Twenty-seven percent of mTBI patients with a normal CT scan showed evidence of abnormalities on brain MRI.

MRI may be better than CT scans at predicting whether patients with mild traumatic brain injuries (mTBI) are likely to have persistent neurologic problems, according to the results of a clinical trial published in the December 2012 Annals of Neurology.

Approximately 15% of patients with mTBI have measurable neurologic deficits at one year after injury, but clinicians have no definitive method of predicting patient outcomes.

To address this clinical need, Esther Yuh, MD, PhD, Assistant Professor in Residence at the University of California, San Francisco, School of Medicine, and her colleagues examined the potential of MRI to predict patient outcome three months after mTBI. The researchers prospectively followed 135 patients who were evaluated for acute head injury in the emergency departments of three level I trauma centers—San Francisco General Hospital and Trauma Center, the University of Pittsburgh Medical Center, and the University Medical Center Brackenridge in Austin, Texas. These centers were part of the Transforming Research and Clinical Knowledge in Traumatic Brain Injury study (TRACK-TBI).

Patient Characteristics

Patients came from highly diverse socioeconomic backgrounds, had few exclusion factors, and ranged from age 15 to 86, with a mean age of 40. All patients underwent CT scans when they were admitted, and early brain MRI was performed approximately a week later.

The investigators used univariate and multivariate logistic regression to determine demographic, clinical, socioeconomic, CT, and MRI features that predicted outcomes at three months following the brain injury. Outcomes were assessed with the eight-point Extended Glasgow Outcome scale, a well-validated summary assessment suitable for clinical trials.

Multivariate models of the three-month outcome scale were analyzed based on three sets of predictive variables. The first set examined only clinical, demographic, and socioeconomic variables, the second set incorporated head CT features, and the third set used all the preceding variables, as well as brain MRI features.

Evidence of subarachnoid hemorrhage on CT was associated with a multivariate odds ratio of 3.5 for poorer three-month outcome, after accounting for demographic, clinical, and socioeconomic factors, said the researchers.

Normal CT Is Not Enough

However, 27% of patients who were admitted with normal head CT had an abnormal early brain MRI. After adjusting for head CT findings and demographic, clinical, and socioeconomic factors, the investigators found that one or more brain contusions and four or more foci of hemorrhagic axonal injury on MRI were each independently associated with poorer three-month outcome. Multivariate odds ratios were 4.5 and 3.2, respectively.

This work raises questions of how we’re currently managing patients via CT scan,” said senior author Geoff Manley, MD, PhD, Chief of Neurosurgery at San Francisco General Hospital. “Having a normal CT scan doesn’t, in fact, say you’re normal,” he added.

A Step Forward

Each year, at least 1.7 million Americans seek medical attention for acute head injuries, and 75% of those injuries are mTBIs, most with mild symptoms such as temporary loss of consciousness, vomiting, or amnesia.

The majority of patients with mTBI recover fully, but approximately one in six eventually develop persistent and sometimes permanent disability from the injury. In the past, some socioeconomic factors have helped to predict disability, but Dr. Yuh’s study shows that an imaging feature can help to predict the rate or extent of a patient’s recovery.

According to Dr. Manley, this study represents an important step toward developing a more quantitative, precise method of evaluating, monitoring, and treating patients with mTBI. At present, performing routine brain MRI on mTBI patients may not be cost-effective, but smaller and less-costly MRI scanners that examine only the patient’s head are in development. Furthermore, continuing advances in the MRI field may eventually reduce expenses to a manageable level.

The study’s strengths are its greater specification of types of lesions that may predict outcome, control for other predictors, multicenter patient sample, and use of TBI Common Data Elements to categorize the imaging results, the investigators said.

They believe the findings will benefit clinicians and researchers conducting clinical trials. “Progress beyond mere definition of mTBI toward evidence-based diagnosis is essential for clinical trials that evaluate treatments and, ultimately, more effective triage to follow-up care,” stated the authors.(Lauren LeBano)

Concern has grown over concussion brain injuries in professional athletes as well as in teens and children. Youngsters — whose brains are still developing — are competing at ever-earlier ages in concussion-prone contact sports. The concern spotlights the need for more awareness of concussion dangers and how to prevent them.

A concussion occurs when there’s a blow to the head or a sudden jolt that shakes the head and causes the brain’s gelatin-like cortex to rapidly collide into or bounce off the inside of your skull or to rotate within it. When it occurs, the brain’s function is altered. Loss of consciousness may or may not happen, which is one of the reasons some concussions go unrecognized.

