PHILADELPHIA (AP) - A federal judge in Philadelphia says retired NFL players seeking testing as part of a $1 billion concussion settlement must see a doctor close to home to prevent fraud and "doctor shopping."

Lawyers for thousands of ex-players say they agreed to the settlement because they could choose their own neurologist. Their lawsuits alleged the NFL long hid what it knew about concussions and brain injuries.

Some players' lawyers call the ruling Thursday from Senior U.S. District Judge Anita Brody a significant change to the 2013 settlement.

The league and the former players are battling over dementia claims after first handling cases involving Alzheimer's disease and other serious diagnoses. Less than 15 percent of the 1,700 dementia claims filed so far have been approved and paid.

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