CASTLE ROCK — Scott Parker lies in bed, dreading what might come next. Soon after awakening, his ears ring so loud they seem like the equivalent of a hundred fire alarms. Waves of nausea wash over him until he vomits. His eyes glaze over.

One of the toughest men to ever play in the NHL is knocked out, not from an opponent’s punch, but from simply getting out of bed.

Nearly six years since he retired from the NHL as one of its toughest enforcers, Parker is finding everyday life a more fearsome opponent than any he dropped the gloves against. Some days he feels fine. Many days he finds himself paying the price of years of blows to his head. The 6-foot-6, 245-pound Parker — nicknamed “The Sheriff” as a player — frequently is debilitated by seizures. He has to wear sunglasses most of the time because too much light can bring on headaches that leave him incapacitated. When Parker looks down, he cannot “track” objects. Otherwise, he gets dizzy and nauseous.

He is only 35, but Parker’s short-term memory resembles someone much older. He is so forgetful that he has to write down routine things such as needing to make a trip to the grocery store. He often takes pictures and videos with his phone to remember how to do things such as use tools in his woodworking and metal shop.

“I can see right away when he’s having a bad day,” said Francesca, his wife of 15 years. “When he wakes up, he’s in a fog. I can talk to him and I can see it’s just going right through him. And then he’s forgetful. He has words in his head, but what comes out of his mouth is totally different than what he’s thinking.”

Parker’s symptoms closely resemble those of a growing number of former NHL fighters, as well as athletes in other sports, who suffer from repeated head trauma, an issue both doctors and the governing bodies of pro sports are attempting to address.

Parker spent his whole career trying to protect others, to keep them safe. That’s the job of an NHL enforcer. They roam the ice as hired muscle, the guy called upon to retaliate if someone attacks their teammate. Parker took it as a solemn vow. He estimates he participated in around 400 fights, absorbed at least 4,000 punches to the head and face, and suffered 20 to 25 concussions, but part of the “code” of being an enforcer in the NHL is never letting anyone know you’re too hurt to get back on the ice and fight.

The NHL, like the NFL, is grappling with how to effectively deal with brain injuries caused by concussions. In recent years, the league was rocked in short succession by the deaths of former enforcers Wade Belak, Derek Boogaard and Rick Rypien, and there is a growing chorus within the NHL who believe fighting should be banned.

Last week, 10 former NHL players filed a class-action lawsuit, claiming the league hasn’t done enough to protect its players from concussions. The suit comes just three months after the NFL agreed to pay $765 million to settle lawsuits from thousands of its former players who developed dementia or other concussion-related health problems.

Parker is not part of the suit. To this day, he defends fighting and says he understood the risks.

Since his retirement, he has continued to help others, opening his Lucky 27 Social Club barbershop and tattoo parlor — named after his uniform number — in Castle Rock to any military veterans who need a place to hang out and talk. Parker has had a charitable foundation for years that, among other things, organizes fishing and outdoor trips for wounded veterans, particularly those with post-traumatic stress disorder.

Now it’s Parker who could use some help.

Less angry than puzzled

In many ways, Parker is lucky. He has a wide network of friends and a devoted wife. Less angry than puzzled, he has concern about chronic traumatic encephalopathy, a progressively degenerative disease that primarily affects victims of repeated brain trauma.

“I’m not really afraid. I just want to get some answers,” he said. “For me to have to explain the symptoms to people, they don’t know. I sometimes say, ‘Let me give you 20-plus concussions and then we can talk.’ You just want someone to believe in you, for someone to say, ‘You’re not going crazy, it’s not you.’ They haven’t pinpointed what’s wrong. It’s not conclusive.”

Parker might soon get some answers. On Jan. 20, he will travel to the National Institutes of Health in Bethesda, Md., to take part in a three-day series of tests on the brain that are part of a larger initiative involving military veterans with brain injuries.

Dr. James Kelly, a pioneer in the development of baseline concussion tests that are standard in sports at all levels today, will consult based on the findings of the studies. Kelly primarily works with military victims of head trauma at the National Intrepid Center of Excellence in Bethesda, but has agreed to advise on testing that will be conducted on a civilian segment of the population that will include Parker.

Kelly, who commutes to his Centennial home from Washington, D.C., on weekends and is on leave from his job as a clinical professor of neurosurgery at the University of Colorado’s Anschutz Medical Center, has a keen interest in learning why Parker’s symptoms won’t clear up.

In 2008, while working at Anschutz Medical Center, Kelly was the one who had to tell Parker he would never play hockey again after administering what should have been a simple test for a pro athlete to achieve. Kelly asked Parker to keep one foot in a box then hop up and down in place for a few seconds.

“He couldn’t do it, and he was showing other neurological dysfunction. But for a pro hockey player — these guys are built like Greek gods — not to be able to hop up and down in place a few times was very abnormal,” said Kelly, whose protocol for baseline tests was first adopted by the NHL in 1997, ahead of every major pro sport.

At age 30, Parker’s career was over.

“I remember he put his hand on my knee and said, ‘Scott, you’ll never play hockey again,’ ” Parker said. “I was shocked, flabbergasted. I thought he was crazy and went into denial. But here I am still today, having the same symptoms. In fact, it’s worse. Dr. Kelly was right, and now I’m just hoping for some answers, because not knowing what’s wrong with you is the worst part.”

Despite the thousands of punches he received, Parker believes the downward spiral of his health started not from a fist, but a puck that hit him in the right eye in a 2005 preseason game when he was playing for San Jose. He immediately felt symptoms he had never experienced before.

“I always thought I was invincible. You could hit me over the head with a two-by-four and I’d just laugh,” said Parker. “I used to train by wrapping my hands in chains and punching trees as hard as I could.”

