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Aerobic exercise preserves brain volume and improves cognitive function
The brains of adults with mild cognitive impairment (MCI) increased in volume following exercise four times per week over a six-month period, a study has revealed.
The study, which made use of a new MRI technique that measured changes in brain volume in specific areas of the brain, was led by Dr Laura D Baker, Wake Forest School of Medicine, North Carolina, US, and presented at the annual meeting of the RSNA.
Adults who participated in the study and took part in aerobic exercise experienced greater gains than those who just stretched, researchers said.
There was a “remarkable” change in the brain, even over a short period of time, among the participants that undertook aerobic exercise.
The study was made up of 35 adults with MCI who participated in a randomised, controlled trial of exercise intervention.
It is known that people with MCI are at risk of developing Alzheimer’s disease, the most common form of dementia.
The participants were divided into two study groups. One group, made up of 16 adults with an average age of 63, engaged in aerobic activity four times per week for six months. The other group, the control group, was made up of 19 adults, with an average age of 67 who did stretching activity four times per week.
High-resolution brain MR images were acquired from all participants before and after the six-month activity period. The MRI results were compared and these measurements found differences in both brain volume and brain shape.
The analysis revealed that for both the aerobic and stretching groups, brain volume increased in most regions, including the temporal lobe, which supports short-term memory.
The study participants were tested to determine the effect of exercise intervention on cognitive performance.
The investigators found that the participants in the aerobic exercise group had statistically significant improvement in executive function after six months, whereas the stretching group did not improve.
Study finds cause of visual impairment in astronauts
The visual problems found to affect astronauts on lengthy space missions are due to volume changes in the clear fluid that is found around the brain and spinal cord, according to new research presented at the RSNA annual meeting.
A syndrome known as visual impairment intracranial pressure (VIIP) has been reported in almost two-thirds of astronauts who have completed long-duration space missions aboard the International Space Station (ISS).
Mankind’s next great manned space adventure is likely to be to Mars, with NASA planning to send a manned mission there sometime in the 2030s.
A trip to Mars, experts currently predict, would take nine months and a round trip — adding in the time spent on Mars itself — would take up to five years.
In that context, it is extremely important for NASA and other space agencies to understand physiological problems that arise during lengthy space missions.
Over the last decade, flight surgeons and NASA scientists began to see a pattern of visual impairment in astronauts flying long-duration space missions.
These long-stay astronauts had blurred vision, while more detailed examination revealed several structural changes, including flattening at the back of the eyeball and inflammation of the head of the optic nerve.
By 2010 there was growing concern about these changes, as it was becoming apparent that some structural changes were not reversible back on Earth.
It has been thought up to now that the problem was primarily due to a shift of vascular fluid toward the upper body that takes place when astronauts spend time in the microgravity of space.
However, researchers led by Prof Noam Alperin, Professor of Radiology and Biomedical Engineering at the University of Miami Miller School of Medicine, US, presented findings at the RSNA which suggested that the problem lay elsewhere — with the cerebrospinal fluid (CSF).
Prof Alperin and colleagues performed high-resolution orbit and brain MRI scans before and shortly after space flights on seven astronauts who had spent long periods of time aboard the ISS.
The researchers compared results with those from nine astronauts who underwent short-duration space missions on the Space Shuttle.
The scans revealed that the long-duration astronauts had significantly greater post-flight increases in orbital and ventricular CSF volume.
The researchers said this is the first quantitative evidence for the direct role of CSF in the structural deformations causing visual impairment syndrome. NASA is studying a number of possible countermeasures, said Prof Alperin.
Obesity in adolescence may cause permanent bone loss
Teenagers who are obese may be causing irreparable damage to their bones, according to a study presented at the annual RSNA meeting.
Obesity in childhood has already been linked with a number of health risks, including cardiovascular disease and diabetes. In this study, researchers looked at how excess weight may affect bone structure.
In the past, said Dr Miriam A Bredella — Radiologist at Massachusetts General Hospital, Associate Professor of Radiology at Harvard Medical School, US, and lead author on the study — obesity was believed to be protective for bone health.
However, recent studies have shown a higher incidence of forearm fractures in obese youths, said Dr Bredella.
