Thursday, 24 March 2016

ClinicSpeak: what type of pain are you suffering from?

Are you in pain? #ClinicSpeak #MSBlog #MSResearch

"As most of you with more advanced MS know pain is a big problem and is very poorly managed outside of specialist clinics. Why? Because most neurologists and pain experts don't understand the mechanisms that underpin MS pain syndromes. In addition to this pain affects mood; pain reduces your affect and is strongly correlated with depression. People who are depressed handle pain poorly and this leads to a downward spiral. This is why the management of pain in MS is so important and needs an holistic approach."
"The study below tries to differentiate two major types of pain using neurophysiological testing. Nociceptive pain means there is a peripheral painful stimulus that is causing pain. For example, urinary tract infection stimulates pain receptors in the bladder and you feel pain. Neuropathic pain is due to central mechanisms and usually occurs in MS due to lesions affecting the pain pathways with aberrant transmission of signals to the brain that is perceived as pain. The investigator's found that using laser evoked potentials (LEPs) they are able to work out the cause of the pain. When a laser light is targeted to the skin it causes a painful/hot stimulus that is activates pain or nociceptive receptors. The signal from this travels to the brain and is persceived as pain. We can measure the transmission of these electrical signals to brain; we call these evoked potentials or LEPs. Abnormal LEPs were associated with neuropathic, or central pain. This is important as this type of pain responds to different centrally acting drugs for example, sodium channel (carbamazepine or oxcarbazepine) or calcium channel (gabapentin, pregabalin) blockers and drugs that modulate pain perception (tricyclic or atypical anti-depressants; amitriptyline, duloxetine, etc.)."


"Do we need to do these tests to decide on what pain you have? No not really. We tend to make a call on the type of pain based on the history and examination and  then decide on a management plan. If you are in a lot of pain you need to see your neurologist. We are pretty good at managing pain in pwMS. You don't need to suffer in silence, which a lot of pwMS tend to do; they accept pain as another MS burden to live with. Why?"

Turri et al. Laser evoked potentials and quantitative sensory testing in patients affected by multiple sclerosis: Clinical, neurophysiological and psychophysiological correlates. Clinical Neurophysiology 2016;127:4(e137).

Background: Pain is a common finding in patients affected by Multiple Sclerosis (MS). Many different types of pain can afflict MS patients, including neuropathic, nociceptive, or mixed pain. TSA-II-Thermotest (QST) and Laser evoked potentials (LEPs) are psychophysical and neurophysiological tests commonly used to explore pain. 

Aims: The study aims to determine psychophysical and neurophysiological correlates in MS patients. 

Methods: 16 MS patients (5 men, 11 women, mean age 59years, mean EDSS 7) where clinically and neurophysiologically tested. 5 patients presented neuropathic central pain (according to NeuPSIG 2011 guidelines), 8 patients presented nociceptive or mixed pain, and 3 patients were pain-free. For QST, the dorsum of both hands and feet were examined; for LEPs, the dominant hand and both feet were tested. 

Results: Results were collected and compared to age and sex matched controls. Pin-prick was altered in 37.5%, LEPs were abnormal in 57.8% and QST was pathological in 85.9% of examined sites. We detected a significant correlation between pain and clinical examination (0.022), pain and altered QST (0.042), while LEP abnormalities correlated well with the presence of neuropathic pain (0.012). 

Conclusions: Our results suggest that LEPs are more specific than QST to differentiate neuropathic from nociceptive pain.

11 comments:

  1. I've tried four pain killers, not had much luck with them and have been prescribed a fifth one to start. Have been reading that magnesium may help with aches and nerve pain.

    Prof G what are your thoughts on magnesium for decreasing pain?, thank you.

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  2. Pain has been my main symptom since being diagnosed two years ago. I use magnesium flakes in my bath and it helps relax my muscles. I did not get relief from pain (aches, burning sensations) until I started pregabalin, which has reduced the pain by about 70%. I see magnesium as a supplement to an approved symptomatic treatment. MS pain is horrible and I hope you find relief, I can certainly relate to what you're going through.

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  3. On the bottom of NHS letters they sometimes say "You can be seen at any NHS provider in England who treats your condition".

    Does this mean I can find a specialist MS clinic in England, that may be outside of my area and get an appointment there?

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  4. If you are in a lot of pain you need to see your neurologist. We are pretty good at managing pain in pwMS. You don't need to suffer in silence, which a lot of pwMS tend to do; they accept pain as another MS burden to live with. Why?"

    Do all neurologists agree that patients should ask for an appointment if they are in a lot of pain ?

    Speaking from my own, and my friends', experiences we have annual reviews with our neurologist that the hospital administration notifies us about. The expectation is that we come when the neurologist is prepared to see us, rather than us asking for an appointment.

    Pain, both muscular and neuropathic is a major symptom for me and I do take medication for it. When things worsen I contact my MS nurse and they contact my GP to request additional medication. Other friends tend to go direct to their GP, not always successfully.

    PwMS should be given information about help (pharmaceutical or otherwise) that can be given when various symptoms appear or worsen, and how to access that help.

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  5. I HATE neuropathic pain it is my absolute worst MS symptom and is totally invisible. It has been with me for the past 4 years and will be with me all day everyday for the rest of my life.

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  6. My neurologist prescribes Lyrica for my burning legs but won't give me any medication for my back pain as he says this is not MS pain. I told him GP will not prescribe anything for back pain (there is a move towards less prescribing of pain killers in Aust - neuro told me this). But he wouldn't help me. He just told me to take Panadol which is useless. Above the question is asked why do people with MS accept pain as another MS burden to live with. This is my experience of why I put up with pain. I don't want to - I am forced to.

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    1. Find another neuro. I know of a few "renowned" ones in Melbourne who still believe pain is not a symptom of MS. Even after they send their patients to pain specialists, who rule out all other possible causes. My anecdotal experience with a few neuros at the Austin in Melbourne is that many of them seem to be concentrated there. Bojana

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    2. or better yet, find a pain specialist to manage your pain meds. neuros don't have to do everything just because it has the word ms in front of it. Bojana

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  7. My lesion that caused my first outbreak was in between cervical C1-C2, so I felt a lot of pain and cervical a really strong pain. I can say that Gabapentin, despite having given me a lot of dizziness, too helped me in pain management at the time. Today no longer feel more pain, still good.

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  8. I suffer from neuropthis nerve pain, have been for the last seven years. Gabapentin helps take the edge off of it, but it's always in the background.

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