (21st) and Sheena Derry (24th). Pain perception, analysed by neuroimaging, is Herta Flor’s (17th) and Irene Tracey’s (19th) area of expertise.

Whether the decision makers will respond to the calls for a higher appreciation of pain research or not, one can be sure that our top 30 scientists and all the others, who didn’t make our ranking this time, will spare no pains to take ours away.

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Last Changed: 01.10.2017