Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

High levels of tau protein linked to poor recovery after brain injury

14.12.2011
High levels of tau protein in fluid bathing the brain are linked to poor recovery after head trauma, according to a study from Washington University School of Medicine in St. Louis and the Fondazione IRCCS Ca Granda-Ospedale Maggiore Policlinico in Milan, Italy.

“We are particularly interested in finding ways to predict prognosis after traumatic brain injury,” says senior author David L. Brody, MD, PhD, assistant professor of neurology at Washington University. “Right now, it’s very hard to tell who is going to live, who is going to die, who is going to have severe disability and who is going to recover well.”

The results, reported online Nov. 23 in the journal Brain, show that initial tau levels in all injured patients are high and drop off over time. Those who had the highest tau levels in the first 12 hours of monitoring had worse outcomes six to 12 months later. Recovery was measured using the eight-category Extended Glasgow Outcome Scale (GOS-E): 1 indicates death, 2 is vegetative state, 3-4 is severe disability, 5-6 is moderate disability, and 7-8 is good recovery.

“If we can identify early who is likely to have a poor outcome, we can design better clinical trials that don’t include those patients who are going to do fine,” he says.

Brody says the correlation between high tau levels and worse outcome is not perfect, at 0.6 (with a perfect correlation being 1 and no correlation being 0), but they found it to be a better predictor of recovery than markers currently used, including measures of glucose, glutamate and the ratio of lactate to pyruvate in the brain.

Tau is part of the cellular scaffolding that supports and protects the brain’s nerve cells, especially the cells’ long, thin “wires” known as axons that connect different parts of the brain. Abnormal tau protein that forms clumps called “tangles” is also a marker of some forms of dementia, including Alzheimer’s disease.

To fill its structural role, tau is inside nerve cells. Therefore, Brody and his colleagues suspected that the amount of tau outside the cells, in the fluid bathing the brain’s neurons, might be a good indicator of how badly brain axons are damaged after a head injury.

The researchers studied 16 patients with traumatic brain injury and used a technique called microdialysis to monitor tau levels in the brain every one to two hours. Microdialysis involves inserting a thin tube called a catheter into the brain to collect fluid samples. In this study, the catheter was always placed in conjunction with another procedure deemed necessary for the patient’s care, such as implanting a device to measure cranial pressure.

CT scans of the patients’ brains guided catheter placement. In some patients the location of the injury was obvious and the catheter was placed nearby. In others, no injury was apparent on the scan and the catheters were simply placed in the same consistent location.

None of the 16 patients in the study died as a result of the brain trauma, though one died from unrelated causes about two months after the injury and was not included in the final analysis. In addition, no patient was in a persistent vegetative state at the six-month assessment of outcome (a GOS-E of 2).

Of the 10 patients with a GOS-E of 3 or 4 (lower and upper severe disability), seven had initial tau levels above 10,000 picograms per milliliter. Not fitting the pattern, the remaining three had levels below 10,000. The patient with a GOS-E of 5 (lower moderate disability) was just above the 10,000 mark. Of the four patients with a GOS-E of 6 or 7 (upper moderate disability and lower good recovery), all four had initial tau levels below 10,000. No patient received a GOS-E of 8 (upper good recovery).

Though initial tau levels predicted recovery in the surviving 15 patients better than current clinical measures, Brody says the results need to be confirmed in a larger study that controls for such variables as age and type of injury.

But if confirmed, measuring tau levels by microdialysis could become an additional tool for clinicians assessing brain injury. According to Brody, microdialysis provides some information that imaging does not, including changes over time. Microdialysis is also possible in severely injured patients who can’t be moved to a scanner. But microdialysis only samples a small area, while images provide a view of the whole brain.

“Imaging and microdialysis have strengths and weaknesses that complement each other,” Brody says. “Ongoing work with our collaborators in Italy is to assess axonal injury with both specialized imaging and microdialysis in the same patients.”

Magnoni S, Esparza TJ, Conte V, Carbonara M, Carrabba G, Holtzman DM, Zipfel GJ, Stocchetti N, Brody DL. Tau elevations in the brain extracellular space correlate with reduced amyloid-beta levels and predict adverse clinical outcomes after severe traumatic brain injury. Brain. Nov. 2011.

This work was supported by the Burroughs Wellcome Career Award in the Biomedical Sciences, the National Institutes of Health (NIH) and the Fondazione IRCCS Ca Granda-Ospedale Maggiore Policlinico.

Washington University School of Medicine’s 2,100 employed and volunteer faculty physicians also are the medical staff of Barnes-Jewish and St. Louis Children’s hospitals. The School of Medicine is one of the leading medical research, teaching and patient care institutions in the nation, currently ranked fourth in the nation by U.S. News & World Report. Through its affiliations with Barnes-Jewish and St. Louis Children’s hospitals, the School of Medicine is linked to BJC HealthCare.

Julia Evangelou Strait | EurekAlert!
Further information:
http://www.wustl.edu

More articles from Health and Medicine:

nachricht Collagen nanofibrils in mammalian tissues get stronger with exercise
14.12.2018 | University of Illinois College of Engineering

nachricht New discoveries predict ability to forecast dementia from single molecule
12.12.2018 | UT Southwestern Medical Center

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Data storage using individual molecules

Researchers from the University of Basel have reported a new method that allows the physical state of just a few atoms or molecules within a network to be controlled. It is based on the spontaneous self-organization of molecules into extensive networks with pores about one nanometer in size. In the journal ‘small’, the physicists reported on their investigations, which could be of particular importance for the development of new storage devices.

Around the world, researchers are attempting to shrink data storage devices to achieve as large a storage capacity in as small a space as possible. In almost...

Im Focus: Data use draining your battery? Tiny device to speed up memory while also saving power

The more objects we make "smart," from watches to entire buildings, the greater the need for these devices to store and retrieve massive amounts of data quickly without consuming too much power.

Millions of new memory cells could be part of a computer chip and provide that speed and energy savings, thanks to the discovery of a previously unobserved...

Im Focus: An energy-efficient way to stay warm: Sew high-tech heating patches to your clothes

Personal patches could reduce energy waste in buildings, Rutgers-led study says

What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...

Im Focus: Lethal combination: Drug cocktail turns off the juice to cancer cells

A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.

The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...

Im Focus: New Foldable Drone Flies through Narrow Holes in Rescue Missions

A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.

Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

 
Latest News

Pressure tuned magnetism paves the way for novel electronic devices

18.12.2018 | Materials Sciences

New type of low-energy nanolaser that shines in all directions

18.12.2018 | Physics and Astronomy

NASA research reveals Saturn is losing its rings at 'worst-case-scenario' rate

18.12.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>