Casey Anthony may have suffered from a medical condition that contributed to the death of her daughter, according to her parents, in an excerpt of a "Dr. Phil" interview reported Wednesday.

The episode featuring George and Cindy Anthony, the grandparents of tragic toddler Caylee, will be aired Monday and a Fox News source said that in it they claim Casey may have suffered a gran mal seizure while her daughter was dying.

Gran (or grand) mal seizures -- also known as tonic-clonic seizures -- involve a loss of consciousness and violent muscle contractions. They can be caused by other health problems, such as low blood pressure or a stroke, but most often are caused by epilepsy.

During the taped appearance, Cindy Anthony apparently told the show's host, psychologist Dr. Phil McGraw, that her daughter's former fiance Jesse Grund had told police during a 2008 interview that he had called 911 after Casey suffered such a seizure in 2005.

According to the previously reliable source who spoke to Fox, Casey later suffered at least two additional seizures -- one while home on bond in 2008 and another while incarcerated between 2008 and 2011.

According to the source, Cindy Anthony pointed to the seizures as evidence Casey had "a mental health condition" that may have incapacitated her while Caylee was allegedly drowning "in the swimming pool incident," and further suggests that the seizures may be symptomatic of a condition that at times makes it difficult "to sort fact from fiction," or, as the source said, "maybe it is why she can't tell the truth."

For her part, Casey is said by the source to be "deeply upset that her parents continue to seek the spotlight," and that, "Casey just wants her mom to be her mom."

Dr. Phil said the interview was granted in exchange for a donation to Caylee's Fund, a charity run by the couple. The psychologist said the organization is "intending to focus on promoting processes to educate the public about, and advocate for, grandparents' rights."

Casey, 25, was acquitted July 5 of murdering her two-year-old daughter but found guilty of lying to police during the investigation into Caylee's death. Caylee's remains were discovered in December 2008 in a wooded area almost five months after she was reported missing by Cindy Anthony.

Newscore contributed to this report.