The study involved 23 obese adolescents with a mean age of 17 and a mean body mass index of 44kg/m2. Adolescence is a time when we build our peak bone mass, so bone loss during this time can be a serious problem later on, said Dr Bredella.
“We know from other chronic states that lead to bone loss in adolescence, such as anorexia nervosa, that increased fracture risk persists in adulthood, even after normalisation of body weight,” said Dr Bredella. “Therefore it is important to address this problem early on.”
The researchers used a type of computed tomography examination designed for measuring bone mineral density and bone microarchitecture in the arms and legs to determine the bone structure of the distal radius, an area of the forearm near the wrist. They also performed dual-energy x-ray absorptiometry exams to determine body composition, including lean mass and visceral fat mass.
The findings suggest that having a high amount of visceral fat coupled with a low amount of muscle mass puts adolescents at risk for weakened bone.
Musical training creates new brain connections in children
Taking music lessons increases brain fibre connections and may be useful in treating autism and attention deficit hyperactivity disorder (ADHD).
That is the main finding from a study of 23 healthy children between five and six years of age and presented at the RSNA annual meeting.
It has been known that music lessons, and instruction, can benefit children with autism and ADHD.
However, the researchers behind this latest study said it provides a better understanding of precisely how the brain changes with musical instruction and where the new brain fibre connections are happening.
All the children who took part in the study were right-handed and had no history of sensory, perception or neurological disorders.
None of the children had received any prior training in any artistic discipline.
The children underwent pre- and post-musical training evaluation with diffusion tensor imaging (DTI) of the brain. DTI is an advanced MRI technique, which identifies tiny structural changes in the brain’s white matter.
In healthy white matter, the direction of extracellular water molecules is fairly uniform, but abnormalities are suggested when movement is more random, and this can be detected using DTI by producing a measurement called fractional anisotropy (FA).
Previous studies have linked autism and ADHD with decreases in brain volume, brain fibre connections and FA in the minor and lower forceps — tracts located in the brain’s frontal cortex.
The suggestion, therefore, from these prior studies is that low brain fibre connectivity in the minor and lower forceps could be a biomarker of these disorders.
The DTI results showed that after the children completed nine months of musical instruction, there was an increase in FA, an axon fibre length in different areas of the brain — perhaps most notably in the minor forceps.
“When a child receives musical instruction, their brains are asked to complete certain tasks,” said Dr Pilar Dies-Suarez, Chief Radiologist at the Hospital Infantil de México Federico Gómez in Mexico City and one of the authors of the study.
“These tasks involve hearing, motor, cognition, emotion, and social skills, which seem to activate these different brain areas.
“These results may have occurred because of the need to create more connections between the two hemispheres of the brain,” said Dr Dies-Suarez.
The findings from this study could help in creating strategies for intervention in treating autism and ADHD, the researchers believe.
Light alcohol consumption has no effect on coronary arteries — study
There is no association between light-to-moderate alcohol consumption and coronary artery disease (CAD), according to results of a study using computer tomography angiography (CCTA) presented at the annual RSNA meeting.
Studies have suggested that light alcohol consumption reduces the risk of CVD, but the data on more regular alcohol consumption and CAD have been less clear.
This study investigated alcohol consumption in 1,925 patients referred for CCTA with suspected CAD, as well as the type of alcohol consumed and the presence of coronary plaques, using CCTA technology.
About 40 per cent of the patients reported regular alcohol consumption, with a median of 6.7 units consumed per week, the researchers said.
The researchers found that light or moderate alcohol consumption was not associated with CAD. Neither was there an association found between consumption of different types of alcohol and coronary atherosclerosis.
“When we compared consumption between patients who had coronary artery plaques and those who had none, no difference was detected,” said Dr Júlia Karády, study author, from the MTA-SE Cardiovascular Imaging Research Group, Heart and Vascular Centre at Semmelweis University, Hungary.
“Evaluating the relationship between light alcohol intake and the presence of CAD, we again found no association,” said Dr Karády.
“Furthermore, we analysed the effect of different types of alcohol (beer, wine and hard liquor) on the presence of CAD, but no relationship was found.”