Older news items (pre-2010) brought over from the old website
Nerve-cell transplants help brain-damaged rats recover lost ability to learn
After destroying neurons in the subiculum of 48 adult rats, some were given hippocampal cells taken from newborn transgenic mice. On spatial memory tests two months later, the rats given cell transplants performed as well as rats which had not had their subiculums damaged; however, those without transplants had significantly impaired performance. The new cells were found to have mainly settled in the dentate gyrus, where they appeared to promote the secretion of two types of growth factors, namely BDNF and basic fibroblast growth factor (bFGF).
Rekha, J. et al. 2009. Transplantation of hippocampal cell lines restore spatial learning in rats with ventral subicular lesions. Behavioral Neuroscience, 123(6), 1197-1217.
http://www.eurekalert.org/pub_releases/2009-12/apa-nth120909.php
Amino acid diet helps brain-injured mice
In a study in which brain-injured mice received a cocktail of three branched chain amino acids (BCAAs), specifically leucine, isoleucine and valine, in their drinking water, those who received the cocktail showed normal learning ability and normal activity in the hippocampus. BCAAs are crucial precursors of two neurotransmitters—glutamate and GABA, which function together to maintain an appropriate balance of brain activity. Previously, it’s been found that people with severe brain injuries showed mild functional improvements after receiving BCAAs through an intravenous line. It’s suggested that receiving the BCAAs as a dietary supplement could have a more sustained, measured benefit than that seen when patients receive BCAAs intravenously, in which the large IV dose may flood brain receptors and have more limited benefits.
[584] Cole, J. T., Mitala C. M., Kundu S., Verma A., Elkind J. A., Nissim I., et al.
(2010). Dietary branched chain amino acids ameliorate injury-induced cognitive impairment.
Proceedings of the National Academy of Sciences. 107(1), 366 - 371.
http://www.eurekalert.org/pub_releases/2009-12/chop-waa120209.php
Greater dementia risk in former N.F.L. players
A study commissioned by the National Football League reports that Alzheimer’s disease or similar memory-related diseases appear to have been diagnosed in the league’s former players vastly more often than in the national population: five times the national average among those 50 and older (6.1%)and 19 times for those aged 30 through 49. The findings are consistent with several recent studies regarding N.F.L. players and the effects of their occupational head injuries. The study involved a phone survey of 1,063 retired players (from an original random list of 1,625), who were asked questions derived from the standard National Health Interview Survey. Some health issues were reported at higher than the population rate (sleep apnea and elevated cholesterol — both risk factors for cognitive problems).
http://www.nytimes.com/2009/09/30/sports/football/30dementia.html
Stroke patients regain sight after intensive brain training
In a surprising and exciting finding, stroke victims left partially blind have been trained to use undamaged parts of their brains to improve their vision. The training program, involving an hour a day for at least nine months, forced them to process visual signals with parts of their brain that had not been damaged by the stroke. The seven patients in the study ranged in age from their 30s to 80s, and had suffered a stroke between eight months and three-and-a-half years previously. Impaired vision is a very common result of a stroke.
[1040] Huxlin, K. R., Martin T., Kelly K., Riley M., Friedman D. I., Burgin S. W., et al.
(2009). Perceptual Relearning of Complex Visual Motion after V1 Damage in Humans.
J. Neurosci.. 29(13), 3981 - 3991.
http://www.guardian.co.uk/science/2009/mar/31/stroke-brain-training-blind-sight
Patients who recover well from head injury 'work harder' to perform at same level as healthy people
People who make a full recovery from head injury often report "mental fatigue" and feeling "not quite the same" – even though they scored well on standard cognitive tests. Now brain imaging reveals that even with recovered head injury patients performing as well as matched controls on a series of working memory tests, their brains were working harder — specifically, showing more activity in regions of the prefrontal cortex and posterior cortices. All the patients had diffuse axonal injury, the most common consequence of head injuries resulting from motor vehicle accidents, falls, combat-related blast injuries, and other situations where the brain is rattled violently inside the skull causing widespread disconnection of brain cells.
[798] Turner, G. R., & Levine B.
