Head injuries result in widespread brain tissue loss one year later

March 3, 2008

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.

Source: Baycrest Centre for Geriatric Care

Explore further: Hyperthyroidism vs. hypothyroidism—what's the difference?

Related Stories

Hyperthyroidism vs. hypothyroidism—what's the difference?

January 22, 2018
In our daily life, we may sometimes feel run down, stressed or have unexpected weight fluctuations and think it is nothing out of the ordinary. Yet for some people, these symptoms could be a sign of an underactive or overactive ...

How your brain remembers what you had for dinner last night

January 17, 2018
Confirming earlier computational models, researchers at University of California San Diego and UC San Diego School of Medicine, with colleagues in Arizona and Louisiana, report that episodic memories are encoded in the hippocampus ...

Rocky start for Alzheimer's drug research in 2018

January 19, 2018
The year 2018, barely underway, has already dealt a series of disheartening blows to the quest for an Alzheimer's cure.

Secrets of longevity protein revealed in new study

January 17, 2018
Named after the Greek goddess who spun the thread of life, Klotho proteins play an important role in the regulation of longevity and metabolism. In a recent Yale-led study, researchers revealed the three-dimensional structure ...

Memory loss from West Nile virus may be preventable

January 15, 2018
More than 10,000 people in the United States are living with memory loss and other persistent neurological problems that occur after West Nile virus infects the brain.

Can psychedelic drugs 'reconnect' depressed patients with their emotions?

January 15, 2018
Imperial research suggests psilocybin can help relieve the symptoms of depression, without the 'dulling' of emotions linked with antidepressants.

Recommended for you

Forces from fluid in the developing lung play an essential role in organ development

January 23, 2018
It is a marvel of nature: during gestation, multiple tissue types cooperate in building the elegantly functional structures of organs, from the brain's folds to the heart's multiple chambers. A recent study by Princeton researchers ...

More surprises about blood development—and a possible lead for making lymphocytes

January 22, 2018
Hematopoietic stem cells (HSCs) have long been regarded as the granddaddy of all blood cells. After we are born, these multipotent cells give rise to all our cell lineages: lymphoid, myeloid and erythroid cells. Hematologists ...

How metal scaffolds enhance the bone healing process

January 22, 2018
A new study shows how mechanically optimized constructs known as titanium-mesh scaffolds can optimize bone regeneration. The induction of bone regeneration is of importance when treating large bone defects. As demonstrated ...

Researchers illustrate how muscle growth inhibitor is activated, could aid in treating ALS

January 19, 2018
Researchers at the University of Cincinnati (UC) College of Medicine are part of an international team that has identified how the inactive or latent form of GDF8, a signaling protein also known as myostatin responsible for ...

Bioengineered soft microfibers improve T-cell production

January 18, 2018
T cells play a key role in the body's immune response against pathogens. As a new class of therapeutic approaches, T cells are being harnessed to fight cancer, promising more precise, longer-lasting mitigation than traditional, ...

Weight flux alters molecular profile, study finds

January 17, 2018
The human body undergoes dramatic changes during even short periods of weight gain and loss, according to a study led by researchers at the Stanford University School of Medicine.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.