Polymyalgia rheumatica


With polymyalgia rheumatica, “poly-“ means
many, “mya-” means muscles, and “-algia” means pain. “Rheumatica” comes from rheumatism, which
broadly refers to conditions that affects the joints and connective tissue. So, polymyalgia rheumatica is a disorder that
causes muscle pain and joint stiffness. It is considered to be an immune- mediated
disease, meaning that the immune system attacks our own body. It is important to note that although “myalgia”
means muscle pain, the muscles are usually spared and it’s the tissue around the joints
that mostly gets inflamed. Normally, the cells of the immune system are
always hanging around, ready and excited to spot and fight against anything foreign that
could cause harm inside the body. One particular type of immune cell – the dendritic
cell – is a type of antigen-presenting cell, meaning that it grabs a pathogen for example
a bacteria, destroys it, and presents a part of that bacteria, called an antigen, to other
immune cells. Dendritic cells take their name from the fact
that they have branch like arms called dendrites which help them grab antigen. Dendritic cells take their captured antigen
and move over to a nearby lymph node, where they present the antigen to a helper T-cell. Dendritic cells “present” the antigen
on a protein called a major histocompatibility complex, or MHC, class II molecule which is
on their cell surface. MHC class II molecules are like a serving
platter, which hold the antigen as it gets presented to the helper T-cells. Once these antigens are recognized as foreign,
T-helper cells get activated and start secreting a lot of proinflammatory cytokines, or signalling
molecules, that recruit more immune cells, such as macrophages, to the site of inflammation. At the same time, other cytokines, called
interleukins, trigger B-cells to secrete antibodies against the targeted antigens. These antibodies block pathogens from causing
harm, and also “tag” them so that other immune cells, like macrophages, can recognize
and destroy them. Although the exact cause of polymyalgia rheumatica
is not well understood, it is associated with both genetic and the environmental factors. For example, a person with a certain gene
for an MHC class II molecule, also called a human leukocyte antigen, or HLA–DR4, is
more likely to develop the disease especially after an infection with adenovirus or parvovirus
B19. This may be due to a process called molecular
mimicry, which is where an immune cell mistakes a protein in the body for being a foreign
protein. When our own proteins trigger an immune response,
the protein is called an autoantigen. So, these autoantigens get picked up by antigen-presenting
cells, which go on to activate helper T-cells. These helper T-cells, in turn, activate B-cells
which start producing antibodies against the autoantigens. Then, both helper T-cells and antibodies enter
the circulation and reach the large joints, such as the shoulder and hip. Once there, they secrete cytokines like interferon-γ
to recruit more immune cells like macrophages. Macrophages head over to those joints and
produce inflammatory cytokines, like tumor necrosis factor alpha, or TNF-α, interleukin-1,
and interleukin-6 which together with the T-cell’s cytokines, promote inflammation
of the joint lining. Now, although it’s called polymyalgia, the
muscles themselves are not inflamed and actually appear normal on biopsy. Instead, the pain comes from the structures
surrounding the joints like the tendons and bursae, rather than the joints themselves,
and that affects nearby nerves in the muscle, called referred pain. Meanwhile, these inflammatory cytokines travel
through the bloodstream and reach other organs. For example, interleukin-1 and interleukin-6
travel to the brain, where they act as pyrogens, inducing fever. In fact, polymyalgia rheumatica is also strongly
associated with giant-cell arteritis. That’s a condition where there’s inflammation
of the walls of the arteries in the temples, which is why it’s also called temporal arteritis. Polymyalgia rheumatica often affects women
over 50 years of age, and typically causes symptoms like pain and stiffness of the shoulder
and hip, which often starts on one-side, but typically progresses to both sides within
weeks. The symptoms are usually more severe in the
morning and at night, often lasting for more than an hour, and they typically improve after
activity. The pain can make it hard to get out of bed
or up from a chair, and lifting the arms above shoulder height can be tough. It can also cause a low grade fever, fatigue,
and loss of appetite which can lead to weight loss. Also, many people can develop temporal arteritis
which causes symptoms like severe headache, jaw pain, and vision problems – and even blindness. The diagnosis of polymyalgia rheumatica can
be confirmed by increased inflammatory markers, like a high erythrocyte sedimentation rate,
or ESR, and C-reactive protein, or CRP. Since there is little damage to the muscles,
muscle enzymes like creatine kinase, usually remain normal, which distinguishes polymyalgia
rheumatica from other inflammatory muscle disorders, like polymyositis. Treatment of polymyalgia rheumatica focuses
on suppressing the immune response, usually with low doses of corticosteroids, such as
prednisone. Specific exercises and a healthy diet can
also help strengthen the muscles and bones, as well as improve flexibility of affected
joints. All right, as a quick recap, polymyalgia rheumatica
is an inflammatory disorder that causes pain or stiffness, usually in the shoulders and
hips, and is commonly associated with temporal arteritis. There’s usually an elevation in inflammatory
markers, but the creatine kinase is usually normal, which distinguishes it from other
inflammatory muscle disorders, like polymyositis.

16 thoughts on “Polymyalgia rheumatica

  • I took a rheumatology practise this summer and I asked about this disease today. That is the most random coincidence (didn’t expect this video to pop up ever). My mentor said that oncologies may often manifest with polymyalgia rheumatica, wonder how accurate and true that is, because the last patient with polymyalgia rheumatica turned out to have multiple myeloma.

    P.s. Great video though, but really liked the animated cells on olded videos with more emotions when stimulated 🙈

  • I am 75 and contracted PMR after receiving my annual flu shot. The symptoms are exactly as described here. I was placed on a high dose of Prednisone which eliminated the symptoms over night. The blood tests showed a high SED rate and high C reactive protein. I have been on a Prednisone taper for about eighteen months and my blood tests are back in the normal range. This is an excellent article.

  • Thank you for this video….I got more info from this than the 6 Neurologists, 2 surgeons, 2 Rheumatologists and my PCP ever gave me.

  • If I ever get the chance,
    I would so much like to award you an OSCAR/ or probably a Nobel Prize.
    Or even a handshake would be enough !! Tysm for making ‘med-life’ bearable 🙂

  • "although it's called polymyalgia, the muscles themselves are not inflamed" why the although? It s not a contradiction. Only if it would be polymyositis would it be contradictory right?
    Thanks for the video btw!

  • Really helpful. My poor mum is going through this terrible illness for the third time. Your video explains what is actually going on so we can both understand. Thank you.

  • Thank u my favorite channel .
    Generally; PMR should be suspected in any case of : female older than 50 yo presented with pain and stiffness of her large joints especially at morning and when she is at rest ; but the pain is relieved by activity . The pain in most cases is symmetrical and associated with easy fatiguability 2ndry to anaemia . ESR is almost always high and if was more than 100mm/hr it is highly suggestive of PMR .
    I diagnosed pt with PMR who is previously diagnosed as osteoarthritis.

  • My mother was diagnosed with temporal arteritis in her 60's. She was treated with prednisone but eventually developed PMR also. Now, at 96, she has lost her vision due to macular degeneration. I wonder, is there any connection?

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