"He's got easily between seven and 10 tonic-clonic seizures per month," Mitchell says. Tonic-clonic, or grand mal, seizures describe the dramatic, convulsive type of seizure usually depicted in Hollywood films.
It wasn't until the Mitchells got season tickets to watch the Anaheim Angels professional baseball team that Cindy Mitchell noticed her son's potential sensitivity to fireworks. After each Friday home game, fans are treated to a pyrotechnics show above Anaheim Stadium.
"What he gets is a quick flip or a jerk of his wrist or his ankle ... and sometimes blinking or twitching of the eyes," says Mitchell. But the family still goes to the games, because the fireworks-triggered reactions are not as severe as the tonic-clonic seizures, explains Mitchell.
Despite Thorne's and Mitchell's stories, neurologists who treat patients with epilepsy think such reactions do not occur in a large number of people.
"You may well get some anecdotal reports of firework-provoked seizures ... but this would be a rarity, not by any means the norm," says Dr. James Grisolia, a neurologist at Scripps Memorial Hospital in San Diego, Calif.
Most light-induced seizures require a fixed frequency of light exposure. For example, photosensitive people might be bothered by the rapid shutter effect you see when looking at a sunlit picket fence from a moving car, explains Dr. Shlomo Shinnar, director of the Comprehensive Epilepsy Management Center at Montefiore Medical Center.
The intensity of the light is also a key factor in affecting the brain. "This is why we advise kids to sit away from [the] TV with room lights on if they are somewhat sensitive," says Shinnar. Fireworks, he says, are usually too far off in the sky and fail to erupt with a fixed frequency of bursts.
Other neurologists suspect the sounds generated by the explosions in the fireworks' lift charges and breaks might be to blame.
"I have, in the past, had one patient who had seizures provoked by fireworks, but it was due to the loud percussive sounds causing a startle rather than the lights," says Dr. Orrin Devinsky, director of the New York University Epilepsy Center.
But what about the fireworks finale? Dr. Giuseppe Erba thinks the climactic conclusion we've all come to expect in professional shows is the most fitting time for photosensitivity to kick in.
"I recommend caution at the end of the fireworks, when the whole sky lights up," says Erba, a professor of neurology and pediatrics at the University of Rochester. The blasts are "wider and they occupy most of the visual field," if you're up close to the display.
For most patients with epilepsy who are on the right medication, the pyrotechnic climax should not have an effect, says Erba. His concern is for those people, most likely children around school age, who "do not know they're photosensitive."
When you're watching the fireworks show, "be very observant of how your body responds," he says. "If you start getting some involuntary jerks, that may be the first signal that something is wrong."
Should that happen, Dr. Erba recommends covering one eye with the palm of your hand to block out the light. Cutting light input to the visual cortex by half should be enough to prevent a seizurelike cascade of electrical activity in the brain, explains Erba.