The field was under a caution period in NASCAR’s season-opening race when the rain arrived at Daytona International Speedway at 2:12 p.m. EST.

[Update: The rain stopped by 5 p.m. EST and NASCAR was making efforts to dry the track. But NASCAR officials had yet to say whether the race would be resumed Sunday night amid indications of possibly more rain in the area.]

Kyle Busch was leading, followed by Kasey Kahne, Denny Hamlin and Brian Vickers.

The race was scheduled for 200 laps around the high-banked, 2.5-mile speedway, which has lights should the race need to be concluded after sunset.

The only car out of the race was the No. 78 Chevrolet driven by Martin Truex Jr., which suffered a blown engine on Lap 31 that brought out the caution period.

Rookie Austin Dillon, who started on the pole, was running 10th. Elsewhere in the field, Jeff Gordon was seventh, Dale Earnhardt Jr. was 18th, Danica Patrick was 33rd, Tony Stewart was 34th and defending Daytona 500 winner Jimmie Johnson was 38th.

On Daytona 500 Sunday, Is NASCAR Facing An NFL-Style Concussion Crisis?

As NASCAR begins its 2014 season today with the sport’s biggest race, the Daytona 500, one of the questions to ask is how many of these drivers will suffer a concussion during the course of the year, how many of them will have it properly diagnosed and fully recover before they get behind the wheel, and what will be the long-term effects of these brain injuries?

In a special report published last month, Road & Track  argues that NASCAR may be facing an NFL-style concussion crisis.  An article by veteran motorsports journalist Stephen Cole Smith, tells the story of Fred Lorenzen, one of the sport’s pioneers who is suffering from dementia, possibly caused by a condition called chronic traumatic encephalopathy, or CTE, that has affected so many NFL players.

CTE is characterized by the accumulation of a damaging protein called tau. It’s not clear exactly what causes the disease, although researchers have seen cases in which CTE sufferers have experienced either a single large impact or a series of smaller ones. What is known is that a concussion makes a victim susceptible to suffering another one, a risk that increases if he’s not fully recovered from the first brain injury.
Currently, CTE can only be diagnosed by sectioning brain tissue after death so neither Lorenzen, nor any of his fellow racers, have yet to be definitively diagnosed with the condition. But that’s likely to change as researchers discover new ways to diagnose the disease through sophisticated scanning.

The article, which is well worth reading in its entirety, cites the cases of several drivers who exhibited the mental and neurological symptoms similar to those experienced by NFL players who had CTE.

The number of concussions  in auto racing is relatively low, but the wild card is the number of concussions that go unreported (more on that in a moment.) NASCAR and the drivers themselves, possibly spurred by the NFL’s head injury crisis, seem to be taking steps toward addressing head injuries in active drivers.

For the first time this year, the sanctioning body has mandated imPACT testing which establishes a cognitive baseline that can help doctors diagnose concussions.

And some drivers are taking matters into their own hands. Dario Franchitti, three-time winner of the non-NASCAR Indy 500, retired in the prime of his career on the advice of doctors after suffering his third concussion in crash during a race last season

And in 2012, Dale Earnhardt, Jr. suffered a crash in tire testing, and voluntarily sought out medical treatment that sidelined him for two races.

Other drivers, however, seem less likely to make similar decisions. “Earnhardt knew he’d always have a ride. Less secure drivers may not,” writes Smith.

And even the drivers at the top of the sport seem ready to put on-track achievement ahead of their long-term brain health.

Former NASCAR champion Jeff Gordon, one of the sport’s richest and most accomplished drivers, told SB Nation that he would hide symptoms of a concussion if revealing a head injury would cost him a shot at a title.

“Honestly, I hate to say this, but no, I wouldn’t. If I have a shot at the championship, there’s two races to go, my head is hurting, I just came through a wreck, and I am feeling signs of it, but I’m still leading the points … or second … I’m not going to say anything. I’m sorry.”

NASCAR has to understand that the financial stakes of its reaction to the head injury issue are high, and could even determine the course of the sport’s future. The NFL recently settled a case with its retired players for $765 million.

NASCAR drivers work for individual, privately-owned teams, and, unlike their football counterparts, are not represented by a union. “NASCAR has had success in insulating itself from liability in comparable suits in the past,” wrote Smith. “It maintains that it does not employ drivers—they are independent contractors for their teams, making their own choices.” However, attorneys representing afflicted drivers would likely challenge this position in a lawsuit.

As the season progresses, look for this issue to move to the forefront, as retired drivers wonder if their health problems are related to head injuries suffered during their driving careers, and active drivers–and NASCAR itself–take measures to prevent, diagnose and treat the traumatic brain injuries that can result in diseases like CTE.