Posted on by johanne_marais

Polysomnography: A word long enough to put you to sleep!

So, how did you sleep?

I ask with a greater level of intrigue than simply for the commitment of connecting with you. I ask, because I care. I ask because I am a scientist.

A hundred or so years ago, what we knew about sleep was that we sleep to alleviate sleepiness. Considering that humans spend nearly a third of our lives in the sleeping state, it should come as no surprise that I (and many sleep researchers before me) remain unsatisfied with that deduction. The velocity of sleep research had been exponentiated by Hans Berger’s measurements of the brain’s electrical activity, depicted as waveforms, which he called an electroencephalogram.

Since the tool of electroencephalography (or, EEG) came to the slumber party in the 1920’s, sleep scientists began inquiring into the effects of sleep deprivation on the body, the role of sleep on cognitive power and, remarkably, observing that different stages of sleep occur in cycles through the night. All this is possible with the understanding of the brain as a battery – a component in a circuit that has a finite capacity for work with the inevitable outcome of needing a recharge.

When you are in a state of wakeful awareness, following demands of “to-do” lists and preparing for meetings, your brain may be functioning at maximum capacity. Daydreaming on a walk through a park during lunchtime requires the brain to be far less acutely involved in paying attention. As you read, meditate, or begin drifting off to dreamland, the output of your brain slows down sequentially and allows the initiation of sleep.

A person’s sleep and wakefulness is partially at the mercy of the usual “sleep-hygiene” factors:

  • timing and amount of caffeine intake
  • the stimulation of light exposure and humidity of the sleep environment
  • stressful events in one’s day
  • the body’s apparent chronobiology
  • what was eaten before bed…

The phenomenon of sleep is as unique to your body and lifestyle as the print on your fingertips!

Yet, there are numerous internal decision-makers for adequate or disturbed sleep – some of which the sleeper may not even be aware of.

I work as a collaborator with a team of remarkable clinicians at Ezintsha, a research centre located adjacent to Wits Health Sciences campus, for patients with illnesses like TB or HIV that drive major public health issues in South Africa. The HIV epidemic is currently rather well managed by the early-stage intervention and widespread distribution of antiretroviral therapies across South Africa. This follows nearly three decades of devastation. However, with the prolonged life expectancy and improved quality of life available to people living with HIV, epidemiologists observed the inflation of other devastating epidemics like hypertension, diabetes, metabolic syndrome, and heart attacks.

Cardiometabolic risk indicators like high blood pressure, sugar intolerance and cholesterol imbalances are on the rise, and researchers in HIV-related trials begin to engage with a new class of reported symptoms: those of obstructive sleep apnoea. Obstructive sleep apnoea describes the short-lived but repeated pauses in breathing during sleep, often indicated by snoring. This is frightening to both the patient and housemates who have heard the gasping snores that accompany the breathless event but fear not! Obstructive sleep apnoea is treatable.

So, why is this story important?

Sleep apnoea remains underdiagnosed in the general South African population, despite as many as 30% of people being at risk for this sleep-related breathing disorder. Its side effects include daytime sleepiness, chronic inflammation, reduced motivation, brain fog, changes in mood and of course a further rise in those nasty cardiometabolic risk factors. Cardiometabolic diseases are responsible for one out of every five deaths in South Africa. This is a public health crisis, which we can aim to mitigate with routine diagnostics for obstructive sleep apnoea.

Without the foundation of an EEG, an even more comprehensive sleep measurement tool would never have been possible. Cue, polysomnography! Polysomnography measures brainwaves in various sleep stages, but the addition of other physiological measurements like heart rate, chest and belly movement, blood oxygen levels and air moving through the nose opens the door to diagnosing obstructive sleep apnoea through overnight sleep observation – which is exactly what I do! Polysomnography tells the story of how we sleep – I am simply the reader.

Posted on by ScientistSim

The dangers of misinformation and miscommunication

I will start this article, I’m fairly confident, the way that no good story has ever started:

I was standing in the line at home affairs last week. I happened to strike up the usual conversation one has at these places; “Why is the line so long? Do you need photos?  (It amazes me that no one ever knows the answer to this question!) Are we going to be here so long that the sun will absorb all of our moisture and when our families come looking for us all that will remain is our tortured souls still hoping for our passports?” Having run out of things to complain about, I asked my fellow brave soul what he did for a living. He was a very high powered investment banker who also had a PhD. I learnt that day that education truly is not enough when ignorance is a dominating plague.