(2008). Augmented neural activity during executive control processing following diffuse axonal injury.
Neurology. 71(11), 812 - 818.
http://www.eurekalert.org/pub_releases/2008-09/bcfg-pwr090308.php
Feed TBI patients early and well
Analysis of the results of 797 comatose brain trauma patients treated at 21 trauma centers in New York over six years has found that patients who did not get fed within five or seven days were two-fold and four-fold more likely to die in the two week period following initial trauma. The amount of nutrition in the first 5 days was related to death; every 10-kcal/kg decrease in caloric intake was associated with a 30–40% increase in mortality rates. The findings overturn current guidelines for TBI patient care, pointing to the importance of aggressive early nutrition.
[832] Härtl, R., Gerber L. M., Ni Q., & Ghajar J.
(2008). Effect of early nutrition on deaths due to severe traumatic brain injury.
Journal of Neurosurgery. 109(1), 50 - 56.
http://www.sciencentral.com/articles/view.php3?article_id=218393144
Head injuries result in widespread brain tissue loss one year later
A study of traumatic brain injury (TBI) patients who span the full range of severity from mild to moderate and severe has revealed that the more severe the injury, the greater the loss of brain tissue one year after injury, particularly white matter. Researchers were surprised at the extent of tissue loss, which was widespread even in patients who had no obvious lesions, and was discernible even in the mild TBI group.
[408] Levine, B., Kovacevic N., Nica E. I., Cheung G., Gao F., Schwartz M. L., et al.
(2008). The Toronto traumatic brain injury study: Injury severity and quantified MRI.
Neurology. 70(10), 771 - 778.
http://www.eurekalert.org/pub_releases/2008-03/bcfg-hir022808.php
Brain-injured war veterans show a faster decline in cognitive functioning as they age
A study of Vietnam war veterans who suffered brain injuries during the conflict has found that the men show a faster decline in their cognitive functioning as they grow older than veterans without such injuries. Greater intelligence and a higher level of education before the injury was sustained were associated with a smaller decline in cognitive functioning — perhaps because of a greater number of neural connections, enabling the brain to recover better from injury.
[388] Raymont, V., Greathouse A., Reding K., Lipsky R., Salazar A., & Grafman J.
(2008). Demographic, structural and genetic predictors of late cognitive decline after penetrating head injury.
Brain: A Journal of Neurology. 131(Pt 2), 543 - 558.
http://www.eurekalert.org/pub_releases/2007-12/oup-bwv121707.php
Early lead exposure impedes later recovery from brain injury
We know that lead exposure in early years can affect the brain. We also know that it increases the risk of various disorders later in life. Now a rat study reveals that animals exposed to lead earlier in life were significantly less able to recover from an induced stroke than those not so exposed. The study only looked at a short time-frame, so it is not yet known if the lead-exposed animals would catch up in their recovery in a longer period of time. There was some recovery in the lead group, but then it leveled off. The control group continued to get better. The findings support the suggestion that lead poisoning impairs neural plasticity.
[698] Schneider, J. S., & Decamp E.
(2007). Postnatal lead poisoning impairs behavioral recovery following brain damage.
Neurotoxicology. 28(6), 1153 - 1157.
http://www.eurekalert.org/pub_releases/2007-12/tju-jnf120307.php
Imaging shows structural changes in mild traumatic brain injury
A study involving patients with all severities of traumatic brain injury has found that abnormalities in white matter existed across the spectrum, and that diffusion tensor imaging could identify structural changes even in patients with mild traumatic brain injury, who had minimal or no loss of consciousness, and even in those with no self-reported cognitive deficit. The imaging could also distinguish between axonal damage (tearing of the axons that allow one neuron to communicate with another) in white matter versus abnormalities in the myelin.
[397] Kraus, M. F., Susmaras T., Caughlin B. P., Walker C. J., Sweeney J. A., & Little D. M.
(2007). White matter integrity and cognition in chronic traumatic brain injury: a diffusion tensor imaging study.
