One after another, former athletes from high-contact sports have been diagnosed with chronic traumatic encephalopathy, or CTE, upon death. Most played football though a wide spectrum of other sports has been represented as well.

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CTE is believed to be a progressive neurodegenerative disease that can only be assessed postmortem. But physicians at Michigan NeuroSport have begun their own clinical approach for living patients who have experienced repeated head trauma. They published a framework in JAMA Neurology.

"Health care providers need a way to address patients with a history of repetitive brain trauma who are exhibiting neurologic signs or symptoms," says first author Nicole Reams, M.D., a former sports neurology fellow at the University of Michigan who now practices in Chicago. "Our work aims to provide that clinical construct for living patients."

That diagnosis, called traumatic encephalopathy syndrome, is related to a history of concussions. But a person who has TES may not have CTE, and vice versa. The relationship between the two is unknown.

The clinical approach

The most important part of determining whether a patient has possible or probable TES is time: two years of symptoms. That helps avoid false positives; this isn't a diagnosis from a single concussion. It's also important to rule out any other neurologic disorder that could be causing the symptoms associated with TES.

The patient has to have a history of head trauma exposure that's repetitive in nature, which typically means a history of concussion.

The physicians look for cognitive dysfunction, behavioral symptoms and mood changes that are progressive, such as:

• Depression

• Anxiety

• Paranoid thoughts

• Violence

• Socially inappropriate behavior

Declining motor function is related as well, including slowness of motion, or bradykinesia, tremor and instability.

How is TES treated?

The various specialties at Michigan NeuroSport come together, from sports neurology to physical medicine and rehabilitation to neuropsychology, to address the patient's individual issues, whether from possible or probable TES.

"We assess comorbid conditions, like obstructive sleep apnea, migraines, mood disorders and substance abuse," says Matthew Lorincz, M.D., Ph.D., associate professor of neurology and co-director of Michigan NeuroSport. "It's important to treat what we can treat to improve the patient's health, since TES itself is believed to be neurodegenerative and progressive."

It could be a CPAP for sleep apnea, vestibular therapists for balance or a neuropsychologist to address behavioral and memory changes.

"A team approach is always best when assessing and managing a complex neurological disease process like TES," says James T. Eckner, M.D., M.S., co-author and U-M assistant professor in physical medicine and rehabilitation.

Next steps for head trauma research

Reams notes the understanding of TES is early and evolving.

"With continued research, we'll gain more answers about the prevalence of this syndrome, how much head impact exposure is too much, why some with repetitive impacts develop symptoms and others don't and TES' possible relationship to CTE," she says.

Lorincz adds, "We wrote this framework as a guide to inform clinical practice. The research continues to advance, but if all physicians who see patients with concerns about the long-term consequences of head trauma approach it the same way, it will be easier to see patterns and define the true long-term risks of concussion."