Study Reveals IC Patients Are More Sensitive to Pain

Italian researchers have reported through a new study that they have “direct evidence” for central sensitization in Interstitial Cystitis patients.

Central sensitization—essentially amplification of pain signals in the central nervous system—is thought to contribute to perpetuation of pain—and possibly its initiation—in the condition.

This theory, if true, may help explain why IC Disease patients also suffer from other pain-related conditions such as Fibromyalgia and IBS.  There was also recently another study that found that Interstitial Cystitis patients are also more likely to suffer from Vulvodynia – another pain-related condtiion.

This news on IC was recently presented at the International Continence Society annual meeting by Dr. Silvia Malaguti & Dr. Mauro Cervigni, both from Rome.

According to the study, these doctors…

…investigated spinal transmission of pain signals and diffuse noxious inhibitory controls in 14 IC/PBS patients—12 women and two men—and in 10 age- and sex-matched healthy controls. Diffuse noxious inhibitory control is the phenomenon of inhibition of perception of a painful stimulus by a second painful stimulus administered distally. In subjects who do not have chronic pain disorders, pain from the test stimulus is decreased or inhibited when a conditioning stimulus is applied at a distal site.

The investigators did this using the nociceptive flexion reflex (NFR) RIII and the cold pressor test (CPT), both of which are standard tests in pain research.

The NFR is administered by electrically stimulating the sural nerve. The test’s RIII, or long-latency, component is evoked by stimulation intense enough to activate the A-delta and C fibers responsible for transmission of pain signals. Thresholds for the reflex correlate strongly with subjective pain thresholds, and increases in NFR amplitude correlate with increases in subjective pain intensity.

In the CPT, the patient places a hand in ice water. The patient lets the researcher know when he/she first feel pain and then withdraws the hand when the pain becomes unbearable. This measures a threshold for and tolerance of this type of pain. In this study, the CPT was used as the noxious conditioning stimulus. The investigators measured the NFR RIII at baseline and then during the CPT.

What the research showed was that Interstitial Cystitis patients had significantly lower pain thresholds than that of the non-IC subjects in the study.  The  RIII reflex thresholds were also significantly lower than that of the non-IC subjects.  But when the non-IC subjects did the test with placing their hands in ice water, their NFR RIII reflex was significantly inhibited (down 39%).  In the IC patients, their NFR RIII reflex was stronger during this test and went up 35%. 

Apparently, patients with IC/PBS do modulate pain differently from those without the condition.


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  1. m masterson says:

    Central sensitization research is popping up all over the place. Since there are medicines on the horizon that appear promising we will likely continue to see more research results.
    I am however concerned about the big switch from the thinking that fibromyalgia is an auto immune disease to thinking it a Central sernsitization issue.
    When I was diagnosed in 2002 with fibromyalgia, the condition had an official disease number and was considered one of the “fibro” five. Lupus was one of the other maladies in the group.
    I have done extensive research on the issue. Some of the better research, I have seen was done on dna . Auto immune disease was shown to have its own marker, including such maladies as diabetes 1 and psoriatic arthritis.
    I would welcome help for this stupid malady. It’s embarassing when you are asked, what is it you have. Then you get this glazed over look and professionals tell you, well you are a very sensitive person. Even in the Ciba-Geigy medical manual, it is concluded that fibromyalgia patients, all seem to have a specific type of sensitive personality . Much ado is given to the depression that patients suffer. What is it going to take in order for the medical community to understand. This is an incredibly obnoxious tyrant we have on our hands. Tailoring what medicines can do, then arranging and reorganizing symptoms to fit, is not the kind of help I am looking for. It will make anyone connected with the “new miracle ” drug better off. I am concerned, because we are not getting to the core of what causes these maladies.
    Medicine needs to re-think the current direction. We need real help.