To that point, he was doing well as one of the league’s most feared fighters, earning salaries between $600,000 and $800,000 a year.

“When Scott first broke in, I thought he was the man-child,” said former enforcer Stu Grimson, who had a few fights with Parker. “He was a strong, determined and very formidable opponent. He never shrunk from his responsibility. I had a lot of respect for Scott.”

Said former Avalanche captain Joe Sakic: “Parks would do anything for the team; guys always respected that and appreciated that. You hope that he lives a healthy life from here on in.”

Everything changed with the puck to the eye.

“What the hell?”

Initially, Parker thought he had been leveled by a cheap shot.

“All I remember was (teammate) Jim Fahey doing a turnaround in the corner and passing me the puck and I went to one-time it and the next thing I know I’m down (on the ice) wondering, ‘What the hell?’ I thought somebody had smoked me from behind. I remember getting up ready for war and come to find out that I guess the puck had hit a divot and the way I had my stick, it hit my shaft and shot straight up and smoked me in my right eye socket.

“For months, I was just hacking up blood from my sinuses. It was brutal. I almost felt like my head was a helium balloon and I just wanted to pop it. It felt like my head was in the clouds and I just wasn’t all there.”

Afraid to report his symptoms to team trainers and doctors, Parker told San Jose officials he was fine.

“He was having seizures, but when the trainer would ask him, ‘You good to go, Parks?’, he would say, ‘(Bleep) yeah, I’m good to go.’ But he wasn’t good to go in reality,” Francesca said. “Parks just wanted to do his job, to fight for his teammates. It’s amazing, even today, through all this, he’s still like that. Somebody could mouth off to one of the Avs like Cody (McLeod) and Parks would want to climb the glass to go after him. That’s just the way he’s wired.”

Parker played another four seasons after the blow to his eye — with San Jose and Colorado, but only 56 games total — before Kelly told him to walk away. His final fight was in 2008, in a preseason Avs game against Los Angeles in Las Vegas, against rookie Kings enforcer Kevin Westgarth.

“He went up to Parks and said, ‘Mr. Parker, I need some (penalty minutes) or else they might send me down. Could I fight you?’ ” Francesca recalled. “And Parks was like, ‘Sure, kid.’ He was trying to help the kid out. He’s always trying to help others.”

Parker is fortunate in that he has received plenty of emotional support since his retirement. Francesca is tireless in her care for her husband, and the Lucky 27 shop the couple own sees plenty of current and former Avs and NHL players who stop by to check up on their friend. Francesca said the strain of worrying about her husband and what lies ahead is difficult to handle.

“He can’t ride his Harleys anymore. He can’t work out, can’t really handle any physical activity,” she said, although Parker can drive his car short distances. “Of course, my life has drastically changed, too. The barbers here will tell you, there are days where I have to go home; he’s having a tough day and he can’t be left alone. He just gets in a fog.”

They both say they get a deep sense of fulfillment in opening their shop to any military veteran who needs a place to talk.

“We get a lot of them, and while I can’t relate to what they went through on a battlefield, I can understand a lot of what their symptoms are,” Parker said. “Guys don’t like to talk about their problems. But in here, we can. I just hope maybe that what they find out on me in these tests I’ll do soon can help others.”

Parker has been fortunate, too, in having good health insurance. Although she and her husband had to battle the NHL initially over it, Francesca said her husband is on a COBRA health insurance plan from the league for $1,800 per month, and can see any doctor he wants and get any treatment he needs. The family, which includes Francesca’s 27-year-old son, D.J., from a previous relationship, is “doing OK” financially, Francesca said. They live on income from Lucky 27 and from money Parker saved from his playing days.

Fighting has its place

From someone who suffered upward of 25 concussions and thousands of hits to the head, Parker is nevertheless adamant that fighting has its place in hockey. He gets animated when asked whether fighting should be eliminated.

“No way,” he said. “I guarantee you, fighting prevents more injuries in the game than it causes. I just saw a stat recently on Hockeyfights.com that showed, of the first 80 documented injuries in the league this year, only one was caused in a fight, and that was when George Parros slipped and hit his head in a fight with Colton Orr.

“Hockey is a game of accountability. Without the deterrent factor that guys like me could provide, you’d see guys breaking guys’ bones every game from slashing and hitting and not having to account for yourself.”

The NHL keeps chipping away at the edges of the fighting issue, implementing rules that make it harder to fight — such as requiring any player who enters the league now to wear a protective visor and eliminating fights in the final five minutes. But so far, the league has resisted all efforts to take the subject head-on and call for its elimination, although the lawsuit filed last week could have huge ramifications in years to come.

Bill Daly, the league’s deputy commissioner, said in a statement: “We are completely satisfied with the responsible manner in which the league and the players association have managed player safety. We intend to defend the case vigorously.”

Asked whether he had any regrets about the career he chose, Parker said no. “What I regret is getting hit in the eye with that puck,” he said.

Dig a little deeper, though, and he admits he wishes he hadn’t allowed himself to be stereotyped as “just a fighter” early in his career.

“I wish I could have been a more rounded player,” said Parker, a first-round draft choice of the Avs who was pegged to be a power forward. “But the teams I played on, there just wasn’t quite a need for that kind of player. But me, I just wanted to do my job and you did whatever you had to do. If that meant hopping over the boards to protect a guy, even though my ears are ringing and my head is blasting with pain, then that’s what I had to do. I loved to do my job and miss doing it.”

Sitting across the room from her husband one recent day, Francesca said, “Parks, if Dr. Kelly walked into this room right now and cleared you to play, would you play?”

“I would,” he replied.

“See,” Francesca said, turning to another observer. “It never goes away.”

Adrian Dater: adater@denverpost.com or twitter.com/adater

Coming Monday: The hold fighting has on hockey.