Her Incredible Sense of Smell Led Scientists to Develop the First Parkinson's Test
Thirty-seven years ago, Joy Milne, a nurse from Perth, Scotland, noticed a musky odor coming from her husband, Les.
To her surprise, at a local support group meeting, she caught the familiar scent once again, hanging over the group like a cloud.
At first, Milne thought the smell was a result of bad hygiene and badgered her husband to take longer showers. But when the smell persisted, Milne learned to live with it, not wanting to hurt her husband's feelings.
Twelve years after she first noticed the "woodsy" smell, Les was diagnosed at the age of 44 with Parkinson's Disease, a neurodegenerative condition characterized by lack of dopamine production and loss of movement. Parkinson's Disease currently affects more than 10 million people worldwide.
Milne spent the next several years believing the strange smell was exclusive to her husband. But to her surprise, at a local support group meeting in 2012, she caught the familiar scent once again, hanging over the group like a cloud. Stunned, Milne started to wonder if the smell was the result of Parkinson's Disease itself.
Milne's discovery led her to Dr. Tilo Kunath, a neurobiologist at the Centre for Regenerative Medicine at the University of Edinburgh. Together, Milne, Kunath, and a host of other scientists would use Milne's unusual sense of smell to develop a new diagnostic test, now in development and poised to revolutionize the treatment of Parkinson's Disease.
"Joy was in the audience during a talk I was giving on my work, which has to do with Parkinson's and stem cell biology," Kunath says. "During the patient engagement portion of the talk, she asked me if Parkinson's had a smell to it." Confused, Kunath said he had never heard of this – but for months after his talk he continued to turn the question over in his mind.
Kunath knew from his research that the skin's microbiome changes during different disease processes, releasing metabolites that can give off odors. In the medical literature, diseases like melanoma and Type 2 diabetes have been known to carry a specific scent – but no such connection had been made with Parkinson's. If people could smell Parkinson's, he thought, then it stood to reason that those metabolites could be isolated, identified, and used to potentially diagnose Parkinson's by their presence alone.
First, Kunath and his colleagues decided to test Milne's sense of smell. "I got in touch with Joy again and we designed a protocol to test her sense of smell without her having to be around patients," says Kunath, which could have affected the validity of the test. In his spare time, Kunath collected t-shirt samples from people diagnosed with Parkinson's and from others without the diagnosis and gave them to Milne to smell. In 100 percent of the samples, Milne was able to detect whether a person had Parkinson's based on smell alone. Amazingly, Milne was even able to detect the "Parkinson's scent" in a shirt from the control group – someone who did not have a Parkinson's diagnosis, but would go on to be diagnosed nine months later.
From the initial study, the team discovered that Parkinson's did have a smell, that Milne – inexplicably – could detect it, and that she could detect it long before diagnosis like she had with her husband, Les. But the experiments revealed other things that the team hadn't been expecting.
"One surprising thing we learned from that experiment was that the odor was always located in the back of the shirt – never in the armpit, where we expected the smell to be," Kunath says. "I had a chance meeting with a dermatologist and he said the smell was due to the patient's sebum, which are greasy secretions that are really dense on your upper back. We have sweat glands, instead of sebum, in our armpits." Patients with Parkinson's are also known to have increased sebum production.
With the knowledge that a patient's sebum was the source of the unusual smell, researchers could go on to investigate exactly what metabolites were in the sebum and in what amounts. Kunath, along with his associate, Dr. Perdita Barran, collected and analyzed sebum samples from 64 participants across the United Kingdom. Once the samples were collected, Barran and others analyzed it using a method called gas chromatography mass spectrometry, or GS-MC, which separated, weighed and helped identify the individual compounds present in each sebum sample.
Barran's team can now correctly identify Parkinson's in nine out of 10 patients – a much quicker and more accurate way to diagnose than what clinicians do now.
"The compounds we've identified in the sebum are not unique to people with Parkinson's, but they are differently expressed," says Barran, a professor of mass spectrometry at the University of Manchester. "So this test we're developing now is not a black-and-white, do-you-have-something kind of test, but rather how much of these compounds do you have compared to other people and other compounds." The team identified over a dozen compounds that were present in the sebum of Parkinson's patients in much larger amounts than the control group.
