The Thyroid Gland

Mr Kirkby-Bott is happy to consult on any stage of diagnosis or treatment for this condition

Graves' disease: An overactive thyroid

Surgery is one of 2 treatments for recurrent disease. Mr James Kirkby-Bott explains

Most overactive thyroids are due to an autoimmune disease called Graves' disease. It affects women more than men and often affects younger women in their 20s and 30s. Other causes of overactivity include Thyroiditis is it's initial stage before causing an underactive thyroid and Plummer's disease when a nodule in the thyroid is responsible for it's overactivity rather than the whole gland. 

What Symptoms does it cause?

It makes you feel on edge and anxious, As the metabolic rate increases weight loss sometimes occurs. It can cause a racing heart - palpitations, headaches. Swelling of the eyes so they stick out is sometimes seen in this condition. It can affect eyesight if left untreated.

How is it diagnosed?

On blood tests. A simple blood test will show a low TSH and a high free T4 and/or free T3. From this a further test to look for the responsible antibodies is performed. TPO antibodies can be raised in thyroiditis or Graves' disease. But the Thyroid receptor Immunoglobins are diagnostic of Graves' disease. If these are raised and your thyroid is overactive Graves' is the diagnosis. If you have an overactive thyroid and a normal Thyroid receptor immunoglobulin then you may have Plummer's disease and an ultrasound and Thyroid uptake scan can show if a single part of the thyroid is responsible. Eye swelling can affect some. it's action is due to the thyroid receptor immunoglobulins also affecting the muscle of the eye orbit. It only affects a few sufferers of Graves' disease. To treat this disease you need to have had thyroid surgery before any eye surgery. 

Treatment

• Medical treatment with anti thyroid drugs such as Carbimazole or Propothiouracil can inhibit the thyroid gland. You either titrate the dose to the thyroid function or completely block the thyroid and give Levothyroxine as well as the anti-thyroid drug. Initial treatment is for 6-12 months. At this point it can be stopped and hopefully it doesn't recur. If it does then these medicines can be tried again for  18+ months. Propanolol is a drug that inhibits the thyroid hormones affect on the heart and directly affects thyroid hormone in the cells too. This is usually prescribed with these medicines for symptom relief. The anti-thyroid medication can have serious side effects in some and stop the bone marrow from producing cells when needed. For this reason it is not used long term and if you feel unwell whilst taking it you should have a blood test known as a full blood count. It can also cause fetal malformation and it is important to use this drug with effective contraception to avoid pregnancy.

• Radioactive Iodine is used in some patients when stopping medicines causes a relapse. It is a single dose of a radioactive Iodine. Iodine is predominantly used by the thyroid so it all ends up in the thyroid causing a very selective destruction of the thyroid gland. The size of response is dose dependent. Recurrent disease is a potential complication. In addition to this, the tear gland, sweat glands and salivary glands also take up a bit of iodine and be be affected by this treatment sometimes causing -  dry skin, dry eyes and a dry mouth. It only reduces the size of a goitre by a small amount (approx 25%) so won't treat a co-existing goitre. After treatment you remain 'radioactive' for a period of time. This means not being able to try and fall pregnant for 6 months after treatment and also not being around small children. It can also have a significant negative impact on small pets such cats and small dogs. Despite these inconveniences it is safe and can be a good choice for those not wanting to conceive or having to look after young children. This can exclude a significant proportion of women affected by Graves' disease. Thyroid function is replaced by a daily dose of Levothyroxine in most cases. Surgery is possible or a 2nd dose of radioactive iodine is possible if treatment fails.

• Thyroid Surgery - Total Thyroidectomy is the surgical treatment of choice. It removes all the thyroid tissue so the disease cannot recur. You would become reliant on Levothyroxine to replace your lost thyroid function for life. The surgery requires an overnight stay in hospital. Pre surgery I prepare all Graves' patients with a 12 day course of Potassium iodide drops taken in water or milk three times a day. It can taste strange but it's effect is very important. Graves' disease has the effect of making the thyroid gland and surrounding structures very prone to bleeding significantly - it feels delicate like a blancmange and easily bleeds. The volume of blood loss is never high but it can seriously reduce the surgeons ability to see the nerve to the voice box and the very fragile parathyroid glands with even more fragile blood supply. This makes thyroid surgery for Graves' disease prone to complication. More information on the risks of thyroid surgery can be found here. 

