Hi there. Readers with a moderate amount of grey hair will recall the enthusiasm one "Frans from Holland" had for the overlap between the work of a young graduate student, Frank Huygen and the so called "Marshall Protocol." We haven't heard much about the Marshall Protocal in a longtime, but Professor Frank JPM Huygen of the Erasmus Medical College in Rotterdam has gone on to be one of the leading RSD/CRPS specialist in the world.

And remember all that research that's been done on the microvascular aspects of CRPS? (And our old friend how liked to talk about ischemic reperfusion injuries?) Well, Prof. Huygen et al just tested the obvious: using Cialis to dialate blood vessels to see if it offers any relief to "cold CRPS" patients. And it just may work.

Here is the "Results" paragraph from their abstract:

At the end of the study period, the temperature asymmetry was not significantly reduced in the tadalafil group compared with the placebo group, but there was a significant and clinically relevant reduction of pain [15%] in the tadalafil group. Muscle force improved in both treatment groups and the AM [activity monitor] revealed small, non-significant improvements in time spent standing, walking, and the number of short walking periods.

The last two paragraph of the discussion part of the article are perhaps the most interesting, and I violate the "quote one paragraph" maxim of NT only because it is an explicitly "Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited":

This trial was limited to a period of 12 weeks. Little is known about the effects of using PDE-5 inhibitors over a longer period. In patients who experienced reduced pain as a result of tadalafil, a remarkable improvement in function was observed. The use of crutches was reduced and the number of short walking periods increased. However, the perceived improvements were small, as reported in the walking ability questionnaire. Thus, it may take a longer period of time for patients to acknowledge the extent of improvements. We speculate that over time, with tadalafil patients may acquire an activity pattern closer to normal and improvements in function due to the reduction of pain and the subsequent reduction in fear-avoidance, which has been described as one of the limiting factors in CRPS.

It has been suggested that CRPS is primarily a disease of the central nervous system. In any case it is a multifaceted disorder, and any effort to treat only one facet is bound to result in failure. However, in this trial we have solely concentrated on the question, whether the inhibition of PDE-5 could improve the blood flow in CRPS. Future investigations should include a larger study group of patients with chronic cold CRPS and an effort should be made to select only patients with endothelial dysfunction. A longer trial period would be required to investigate whether the improvements last. It would also be interesting to investigate whether this newly gained improvement in function, supported by an activity program if necessary, would be sufficient to sustain further progression in activity. [Citations omitted.]

The full version of "Effect of tadalafil on blood flow, pain, and function in chronic cold Complex Regional Pain Syndrome: a randomized controlled trial," George Groeneweg, Frank JPM Huygen, Sjoerd P Niehof, Feikje Wesseldijk, Johannes BJ Bussmann, Fabienne C Schasfoort, Dirk L Stronks, and Freek J Zijlstra, BMC Musculoskelet Disord. 2008; 9: 143, published online 2008 October 20, doi: 10.1186/1471-2474-9-143, can be accessed free of charge here: http://www.pubmedcentral.nih.gov/art...?artid=2575214

See, something to look forward to.

Mike

In the "Effect of tadalafil on blood flow, pain, and function in chronic cold Complex Regional Pain Syndrome: a randomized controlled trial," George Groeneweg, Frank JPM Huygen, Sjoerd P Niehof, Feikje Wesseldijk, Johannes BJ Bussmann, Fabienne C Schasfoort, Dirk L Stronks, and Freek J Zijlstra, BMC Musculoskelet Disord. 2008; 9: 143, published online 2008 October 20, doi: 10.1186/1471-2474-9-14

The Conclusion states that "Tadalafil may be a promising new treatment for patients that have chronic cold CRPS due to endothelial dysfunction."

How does one know if one has CRPS due to endothelial dysfunction? I've had CRPS for 11 years and I've never heard a doctor even mention that before. Is there an easy test for this?

If one doesn't have CRPS due to endothelial dysfunction, then does that mean it's not worth trying Tadalafil?