Endocrine Myopathy - Another reason for pain in muscles

Discussion in 'Fibromyalgia Main Forum' started by darude, Jun 27, 2005.

  1. darude

    darude New Member

    Background: A myopathy, simply, is any abnormal state of striated muscle. Clinically, the patient generally experiences muscle weakness, pain, cramps, muscle tenderness, and spasms in various degrees.

    Disease of the endocrine system, including the thyroid, parathyroid, suprarenal, and pituitary glands, the ovaries, the testes, and the islands of Langerhans of the pancreas, usually results in multisystem signs and symptoms. A myopathy very often is present, and it rarely may be the presenting symptom.

    Major categories of endocrine myopathy include those associated with (1) adrenal dysfunction (as in Cushing disease or steroid myopathy); (2) thyroid dysfunction (as in myxedema coma or thyrotoxic myopathy); (3) parathyroid dysfunction (as in multiple endocrine neoplasia); (4) pituitary dysfunction; and (5) islands of Langerhans dysfunction (as in diabetic myopathy from ischemic infarction of the femoral muscles).

    Articles on the specific endocrine diseases that may result in myopathy may be found in detail in this and the Medicine journals of eMedicine.


    Pathophysiology: Although abnormal endocrine states usually present with muscle weakness—most often proximal weakness—the exact pathophysiology remains incompletely understood. Even histologic analysis and electromyographic testing may not show consistent, reproducible abnormalities in all cases, although some patterns are recognized and are discussed in the sections below.

    Adrenal dysfunction


    The etiologies of hypoadrenalism are many, including infection, inflammatory disease, and tumor. Notably, adrenal failure may follow pituitary failure.

    In hypoadrenalism, neurological manifestations such as disturbances of behavior and mentation are prominent; myopathy is not likely to be a presenting finding.

    Factors contributing to muscle weakness in adrenal insufficiency include circulatory insufficiency, fluid and electrolyte imbalance, impaired carbohydrate metabolism, and starvation.

    The etiologies of hyperadrenalism include pituitary or ectopic overproduction of adrenocorticotropic hormone (ACTH), adrenal tumors, or exogenous corticosteroid administration. Pituitary ACTH hypersecretion (ie, Cushing disease) is caused by a corticotroph microadenoma in 90% of patients and by a macroadenoma in most of the rest.
    Thyroid dysfunction


    Thyroid hormone deficiency states result in neurological syndromes that vary depending on the age of onset of the deficiency. Muscle weakness occurs most prominently in the adult forms of myxedema.

    Thyroid hormone excess also results in myopathy. Thyrotoxic myopathy is believed to be secondary to a disturbance in the function of the muscle fibers from increased mitochondrial respiration, accelerated protein degradation and lipid oxidation, and enhanced beta-adrenergic sensitivity due to excessive amounts of thyroid hormone.

    The heterogeneity of the endocrine myopathies is illustrated nicely by Rodolico and colleagues, who described 10 patients with primary autoimmune hypothyroidism presenting solely with myopathy.
    Parathyroid dysfunction


    Hypoparathyroidism causes tetany, with or without carpopedal spasm. The pathophysiology may involve either deficiency of parathyroid hormone or inability of the hormone to have an effect at end-receptors because of dysfunction of the hormone receptors.

    Hyperparathyroidism does not cause tetany but results in muscle wasting and myopathy (ie, proximal muscle weakness). The pathophysiology is oversecretion of hormone, frequently from a parathyroid adenoma.

    Myopathy related to parathyroid dysfunction appears to result from altered parathyroid hormone (PTH) level and impaired action of vitamin D.
    Pituitary dysfunction


    The myopathy from pituitary disease may be a result of secondary adrenal dysfunction and/or other endocrine disturbance such as thyroid dysfunction.

    Hypopituitarism as well as hyperpituitarism may result from multiple causes, from simple trauma, or from infection or tumor.

    Frequency:


    In the US: In general, endocrine myopathies are recognized increasingly. However, the exact incidence and prevalence are unknown. Patients with endocrine dysfunction frequently complain of fatigue and weakness. These symptoms are referred to as a "myopathy" despite lack of defined histologic or electrophysiologic criteria fulfilling such a diagnosis. In fact, many of these patients show only muscle atrophy without muscle degeneration. Corticosteroid myopathy is the most common endocrine-related myopathy. Patients who have myopathy as the sole manifestation of endocrine dysfunction may sometimes have a delayed diagnosis.
    Internationally: As in the United States, the exact frequency is not known as the myopathies are heterogeneous.
    Mortality/Morbidity:

    Myopathy may result in weakness and/or pain. Either may significantly influence the quality of life and impair daily function. Myopathy also may result in muscle atrophy.
    Mortality is related to the underlying cause of myopathy. For example, myxedema coma may have a mortality rate between 50% (if treated aggressively) and 100%.
    Sex:

    Hyperparathyroid myopathy - Female-to-male ratio 2:1


    Hyperthyroid myopathy - Female-to-male ratio 1:1
    Iatrogenic steroid myopathy - Female-to-male ratio 2:1


    Hypothyroid myopathy - Female-to-male ratio 5:1
    Cushing myopathy - Depends on the etiology of Cushing syndrome
    Age:

    Hyperparathyroid myopathy - Peak incidence 40-60 years


    Hyperthyroid myopathy - Peak incidence 20-60 years
    Hypothyroid myopathy - Incidence increases after 40 years
    Cushing myopathy - Peak incidence 20-40 years
    CLINICAL Section 3 of 10
    Author Information Introduction Clinical Differentials Workup Treatment Medication Follow-up Miscellaneous Bibliography



    History: Usually, multiple organ systems are involved and myopathy is only one part of the history, although exceptions do occur and are noted in Pathophysiology.