No matter the cause, when a firsttime concussion brain injury is identified and the brain is given adequate rest and time to heal properly, most recover completely. However, changes that occur in the brain due to concussion make it potentially vulnerable to repeat injury and possibly even permanent damage. For someone who’s had multiple concussions, recovery becomes less certain with each concussion.

Inside matter

According to the Centers for Disease Control and Prevention, concussions make up the majority of traumatic brain injuries each year. Among adults 65 and older, falls are the number one cause of traumatic brain injury. For all
age groups, motor vehicle accidents are the second-leading cause. Part of the concussion conundrum is that the brain has no pain receptors. So, during a concussion — when the brain is slung through its cushion of cerebrospinal
fluid and crashes full force into the cranium — that impact registers indirectly. Initially, or within several minutes, you may experience confusion and memory loss. This may or may not be preceded by loss of consciousness.

Although you may appear to be fine immediately after a concussion, it’s a different story inside the brain. The instant after a concussion the brain is in crisis. Many brain cells (neurons) can become activated all at once. This can
cause a sudden release of brain chemicals (neurotransmitters). Within minutes to hours after a concussion, the brain’s power drain produces signs and symptoms that may include headache, dizziness, imbalance, nausea or vomiting, slurred speech, fatigue and being unaware of your surroundings.

While some symptoms are more immediate, others may show up in the hours and days that follow, including:

• Difficulty concentrating or remembering things
• Sensitivity to light and noise
• Persistent headache
• Unexplained irritability or other personality changes
• Sleep disturbances
• Depression and problems adjusting psychologically
• Altered senses of taste and smell

As long as symptoms are present, it’s critically important to avoid a second concussion. During this time, the brain is vulnerable to a rare but fatal brain-swelling complication.

Long-term changes from a brain concussion are more uncertain. Although symptoms due to concussion may no longer be apparent, structural damage to the brain may be slower to recover. Recent studies using specialized
magnetic resonance imaging (MRI) scans show changes in certain brain structures even at six months.

Medical care matters

A head injury should be evaluated by a medical professional. That person may be your care primary doctor or any other member of your primary health care team capable of giving you advice and assuring follow-up. Young athletes or children should be removed from play for any suspected concussion.

Typically, a neurological exam is done for a head injury. This may include evaluation of your memory and ability to concentrate, vision and hearing, pupils, strength and sensation, balance, coordination, and reflexes.
Although brain imaging isn’t always done, depending on your symptoms, a computerized tomography (CT) scan or MRI may be done to assess the brain right after injury. However, the findings are usually normal. Imaging is also likely if you’re 65 years of age or older or are taking medicines that affect blood clotting.

Depending on the findings, you may need to be hospitalized overnight for observation. Monitoring is important in the hours after a concussion because brain injury may lead to more-serious problems, including bleeding in or around the brain.

If your doctor says home observation is reasonable, you’ll need to have someone check on you every few hours for at least 24 hours to be sure that your symptoms don’t get any worse. Emergency
care is needed if your symptoms get worse or you experience any of the following:

• Repeated vomiting
• Severe headache
• Loss of consciousness
• Difficulty with mental function or physical coordination

Time for recovery

Because the brain is fragile after a concussion, the focus during recovery is rest — both physical and mental. It takes time for the brain to restore itself. And how much time varies. Several factors can influence how quickly you
recover, including your age, severity of the concussion and whether you have other health conditions. Recovering from a concussion is no time to ignore your symptoms and “tough it out” — doing so can make
symptoms worse. Instead:
■ Take time to rest — Get plenty of sleep at night and rest during the day.
■ Moderate how much and how intensely you think — Special imaging scans show that thinking causes the brain to use energy, which is fine when the brain isn’t in the process of healing. But after a concussion, energy use from
thinking takes away from the brain’s efforts to heal and recover. Concentration slows recovery and can even make symptoms worse. That’s why it’s important to avoid activities that require a lot of concentration.
■ Avoid physically demanding activities — Put your workout aside for now. Let someone else mow the lawn or clean the house. Save the energy you have each day for activities that are most important to you.

If your doctor says you can ease into some regular activities, see how you do. If your symptoms return or you get new symptoms, more rest is needed.

When concussion recovery is managed properly, most people recover completely within a week or two and have no further symptoms. However, for those whose recovery from concussion takes longer, persistent headache
can be a common challenge.

Read full article at http://healthletter.mayoclinic.com/year/year.cfm/i/2012