Having been scorned and discredited for many years, an American-based Nigerian physician, Dr. Bennet Omalu, has finally been honoured by the American Medical Association (AMA) for the discovery of Chronic Traumatic Encephalopathy (CTE).

Dr Omalu, who graduated from the University of Nigeria, Nsukka, first diagnosed the disease in an NFL player in 2002 but was discredited by researchers. The disease which has been confirmed by post-mortem examination in dozens of American athletes is now the subject of a film, Concussion, featuring Will Smith as the star actor.

Omalu was working as a forensic neuropathologist in Pittsburgh when he conducted postmortem examinations of former NFL offensive lineman Mike Webster’s brain and spotted what would become the hallmarks of CTE.

After his discovery, Omalu, the forensic neuropathologist, underwent a lot of criticism but has overcome massive efforts to discredit him and his research because CTE has been widely recognized as a health risk in millions of patients with histories of repetitive brain trauma, including military veterans.

In recognition and acknowledgement of his discovery, the American Medical Association on Saturday, November 12, 2016 honoured Omalu with its Distinguished Service Award during the opening session of the 2016 AMA Interim Meeting, in Orlando, Florida.

Speaking about how he discovered the disease in Mike Webster’s brain, Omalu said “When I looked at his brain and he had diffuse amyloid plaques everywhere and there were no neurotic plaques … I took the slides home with me. “I spent six months with those slides. I saw CTE randomly situated, and not reminiscent of any other dementia that I knew. My first reaction, when I went to the literature, was that I expected to find previous reports like this, but I didn’t find even one.”

Omalu had the case published in 2005 and went on to identify CTE in post-mortem examinations of numerous other former NFL players. At the time he discovered CTE,  the Nigerian-born Omalu was not a U.S. citizen, and his immigration status was dependent on his continued employment. He however, became a citizen in 2015.

Omalu stuck to his findings in the face of intense pressure, and in 2009—seven years after his discovery—the NFL relented and publicly acknowledged the link between concussions sustained in football and CTE.

AMA President, Andrew W. Gurman, said in a statement “Because of the service Omalu has rendered to every player and every family member in the football and other sporting communities, I am delighted to present him, on behalf of the AMA, with the Distinguished Service Award—our highest honour. His meritorious service is all the more remarkable given that Dr. Omalu was relatively junior at the time of his discovery, having only completed his pathology residency a few years prior to describing CTE.”

Dr. Gurman said he strongly believes “that Dr. Omalu—by his work, determination and dedication—strongly exemplifies the best of American medicine.”

A 20-year member of the AMA, Dr. Omalu serves as chief medical examiner for the San Joaquin County Coroner’s Office in California and is a clinical associate professor in the University of California, Davis, Department of Medical Pathology and Laboratory Medicine.