Brain. 130(10), 2508 - 2519.
http://www.eurekalert.org/pub_releases/2007-10/uoia-iss102507.php
Stem cells improved memory in mice after brain injury
Brain damage in mice that significantly impaired memory was repaired through the introduction of neural stem cells. Interestingly, the stem cells did not primarily replace the dead neurons, but somehow supported the injured neurons by, it is thought, making beneficial proteins called neurotrophins. If so, it may be that a similar effect can be achieved by creating a drug that increases the release of neurotrophins.
[546] Yamasaki, T. R., Blurton-Jones M., Morrissette D. A., Kitazawa M., Oddo S., & LaFerla F. M.
(2007). Neural Stem Cells Improve Memory in an Inducible Mouse Model of Neuronal Loss.
J. Neurosci.. 27(44), 11925 - 11933.
http://www.eurekalert.org/pub_releases/2007-10/uoc--scc102507.php
Successful treatment for chronic TBI in rat study
A rat study has found that hyperbaric oxygen therapy (HBOT) improved spatial learning and memory in a model of chronic traumatic brain injury.
[1169] Harch, P. G., Kriedt C., Van Meter K. W., & Sutherland R J.
(2007). Hyperbaric oxygen therapy improves spatial learning and memory in a rat model of chronic traumatic brain injury.
Brain Research. 1174, 120 - 129.
http://www.eurekalert.org/pub_releases/2007-10/lsuh-1st101107.php
Drug improves memory loss for traumatic brain injury patients
A study involving 157 men and women with traumatic brain injury found attention and verbal memory test scores significantly improved among those with moderate to severe memory impairment who took rivastigmine for 12 weeks. However, the drug was not effective for patients with less severe memory loss. Rivastigmine, a drug used to treat Alzheimer’s, is thought to enhance the function of acetylcholine, a neurotransmitter involved in memory and learning.
[485] Katz, D. I., Gunay I., Silver J. M., Koumaras B., Chen M., Mirski D., et al.
(2006). Effects of rivastigmine on cognitive function in patients with traumatic brain injury.
Neurology. 67(5), 748 - 755.
http://www.eurekalert.org/pub_releases/2006-09/aaon-dim090506.php
More light on adult neurogenesis; implications for dementia and brain injuries
New research has demonstrated that adult mice produce multi-purpose, or progenitor, cells in the hippocampus, and indicates that the stem cells ultimately responsible for adult hippocampal neurogenesis actually reside outside the hippocampus, producing progenitor cells that migrate into the neurogenic zones and proliferate to produce new neurons and glia. The finding may help in the development of repair mechanisms for people suffering from dementia and acquired brain injury.
[977] Bull, N. D., & Bartlett P. F.
(2005). The Adult Mouse Hippocampal Progenitor Is Neurogenic But Not a Stem Cell.
J. Neurosci.. 25(47), 10815 - 10821.
http://www.eurekalert.org/pub_releases/2005-11/ra-nrt112305.php
Concussions increase chance of age-related cognitive impairment
A study involving retired National Football League players found that they had a 37% higher risk of Alzheimer's than other U.S. males of the same age. Some 60.8% of the retired players reported having sustained at least one concussion during their professional playing career, and 24% reported sustaining three or more concussions. Those with three or more concussions had a five-fold greater chance of having been diagnosed with mild cognitive impairment and a three-fold prevalence of reported significant memory problems compared to those players without a history of concussion. As the study was based on self-reported answers to the health questions, further studies are needed to confirm the findings, but it does seem likely that head injuries earlier in life increase the chance of developing dementia or mild cognitive impairment.
[345] Guskiewicz, K. M., Marshall S. W., Bailes J., McCrea M., Cantu R. C., Randolph C., et al.
(2005). Association between recurrent concussion and late-life cognitive impairment in retired professional football players.
Neurosurgery. 57(4), 719-726; discussion 719-726 - 719-726; discussion 719-726.
http://www.eurekalert.org/pub_releases/2005-10/uonc-nsa101005.php
Shift in brain's language-control site offers rehab hope
Language activity in right-handed people is initially localized in the left side of the brain, but a new study shows that this gradually becomes a function shared by both sides. From ages 5 to 25, language activity increases in the dominant hemisphere; from 25 to 67, the nondominant hemisphere increasingly shares the load. The discovery gives new hope for rehabilitation of brain function in adults after stroke or traumatic brain injuries.