Using only the GC-MS and a sebum swab test, Barran's team can now correctly identify Parkinson's in nine out of 10 patients – a much quicker and more accurate way to diagnose than what clinicians do now.
"At the moment, a clinical diagnosis is based on the patient's physical symptoms," Barran says, and determining whether a patient has Parkinson's is often a long and drawn-out process of elimination. "Doctors might say that a group of symptoms looks like Parkinson's, but there are other reasons people might have those symptoms, and it might take another year before they're certain," Barran says. "Some of those symptoms are just signs of aging, and other symptoms like tremor are present in recovering alcoholics or people with other kinds of dementia." People under the age of 40 with Parkinson's symptoms, who present with stiff arms, are often misdiagnosed with carpal tunnel syndrome, she adds.
Additionally, by the time physical symptoms are present, Parkinson's patients have already lost a substantial amount of dopamine receptors – about sixty percent -- in the brain's basal ganglia. Getting a diagnosis before physical symptoms appear would mean earlier interventions that could prevent dopamine loss and preserve regular movement, Barran says.
"Early diagnosis is good if it means there's a chance of early intervention," says Barran. "It stops the process of dopamine loss, which means that motor symptoms potentially will not happen, or the onset of symptoms will be substantially delayed." Barran's team is in the processing of streamlining the sebum test so that definitive results will be ready in just two minutes.
"What we're doing right now will be a very inexpensive test, a rapid-screen test, and that will encourage people to self-sample and test at home," says Barran. In addition to diagnosing Parkinson's, she says, this test could also be potentially useful to determine if medications were at a therapeutic dose in people who have the disease, since the odor is strongest in people whose symptoms are least controlled by medication.
"When symptoms are under control, the odor is lower," Barran says. "Potentially this would allow patients and clinicians to see whether their symptoms are being managed properly with medication, or perhaps if they're being overmedicated." Hypothetically, patients could also use the test to determine if interventions like diet and exercise are effective at keeping Parkinson's controlled.
"We hope within the next two to five years we will have a test available."
Barran is now running another clinical trial – one that determines whether they can diagnose at an earlier stage and whether they can identify a difference in sebum samples between different forms of Parkinson's or diseases that have Parkinson's-like symptoms, such as Lewy Body Dementia.
"Within the next one to two years, we hope to be running a trial in the Manchester area for those people who do not have motor symptoms but are at risk for developing dementia due to symptoms like loss of smell and sleep difficulty," Barran says. "If we can establish that, we can roll out a test that determines if you have Parkinson's or not with those first pre-motor symptoms, and then at what stage. We hope within the next two to five years we will have a test available."
But a definitive Parkinson's test, however revolutionary, would likely not be made available to the general population – at least, not for a while.
"We would likely first give this test to people who are at risk due to a genetic predisposition, or who are at risk based on prodomal symptoms, like people who suffer from a REM sleep disorder who have a 50 to 70 percent chance of developing Parkinson's within a ten year period," Barran says. "Those would be people who would benefit from early therapeutic intervention. For the normal population, it isn't beneficial at the moment to know until we have therapeutic interventions that can be useful."
Milne's husband, Les, passed away from complications of Parkinson's Disease in 2015. But thanks to him and the dedication of his wife, Joy, science may have found a way to someday prolong the lives of others with this devastating disease.
[Ed. Note: This hit article from our archives originally ran on September 3, 2019.]
A few days before Christmas 2015, Paige Alexandria, a 28-year-old counselor at the Austin Women's Health Center in Texas, found out she was pregnant.
Alexandria had missed the cutoff for a medication abortion by three days.
"It was an unplanned pregnancy, and instantaneously I knew I needed an abortion," Alexandria recalls. Already a mother of two children, one with special needs, a third child was not something Alexandria and her husband felt prepared to take on. "Mentally, I knew my limit. I wasn't prepared for a third and I didn't want one," she says.
