CLOSE
iStock
iStock

4 Hopeful Approaches to the Future of Alzheimer's Treatment

iStock
iStock

Anyone who has watched the slow unraveling of the mind of a loved one to Alzheimer’s disease knows how crucial it is to develop new treatments. In America alone, currently more than 5.3 million people are living with Alzheimer’s and 15 million are providing care for loved ones with the disease. Unless treatments are developed to slow or even cure it, 28 million baby boomers will fall ill with Alzheimer's by 2040, consuming 24 percent of Medicare spending, according to a report from the 2015 Alzheimer’s Association International Conference (AAIC).

Alzheimer’s, an aggressive form of age-related dementia (of which there are several forms), is a result of accumulations and “misfolding” of proteins in the brain known as amyloid fibrils and tau tangles. In large amounts, these proteins are toxic to brain cells and cause degeneration.

But there is hope on the horizon for earlier detection due to new research, and new studies into treatments that may eventually lead to drugs and, possibly, a cure. Since Alzheimer’s is generally considered an elderly person’s disease, very early onset Alzheimer’s—which can begin as early as age 50—often goes undetected until it’s far too late for significant symptom treatment. That's why earlier detection is such a focus of research. 

1. Testing Saliva May Allow for Earlier Detection

Alzheimer’s researchers are excited about the potential of a new saliva test, the work of a neuroscience graduate student at the University of Alberta, Canada named Shradda Sapkota, who presented her research at the AAIC in July. Using a form of protein analysis called liquid chromatography-mass spectrometry (LCMS), researchers analyzed saliva samples to determine which substances were predominant in the saliva of Alzheimer’s patients, and considered this in conjunction with cognitive information on the patients. The results suggest that higher levels of certain substances are present in the blood of Alzheimer’s patients and predicted “worse episodic memory performance” and “slower speed in processing information.

Currently, no known blood or saliva test exists, though research has and continues to be done on potential blood-based biomarkers and a saliva test that could be used for early detection. “This is the first we’ve seen a potential saliva test presented,” Heather Snyder, director of medical and scientific operations at the Alzheimer’s Association, tells mental_floss. While it’s still in the very early days, we are going to need this tool, and it may be a low-cost way to look at who will need more aggressive screening and treatment.”

2. Sampling Cerebrospinal Fluid: the Canary in the Coal Mine

The cerebrospinal fluid (CSF) that offers protection to the brain and spinal cord might also contain a key biomarker of Alzheimer’s. When the brain experiences injury or toxicity, certain proteins are released into the CSF. One such protein, neurogranin—which is found only in the brain—has turned up in significantly higher amounts in the CSF of Alzheimer’s patients, suggesting it may be a powerful marker for diagnosis and prognosis of Alzheimer’s. However, this is a more invasive form of obtaining diagnosis, usually reserved for those who are younger or in what is known as “mild cognitive impairment” stage, where they still have relatively good memory and functioning.

The earlier Alzheimer’s is caught, the better the effectiveness of existing medications like Aricept. These medications don’t slow the disease or cure it but, says Snyder, “they turn up the volume so the brain cells that are still there can talk to one another longer—like a hearing aid.”

3. Imaging Inflammation: PET Scans Offer Noninvasive Diagnostics

PET scan technology, an imaging technique in which a radioactive tracer is used to look for disease in the body, has made it possible to isolate out tau tangles in the brain, which—along with amyloid plaques—are a key marker of Alzheimer’s. The presence of tau tangles helps to understand how advanced a person’s disease may be. PET scan imaging is also a relatively noninvasive detection method that may help with earlier diagnosis. “We’ve seen real development of this technology,” Snyder says. “It gives us the ability to look at the change and build-up of proteins over time in the brain.” The imaging can also be used to track inflammation, whose role in Alzheimer’s is still being investigated. PET scans can also monitor microglial cells, the brain’s immune cells, by tracking a protein that turns up when these healthy cells are destroyed and give a better picture of brain health.

4. An Inhibitor Molecule Breaks the Cycle

Of the breakthroughs that hold the most promise for a cure, inhibitor molecules, which bind to enzymes and proteins and help keep their homeostasis, show potential to stop formation of the amyloid proteins that build up in Alzheimer’s disease. One such molecule, known as Brichos,” which is technically a “chaperone” molecule—a type of molecule that helps proteins in the brain to form properly—has the ability to stick to misbehaving amyloid fibrils that cause brain degeneration, according to a study published in the journal Nature Structural & Molecular Biology.

These inhibitors may be able to interrupt the key phase where amyloid fibrils become toxic clusters, the hallmark of Alzheimer’s disease, but also a key in diseases like Parkinson’s. Inhibiting amyloid fibrils is the most critical stage in prevention of Alzheimer’s because once amyloid proteins misfold, they can create a chain reaction where other proteins follow suit—known as oligomers, creating swifter toxicity and degeneration of brain neurons. Although the studies were done on mice, this discovery is a promising area of research for treatments, and maybe even a cure. Preliminary research is promising, though it is still in the early stages of study.

