A new study shows promising results for the future of therapy for those with Down’s syndrome, writes Dr. Henry Mahncke.
Results from a recent study among people with Down’s Syndrome underscore that genetic conditions do not prescribe an inalterable destiny. Researchers have hypothesized that plasticity-based cognitive training and physical exercise could trigger increased plasticity in the brain, driving positive structural and functional brain changes.
Participants in a novel pilot study were assigned a modest amount of cognitive and physical training and showed gains in standard physical and cognitive measures, as well as structural reorganization of the brain, as seen in electroencephalogram (EEG) recordings. Those results highlight that, when it comes to the brain, positive change is almost always possible – regardless of age or condition. Before turning to the newly released results, let’s briefly look at the scientific developments that have changed how researchers approach once-deemed immutable cognitive conditions.
In scientific terms, the discovery that the brain is “plastic” throughout life – capable of chemical, structural, and functional change based on sensory and other inputs – is relatively new. In the 1980s, most experts believed that the brain was only plastic during childhood. when new learning is ubiquitous, and the initial neural pathways are formed. The brain was thought to be fully formed by adulthood, by which time it was “hard-wired” and incapable of change. More information might be pushed through it, but the brain’s basic performance capabilities were thought to be fixed by your late teens or early twenties and destined only to degrade later in life. We now know all that was wrong. This is thanks, in large part, to the work of Dr. Michael Merzenich of the University of California at San Francisco (UCSF) and his colleagues around the world. We now know that every major system of the brain is plastic from birth until death and will change – to get better or worse – depending on your efforts and what happens in your life. That’s a powerful scientific concept, and we’ve learned that plasticity is a very powerful neurological force constantly re-shaping the brain and its abilities.
Putting Brain Plasticity to Work
Following his groundbreaking experiments that led to the discovery of lifelong plasticity, Dr. Merzenich turned to how such a “force” could be harnessed for human benefit. He joined a team at UCSF that was working on building an artificial cochlea to address the most common causes of deafness. The natural cochlea is the part of the inner ear which turns sound vibrations into neural electrical impulses, which the brain then interprets as hearing. The researchers quickly figured out how to build a device that turned vibrations into electrical impulses. However, the challenge to the invention of the cochlear implant was that the natural cochlea has thousands of connections to the brain, making an implant of such a device seemingly impossible.
Dr. Merzenich proposed harnessing the brain’s plasticity to simplify the implant procedure. The device could be implanted with only a handful of connections, and, over time, the new electrical pulses would cause the brain to adapt its structure by rewiring to make sense of the new sensory information. Amazingly, this allowed implanted patients to hear sooner and much better than ever believed possible, yielding the first practical cochlear implant, and, over time, curing deafness in hundreds of thousands of people. This was the first intentional and practical technological application of brain plasticity. Dr. Merzenich and his team then began to look for less invasive ways to drive the brain in a positive direction. In the 1990s, he realized he might make use of the newly-popular personal computer to help harness plasticity. He observed that each of us comes out of the womb with two easily accessible brain systems – hearing and seeing – which computerized brain exercises could access (without implants) to change the chemistry, structure and function of the brain.
Neuroplasticity-based Brain Training
Over the past twenty-five years, hundreds of studies using forms of those plasticity-based computerized exercises (across varied populations) have demonstrated that such training can drive improvements in many areas. These include; in standard measures of basic cognitive abilities (e.g., attention, speed of processing, memory, decision-making, and social cognition); in standard measures of quality of life (e.g., feelings of control, depressive symptoms, anxiety/stress/fatigue, health outcomes, and health-related quality of life); and in real world measures (gait/balance, driving, hearing/seeing/reading, healthcare costs, and the ability to live independently).
With advances in imaging and other technologies in recent years, dozens of studies have also shown that such exercises drive positive changes in the chemistry and physical structure of the brain – including improvements in the levels of neural growth factors, integrity of white matter myelination, volume of the hippocampus, and strength of connectivity and coherence across information processing systems in the brain.
“such exercises drive positive changes in the chemistry and physical structure of the brain”
Initially, this work focused on healthy children and seniors. More recently, it hasb een shown to be effective in studies across the age span, including recent studies showing productivity and safety improvements among people of various ages and abilities in the workplace.
The neuroplasticity-based exercises have also shown promise in initial studies in a wide variety of clinical populations with cognitive symptoms, including neurodegenerative diseases (pre-dementia, dementia, Parkinson’s, multiple sclerosis); mental illnesses (depression, schizophrenia, bi-polar disorder, addiction, ADHD); and brain injuries (traumatic brain injury, stroke, chemobrain, cardiobrain, HIV).
Down’s Syndrome Results
Most studies of neuroplasticity-based brain training in clinical populations have focused on conditions that arise over the course of life, such as schizophrenia (which typically first affects people in their late teens or early twenties) or mild cognitive impairment (which generally starts to affect people as senior citizens).
One of the most exciting aspects of the Down’s Syndrome research is that it looks at a genetically-determined condition, which affects people before they are born.
Down’s Syndrome is caused by the presence of all (or part) of a third copy of chromosome 21. It is found in about 1 in 1,000 births each year, making Down’s Syndrome one of the most common genetic differences in humans. Down’s Syndrome is typically associated with physical growth delays and characteristic facial features. While cognitive abilities vary enormously among people with Down’s Syndrome, one study estimates the average IQ of a young adults with the condition is about 50 (comparable in cognitive abilities to average 8 or 9 year olds).
In this pilot study among people with Down’s Syndrome, researchers at Aristotle University of Thessaloniki, Greece found that a 10-week combined protocol of physical exercises and computerized brain training led to a reorganization of the brain and to improved performance on both cognitive and physical standard assessments. The research team took physical, cognitive and resting-state EEG assessments of 12 adults with Down’s Syndrome before and after the 10-week course of combined physical and cognitive exercises.
The physical training included aerobic, flexibility, strength, and balance exercises. The cognitive training was the Greek version of the commercially-available BrainHQ app, composed of 29 visual and auditory exercises targeting memory, attention, processing speed, problem-solving, navigation, and social skills.
The researchers had hypothesized that the training would trigger the brain’s neuroplasticity – its ability to change chemically, structurally and functionally. Their results showed increased connectivity within the left hemisphere and from left to right hemisphere, as well as improved performance on standard physical and cognitive assessments.
Physical improvements were reported in upper body strength and endurance (using the Arm Curl assessment), and in mobility, and static and dynamic balance (using the Timed Up and Go assessment). Cognitive gains were reported in improved general cognitive capacity, planning and organization skills), and in short-term memory, attention, and concentration.
The researchers wrote “Our results reveal a strong adaptive neuroplastic reorganization, as a result of the training that leads to a more complex and less random network, with a more pronounced hierarchical organization.” In their report, the researchers note that the widespread cortical reorganization and increases in cognitive performance indicate the brain has entered into a more flexible state.
“Our findings underline that the brains of those with Down’s syndrome have the ability to respond to the cognitive demands of external stimuli, reflecting the possibility of developing independent-living skills,” the researchers conclude.
These are early results from a small pilot study. However, they suggest that brain plasticity is a powerful force in the brains of people with Down’s Syndrome, just as it is elsewhere. That’s consistent with the science of brain plasticity, and it’s a novel and hopeful way to think about the potential of people with Down’s Syndrome – and people, generally. These initial results merit scientific attention and should spur further research, including randomized controlled trials.