An elusive illness - coping with rare glandular condition which causes fatigue
After months of unexplained fatigue, migraines and low mood, Deirdre Kelly finally learned the cause of her symptoms - hyperparathyroidism, a little known glandular condition which causes excess calcium in the blood
Six months of fatigue, migraines and double vision reached a crescendo for postgraduate student Deirdre Kelly when she collapsed in a heap at the gates of the University of Limerick.
She been struggling with a raft of unexplained but debilitating symptoms for months when she experienced an overwhelming sensation of dizziness and sweating as she drove to meet her thesis supervisor.
Deirdre slammed on the brakes and was stumbling out of the car when her legs gave way.
That was in March 2014 and Deirdre, who was studying the history of art, had been struggling with fatigue, low mood and migraines since the previous October.
Because she was in her 40s - she's now 48 - the Limerick woman had initially been diagnosed as perimenopausal and had started a course of Hormone Replacement Therapy (HRT).
Some months later, however, HRT didn't appear to be helping, and by the following March, Deirdre's migraines had become very frequent - she was getting full-scale attacks, complete with auras and double vision every two or three days. Eventually, she stopped taking HRT, she recalls.
Her migraines stopped too, but as it was to emerge, things weren't really improving.
On March 26, when Deirdre was driving from her home in the village of Shanagolden to attend a meeting with her PhD supervisor at the university, she became dizzy and sweaty and experienced a strange tingling sensation in her fingers and toes.
"I pulled over, got out of the car, got fresh air, drank some water and then continued," she recalls.
However, when she reached the campus gates, the same thing happened - except that when she left the car this time, she collapsed.
Subsequent blood tests showed nothing apart from slightly high calcium levels. Two days later, however, she got another, similar attack. The following week, she was suddenly unable to swallow.
"It was very frightening," says Deirdre, who was referred to a consultant endocrinologist. She met with him in September of that year and was diagnosed straightaway.
"He said he believed I had hyperparathyroidism. He knew from the chronic fatigue, the rapid heartbeat, palpitations, anxiety, low mood and other symptoms."
A series of tests and scans confirmed the expert's diagnosis. Deirdre was very lucky to be diagnosed - because little is known about her condition and it's suspected that many cases go undiagnosed.
Experts don't know for sure what causes primary hyperparathyroidism, a condition where the parathyroid glands in the neck malfunction and release excess calcium into the body, causing a range of problems, explains Professor James O'Hare, consultant endocrinologist at the University Hospital Limerick Group and Adjunct Associate Professor at the University of Limerick.
However, the condition is two or three times more common in women and the average age of onset is 60 - but, he points out, patients can be affected from age 15 right up to age 90 or over.
"We don't really know the cause of primary hyperparathyroidism but it's thought to be genetic and to result from the mutation of the genes that control parathyroid hormone (PTH) cell growth.
"When these cells malfunction, they produce excess parathyroid hormone which causes excess calcium to be released."
The parathyroid hormone, he explains, is the main regulator of calcium levels in the blood.
"When it malfunctions, the calcium levels in the blood increase and cause kidney stones and can cause kidney damage."
High calcium levels can cause depression and fatigue, damaged brain function and in extreme cases, even cause the heart to stop - so, in severe cases, it is potentially fatal. Primary hyperparathyroidism is believed to affect approximately one-in-5,000 people, but it's thought that many cases are not being diagnosed.
"Traditionally, it is defined as where blood calcium levels are consistently elevated and where parathyroid hormone levels are elevated," Prof O'Hare explains.
The whole problem, as Deirdre discovered, had begun in her neck, in the tiny parathyroid glands which produce a hormone called PTH (parathyroid hormone).
There are four such glands, each of which is about the size of a large grain of rice. They are situated at the back of the thyroid gland.
In about half of cases, when problems occur, the malfunctioning glands must be removed in what is a very skilled operation: "You are operating in a very confined area with a lot of delicate structures nearby and it requires considerable skill and experience," explains Prof O'Hare, who adds that only about 50pc of patients diagnosed with the condition receive the operation - and they only get it when a clear-cut benefit can be demonstrated.
For the other 50pc, treatment revolves around close observation of the patient's symptoms or medication to control the parathyroid hormone levels or to strengthen the bones.
As a result of her condition, Deirdre had to take a year's absence from her studies and undergo surgery on two occasions.
The first operation, in December 2014, removed a series of nodules on her thyroid gland.
In the second, which took place in February 2015, three of her four parathyroid glands had to be removed because they were malfunctioning.
A major problem with this condition, says Prof O'Hare is the lack of research carried out on it: "There has been no consistent community studies done because the measurement of parathyroid hormone only became reliable in the last 20 years.
"We have limited information on the condition, and on its long-term natural history, that is, over a period of 20 years."
Part of the difficulty in diagnosing it, he explains, is that while some patients will display a number of symptoms known to be closely associated to the condition, others manifest symptoms which may or may not be associated with the condition - while in some cases, there are no symptoms at all.
"Kidney stones with calcium is a classic marker of primary HPT," he explains.
"These days anyone who comes into hospital with a kidney stone will have their calcium levels measured."
The second way the disease can be spotted is through osteoporosis, where it may come to medical attention via a fractured bone.
"Most GPs will be alert to investigating someone who has had a bone fracture and the person will be sent for a DXA, or bone density scan. If osteoporosis is identified, checking for HPT will be suggested.
The condition can also present in the form of bone cysts - for example, in the jawbone - but this usually indicates an advanced form of the condition.
More frighteningly, hyperparathyroidism can also present through a 'hypercalcaemic crisis', which can result in vomiting and kidney failure. This, he says, is a life-threatening condition in which a patient presents with kidney failure, is drowsy, can experience cardiac arrest and can die unless the problem is detected and treated.
Another category of symptoms presented by patients is vague and non-specific - patients may complain, for example, of tiredness, fatigue, unexpected weight loss, vague abdominal pain, aches and pains, mood changes towards depression, or of frequently getting up in the night to urinate.
The majority of people who present with these unspecified symptoms may end up with an equally vague diagnosis - however, he says, some patients will have high calcium levels, which is a strong indicator.
"There has been a big improvement in GP awareness and screening for calcium levels."
The third and largest category of patients with HPT are those without any symptoms at all. These are often only picked up by accident.
"Their high calcium levels may be picked up in routine screening for something else - this is particularly the case in older patients," Prof O'Hare explains.
For Deirdre, who is soon to be conferred with the prestigious title of Doctor of Art History following the completion of her PhD course, life is improving steadily - but she still experiences significant pain.
"I'm okay now but I still have a lot of tiredness and bone pain in my neck," she says, adding that she is on medication for an underactive thyroid gland, and also has high cholesterol, a problem which is linked to her problems with the parathyroid glands.
"I had three glands removed as they were malfunctioning, but it took a whole year to get diagnosed. It was the most awful year of my life!"
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