Jason Doig made headlines earlier this week when he gave Rangers star Eric Lindros a concussion (not the action for which he was suspended).

The concussion suffered by New York Rangers star Eric Lindros on Wednesday was the latest in a rash of head injuries that has seen a rocket-like rise in the number of concussions suffered by National Hockey League players this season -- an increase of more than 60 per cent from this time last season.

Rangers spokesman Jason Vogel said the team might not know the full extent of Lindros's concussion until today. He flew to Montreal to be examined by concussion specialist Karen Johnston, Bloomberg News reported.

Statistics collected by the NHL's injury analysis panel list Lindros's latest concussion -- the eighth of his hockey career -- as the 47th concussion suffered this season in the NHL as the league approaches the 500-game mark and the all-star game break. In 2002-03, there were 29 concussions at the 500-game mark. The concussion increase has occurred while the hockey community has focused much attention on the hot-button issue of high sticks and the need for visors to save eyesight.

The injury analysis panel, which has been in place for three years, will report its numbers to league managers, officials and doctors during the all-star weekend, Feb. 7 and 8, in Minnesota, NHL spokesman Gary Meagher said.

"Right now, the chairman of the panel, Dave Dryden, says they haven't interpreted a rhyme or reason for the increase of concussions at this point in the season," Meagher said.

"They're looking for peaks and valleys and spikes, but no conclusions have been drawn yet."

The number of concussions could be tied, for instance, to the increased intensity of games as the playoffs approach. The figure of 47 concussions at the 500-game mark extrapolates to 76 by the end of the season. But last season, the reality at season's end was much harsher than anyone would have projected. The 29 concussions at the 500-game mark more than tripled to 94 by season's end.

This season's concussion statistics have included heavy losses by the Los Angeles Kings. Two key players have been missing all season, as Adam Deadmarsh and Jason Allison have lingering post-concussion syndrome. Ian Laperriere also missed several games because of a concussion.

The Rangers, who have struggled for most of this season even though they have the largest payroll in the NHL, were anxious about the cost of the latest Lindros concussion to their playoff hopes.

Lindros left in the second period of the Rangers' 2-1 loss to the Washington Capitals on Wednesday. He ran into a hard, legal check from Capitals defenseman Jason Doig. The concussion was Lindros's first since Dec. 28, 2001, when he missed four games and sat out a week after colliding with San Jose Sharks forward Mark Smith.

On Wednesday, Lindros was trying to rush the puck in the neutral zone and stumbled as Caps forward Mike Grier tried to stick-check the puck. Lindros put his head down to locate the puck, and Doig stepped up with a shoulder check. Lindros didn't black out. In fact, he dropped his gloves and challenged Doig to a fight.

A few minutes later, when Lindros came out of the penalty box, head coach Glen Sather reported Lindros "saw some stars."

Having been knocked down this path seven times before, Lindros recognized he had to act with caution, and he stayed out of the rest of the game. There was a consultation with internist Ron Preston and team physician Andrew Feldman in the trainer's room and a telephone conversation with neurosurgeon Johnston, the Montreal-based concussion expert who has examined Lindros numerous times in the past four years.

"There's no sense guessing with something like this," Sather said, although he was hopeful after the conversation with Johnston "they don't think it's that severe."

Understanding the severity of a concussion remains an elusive thing, said Paul Comper, a neuropsychologist at the Toronto Rehabilitation Institute. He has been part of a four-man team studying concussions on varsity athletes for the past six years. The study is designed to figure out when it's safe for a concussed athlete to return to action. Tests are conducted on varsity athletes entering into contact sports, and after a concussion is suffered, athletes are tested to see how long it takes to recover motor and cognitive skills.

Give you head a shake

Eric Lindros took a hard hit along the boards from Capitals defenseman Jason Doig in the second period of Wednesday's game. He was knocked to the ice, suffering his eight concussion.

Traumatic brain injury

A concussion is a head injury that produces an altered mental state or unconsciousness. Direct impact is the leading cause of concussions, but an abrupt acceleration or deceleration of the head can cause one as well.

The brain is cushioned by blood and spinal fluid within, but not touching, the cranial bones of the skull.

The force of impact causes the brain to bounce against the rigid bone of the skull. This can cause a tearing or twisting of the structures and blood vessels of the brain, which can result in memory loss, confusion, disorientation or unconsciousness.

A history of Lindro's concussions

March 7 - missed 8 games

Dec. 29 - missed 2 games

Jan. 14 - missed 4 games

March 4 - missed rest of regular season

May 27 - didn't play again until Oct. 2001

Dec. 28 - missed 4 games

Jan. 28 - most recent concussion