    The history of myopathy in general is that of proximal more than distal muscle weakness, with or without associated muscle pain, cramps, and/or spasms. The weakness is typically symmetric or rapidly becomes symmetric. Muscle atrophy may or may not be present.

    Adrenal dysfunction
    Hypoadrenalism: In hypoadrenalism, the neurological manifestations of behavioral disturbance and mentation are prominent; myopathy is not a frequent presenting finding.
    Hyperadrenalism: Cushing syndrome may present with the usual cushingoid features plus pain and weakness. Corticosteroid myopathy is the most common endocrine-related muscle disease. Please refer to the article Cushing Syndrome for details.
    Thyroid dysfunction
    Hypothyroidism: Muscle weakness occurs most prominently in the adult forms of myxedema. General symptoms include weight gain, neuropathy, fatigue, cold intolerance, sleepiness, and emotional disturbances in addition to muscle stiffness, weakness, and pain. Notably, psychiatric disease may be prominent. Cerebellar ataxia may be seen in adults, less often in children, in whom cerebellar involvement is more midline.
    Hyperthyroidism: General symptoms include weight loss, sweating, tremor, muscle wasting, and painless weakness. Occasional patients have myalgia, cramps, and bulbar and ocular muscle weakness. Ocular symptoms (diplopia, reduced blinking, lid droop) and skin disease may be present, especially in the case of Graves disease.
    Parathyroid dysfunction
    Hypoparathyroidism: Tetany with or without carpopedal spasm is seen. Muscle pain, cramps, and spasms are present in up to one half of patients. Muscle weakness is usually mild. General symptoms include short stature with rounded face, thickened calvarium and other bony abnormalities, and neurological symptoms (eg, seizures, mentation defects).
    Hyperparathyroidism: Muscle wasting and myopathy (ie, proximal muscle weakness) are common. Other symptoms may include the findings denoted by the well-known phrase "(painful) bones, (renal) stones, (gastrointestinal) groans, and (psychiatric) moans." Notably, depression, mentation defects, memory loss, and mood changes may be present. Also, renal stones are an almost constant feature of this disease syndrome.
    Pituitary dysfunction: The myopathy from pituitary disease may be a result of secondary adrenal dysfunction or other endocrine disturbance.
    Hypopituitarism: Often, the myopathy results from secondary adrenal dysfunction. General symptoms include amenorrhea, loss of libido, "alabaster skin," lethargy, constipation, and cold intolerance.
    Hyperpituitarism: As with hypopituitarism, secondary adrenal effects may be responsible for the myopathy. General symptoms include infertility, impotence, headaches, and mass effects of the pituitary tumor.
    Physical: Physical examination should focus on the entire body, as the endocrine diseases usually present with multiple system findings.

    Neck flexor weakness reflects proximal muscle weakness and may be noted in myopathies; dysphagia from bulbar weakness also can occur.
    Respiratory muscle weakness may occur in endocrine disease (Siafakas et al, 1999).
    Physical examination findings should correlate with the underlying endocrine disease. However, the following patterns may be observed:
    In thyrotoxicosis, muscle weakness and atrophy may affect muscles of proximal arms more than those of the legs.
    Muscle stretch reflexes are usually present (may be depressed) even in weak muscles.
    Adrenal dysfunction
    Hypoadrenalism: Examination may show an ataxic gait. Cognition may be poor.
    Hyperadrenalism: Papilledema and other signs and symptoms of increased intracranial pressure may be present.
    Thyroid dysfunction
    Hypothyroidism: Motor movements can have a reduced velocity with delayed relaxation of muscle stretch reflexes. Median neuropathy at the wrist commonly accompanies this diagnosis.
    Hyperthyroidism: In addition to the findings of Graves disease, muscle weakness with atrophy of the pelvic girdle musculature may be present.
    Parathyroid dysfunction
    Hypoparathyroidism: Tetany is a common finding; cataracts may be present. Increased intracranial pressure is not a constant finding, but may be present.
    Hyperparathyroidism: Myopathy is a prominent finding. Both symmetric weakness of the proximal limbs and atrophy are present.
    Pituitary dysfunction: The myopathy from pituitary disease may be a result of secondary adrenal dysfunction or other endocrine disturbance.
    Hypopituitarism: Multiple endocrinopathies may result from pituitary dysfunction. Pituitary tumor may have focal mass effects.
    Hyperpituitarism: Multiple endocrinopathies may result from pituitary dysfunction. Mass lesions may have local effects.
    DIFFERENTIALS
  2. darude

    darude New Member

    yea I was looking up stuff about the pituitar tumour I have and came across this. Very interesting isn't it. I'm seeing an endo soon so perhaps can figure out my problems.
  3. Mikie

    Mikie Moderator

    Thanks for posting this. I especially found the part about muscle atrophy of the arms interesting. In "Osler's Web," wasting of the forearm muscles is mentioned in relation to CFIDS.