Editor's note: this post has been updated.

nextArticle.image_alt|e
iStock
arrow
science
Beyond Yanny or Laurel: 6 Other Aural Illusions and How They Work
iStock
iStock

You know can't always believe your eyes, as optical illusions—or "brain failures," as Neil deGrasse Tyson calls them—make clear. It turns you can't always believe your ears either. Recently the internet went nuts over a four-second audio clip that sounded like "Yanny," "Laurel," or both. Audiologists contend that the clip has two distinct tracks laid on top of each other at different frequencies. Scientists call this an aural illusion—and it's not the only one. Here are six others that will make you doubt what you hear.

1. BRAINSTORM OR GREEN NEEDLE

The Illusion: Twitter users bored with the Yanny/Laurel question have been sharing this equally divisive clip. Some people think the garbled recording says "brainstorm," while others hear "green needle." Many have discovered that their thoughts can change the outcome. If you repeat the phrase "green needle" in your head, that's exactly what you'll hear when you listen to the clip. But if you've got "brainstorm" on your mind, then "brainstorm" is the term your ears are going to pick up.

How It Works: The video is a clip from a 2014 YouTube toy review. Uploaded by critic DosmRider, it's about a plastic space station from the Ben 10 collectibles line. The playset comes with a loading dock for action figures that trigger different sounds when they get plugged in. A crab-like character called Brainstorm is represented by one of these models. Put him on the station, and his name blares from the speakers. While listening to the soundbite, many people thought the toy was saying "green needle."

The clip contains a variety of different acoustic patterns—some of which are consistent with the term "green needle" while others match "brainstorm." Your expectations of which words you'll hear—coupled with the low-quality audio—do the rest. "When faced with an acoustic signal which is somewhat ambiguous because it is low-quality or noisy, your brain attempts a 'best fit' between what is heard and the expected word," Valerie Hazan, a professor of speech sciences at University College London, told The Telegraph.

2. SHEPARD TONES

The Illusion: In the above video, you hear what sounds like a single, perpetually swelling tone. A common fixture in the movie scores of composer Hans Zimmer, whose work you've heard in films like Dunkirk and Interstellar, this effect makes us believe that we're hearing the impossible: sounds whose pitch seems to rise endlessly without ever peaking or actually getting louder.

How It Works: The clip is in fact three separate sounds being played together—what are called Shepard tones. Each of these is an octave higher than the one beneath it. When separated into individual tones, as this Vox video explains, you can hear that the highest tone fades in volume, the middle one remains constant, and the lowest one increases. Because we're constantly hearing two upward-moving waves, we convince ourselves that the three-layered sound (taken as a whole) is growing higher and higher at a steady pace. It works for tones moving down in octaves as well.

3. CIRCLES, BEEPS, AND SENSORY CONFUSION

The Illusion: The opening 15 seconds of this video contain two multisensory displays. In the first, a lone black circle flashes onto the screen. This is accompanied by one high-pitched beep. You will then see the exact same thing happen again, with another solitary black circle popping into view. But this time, there will be two beeping sounds instead of one. Even though the animation is identical in both runthroughs, some viewers think they can see two flashing circles in that second display.

How It Works: Dubbed the sound-induced flash illusion by its discoverers, the trick plays on the fact that your brain sometimes consults other senses to figure out what your eyes are seeing. That's how the back-to-back beeps can fool you into mistaking a single flash for two separate ones. Some people might be especially vulnerable to the illusion. A 2012 study found that in a pool of 29 volunteers, nearly everyone reported seeing the second flash in at least a few trial runs. However, participants with small visual cortexes—a region of the brain which deciphers optical signals—saw it way more often than their peers did.

4. THE MCGURK EFFECT

The Illusion: In the previous entry, sound may have changed what you saw. In this one, seeing might change what you hear. A man says "bah" over and over. Or does he? Turn off the sound and see the shape his mouth makes as he speaks. He's actually saying "fah."

How It Works: First documented in the 1970s by researcher Harry McGurk [PDF], the McGurk Effect involves an incongruence between audio information and visual information. The brain's desire to reconcile these incongruent inputs is so strong, it can change what you hear to align with what you see.

5. SPEECH TO SONG

The Illusion: Diana Deutsch, who teaches at the University of California, San Diego, is an authority on the psychology of music. One day in 1995, Deutsch was editing an audio lecture she'd recorded. The sentence fragment "sometimes behave so strangely" was playing on a loop in her office. As she heard repeated over and over again, the phrase began to sound less like talking (which it was) and more like singing. It's had the same effect on other people. In the above video, notice how, after a certain point, this spoken-word recording picks up a musical quality, even though the speaker never actually sings.

How It Works: It's a phenomenon Deutsch has named the speech-to-song illusion. Repetition is a core component of all music, and it seems our brains try to create little melodies out of statements or sounds repeated to excess. How or why this occurs isn't completely understood. As future experiments dissect the illusion, psychologists may learn new things about how the mind organizes and processes the things it perceives [PDF].