At an ultrasound appointment one week later, scans showed she was a little over eight weeks pregnant. Alexandria opted to have an abortion as soon as possible, and preferably with medication. "I really wanted to avoid a surgical abortion," she says. "It sounded a lot more invasive, and I'm already uncomfortable with pap smears and pelvic exams, so I initially went in wanting to do the pill."
But at the time, medication guidelines stipulated that one of the pills, called Mifepristone, could only be prescribed to end a pregnancy at eight weeks gestation or earlier – Alexandria had missed the cutoff by three days. If she wanted to end the pregnancy, she would need to undergo a surgical abortion, otherwise known as a vacuum aspiration abortion.
With a vacuum aspiration abortion, doctors dilate the cervix and manually aspirate out the contents of the uterus. Medication abortion, on the other hand, consists of the patient taking two pills – Mifepristone, which blocks the hormones that help the pregnancy develop, and Misoprostol, which empties the uterus over a period of days, identical to a miscarriage.
Alexandria was upset about the change of plans but resolute in her decision to end the pregnancy. "The fact that I didn't really have a choice in how my procedure was performed has made the experience just a little more sensitive for me," she says. She scheduled the earliest available appointment for a surgical abortion.
Paige Alexandria would have chosen to terminate her pregnancy with medication if the regulations were less stringent.
(Photo courtesy of Alexandria)
Like Alexandria, many people looking to terminate a pregnancy opt to do so with medication. According to research from the Guttmacher Institute, medication abortions accounted for nearly 40 percent of all abortions in the year 2017 – a marked increase from 2001, when medication abortions only accounted for roughly five percent of terminations. Taken 24-48 hours apart, Mifepristone and Misoprostol have a 95-99 percent success rate in terminating pregnancies up to 63 days – or nine weeks – of gestation, according to the American College of Obstetrics and Gynecology (ACOG).
But even though the World Health Organization (WHO) considers medical abortion to be highly safe and effective, the medication is still carefully guarded in the United States: Mifepristone is only available for terminating pregnancies up to 10 weeks gestation, per the FDA, even though limited research suggests that both are safe and effective at terminating pregnancies between 12 and 20 weeks.
Additionally, a separate set of regulations known as a Risk Evaluation and Mitigation Strategy (REMS) means that patients can only take Mifepristone under specific circumstances. Mifepristone must be distributed in person by a healthcare provider – usually interpreted in most states as a doctor or nurse practitioner – who has registered with the drug's manufacturer. The medication cannot be distributed through a pharmacy, so doctors who wish to provide the drug must stock the medication in-office, and both the provider and the patient must sign a form that warns them of the "risk of serious complications associated with Mifepristone," according to the FDA.
"REMS is a set of restrictions that the FDA puts on the distribution of drugs it considers dangerous or risky in some way," says Dr. Elizabeth Raymond, an OB-GYN and senior medical associate at Gynuity Health Projects. Although not always called REMS, these restrictions have been imposed on Mifepristone since the medication was approved by the FDA in 2000, Raymond says.
Raymond is part of a growing number of physicians and researchers who want to eliminate the REMS requirements for Mifepristone, also known by its brand name Mifeprex. In 2017, Raymond and several other physicians authored a paper in the New England Journal of Medicine (NEJM) arguing that Mifepristone is extremely safe and needlessly over-regulated.
"When the FDA first approved [Mifepristone] and imposed these requirements, they might have made sense 19 years ago when there was limited information about the use of this treatment in the United States," says Dr. Daniel Grossman, director at Advancing New Standards in Reproductive Health at UCSF and co-author of the 2017 report in the NEJM. "Now, after 19 years, it's clear that this medication is very safe, and safer than a lot of others available in a pharmacy."
Since 2000, Mifepristone has been implicated in 19 deaths, making its mortality rate 0.00063 percent.
According to their research, over three million people have taken Mifepristone since it was approved in 2000. Since then, Mifepristone has been implicated in 19 deaths, making its mortality rate 0.00063 percent. Even then, the risk is inflated, Grossman says.