    This is one area where I think it would be helpful to get tested. Most of us never get beyond having our thyroid levels tested. The endocrine system is all interrealted and a problem in any one area affects the other areas as well.

    I wonder how well received CFIDS patients are by most endocrinologists.

    Love, Mikie
  4. darude

    darude New Member

    Well I'm about to find out seeing as I'm being referred to an endo! Mine is for the pituitary tumour tho. IF thats was it is as the latest MRI says unusual mass central pituitary abbutting the optic chiasm. Could be due to pituitary adenoma or proteinacous mass. Does not contain any blood products so no aneurysm. When I read the article a lot of it applies to me over the years so I figure I might be onto something. Pituitary is basically the master control gland and a problem with that can mess up everything.
  5. darude

    darude New Member

    One in five of the population has a pituitary tumour. Usually found when they are looking for something else. They can be producing (tumours produce hormones) or they can stop the gland from producing certain hormones. I posted this awhile back and it is very interesting. Human growth hormone and ACTH can be messed up by these.
  6. tansy

    tansy New Member

    For me, and judging by the replies so far, others as well. Few of us have our endocrinological problems investigated properly even though they are major features of ME/CFIDS, FM and borreliosis/lyme. I have symptoms that mimic graves disease, and other blips in the HPA, so some of this makes sense to me.

    Good luck with your endo appt.

    Mikie

    I had gluten intolerance and all the signs of celiac sprue in the early years of my illness. As a result I lost a lot of weight and muscle. After that was identified I was able to regain weight and some muscle but my forearms are so thin if I wear loose clothes I am asked if I eat enough, even though in more recent years I have put weight on.

    Stormyskye

    Yes we do seem to find ourselves experiencing domino effects and in vicious circles that we need to break if we are to improve and go into remission. It was reading all the heated debates over vitamin D that helped me decide rather than avoiding it I should be getting more. One of the reasons was vit D’s modulating effects on the endocrine system and on hormones; daylight is needed too. That’s what I need, not something to up or down my hormones, but to balance them just as I’ve been trying to do with my immune system.

    It’s too early to be sure but so far the signs are this was the right decision, it will be some time before I know whether I am right.

    Love, Tansy
  7. darude

    darude New Member

    Things are beginning to make sense for me anyway. I will let you know the outcome of my appointments
  8. poodlemommy

    poodlemommy New Member

    Interesting. I have fibro and lots of pain and muscle weakeness. 2 years ago my thyriod was removed due to cancer. I am now on a stronger than normal does of thyroid med to keep the cancer from coming back. I now have more energy, less muscle fatigue, and my slim body is back. So there is a big link for sure.
  9. ephemera

    ephemera New Member

    Thanks for this post. I was diagnosed 2 years ago with hyperparathyroidism, but doctors told me to do nothing. One advocated for surgery (to line his pocket of course!). Had no symptoms & tests weren't that "bad". Now that I'm having muscle weakness, spasms & numbness in my extremeties I'll check into this again.
  10. Mikie

    Mikie Moderator

    Darude, good luck with your treatment. I will keep you in my prayers.

    Tansy, this is such a strange thing. You are the first person I have heard of personally who has this. The book also mentioned that some PWC lost their fingerprints. As if these illnesses weren't strange enough already.

    Love, Mikie
  11. darude

    darude New Member

    A lot of symptoms that we have. Will let you know my results!!!!!!!!!!
    [This Message was Edited on 06/28/2005]
  12. darude

    darude New Member

    For tansy
  13. tansy

    tansy New Member

    several problems contributing to my thin forearms, they are not helped by my problems in rebuilding muscles through exercise and there is pressure/irritation of nerves in my cervical spine.

    The loss of fingerprints is an interesting one, it's been observed for decades in ME/CFIDS.

    love, Tansy
  14. tansy

    tansy New Member

    things are starting to make sense for you at last. It's just so frustrating that it can take so long.

    In another post you complained when told some of your problems were due to your age, well I expected that too when I saw my GP today, the first time I’ve seen her since my cervical spine results were reported. Well to my amazement she didn’t. First she said she was sorry it was worse than she had suspected – might have helped if a few doctors had not taken liberties when writing their reports or even done the right investigations years ago. So now at least she acknowledges this has been a long-standing problem and explains some of my physical disability.

    Hope you keep getting your problems explained and there are effective solutions for them. I look forward to reading about the outcome of your appts.

    Love, Tansy
  15. pika

    pika New Member

    decided to bump this after some reading i've been doing about thyroid/parathyroid.
  16. darude

    darude New Member

    Old post but worth reading