Using the eyes to diagnose cognitive risks, blue light therapy for cognitive repair, and… fecal transplant pills as a neuro treatment?
Neuroscience research never ceases to amaze us, and this week, there’s a ton of new studies to catch up on! Researchers from the University of Arizona have discovered that early morning blue light therapy may actually facilitate recovery in people with mild traumatic brain injuries. Across the pond in the UK, researchers the University of Liverpool have found that studying eye movements may be the key to understanding how the brain works. And, in other news, bacteriotherapy—via fecal transplants—may help to improve the mental health of patients with spinal cord injuries. From the everyday to the incredible, there are lots more interesting findings you won’t want to miss!
Only 30 years ago, Seiji Ogawa, PhD, invented modern functional brain imaging—the blood oxygenated level dependent (BOLD) functional MRI (fMRI). Dr. Ogawa was the first to discover that fMRI was useful for visualizing the parts of the brain activated by external stimuli. He demonstrated that fMRI was dependent on the oxygenation status of the blood—the BOLD effect. His revolutionary discovery has allowed neurologists to study neuronal activation caused by external stimuli in real-time. Among the many awards Dr. Ogawa received for his discovery, the most prestigious was the 2003 Japan Prize in the field of Visualizing Techniques in Medicine.
In the News
Take a pass on the sugar… Weight loss is not the only reason you should avoid sugar in your diet. According to recent findings, sugar affects brain reward circuitry in ways similar to those caused by addictive drugs. No wonder those doughnuts in the staff lounge always disappear so quickly! Researchers studied the neurological effects that 2 L of sugar-water consumption daily for 12 days had on pigs. Brain imaging was done at baseline, after day 1, and then again after day 12. The researchers found major changes in the brain’s dopamine and opioid systems, including quick activation of the opioid system after the very first intake of sugar (day 1). This triggers the brain reward systems and potentially initiates addictive behaviors, similar to what happens in those with any type of addiction. If that’s what happens to the brain after a single day, imagine what years of sugar intake does!
…and on the aluminum! The good news is dietary exposure to dangerous aluminum compounds has decreased globally. The bad news? We’re still ingesting much more than deemed safe by experts, according to German researchers. Aluminum compounds seem to be everywhere—from our drinking water as a purifying agent to processed foods as an additive. These compounds can even be present in fresh produce (growing in contaminated soil), cosmetic products, baking trays, and cooking utensils. The worst offender? Personal hygiene products, especially antiperspirants, which often reach or exceed the tolerable weekly intake per European Food Safety Authority standards, similar to those from the FDA for consumer protection. Frequent exposure to high levels of aluminum has been linked to neurotoxicity, Alzheimer disease, and breast cancer. So, keep aluminum on your radar, and maybe switch to organic deodorant?
And while we’re at it, pass on the soybean oil, too! Soybean oil may affect patients with neurologic conditions such as autism, Alzheimer disease, anxiety, and depression. In the United States, soybean oil is the most widely produced and consumed edible oil, according to the US Department of Agriculture. It is used to fry foods, as a packaged food additive, and as livestock feed. Now, researchers have found that a diet high in soybean oil may affect the hypothalamus and lead to decreases in oxytocin levels—at least in mice.
The researchers studied mice that were fed three different high-fat diets: unmodified soybean oil, soybean oil modified to be low in linoleic acid, and coconut oil. They did not identify any difference between the modified and unmodified soybean oil’s effect on the brain. However, they did observe pronounced effects of soybean oil on the hypothalamus compared with coconut oil. On top of that, about 100 genes in the soybean oil-fed mice were affected, which researchers say could affect energy metabolism and proper brain function. They are currently trying to identify the exact chemicals in the soybean oil that are responsible for these changes. Could this be the key to healthier dietary oils in the near future? We hope so.
How many synapses are there in the brain?
Synapses are the chemical junctions between neurons and astrocytes, and there are over 100 trillion of them in the brain. Synapses help neurons form links with other neurons. They act as traffic controllers, ensuring that impulses between neurons flow only in one direction. Since each neuron can form thousands of synapses, it’s easy to see why they number not in the millions or billions, but in the trillions!
