(CBS News) Famed environmental activist and legal consultant Erin Brockovich is headed to Le Roy in upstate New York Wednesday night to discuss her findings in the case about a mysterious illness that affected at least 15 teens.
Brockovich, whose efforts to expose a toxic chemical cover-up in California inspired the 2000 movie starring Julia Roberts,after a dozen girls from Le Roy Central High School complained of uncontrollable verbal outbursts and involuntary twitching. At least three more cases, including a boy, were reported in February.
School- and state-sponsored environmental tests concluded that there were "no environmental or infectious agents" near or in the small town - about an hour east of Buffalo - that could have caused the tics, but Brockovich remained skeptical.
"In 1971 there was a very serious train derailment that caused one ton of cyanide to spill and 45,000 gallons of TCE," she told HLN earlier this year.
Brockovich hasn't revealed any of her investigation's findings ahead of Wednesday night's meeting, but told reporters in January that two federal agencies discovered that the cyanide may have spread from the train tracks to underneath the Le Roy high school over the years.
"Families have reported that there's an orange-yellow substance that almost kind of oozes from the ground," she said.
(Watch Dr. Laszlo Mechtler explain his diagnosis to CBS News in February -- and video of the girls' symptoms)
The Le Roy teens and their strange illness made national news after they appeared on NBC's "Today" Show and other major news outlets. Local doctors linked the illness to a psychological disorder. Sources told CBS Buffalo affiliate WIVB that since the symptoms first popped up last September, all of the patients have improved drastically.
Thera Sanchez, one of the high school students who suffered from the bizarre tics, said she's been "living on my own" and having a good summer but is looking forward to Brockovich's presentation.
"I'm excited," Sanchez told WIVB. "I'd like to see what [Brockovich] has to say, what she's looking into."
Local doctors who examined some of the teens concluded that the girls had "conversion disorder," a stress-induced affliction which starts as a mental or emotional crisis, but leads to physical symptoms
Sanchez was one of the patients who were treated with antibiotics. Others were treated with intense counseling.
Dr. Jennifer McVige of the DNET Neurological Institute treated a dozen of the teens for mass psychogenic illness, or patients who "caught" the disorder from empathizing with three who originally had it.
McVige told WIVB that the patients improved after media coverage of the illness died down - which is why she's concerned about Brockovich coming back to town.
"They worked to be better and they are better and stronger and incredible individuals, and I'd hate to see anything happen to them, to put them backwards and jeopardize all we worked for," she told the station.
Brockovich and her investigative team will give their presentation at 6 p.m. ET at American Legion Hall in Le Roy.