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San Francisco Chronicle Quotes Dr. Williams: Why a Bay Area football star gave up his NFL dream for blue-collar job


Article Links: What’s a stinger? Is 49ers’ Brock Purdy prone to keep suffering them? (

What’s a stinger and is 49ers’ Brock Purdy prone to keep suffering them? (

Brock Purdy has suffered a stinger in each of the past two games, which leads to a few obvious questions: What exactly is a stinger? And does its reoccurrence in Purdy signal potential problems for the San Francisco 49ers’ quarterback in the final two regular-season games and into the playoffs?

Purdy has entered the blue medical tent on the 49ers’ sideline for two straight weeks dealing with tingling and numbness in his left shoulder and arm due to upper-body hits. The shots have resulted in stingers, which involve the stretching or compression of a group of nerves, known as the brachial plexus, that start in the back of the neck and move into the arm and hand.

Blows to the brachial plexus result in sensations that are often described as a burning pain or an electric shock.

Purdy’s first stinger came when he was hit in the upper chest by Cardinals linebacker Dennis Gardeck on Dec. 17 in the second quarter of a 45-29 win at Arizona. Purdy quickly regained full sensation and missed just two snaps. On Monday, in a 33-19 loss to the Ravens, Purdy suffered his second stinger when he was sacked in the fourth quarter by defensive end Jadeveon Clowney, causing the same lightning-bolt pain.

"It sort of just lit up again just like last week," Purdy said.

Purdy soon regained sensation in his arm and was medically cleared before the 49ers’ next possession, although head coach Kyle Shanahan decided to keep him out due to the late-game score and several injuries along the offensive line.

With the 49ers readying to visit Washington on Sunday, it’s fair to wonder if Purdy’s second stinger suggests he’s more susceptible to continue suffering the same injury, with potentially longer-lasting symptoms.

Dr. Vernon Williams, the team neurologist for the Los Angeles Rams and a sports neurology consultant for the NFL Players Association, provided largely encouraging answers relating to Purdy’s prognosis Thursday.

Williams said it was notable that Purdy had no previous history of stingers. Purdy said that before his injury in Arizona he never had suffered a stinger in a career that included 46 starts at Iowa State. Players who habitually deal with stingers are often predisposed to suffering them due to specific anatomical features.

"And that’s a little more concerning," said Williams, the founding director of the Center for Sports Neurology and Pain Medicine at Cedars-Sinai Kerlan-Jobe Institute in Los Angeles. "That could be due to the way their muscles are developed. Or some of the spaces where these nerves are traveling between muscles — between muscles and bone. Sometimes those can be narrowed and that person is predisposed.

"So the fact that (Purdy) had never had one before is a good thing. Usually, those nerves will recover fairly quickly. And as long as that person’s strength is back to normal and their sensation is back to normal, they can return to play and it’s not an issue."

However, Williams did acknowledge stingers are typically "one-off events."

"It occurs," Williams said. "It wears off. It heals. The person lives happily ever after."

If so, why did Purdy suffer two stingers in nine days? Williams said it’s "within the realm of possibility but unlikely" that Purdy had an anatomical change, such an enlargement of muscle, that has made him more prone to the injury. It’s more likely, however, that Purdy wasn’t fully recovered from his first stinger, even if he had no symptoms.

"Sometimes people can have clinical recovery," Williams said. "They feel better. You test them. Everything looks better. But there’s still some recovery going on with the nerve physiologically. It may not be completely normal yet even though we can’t detect dysfunction by examination or that person is unaware of any ongoing dysfunction. So it may have been subclinical, but still at risk."

Purdy, who has not been limited in practice this week, said Thursday that he has been receiving treatment to work out soreness in his shoulder and upper back.

"I didn’t even know (reoccurrence) was a thing until I got it against the Ravens again," Purdy said. "It sort of got explained that the nerve is a little more susceptible to stinging again. But with treatment and some time and recovery, it will go down and be good to go."

It’s unlikely Purdy’s symptoms would take significantly longer to resolve if he suffered another stinger, although there are no guarantees.

Williams, a Detroit native who received his medical degree from the University of Michigan, was asked how concerned 49ers’ fans should be in personal terms. With Michigan poised to play Alabama in college football’s national semifinals on Monday, he was asked how he would feel if Wolverines quarterback J.J. McCarthy shared Purdy’s recent history of stingers.

"I would be cautiously optimistic," Williams said. "He’s probably going to be just fine, but let’s keep a close eye on it."