(CNN) -- An examination suggests former NFL linebacker Junior Seau had the brain disease CTE, the National Institutes of Health said Thursday. "On initial examination the brain looked normal but under the microscope, with the use of special staining techniques, abnormalities were found that are consistent with a form of chronic traumatic encephalopathy," the NIH said in a statement. There was also a small part of his brain with "evidence of scarring that is consistent with a small, old, traumatic brain injury," the NIH said. Seau's May 2012 death was classified as a suicide.