I wish I had told this man I was a struggling actor or an astronaut – but then again he would have had an opinion on that too. “An astronaut? Really? I heard the earth is flat and the moon is Gorgonzola. Is that true? Wait, I know it’s true. So don’t respond.” I didn’t though. Sadly I said I was a HIV researcher and his face darkened. A frown dug its way into his forehead and I could hear the 10 ton piano that was about to fall on me strain in its support. “You know,” he said in a suddenly condescending tone, “I don’t buy this whole ‘HIV’ thing. (He actually did the inverted commas with his fingers, which somehow made the whole thing worse.) I heard that it was the Americans.” I realised by the way he sneered the last part of his sentence that nothing I said was ever going to change his opinion. Valiantly I tried to explain that HIV was a zoonosis and had jumped species on at least 3 different occasions. (Read more about why this doesn’t happen that often.) I spent what felt like an entire lifetime trying to convince him about the scientific evidence. And in the end, the best line emerging from this conversation was his, “Well, you can have your opinion and I will have mine.”

The benefit of having a science degree is knowing that the most popular opinion is not always the right one. Having been trained to question everything, I’ve since understood, is not a skill everyone has. In society, the loudest (most obnoxious!) person is the one who gets heard (once again think Donald Trump) while in science you will get laughed off of a conference stage without any data. This is possibly the root of misunderstandings in science. The people listen to the strongest voice and all the while the white coats are in a corner throwing around statistics. Even when scientists are completely right, some rapper may still convince a few people the earth is flat (see this hilarious exchange between B.O.B and Neil Degrasse Tyson – thank goodness for him!).

Another huge contributor to the hall of misunderstanding and strange theories is the media. Now let me be clear; it is not just the journalists who misinterpret. It is the job of a scientist to simplify and explain their work. One of my science heroines Françoise Barré-Sinoussi (co-discover of HIV), who I was privileged to hear speak, said that at the end of your life you do not remember the journal articles you published or how high their impact number was, but the lives you have changed with the work. If you can’t communicate and translate your work, who will it ever truly benefit? I find that if you can explain your project to your Granny so she understands why you are doing it and how it may help the world, you really understand it yourself.

As a postgrad it’s easy to feel lost; to feel that your work is too far removed from any kind of real-world application. It is easy to think that you’re just doing this to get a degree. However, it’s good to communicate your science for lots of reasons: 1) you can prevent misinterpretation, 2) you can make people feel that they can engage with science and not have their heads explode, 3) you can help scientists in queues at Home Affairs retain their sanity when non-scientists begin to ask questions and 4) you can feel relevant. It’s important to remember it really is our duty to not lock ourselves in a lab, but to reach out: to teach not only the uneducated but the ignorant too. It’s up to scientists to add their voice, otherwise we may be drowned out by the loudest opinions. It’s up to us to build public trust in science. If we are only heard when there is crisis then we are never heard in calm (see this article by Tolu Oni).

 

Scientist news cycle
How science communication works… (www.phdcomics.com)

There have been miscommunications that have done very serious damage too. One is most certainly the notion that vaccinating your child will result in autism (read here why this isn’t true). This has resulted in 100s of unnecessary deaths from measles in small children. Another is that HIV doesn’t cause AIDS, perpetuated by our very own ex-president Thabo Mbeki. Some “facts” are even started out of fear as a rumour: in a small town called Vulindela, wonderful things are being done by the organisation we work with (CAPRISA), to try to reduce unwanted pregnancies and HIV incidence. One of the proposed ways to do this was to insert IUDs into young girls following extensive education on the matter. The programme had to be stopped because one of the girls told all her peers that maggots would grow internally. Naturally teenage girls were then hesitant about IUDs. A far more famous case of misinformation is what happened to Hendrietta Lacks in 1951. With questionable ethical practice, doctors treating this woman took samples of her cervical cancer and made a cell line (cells that are descended from one cell and have the same genetic features) that was able to be kept in culture indefinitely. This cell line is one of the most widely used in clinical trials today; a form of which we use to test the efficacy of HIV vaccines. This woman had no idea what these doctors and scientists were doing and many years later, her family thought that she was still alive because scientists had “immortalised” her cells (Read more about this incredible story in Rebecca Skoot’s novel).

Miscommunications in science can be deadly and disturbing and we have to find ways of changing this. As a PhD student it is my job to pick the hard questions and find answers but, it is imperative that I find ways to explain the hard questions in a way that anyone can engage with them. Solutions can come from the strangest places, even the line in home affairs.