[2575] Szaflarski, J. P., Holland S. K., Schmithorst V. J., & Byars A. W.
(2006). fMRI study of language lateralization in children and adults.
Human Brain Mapping. 27(3), 202 - 212.
http://www.eurekalert.org/pub_releases/2005-10/uoc-sib100605.php
Post-concussion migraine may signal greater neurocognitive impairment
Another study suggesting sports’ concussions should be taken more seriously. The study found that young athletes who experienced migraine headache symptoms (even one week after concussion) were likely to have increased neurocognitive impairment. Headaches are reported in as many as 86% of such injuries; the researchers suggest that athletes should not be allowed to return to play before the headache resolves.
[889] Mihalik, J. P., Stump J. E., Collins M. W., Lovell M. R., Field M., & Maroon J. C.
(2005). Posttraumatic migraine characteristics in athletes following sports-related concussion.
Journal of Neurosurgery. 102(5), 850 - 855.
http://www.eurekalert.org/pub_releases/2005-06/uopm-yap062105.php
Lead exposure may affect recovery from brain injury
Lead exposure at a young age can hurt the brain's development and cause learning and behavioral problems. Now it seems that it might also affect a child’s ability to recover from brain injury. A new study found young rats exposed to low levels of lead took significantly longer to recover from a brain injury than those animals that weren't lead-exposed, as well as recovering less well.
[366] Dye, M. W. G., Green S. C., & Bavelier D.
(2009). Increasing Speed of Processing With Action Video Games.
Current Directions in Psychological Science. 18(6), 321 - 326.
http://www.eurekalert.org/pub_releases/2004-10/tju-jnf102404.php
After serious head injury, survivors may still be able to learn without awareness
Severe closed-head injury (CHI), like that caused in a car accident, can impair the ability for purposeful learning. New research suggests however, that severe-CHI survivors may still be able to learn without awareness that they’re learning. In the first study of implicit learning in CHI using a perceptual task, participants were asked to identify the location of a target number -- 6 -- on a computer screen, as it moved in a seemingly random fashion around a matrix of numbers. The target’s location was actually determined by an underlying pattern of relationships between that location and the arrangement of other numbers in the display. Despite slower search rates, the CHI group’s improvement in locating the “6” was consistent with that of the control group. These findings suggest an alternative approach to remediation for such sufferers — for example, therapists could “teach” complex skills by breaking them down into sub-components that can be learned implicitly and/or made automatic. The findings also support the idea that different neural mechanisms might underlie explicit and implicit learning.
[1327] Nissley, H. M., & Schmitter-Edgecombe M.
(2002). Perceptually based implicit learning in severe closed-head injury patients.
Neuropsychology. 16(1), 111 - 122.
http://www.eurekalert.org/pub_releases/2002-01/apa-ash011702.php
Skill-specific exercises better for people who suffer from attention problems following stroke or brain injury
Treatment programs for people who suffer from attention problems following a stroke or other traumatic brain injuries often involve abstract cognitive exercises designed to directly restore impaired attention processes. But a review of 30 studies involving a total of 359 participants shows that an alternative and lesser-used therapy that teaches patients to relearn the tasks that affect their daily lives the most may be more effective. In this specific skills approach, people with brain damage learn to perform attention skills in a way that is different from non-brain-damaged people. In one study, for example, participants whose brain injuries affected their ability to drive a car used small electric cars in the lab to practice specific driving exercises, such as steering between pylons that were moved closer and closer together. Those that practiced specific exercises showed substantial improvement on a variety of driving related tasks compared to those who drove the car, but did not practice the exercises.
[2548] Park, N. W., & Ingles J. L.
(2001). Effectiveness of attention rehabilitation after an acquired brain injury: A meta-analysis..
Neuropsychology. 15(2), 199 - 210.
http://www.eurekalert.org/pub_releases/2001-04/APA-Rlsm-0704101.php