  2. I totally disagree with you. I have had IC and Pelvic floor dysfunction since I had a hysterectomy and a burch procedure. My muscles used to urinate do not work in the normal fashion as you relax and you urinate. I have to use my muscles to urinate and thus a viscous cycle started. I then had a very bad UTI that took two rounds of antibiotics to treat it and it still didn’t go away and that is when I was diagnosed with IC. I never had pain or took pain meds. In 1999 they didn’t give you pain meds they gave you DMSO treatments once a week. That in no way touched the pain. The pain is real and to say the IC patients are sensitive to pain is ridiculous it obviously comes from someone who has never suffered from the terrible pain of IC. I see a pelvic floor physical therapist and she says I am the worst patient she has ever seen, all my muscles are spasming. I cannot invent that pain in my head. I have rectal and vaginal spasms. The burning in the urethrae is the worst thing I have ever dealt with. It is like you are on fire after you pee. The only relief you get is uristat and prelief and morphine and ice paks and taking muscle relaxants to break the spasms. I also had a interstim implanted to help with the frequency and urgency, which it does as long as you don’t have a UTI. For anyone to say that IC patients are more sensitive to pain yeah they are sensitive to pain because they are in so much pain and no one understands not even the medical establishment. I am a RN and they don’t understand that when they put you NPO they are sentencing you to a pain you can’t get away from until they put you to sleep or do the test and you can get to your meds. I self cath and use sodium bicarb/lidocaine/heparin and put it in my bladder and pray I can hold it and the spasms won’t make me lose it. I use suppositories from a compounding pharmacy in North Carolina and doing all this I still have pain on a scale of 1-10 I am a 8 or 9 until my meds kick in. IC is acid in your bladder leaking thru the walls of the bladder, IC is what causes you to be sensitive to pain the disease not something wrong with the person in their mind or if your trying to say they are an addict you are so off. I wish you could spend one day in my shoes. I can only drink water, can’t eat hardly anything I like if it has acid in it, no nutrisweet or artificial sweetners, no colas, no coffee, nothing with caffiene, no alcohol, certain medications for colds and flu the list goes on. Have you ever studied pain? I go to a pain management Dr and he has done blocks on me, I have had botox put into all the muscles to keep them from spasms. I feel like I can’t go anywhere or I can’t cath if I need to and I need that medicine to deaden the area. It really hurts when studies come out and make bold statements blaming the IC sufferer to being more sensitive to pain than the regular person. I never took pain medicine or was overly sensitive to pain until I have suffered so much pain and the DR looks at you and says there is nothing more we can do for you. I was just at the Cleveland Clinic in Ohio last week and that is exactly what happened. He rammed his hand up inside of me and felt the muscles and said there is nothing more we can do for you. Well you knew that before you rammed your hand up me. We are human beings, that feel, love, hurt, and want to be treated like a person and not some disease. If it weren’t for my pelvic floor physical therapist no one would care. She is the only one that tries to help and really knows what is going on with the patients because she feels their insides everyday and knows. But I bet nobody has thought to interview people like her. It is a disease that causes terrible pain and they don’t know why. It is not people with IC are sensitive to pain. There is a huge difference. I know I live it everyday.

  3. Hi,
    I realize this is an older post but am moved to share just a little about Central Sensitivity Syndrome (CSS). First of all CSS does not mean pain is all in the mind, not at all. It is actually giving more credibility, due to more understanding of what is going on in the brain, not the mind. CSS refers to the pain center and should not be confused with ‘being a sensitive person’ — Now that my Duke doctor understands more about CSS, when I say things that suggest I myself feel like I’ve not done something well enough, like my exercises, or let myself get too stressed out and that this is why I have so much pain (I have fibro and severe chronic bladder pain)- my doc always reminds me that the central nervous system is working overtime in a big way. A cut to my finger can actually trigger fibro pain in other parts of my body. I think it makes a lot of sense, but I also feel like we will learn a lot in the next several years. One thing is clear though. CSS is not part of the mind, but instead the brain.
    My heart goes out to Julie. I know that bladder pain is a kind of pain that you must get relief for. I would be upset too if someone told me my pain came from being sensitive. CSS has nothing to do with our personality or character traits. Good luck Julie.
    Thanks for this post. What a resourceful site you have here!