"The requirement is that practitioners need to report any deaths that occur after taking these medications, and so you'll see deaths included in that figure which are homicides or suicides or something unrelated to taking Mifepristone," says Grossman. In contrast, Acetaminophen – better known as Tylenol – was associated with 458 overdose deaths between 1990 and 1998, as well as 56,000 emergency room visits and 26,000 hospitalizations. Sildenafil, better known as Viagra, was linked to 762 deaths in the first twenty months after it was approved by the FDA. Yet neither Tylenol nor Viagra have been burdened with the same REMS restrictions as Mifepristone.
"It's clearly about more than just the safety of the medication at this point," says Grossman. "It's more about stigma related to abortion and politics."
For people who want a medication abortion, the REMS requirements mean they often need to take off work to schedule a doctor's appointment, arrange for transportation and childcare, and then arrange an additional doctor's appointment days afterward to take the second dose of medication. While surgical abortion procedures are quicker (usually a one-day outpatient procedure, depending on gestation), many people prefer having the abortion in the comfort of their home or surrounded by family instead.
Paige Alexandria, who counsels people seeking abortions at her job, says that survivors of sexual violence often prefer medical abortions to surgical ones. "A lot of time survivors have a trauma associated with medical instruments or having pelvic exams, and so they're more comfortable taking a pill," she says.
But REMS also creates a barrier for healthcare providers, Grossman says. Stocking the medication in-office is "a hassle" and "expensive," while others are reluctant to register their name with the drug manufacturer, fearing harassment or violence from anti-choice protestors. As a result, the number of practitioners willing to provide medical abortions nationwide is severely limited. According to Grossman's own research published in the journal Obstetrics and Gynecology, 28 percent of OBGYNs admitted they would administer medication abortions if it were possible to write a prescription for Mifepristone rather than stock it in-office.
Amazingly, the restrictions on Mifepristone have loosened since it first came on the market. In 2016, the FDA updated the guidelines on Mifepristone to allow its use until 10 weeks gestation, up from eight weeks. But doctors say the REMS restrictions should be eliminated completely so that people can obtain abortions as early as possible.
"REMS restrictions inhibit people from being able to get a timely abortion," says Raymond, who stresses that abortion is generally more comfortable, more affordable, and safer for women the earlier it's done. "Abortion is very safe no matter when you get it, but it's also easier because there's less risk for bleeding, infections, or other complications," Raymond says. Abortions that occur earlier than eight weeks of gestation have a complication rate of less than one percent, while an abortion done at 12 or 13 weeks has a three to six percent chance of complications.
And even for people who want a medication abortion early on in their pregnancy, REMS restrictions make it so that they may not have time to obtain it before the 10-week period lapses, Raymond says.
"If you're seven weeks pregnant but it takes you three weeks to figure out travel and childcare arrangements to go into the doctor and take this medication, now you're at the cutoff date," she says. "Even if you manage to get an abortion at nine weeks, that's still a later gestational age, and so the risks are increased."
In 2016, at a little over nine weeks gestation, Alexandria completed her abortion by having a D&E. But because she didn't have anyone to drive her home after the procedure, she wasn't able to have sedation throughout, something she describes as "traumatic."
"I had the abortion completely aware and coherent, and paired with the fact that I hadn't even wanted a surgical abortion in the first place made it harder to deal with," Alexandria says.
"When you're just a day or two past eight weeks and you want an abortion – why is medication not immediately available?"
Today, Alexandria shares her story publicly to advocate for abortion care. Although she doesn't regret her surgical abortion and acknowledges that not everyone experiences surgical abortion the same way she did, she does wish that she could have gone a different route.
"If I had to do it over, I would still try to do the pill, because [the surgical abortion] was such a terrifying experience," she says. "When you're just a day or two past eight weeks and you want an abortion – why is medication not immediately available? It just doesn't make sense."
Kelly Mantoan was nursing her newborn son, Teddy, in the NICU in a Philadelphia hospital when her doctor came in and silently laid a hand on her shoulder. Immediately, Kelly knew what the gesture meant and started to sob: Teddy, like his one-year-old brother, Fulton, had just tested positive for a neuromuscular condition called spinal muscular atrophy (SMA).