• By giving Potassium iodide for the 12 days pre-surgery the thyroid is less densely filled with blood vessels and becomes much firmer so safer to handle and remove without any bleeding. The reduced level of TSH pre-surgery makes the bones thinner and they hold less calcium. Once the thyroid gland is removed this effect is immediately reversed and the bones take on a lot of calcium from the blood to replace what has been lost due to having a low TSH - just at the moment the parathyroid glands that regulate this are bruised and often are not working fully for the first 7-10 days post surgery. This makes low calcium after thyroidectomy for Graves' disease very common. Pre surgery I like to replace vitamin D as this is usually relatively low in UK patients. Doing this helps to modulate the bone's response to parathyroid bruising or damage and help prevent symptoms of a low calcium post surgery. This replacement of vitamin D and pre-op preparation with Potassium Iodide helps to significantly reduce the risk of voice change and duration of any low calcium symptoms perceived. Some of my biggest impact clinical research has been on the role of vitamin D in thyroid function. My surgery outcomes can be found here

Mr Kirkby-Bott is happy to consult on any stage of diagnosis or treatment for this condition

Thyroid Goitres. Solitary nodules & Cancer

Thyroid cancer is uncommon and cured in >93%. Mr James Kirkby-Bott explains

Thyroid nodules are very common. Either alone or as part of a multi-nodular Goitre. A goitre is the term used to describe an enlarged thyroid gland. As the thyroid enlarges it is often due to an asymmetrical enlargement of nodules within a goitre or a single sided nodule. Thyroid cancer is uncommon. The most common 2 types can be cured in >93%. All types are best treated by surgery.

Symptoms of a Goitre

These can be felt in the neck and depending upon a combination of factors can cause 'compressive' symptoms such as difficulty swallowing or a sense of choking in certain positions. Especially lying flat at night. Goitres usually have a normal thyroid function, but can be associated with either an over or under active gland due to an autoimmune condition such as Hashimotos's disease or Graves' disease. 

Diagnosis of Thyroid nodules & Goitre

First a blood test is needed to look for thyroid function and presence of autoantibodies such as TPO. At this stage we also check your parathyroid function and vitamin D levels in case surgery might be indicated. 

An ultrasound of the neck is required to look at the number, size, position and characteristics of these nodules. Ultrasound is very reliable for diagnosing benign thyroid nodules. If the ultrasound suggests all are benign then no further investigation of their nature is required. If the ultrasound is unable to say a nodule is definitely benign then a needle sample is needed for cytology to help make the diagnosis. This can diagnose a benign lump or say a lump is clearly a cancer. But a significant proportion of lumps are made up of follicular cells and cytology cannot distinguish a benign follicular lump from a follicular thyroid cancer when follicular cells are present. In such cases the chance of the lump being cancer is low - about 20% - but not so low as to feel safe to ignore it. Because these are so slow growing we advice and offer surgery to remove the side with the undiagnosed nodule. This is called a thyroid lobectomy. It leaves behind enough normal thyroid not to require thyroid hormone replacement in the vast vast majority. However, we confirm this by checking your thyroid function after 6-8 weeks. If the histology (microscope examination) of the resected thyroid lobe is benign no further treatment is required. You will not develop calcium problems after a lobectomy, but voice change can still occur and is the main risk of a thyroid lobectomy. My results can be found here. 

If the histology does show a cancer then depending upon it's size and other features we usually recommend a completion thyroidectomy so that all your thyroid has been removed. You then require Levothyroxine to replace your thyroid hormone. This has dual roles. It replaces lost thyroid function but if given at a slightly higher dose will suppress any remnant thyroid cells to reduce the risk of recurrent disease. We can also offer Radioactive iodine to mop up any cells still left behind to also reduce the risk of disease recurrence. Because we have taken all of your thyroid out your body cannot make any thyroid proteins. As a part of follow up for thyroid cancer we can take  blood samples to look at thyroid protein levels after total thyroidectomy as if they do return it can signal recurrent disease which can then be located and treated. By doing this the risk of a shortened life span from a thyroid cancer is low. Most - over 93% have no recurrence and no reduction in their natural life span.

The vast majority of thyroid nodules are benign with normal function. Those that cause compressive symptoms are best treated by surgery. Usually a thyroid lobectomy is enough. Occasionally both sides are equally enlarged and a total thyroidectomy is required. Risks of surgery and post operation advice can also be found here.