6. PHANTOM WORDS

The Illusion: Once you click play on the video above, some bombastic, repeating syllables are going to hit your eardrums. For best results, place yourself between two speakers, but a decent set of headphones should also do the trick. Amidst this aural onslaught, your mind will probably identify some recognizable words or phrases. Test subjects who've listened to this have reported hearing words such as "no brain," "window," "raincoat," "mango," and "Broadway."

How It Works: Have you ever looked at a bowling ball and thought the three holes on its side resembled a human face? That's called pareidolia. Something like that is going on here. We're hard-wired to seek out patterns, both visually and aurally. There are two tracks in this audio clip, with each containing an ambiguous word or two. These sounds mix together in the air and then reach your ears as an unrecognizable racket. Listen long enough, and sooner or later you'll begin to hear "phantom words"—words or statements that aren't really being said. Since humans crave patterns, we force ourselves to hear them.

This experiment was another brainchild of Diana Deutsch's. She's found that the phantom words a person hears are liable to reflect their current mood. For example, weight-conscious test subjects might hear food-related terms.

nextArticle.image_alt|e
iStock
arrow
Big Questions
What Is Foreign Accent Syndrome?
iStock
iStock

One night in 2016, Michelle Myers—an Arizona mom with a history of migraines—went to sleep with a splitting headache. When she awoke, her speech was marked with what sounded like an British accent, despite having never left the U.S. Myers is one of about 100 people worldwide who have been diagnosed with Foreign Accent Syndrome (FAS), a condition in which people spontaneously speak with a non-native accent.

In most cases, FAS occurs following a head injury or stroke that damages parts of the brain associated with speech. A number of recent incidences of FAS have been well documented: A Tasmanian woman named Leanne Rowe began speaking with a French-sounding accent after recovering from a serious car accident, while Kath Lockett, a British woman, underwent treatment for a brain tumor and ended up speaking with an accent that sounds somewhere between French and Italian.

The first case of the then-unnamed syndrome was reported in 1907 when a Paris-born-and-raised man who suffered a brain hemorrhage woke up speaking with an Alsatian accent. During World War II, neurologist Georg Herman Monrad-Krohn compiled the first comprehensive case study of the syndrome in a Norwegian woman named Astrid L., who had been hit on the head with shrapnel and subsequently spoke with a pronounced German-sounding accent. Monrad-Krohn called her speech disorder dysprosody: her choice of words and sentence construction, and even her singing ability, were all normal, but her intonation, pronunciation, and stress on syllables (known as prosody) had changed.

In a 1982 paper, neurolinguist Harry Whitaker coined the term "foreign accent syndrome" for acquired accent deviation after a brain injury. Based on Monrad-Kohn's and other case studies, Whitaker suggested four criteria for diagnosing FAS [PDF]:

"The accent is considered by the patient, by acquaintances, and by the investigator to sound foreign.
It is unlike the patient’s native dialect before the cerebral insult.
It is clearly related to central nervous system damage (as opposed to a hysteric reaction, if such exist).
There is no evidence in the patient’s background of being a speaker of a foreign language (i.e., this is not like cases of polyglot aphasia)."

Not every person with FAS meets all four criteria. In the last decade, researchers have also found patients with psychogenic FAS, which likely stems from psychological conditions such as schizophrenia rather than a physical brain injury. This form comprises fewer than 10 percent of known FAS cases and is usually temporary, whereas neurogenic FAS is typically permanent.

WHAT’S REALLY HAPPENING?

While scientists are not sure why certain brain injuries or psychiatric problems give rise to FAS, they believe that people with FAS are not actually speaking in a foreign accent. Instead, their neurological damage impairs their ability to make subtle muscle movements in the jaw, tongue, lips, and larynx, which results in pronunciation that mimics the sound of a recognizable accent.

"Vowels are particularly susceptible: Which vowel you say depends on where your tongue is in your mouth," Lyndsey Nickels, a professor of cognitive science at Australia's Macquarie University, wrote in The Conversation. "There may be too much or too little muscle tension and therefore they may 'undershoot' or 'overshoot' their target. This leads to the vowels sounding different, and sometimes they may sound like a different accent."

In Foreign Accent Syndromes: The Stories People Have to Tell, authors Nick Miller and Jack Ryalls suggest that FAS could be one stage in a multi-phase recovery from a more severe speech disorder, such as aphasia—an inability to speak or understand speech that results from brain damage.

People with FAS also show wide variability in their ability to pronounce sounds, choose words, or stress the right syllables. The accent can be strong or mild. Different listeners may hear different accents from the speaker with FAS (Lockett has said people have asked her if she's Polish, Russian, or French).

According to Miller and Ryalls, few studies have been published about speech therapy for treating FAS, and there's no real evidence that speech therapy makes a difference for people with the syndrome. More research is needed to determine if advanced techniques like electromagnetic articulography—visual feedback showing tiny movements of the tongue—could help those with FAS regain their original speaking manner.

Today, one of the pressing questions for neurologists is understanding how the brain recovers after injury. For that purpose, Miller and Ryalls write that "FAS offers a fascinating and potentially fruitful forum for gaining greater insights into understanding the human brain and the speech processes that define our species."

Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at bigquestions@mentalfloss.com.

SECTIONS

arrow
LIVE SMARTER
More from mental floss studios