Our ‘Spotlight On’ this month features hypothyroidism.
EM related research suggests that many EM sufferers either present extant hypothyroidism ( developed many years prior to EM) , get diagnosed as hypothyroid (around the same time as EM symptoms) , or develop future hypothyroidism.
“Hypothyroidism occurs when you produce insufficient amounts of thyroid hormone or when you have thyroid hormone resistance. As a result, your body cannot maintain normal metabolism, and your ability to convert tyrosine to dopamine, norepinephrine and epinephrine is impaired. This can cause a ripple effect of symptoms”
No research actually investigates this finding. But we have pieced together a few articles to kick - start our discussion. Immune, endocrine, molecular (sodium channels), and nervous system (autonomic dysfunction/ central sensitisation), as well as co-existing medical conditions, side effects from other medications and mere co-incidence are amongst schools of thought.
The mod team hope this makes for an interesting and insightful discussion.
(1) How does living with hypothyroidism and EM affect you?
(2) Why do you think many EM’ers are hypothyroid or thyroid hormone resistant?
(3) Is hypothyroidism a cause or effect of EM?
- Research on the mechanism of chronic pain in burning mouth syndrome (BMS) underpin immune-endocrine system substantially involved, and may have a key role, Immune function was significantly and specifically suppressed in BMS, although the hypothalamic-pituitary-adrenal axis and sympathetic nervous system were predominantly activated by psychological stress that was not specific to BMS. http://www.ncbi.nlm.nih.gov/pubmed/24398391?dopt=Abstract
- Burning feet syndrome. Most sufferers were hypothyroid http://www.ncbi.nlm.nih.gov/pubmed/14708150
- Many autoimmune disorders increase the risk for hypothyroidism. Type 1 (insulin-dependent) diabetes ,systemic lupus erythematosus, pernicious anaemia, and rheumatoid arthritis
- Perimenopause/menopause .Women over 50 are susceptible to thyroid problems.http://www.thyroid.org/
- Interestingly for EM’ers some patients treated for hypothyroidism have symptoms and findings compatible with small-fiber neuropathy or "hyper phenomena" indicating central sensitization.http://www.painjournalonline.com/article/S0304-3959(10)00584-1/fulltext http://www.ncbi.nlm.nih.gov/pubmed/16966538
- Hypothyroidism frequently found in chronic urticaria – otherwise known as heat allergy (we call it EM), and associated to autoimmunity. http://www.medscape.com/viewarticle/815273_2 http://www.medicaljournals.se/acta/content/?doi=10.2340/00015555-0244&html=1
- Threshold of pain perception to heat decreased in hypothyroid rats. Synaptic transmission ( firing of neurons – pain receptors) alteredhttp://www.molecularpain.com/content/pdf/1744-8069-10-38.pdf
- Thyroid hormone regulates voltage‐gated sodium currents and modifies action potentials books.google.co.uk/books?isbn=110920576
- Autonomic dysfunction – dysautonomia - increased incidence of hypothyroidism, or low thyroid function in EM patients.
- Hypothesis that inadequate thyroid hormone regulation may be one of the primary underlying factors in many patients with fibromyalgia. Most fibromyalgia patients are either hypothyroid or thyroid hormone resistant.http://thyroid.about.com/cs/fibromyalgiacfs/a/fibrothyroid.htm
- Endocrine disorder- as in secondary Raynaud’s hormone imbalance .Thyroid requires iodine to produce its hormones and to regulate the body’s metabolism. The simple mineral iodine is like an internal heater. Iodine deficiency causes a loss of myelination of peripheral and central nervous system tissues. A lack of iodine also means the person cannot myelinate their nerves because they cannot access the ketogenic pathway
- Hypothyroidism = low metabolic rate. Animal research points to slower synaptic transmission, which, in theory, should slow pain signals. Sodium channel blockers based on this premise.
- Autoimmune disorder Hashimoto’s thyroiditis http://www.nytimes.com/health/guides/disease/chronic-thyroiditis-hashimotos-disease/print.html
- Numerous medical conditions can involve the thyroid and change the normal gland tissue so that it no longer produces enough thyroid hormone e.g. scleroderma, and amyloidosis
- Drugs and medical treatments can affect thyroid levels e.g. antiarrhythmic, antiepileptic, cancer, some antidepressants.
- Hypothyroidism extremely common. From 10 to 40 percent of Americans have suboptimal thyroid function
Here a few of the most common symptoms of hypothyroidism:
Nervousness and tremor
Mental fogginess and poor concentration
Aches and pains
High cholesterol levels
Hair loss/dry skin - Hair, eyes and other mucous membranes
Fatigue- If you do not have enough dopamine or have too few dopamine receptors due to inadequate thyroid hormone regulation, you end up with extreme fatigue, which is also a common complaint in fibromyalgia patients
Excess muscle tension and trigger points—For muscles to completely relax, filaments must lengthen and separate, which requires energy (ATP molecules). Low thyroid hormone reduces ATP.Delayed deep tendon reflexes (slow relaxation phase of the Achilles reflex)—Thyroid hormone controls gene transcription for calcium ATPase. When you hit the Achilles tendon and your foot goes down rapidly and then raises back slowly, it’s a sign of hypothyroidism or thyroid hormone resistance. This is due to lack of ATP molecules to provide the energy for the contractual filaments to separate and relax; hence you get a visibly slow relaxation phase of the Achilles reflex.
Hypothyroidism is separated into either overt or subclinical disease- Diagnosis is determined on the basis of the TSH laboratory blood tests. The normal range of TSH concentration falls between 0.45 - 4.5 mU/L.Patients with mildly underactive (subclinical) thyroid have TSH levels of 4.5 - 10mU/L are not treated as, blood tests for T4 are still normal Patients with levels greater than 10mU/L are considered to have overt hypothyroidism and treated with medication.
221-174480691038.pdf (732 KB) 222-JNeurolNeurosurgPsychiatry2000Duyff7505.pdf (197 KB) 223-279.full.pdf (154 KB)