What type of concussion is it? The answer could affect treatment

Joe felt irritable and overwhelmed. Carla had blurry vision and didn’t feel safe to drive. Meg had a pounding headache. But all three of them received the same diagnosis: concussion.

Concussion symptoms vary for different people depending on their medical history, age, degree of injury and other factors. To develop the most effective, personalized treatments, concussion experts across the country are working to learn more about how these variables impact concussion symptoms and recovery.

The researchers — including pediatric emergency medicine physician Angela Lumba-Brown, MD, and neurosurgeon Jamshid Ghajar, MD, PhD, from Stanford’s Brain Performance Center — identified five categories of concussions, which have different symptoms and require different initial treatments:

  • Vestibular — Symptoms include dizziness, fogginess, lightheadedness, nausea, vertigo and disequilibrium. Initially treated with balance and vestibular-ocular training with a physical therapist.
  • Ocular-motor — Symptoms include difficulties with reading and driving, eye strain, problems changing focus between near and far, blurred or double vision, eye pain, vision-derived nausea and photophobia. Initially treated with dynamic vision training with an optometrist. 
  • Headache — Symptoms include different types of headaches, including migraines. Initially treated with headache management.
  • Cognitive — Symptoms include problems with attention, reaction time, working memory, new learning, memory retrieval, organization of thoughts and behavior. Initially treated with neuropsychological assessment and treatments.
  • Anxiety-Mood — Symptoms include nervousness, hypervigilance, ruminative thoughts, depressed mood, anger, irritability, loss of energy, fatigue and feeling more emotional, overwhelmed or hopeless. Initially treated with counseling, including cognitive-behavioral therapies.

The findings appear in Neurosurgery.

However, diagnosing concussions and selecting the correct treatments is a bit more complicated than this list may indicate, Ghajar and Lumba-Brown explained. “These subtypes are not mutually exclusive and they frequently cluster together,” Ghajar said.

This interdependence isn’t all bad news though, because the headache, cognitive and anxiety-mood concussion subtypes often resolve after treating for vestibular and ocular-motor concussion symptoms. Also, early cardiovascular exercise is recommended for all subtypes.

In addition, the experts determined the prevalence of these concussion subtypes in adults and children based on a meta-analysis of previous studies. The most common subtype depends on when a patient is seen, as well as their medical history and age.

“Early on, the headache subtype is the most prevalent for both adult and pediatric populations, and it usually co-exists with the vestibular and ocular-motor subtypes,” said Ghajar. “Weeks to months after injury, the mood subtype with symptoms of anxiety and depression predominates, usually because of inadequate interventions. The prevalence of the vestibular subtype was also very high for pediatric patients.”

The working group also found that sleep disturbance and cervical strain were commonly associated with all five concussion categories. Sleep disturbance symptoms include difficulty falling asleep, frequent awakenings and fatigue, whereas cervical strain symptoms include neck pain, neck stiffness and upper extremity weakness.

According to Lumba-Brown, this work is particularly important because it addresses subtypes in children, a vulnerable subset of patients with unique needs. “Children are expected to go to school daily. They often play sports or engage in risk-taking behaviors. And they often have difficulty expressing their symptoms,” said Lumba-Brown, who recently helped develop clinical guidelines for children with mild traumatic brain injury.

The experts said they hope that a better understanding of the different kinds of concussions and their prevalence will ultimately translate into improved treatment and faster recovery for patients of all ages. The team is now investigating the recovery trajectories for the different subtypes — from the acute period through three months following injury.

They offered clinicians guidance in light of the findings: “Clinicians should assess each subtype of impairment in the acute setting following injury, encourage early cardio exercise and provide prognostic counseling for mood and sleep disturbances.”

Photo by Staff Sgt. Jonathon Fowler/U.S. Air Force

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.

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Curious about concussions? A Stanford researcher reflects on current research, outstanding questions

Photo by Steve - Body Slam
Photo by Steve – Body Slam

Football season has begun, reviving concern and discussion over sports-related concussions.

