One of the doctors that gave Bryan the green light was neurosurgeon Dr. Robert Cantu, who works as a consultant on concussions for teams in the NFL, NBA and NHL.
Cantu gave an interview with Newsweek on Friday, offering some interesting insight into Bryan's health when he was examined. Despite having numerous concussions (some of which resulting in seizures) across 16 years in the business, Bryan's brain showed no signs of damage.
"I evaluated Bryan for a neurological opinion on return to WWE on February 26, 2018. Included in his medical records were multiple evaluations by renowned concussion clinicians," Cantu said via email.
"I determined that Bryan is currently asymptomatic, has a normal detailed neurological and cognitive neuropsychological examination, normal EEG, and an MRI that showed no definite evidence of a prior brain injury. It is my medical opinion that there is no absolute contraindication to his return to in-ring action in WWE."
Bryan's concussion shortly after WrestleMania 31 in 2015 forced him to retire from in-ring action nearly a year later in February 2016. However, as he divulged in an interview on the E&C Podcast of Awesomeness back in August, the forced retirement was actually a huge misunderstanding.
Bryan began testing at Evoke Neuroscience in New York City during his time off, and a week before his 2016 retirement the doctors came back with a report that he had a lesion on the back part of his brain.
"I'm just like, 'Holy sh—. A lesion.' I'm like, 'That's it, I'm done. I'm finished,'" Bryan said.
However, mere days after his emotional retirement speech on an episode of Monday Night Raw, a separate doctor who had previously cleared him prior to the testing at Evoke explained that a lesion wasn't nearly as serious as Bryan or WWE thought.
"I told him what happened and I said, 'They found a lesion in the temporal-parietal region of my brain.' He goes, 'Wait, hold up, a lesion?' I said, 'Yeah.' And I don't know what lesion means to you guys, a lesion to me means you have a cut. I have a cut on my brain. He goes, 'No. Lesion, in medical terminology, is a very vague thing. It just means something is there. We don't know what it is, so we call it a lesion in the temporal-parietal region of your brain.'"
Bryan discovered that the "lesion" Evoke had marked down was merely that his reflexes were slower than that of the athletes the facility normally tests. Meaning all he had the reflexes of a normal person.
"So I have average reflex time. I was like, 'Oh no. I don't think they understand. I'm just an average person, I'm not a real athlete!' It's just like, 'Oh no, there's been this huge, huge misunderstanding!'" Bryan said.
After being brought in as SmackDown Live's general manager, Bryan began working with the Joe Namath Neurological Research Center in Florida to heal and improve his brain function via experimental Hyperbaric Oxygen Therapy Treatments.
In a press release, WWE mentioned Dr. Canut as well as three other concussion experts Bryan was sent to prior to getting his clearance.
"Following more than two years of extensive evaluations, WWE Superstar Daniel Bryan has been medically cleared to return to in-ring competition by leading neurosurgeons, neurologists and concussion experts, including Dr. Robert Cantu, Dr. Javier Cárdenas and Dr. Jeffrey Kutcher Bryan underwent a full review of his medical history and received comprehensive neurological and physical evaluations independent of WWE. He was cleared by each doctor as well as WWE's Medical Director, Dr. Joseph Maroon."