  4. To Julie the RN , I had a total hysterctomy in 2003 and when i looked at your symptoms it was as if i read my own to the tee i started sobbing. When I was tested for IC 2 1/2 yrs ago (due to constant vaginal burning) the uro dr said i did not have that, he said i had chronic urethritis and magically my symptoms went away up until 4 months ago when i started burning in vagina and rectum and spasms in the rectum now that are horrific (will make you want to pass out). My barium (lower) showed an irregular rectal shelf but I was told it was not a mass or cancer but that they had never seen that type irregularity before and want me to have a follow up colonoscopy , i am scared by that comment and confused and still in pain which i manage with meds i also forgot to mention that when the symptoms first started a month prior to them i had a onetime night episode of a 20 min. rectal spasm then a month later the vaginal burning started now it burns in my stool too. Sometimes it feels like a knife in my vaginal area, i have to sit on the toilet 15 min to literally push all my urine out but i still leak a little afterward anyway i constantly feel irritable up there night and day and i was wondering if you had any thoughts or suggestions? Thank you.

  5. To Kat:
    I am so sorry I have just now come back to this site and stumbled upon your letter to me. My first thoughts is that your barium test of the lower colon showing a rectal shelf is probably due to to pelvic floor dysfunction. I too had a rectocele, and intussuception and hemroroids. All caused from using thiose musles to push the urine out. Yes I do have thoughts on the matter. First I would get a urologist that treats and is well educated in IC. Then I would get a referral to a pelvic floor physical therapist who can help break these spasms. Then I would log onto the ICA website and look at the different treatments. I do home instillations as rescue treatments and they are saving grace for me. I also have botoxed the pelvic floor because I cannot take the rectal spasms. The only thing that helps me with the constant burning is to take prelief, uristat, I see a pain management Dr and I am on fentanyl patches a low dose and then morphine for breakthru pain. The physical therapy will help you greatly and they can do biofeedback to teach you how to pee correctly again. I have many other problems that I deal with that are separate but I think connected. I developed pencil thin stools and could not go to the bathrom because of the spasms so I became severely constipated, then for about three weeks despite everthing known to man to relieve it I could not go but then it would break and I wold have massive diarrhea to the point of dehydration. This became a pattern and then the blood supply got messed up and they had to remove my entire large intestines and I have a ileostomy. I now have 5 autoimmune diseases. So I think early, aggressive treatment is very important. I also had recurrent UTI’s and from so many antibiotics had c-diff and went into septic shock twice and coded twice. I take atarax for the IC, I was on Elmiron but my liver didn’t like it. i take flexeril 3 times a day to stop the spasms and then pain meds as needed and stay n the IC diet. The rescue instillations are such a good thing for me and I have an interstim also which stops the urgency and frequency. I hope this helps, I wish I knew how to get in contact with you and talk to you and see how you were doing. I am so sorry I have not been on here. You will remain in my thoughts and prayers. Julie Osenton

  6. Julie Osenton says:

    Kat I would really like to talk to you to see how you are doing. Please email me or you can contact me on facebook if you have a page. Mine is julie Smith Osenton. I just found this today and I have been very ill and forgot about this site and just found it today. I am going to go back over it . Please get in touch with me. Julie

  7. I see patient are more sensitive to pain due to the fact that they make little serotonin which is a natural pain killer. Serotonin is your “feel good ” hormone and if your body is not producing enough you can also suffering with anxiety, depression etc.

    We can all imagine how painful it must be to suffer with bladder and genital pain 24/7 so imagine on top of that that your also not making serotonin. Yes, the pain become debilitating.

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