The American Academy of Pediatrics defines a concussion as a direct hit to the head or jarring blow to the body that gets transmitted to the head, resulting in a rapid onset of short lived impairment of neurological function. However, some controversy surrounds even this definition. So I reached out to Jessica Little, PhD, director of clinical research and operations at the Stanford Concussion and Brain Performance Center, to learn more about concussion research and Stanford’s clinical study of teenage athletes.

What should we know about concussions?

“I think it is important to note that concussions are still not well understood. There are hundreds of different definitions of ‘what is a concussion’ and there is currently no single evidence-based consensus on how to identify and treat concussions.

Research has shown that one of the biggest risk factors for sustaining a concussion is a history of having a prior concussion. There is a ‘window of vulnerability’ — the concept that a person experiencing symptoms of concussion is more vulnerable to incurring a second concussion during this time, as the brain has not yet fully recovered. If a truly concussed athlete has problems paying attention or is not coordinated, they can then be vulnerable to another injury. Protocols are often used to track signs and symptoms of concussion, and athletes are not allowed to return to play until these have resolved. However, it would be helpful to have more precise ways to measure attention and coordination on the sidelines to keep impaired athletes out of contact sports until those skills recover.

The vast majority of people with a concussion recover fully after the injury, though not all symptoms may improve at the same rate and everyone recovers a little differently.”

Describe your clinical study for athletes between 12-17 years of age.

“Our study just closed recruitment and we’re prepping all the data for analysis, so it is an exciting time. The study was called EYE-TRAC Advance, short for Eye-Tracking Rapid Attention Computation. Our lab used a specific type of eye-tracking called ‘circular smooth pursuit’ where an athlete follows a dot that moves at predictable speed around a circle. The eye-tracking was in the form of custom-designed portable “goggles,” using built-in cameras and infrared pupil detection.

Our hypothesis is that people without a concussion can ‘sync-up’ with the way the dot is moving pretty easily, while a person with a concussion has a disruption in their ability to focus and pay attention. You often hear people saying that they feel “off” or “out of sync” following a concussion, and we’re trying to quantify that experience. For the study, we baseline tested athletes (before sports participation) with the eye-tracking, as well as other neurocognitive tests that measured things like attention and reaction time. If the athlete later got a concussion, we tested them again as soon as possible and again at 1, 3 and 12 months after the injury. In this way, we’re able to get a clear picture of how their brain recovered over time.

Overall, we reached out to over 60 different organizations and recruited over 1,400 people. We had a specially outfitted ‘mobile testing center’ RV. This allowed us to literally drive up to the side of an athletic field and perform the testing on-site at the school or organization, which really reduced common barriers to participating in a research study, such as the costs and time associated with transportation to and from appointments.”

Can technology play a significant role in preventing concussions?

“A lot of current technologies focus on diagnosing a concussion, but there are far fewer that actually focus on preventing concussions. There are some technologies that measure an athlete’s gait and vestibular-balance ability. If there are impairments, the athletes can be provided skill training to improve any deficits, thus reducing the risk of injury. Other technologies, such as helmet technologies, may be helpful in reducing the instance of skull fractures and other serious injuries, but they haven’t yet proved effective at preventing a concussion — that is caused more by brain rotation, which a helmet can’t fully protect against. One possible preventative solution could come from a neck device that stabilizes the rotational forces while still allowing neck movement at low accelerations, so athletes can move about freely until it senses a potentially dangerous level of force.”

Are there issues with under-reporting concussions?

“Historically, there have been some issues with individuals under-reporting symptoms that would lead to a diagnosis of a concussion. This is often motivated by the idea that they should ‘suck it up,’ ‘don’t want to let the team down’ or the fact that their ability to perform athletically is tied to keeping an athletic scholarship. There is research happening in the field right now trying to figure out the best way to dismantle these types of beliefs and make it more likely that athletes can be properly identified, given the treatment they need, and hopefully continue to safely engage in their sport.”

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.