The eye of the beholder. It’s been said that the eyes are the windows to the soul, but could they also be the windows to the brain? Researchers from the University of Liverpool have shown that studying eye movements may be the key to understanding how the brain works. Specifically, they are working on using a newly developed eye movement test to study inhibitory control, the loss of which can be a manifestation of cognitive decline. In their study, researchers asked participants from two different age groups—19-27 years old and 50-72 years old—to look at stationary and disappearing dots. The first dot was stationary and the second appeared and disappeared. Participants were instructed to only look at the second dot when it disappeared, which requires inhibiting normal automatic eye movements. The researchers used an infrared eye tracker to measure eye movements. They found that older participants were more likely to look at the dot when it appeared—not disappeared—and were slower to do so when compared with the younger participants. These results confirmed that inhibitory decline occurs with aging. The researchers concluded that this new test will help precisely measure inhibitory behaviors. They are working on refining the test and hope to use it to further study inhibitory control in patients with neurological conditions and a number of other diseases.
Tremor epicenter. Essential tremor—the most common movement disorder in the United States—can affect as many as 4% of people over the age of 40 years. Because the source of the tremors is unknown, no effective treatments have yet been developed. Well, researchers may have just nailed this down.
In a recent study, researchers found that these tremors may be caused by overactive brain waves at the base of the brain. The good news? There’s a strong possibility that these oscillations can be calmed with neuromodulation. Using a new cerebellar encephalogram (EEG) technique, they searched for unusual brain waves in the cerebellum—the area where structural changes in patients with essential tremor have been identified. Of the 20 patients with essential tremor who had undergone cerebellar EEG, the majority had strong oscillations in the cerebellum (4-12 Hz), which weren’t seen in any of the 20 controls. Furthermore, those who had more severe tremors had stronger oscillations. This finding opens up the possibility for the treatment of essential tremor with neuromodulation, including techniques using transcranial direct-current stimulation or transcranial magnetic stimulation.
Spit into this vial. The loss of diurnal hypothalamus-pituitary-adrenal axis (HPAA) variation may be an early, preclinical predictor of cognitive decline. Researchers conducted a cross-cohort study to determine the association of HPAA dysfunction with global cognitive impairment in later life. They assessed participants from the Whitehall II study and the National Survey for Health (NSHD) and Development. To assess HPAA dysfunction, they evaluated serial salivary cortisol samples collected from participants at mean ages of 61.2 and 65.9 years in the Whitehall II study and mean ages of 60-64 years in the NSHD. They found that participants with increased AM:PM cortisol ratios had better later-life cognitive function and verbal fluency. A simple way to assess a patient’s risk for cognitive decline? Yes please.
Is blue light really all-bad? Not according to researchers from the University of Arizona, who found that early morning blue light exposure therapy could actually help people with mild traumatic brain injuries (mTBI) recover. How? Well, daily exposure to blue wavelength light in the morning can help re-entrain the circadian rhythm, allowing for better, more regular sleep.
In people with mTBI, these improvements in sleep could help improve cognitive function. According to some experts, about 50% of people with mTBI complain of sleep problems. In this study, researchers examined the effect of 30 minutes of early morning blue light exposure therapy for 6 weeks in adults with mTBI. And—surprise, surprise—they found that patients who were “lit” gained an hour in how soon they fell asleep. Better still, they were less sleepy during the day. Patients’ brain processing speeds and efficiency also improved, and their pulvinar nuclei (PN) of the thalamus—which is responsible for visual attention—grew in size. Finally, researchers found evidence of increased strength in neuronal connections and in communications between the PN and the parts of the brain that control alertness and cognition.
