TBI was associated with a 31% greater risk of stroke compared with trauma patients whose injuries did not affect the brain. A significantly increased risk persisted after adjustment for potentially confounding factors.

Although the absolute increase in risk was 0.2%, the higher prevalence of TBI in trauma patients translated into a bigger contribution to ischemic stroke than hypertension, the leading risk stroke risk factor, James F. Burke, MD, of the University of Michigan in Ann Arbor, and co-authors reported in the July 2 issue of Neurology.

“Despite the robust association of TBI and ischemic stroke, the absolute difference between TBI and non-TBI trauma patients in this low-risk cohort is small,” the authors concluded. “Nonetheless, if further research definitively established TBI as a novel stroke risk factor, this would stimulate research to understand stroke pathophysiology after TBI and inform stroke prevention efforts in this young population with few vascular risk factors.”

The findings add support to a previous Taiwanese study, which showed a higher stroke risk associated with TBI compared with a nontrauma control group.

“In our study, the association persisted after selecting non-TBI trauma controls that are likely more similar to the TBI population than the age- and sex-matched controls in the Taiwanese study,” the authors added.

Stroke and TBI cause substantial disability among working-age adults, as 20% of strokes and more than 40% of TBIs occur in adults younger than 65. A large proportion of strokes in younger people remain unexplained. Identification of risk factors in that subgroup of patients might lead to development of prevention strategies to reduce stroke rates in younger adults, the authors wrote.

In theory, trauma to the head and neck could increase stroke risk by several means, including vascular dissection, microvascular injury, and abnormal coagulation. The Taiwanese observational study showed an association between TBI and all strokes, but the strongest relationship involved known effects of TBI (subarachnoid and intracerebral hemorrhage).

Much of the increased stroke risk occurred in the first month after TBI, suggesting that some events classified as stroke might have been sequelae of TBI.

Burke and colleagues continued the investigation of TBI and stroke by examining data on emergency department visits and inpatient discharges in California from 2005 to 2009. Data for the analysis came from several state and national databases.

Investigators compared TBI and non-TBI trauma patients, adjusting for as many confounders as possible. They defined TBI according to CDC guidelines. They limited the analysis to patients with minor strokes and transient ischemic attacks.

Of 1,173,353 trauma patients, 436,630 (37%) had a TBI. Patients with TBI were slightly younger (mean age 49.2 versus 50.3), were less likely to be women (46.8% versus 49.3%), and had a higher injury severity score (4.6 versus 4.1).

During a median follow-up of 28 months from the traumatic injury, 1% of the patients had newly diagnosed ischemic strokes. The TBI group had an incidence of 1.1% and the non-TBI group an incidence of 0.9%. The fully adjusted analysis showed that TBI was associated with a hazard ratio of 1.31 for ischemic stroke hospitalization as compared with the non-TBI trauma patients (95% CI 1.25-1.36).

The hazard ratio varied minimally with the addition of covariates, including demographics (HR 1.34), comorbidities (HR 1.30), vascular risk factors (HR 1.30), and injury severity and trauma mechanism (HR 1.31).

The magnitude of the association between TBI and ischemic stroke remained similar when stroke hospitalization was categorized by intervals ranging from 7 to 365 days from traumatic injury. An age-stratified analysis resulted in the greatest change, as patients younger than 50 had an odds ratio of 1.56 (95% CI 1.32-1.85) as compared with 1.22 for older patients with TBI (95% CI 1.16-1.28).

The authors acknowledged several limitations of their study, primarily related to the diagnostic imprecision inherent to administrative data.

“TBI is associated with ischemic stroke, and further work is needed to assess whether it may be a novel stroke risk factor,” the authors concluded. “Prospective cohort and/or population-based, cross-sectional studies are needed to confirm the association, explore potential mechanisms for the association between TBI and ischemic stroke, and carefully characterize the clinical features of both TBI and subsequent stroke.”

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