The boys were 8 and 10 when Kelly heard about an experimental new treatment, still being tested in clinical trials, called Spinraza.
"We knew that [SMA] was a genetic disorder, and we knew that we had a 1 in 4 chance of Teddy having SMA," Mantoan recalls. But the idea of having two children with the same severe disability seemed too unfair for Kelly and her husband, Tony, to imagine. "We had lots of well-meaning friends tell us, well, God won't do this to you twice," she says. Except that He, or a cruel trick of nature, had.
In part, the boys' diagnoses were so devastating because there was little that could be done at the time, back in 2009 and 2010, when the boys were diagnosed. Affecting an estimated 1 in 11,000 babies, SMA is a degenerative disease in which the body is deficient in survival motor neuron (SMN) protein, thanks to a genetic mutation or absence of the body's SNM1 gene. So muscles that control voluntary movement – such as walking, breathing, and swallowing – weaken and eventually cease to function altogether.
Babies diagnosed with SMA Type 1 rarely live past toddlerhood, while people diagnosed with SMA Types 2, 3, and 4 can live into adulthood, usually with assistance like ventilators and feeding tubes. Shortly after birth, both Teddy Mantoan and his brother, Fulton, were diagnosed with SMA Type 2.
The boys were 8 and 10 when Kelly heard about an experimental new treatment, still being tested in clinical trials, called Spinraza. Up until then, physical therapy was the only sanctioned treatment for SMA, and Kelly enrolled both her boys in weekly sessions to preserve some of their muscle strength as the disease marched forward. But Spinraza – a grueling regimen of lumbar punctures and injections designed to stimulate a backup survival motor neuron gene to produce more SMN protein – offered new hope.
In clinical trials, after just a few doses of Spinraza, babies with SMA Type 1 began meeting normal developmental milestones – holding up their heads, rolling over, and sitting up. In other trials, Spinraza treatment delayed the need for permanent ventilation, while patients on the placebo arm continued to lose function, and several died. Spinraza was such a success, and so well tolerated among patients, that clinical trials ended early and the drug was fast-tracked for FDA approval in 2016. In January 2017, when Kelly got the call that Fulton and Teddy had been approved by the hospital to start Spinraza infusions, Kelly dropped to her knees in the middle of the kitchen and screamed.
Spinraza, manufactured by Biogen, has been hailed as revolutionary, but it's also not without drawbacks: Priced per injection, just one dose of Spinraza costs $125,000, making it one of the most expensive drugs on the global market. What's worse, treatment requires a "loading dose" of four injections over a four-week period, and then periodic injections every four months, indefinitely. For the first year of treatment, Spinraza treatment costs $750,000 – and then $375,000 for every year thereafter.
Last week, a competitive treatment for SMA Type 1 manufactured by Novartis burst onto the market. The new treatment, called Zolgensma, is a one-time gene therapy intended to be given to infants and is currently priced at $2.125 million, or $425,000 annually for five years, making it the most expensive drug in the world. Like Spinraza, Zolgensma is currently raising challenging questions about how insurers and government payers like Medicaid will be able to afford these treatments without bankrupting an already-strained health care system.
To Biogen's credit, the company provides financial aid for Spinraza patients with private insurance who pay co-pays for treatment, as well as for those who have been denied by Medicaid and Medicare. But getting insurance companies to agree to pay for Spinraza can often be an ordeal in itself. Although Fulton and Teddy Mantoan were approved for treatment over two years ago, a lengthy insurance battle delayed treatment for another eight months – time that, for some SMA patients, can mean a significant loss of muscular function.
Kelly didn't notice anything in either boy – positive or negative – for the first few months of Spinraza injections. But one day in November 2017, as Teddy was lowered off his school bus in his wheelchair, he turned to say goodbye to his friends and "dab," – a dance move where one's arms are extended briefly across the chest and in the air. Normally, Teddy would dab by throwing his arms up in the air with momentum, striking a pose quickly before they fell down limp at his sides. But that day, Teddy held his arms rigid in the air. His classmates, along with Kelly, were stunned. "Teddy, look at your arms!" Kelly remembers shrieking. "You're holding them up – you're dabbing!"