Kid-tested, researcher-approved. Kids aged 4 years or older with refractory epilepsy may do well with brivaracetam, a new antiepileptic drug. Since there are limited data on the drug’s use in children, researchers studied brivaractem’s effects in 23 kids (mean age at treatment initiation: 12.5 years; 14 girls) with various forms of epilepsy. The average dose of brivaracetam was 3.9 mg/kg/d, and the mean length of treatment was 8.2 months. Eight of the kids (34.7%) had a 50% or greater decrease in seizure frequency—seven with focal epilepsy and one with Lennox-Gastaut/mixed epilepsy). Side effects included drowsiness, behavioral complaints, and tingling and dizziness. This is good news for children with refractory epilepsy, in whom additional therapeutic options include only surgery, vagus nerve stimulation, and the ketogenic diet.
New in Patient Management
Not what they expected. Treatment with erythropoietin (EPO) doesn’t offer neuroprotection to extremely premature infants. Unfortunately, this runs counter to ample preclinical findings that it would. In the Preterm EPO Neuroprotection Trial (PENUT), over 900 infants were randomized to receive either high-dose EPO or placebo. The study drug cohort received EPO within 24 hours of birth and then several times a week through 32 weeks corrected age (how old the baby would be if born on the due date). Researchers were disheartened to find that EPO didn’t lower risks of mortality or severe brain damage before the babies reached 2 years of age. They were hopeful for better results in light of previous preclinical studies that suggested that EPO would have a protective effect in these infants and lessen the neurologic damage they can sustain. The researchers will follow the children as they grow, however, and assess their later neurologic development.
Fecal transplant pills for spinal cord injury? No, it’s not a misprint. While bacteriotherapy—via fecal transplants—is nothing new, using it to improve the mental health of patients with spinal cord injuries certainly is. Here’s the skinny: The link between diminished mental health and spinal cord injuries is a solid one. And the digestive tract may be the missing link between spinal injuries and mental health changes, such as increased anxiety and depression. Researchers found that in rats with spinal injuries, gut bacteria became altered, and anxious behaviors increased. When these rats received fecal transplants from healthy rats, however, their gut bacteria and behavior remained normal. Injured rats who received fecal transplants also went on to take more risks by venturing out onto an exposed platform after recovery. It’s not glamorous—and not even semi-palatable—but one day, these pills may make a big difference in the physical recovery and mental health of patients with spinal cord injuries. Talk about a stinky situation.
She paid how much for that? Over a span of 7 years, the cost of prescriptions for multiple sclerosis (MS) drugs has almost tripled. Unfortunately, even the introduction of generics—glatiramer acetate in 2015 and 2017—has done nothing to lower the costs. Researchers found that Medicaid spending on 15 MS drugs increased from $453 million in 2011 to $1.32 billion in 2017. The increased spending was mainly caused by prescription cost increases—which doubled during this time frame. But that’s not all—when the initial generic for glatiramer acetate was introduced, the cost of the brand name drug (Copaxone) immediately increased by $441 per prescription. Can you put a price tag on good health? Apparently so.
Get the lead out! Kids living in neighborhoods with a high risk of lead exposure could experience changes in brain structure and cognitive performance, according to researchers from the Children’s Hospital Los Angeles. They studied data from nearly 12,000 kids in the Adolescent Brain Cognitive Development (ABCD) Study. In this study, the kids are followed from ages 9-10 years into adulthood, with data on their health and brain development as the primary goal. It’s the largest and most comprehensive study of its kind. So, when researchers found that lower cognitive test scores and structural brain differences—like smaller cortical volume and smaller cortical surface area—happened only in kids from lower-income families, they took note. They concluded that there are significant relationships between brain structure and cognition in those from low-income families or a higher risk of lead exposure. Pay close attention to your pediatric patients who may fit into this subgroup, and counsel their parents on the importance of removing lead from children’s environments.
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Upcoming Medical Meetings
13th Annual Headache Cooperative of the Pacific (HCOP) Winter Conference CME, in Ojai, CA, January 24-25, 2020
12th Annual Symposium on Neurovascular Disease CME, in Santa Monica, CA, January 25, 2020
North American Neuromodulation Society (NANS) Annual Meeting, in Las Vegas, NV, January 23-26, 2020
53rd Annual Recent Advances in Neurology, in San Francisco, CA, February 12-13, 2020