In a rare, large-scale study of traumatic brain injury (TBI) patients who span the full range of severity from mild to moderate and severe, Canadian researchers have found that the more severe the injury, the greater the loss of brain tissue, particularly white matter.
“This is an important finding as TBI is one of the most common forms of disability,” said Dr. Brian Levine, Senior Scientist at Baycrest’s Rotman Research Institute and lead author of the study which is published in the March 4, 2008 issue of Neurology, the medical journal of the American Academy of Neurology.
TBI causes both localized damage through bruises or bleeds, as well as more diffuse damage through disconnection of brain cells, which ultimately causes cell death. The localized damage is easier to detect with the naked eye than diffuse damage. Yet both kinds of damage contribute to difficulties with concentration, working memory, organizing and planning (vital skills for holding a job), and mood changes often experienced by people following TBI.
According to Dr. Levine, “It can be hard to determine why patients are so disabled, and this study offers a clue to the nature of the brain damage causing this disability.”
In the study, 69 TBI patients were recruited from Sunnybrook Health Sciences Centre, Canada’s largest trauma centre, one year after injury. Eighty percent of the patients sustained their injury from a motor vehicle accident. Injury severity was determined by the depth of coma or consciousness alteration at the time of the initial hospitalization. Some patients had minor injuries and were discharged immediately, whereas others had more severe injuries with extended loss of consciousness lasting weeks. Twelve healthy, non-injured participants were recruited as the comparison group.
Subjects’ brains were scanned with high resolution magnetic resonance imaging (MRI) which provides the most sensitive picture of volume changes in the brain. In addition to using an expert radiologist’s qualitative reading of the MRI scans, which is the standard approach used in hospitals and clinics, the researchers processed the images with a computer program that quantified volumes in 38 brain regions.
The computerized analysis revealed widespread brain tissue loss that was closely related to the severity of the TBI sustained one year earlier. “We were surprised at the extent of volume loss, which encompassed both frontal and posterior brain regions,” said Dr. Levine. Brain tissue loss was greatest in the white matter (containing axons which can be compared to telephone wire interconnectivity), but also involved grey matter (containing the cell bodies important for information processing).
Investigators were surprised to find that volume loss was widespread even in TBI patients who had no obvious lesions on their MRI scans. Even the mild TBI group contributed to the pattern of volumetric changes such that this group was reliably differentiated from the non-injured, healthy group.
“A significant blow to the head causing loss of consciousness can cause extensive reduction of brain tissue volume that may evade detection by traditional qualitative radiological examination,” Dr. Levine noted.
He is leading follow-up studies on the same group of TBI patients to examine more closely the significance of localized white and grey matter volume loss on behaviour.
Kelly Connelly | EurekAlert!
Multi-year study finds 'hotspots' of ammonia over world's major agricultural areas
17.03.2017 | University of Maryland
Diabetes Drug May Improve Bone Fat-induced Defects of Fracture Healing
17.03.2017 | Deutsches Institut für Ernährungsforschung Potsdam-Rehbrücke
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
27.03.2017 | Earth Sciences
27.03.2017 | Life Sciences
27.03.2017 | Life Sciences