Teddy and Fulton Mantoan, who both suffer from spinal muscular atrophy, have seen life-changing results from Spinraza.
(Courtesy of Kelly Mantoan)
Not long after Teddy's dab, the Mantoans started seeing changes in Fulton as well. "With Fulton, we realized suddenly that he was no longer choking on his food during meals," Kelly said. "Almost every meal we'd have to stop and have him take a sip of water and make him slow down and take small bites so he wouldn't choke. But then we realized we hadn't had to do that in a long time. The nurses at school were like, 'it's not an issue anymore.'"
For the Mantoans, this was an enormous relief: Less choking meant less chance of aspiration pneumonia, a leading cause of death for people with SMA Types 1 and 2.
While Spinraza has been life-changing for the Mantoans, it remains painfully out of reach for many others. Thanks to Spinraza's enormous price tag, the threshold for who gets to use it is incredibly high: Adult and pediatric patients, particularly those with state-sponsored insurance, have reported multiple insurance denials, lengthy appeals processes, and endless bureaucracy from insurance and hospitals alike that stand in the way of treatment.
Kate Saldana, a 21-year-old woman with Type 2 SMA, is one of the many adult patients who have been lobbying for the drug. Saldana, who uses a ventilator 20 hours each day, says that Medicaid denied her Spinraza treatments because they mistakenly believed that she used a ventilator full-time. Saldana is currently in the process of appealing their decision, but knows she is fighting an uphill battle.
Kate Saldana, who suffers from Type 2 SMA, has been fighting unsuccessfully for Medicaid to cover Spinraza.
(Courtesy of Saldana)
"Originally, the treatments were studied and created for infants and children," Saldana said in an e-mail. "There is a plethora of data to support the effectiveness of Spinraza in those groups, but in adults it has not been studied as much. That makes it more difficult for insurance to approve it, because they are not sure if it will be as beneficial."
Saldana has been pursuing treatment unsuccessfully since last August – but others, like Kimberly Hill, a 32-year-old with SMA Type 2, have been waiting even longer. Hill, who lives in Oklahoma, has been fighting for treatment since Spinraza went on the U.S. market in December 2016. Because her mobility is limited to the use of her left thumb, Hill is eager to try anything that will enable her to keep working and finish a Master's degree in Fire and Emergency Management.
"Obviously, my family and I were elated with the approval of Spinraza," Hill said in an e-mail. "We thought I would finally have the chance to get a little stronger and healthier." But with Medicare and Medicaid, coverage and eligibility varies wildly by state. Earlier this year, Medicaid approved Spinraza for adult patients only if a clawback clause was attached to the approval, meaning that under certain conditions the Medicaid funds would need to be paid back. Because of the clawback clause, hospitals have been reluctant to take on Spinraza treatments, effectively barring adult Medicaid patients from accessing the drug altogether.
Hill's hospital is currently in negotiations with Medicaid to move forward with Spinraza treatment, but in the meantime, Hill is in limbo. "We keep being told there is nothing we can do, and we are devastated," Hill said.
"I felt extremely sad and honestly a bit forgotten, like adults [with SMA] don't matter."
Between Spinraza and its new competitor, Zolgensma, some are speculating that insurers will start to favor Zolgensma coverage instead, since the treatment is shorter and ultimately cheaper than Spinraza in the long term. But for some adults with SMA who can't access Spinraza and who don't qualify for Zolgensma treatment, the issue of what insurers will cover is moot.
"I was so excited when I heard that Zolgensma was approved by the FDA," said Annie Wilson, an adult SMA patient from Alameda, Calif. who has been fighting for Spinraza since 2017. "When I became aware that it was only being offered to children, I felt extremely sad and honestly a bit forgotten, like adults [with SMA] don't matter."
According to information from a Biogen representative, more than 7500 people worldwide have been treated with Spinraza to date, one third of whom are adults.
While Spinraza has been revolutionary for thousands of patients, it's unclear how many more lives state agencies and insurance companies will allow it to save.