Los Angeles (CNN) -- Casey Kasem's children are taking their fight against their stepmom to see their ailing father all the way to court.
Kasem's daughter Julie Kasem and her husband filed a conservatorship petition in a Los Angeles court Monday, claiming the retired radio host "has been isolated from his daughters, friends and other family" by his wife.
Kasem, who for decades hosted radio music countdown shows "American Top 40" and "Casey's Top 40," is suffering from Parkinson's disease and "may have early onset Parkinson's dementia," according to the court filing. He retired in 2009.
Kasem, 81, has the "ability to shuffle short distances, but is mainly bedridden and requires the assistance of a wheelchair to move any distance," the court document said.
The petition claims that daughter Julie Kasem and her husband, Dr. Jamil Aboulhosn, have been unable to check on Kasem's health even though her father signed papers in 2007 giving them the power of attorney over his heath care in the event he was unable to make his own health decisions.
They "have been prevented from exercising their duties" by Jean Kasem, who has been married to the retired radio host for three decades, the filing contends.
"There is no communication between Jean and us and his daughters," brother Mouner Kasem told CNN Saturday. "We have no knowledge of how he is, what he's doing, if he's better, if he's worse, and we're scared that we'll never see him again."
The petition claims Kasem's wife has refused to provide the children with the name of their father's primary care physician. That doctor would be consulted to determine Kasem's "ability to act on his own behalf," which is the question that would cause the health care power of attorney to take effect, it said.
A hearing date is set for November 19.
Daughter Kerri Kasem told CNN that her stepmother suddenly barred her sister, her uncle and some of Kasem's friends from seeing him about three months ago. She's perplexed by the decision.
"I don't get it, I don't understand it," Kerri Kasem, who co-hosts the radio show "Sixx Sense" with Motley Crue's Nikki Sixx, told CNN. "He has Parkinson's, and all the research we've done indicates socialization would help him."
CNN has reached out to get a statement from Jean Kasem, but has been unsuccessful.
Kerri Kasem and other members of the family held a protest at Kasem's Holmby Hills house to raise public attention to their dispute last week.
The fight is not about an inheritance, Kerri Kasem said.
"My dad told us a long time ago we were not in the will, and we're OK with that. We've known that for years," she said. "I've never asked him for anything, nor have I asked Jean for anything."
Don Pitts, Kasem's agent of more than 35 years, said he did not want to take sides in the argument, but he did say Casey is still of sound mind.
"He has Parkinson's, has it very bad. It took his speech, and for somebody who made millions of dollars using his voice -- for him to lose that gift, that beautiful instrument -- it must be frustrating. But he's handling it very well," Pitts said. "His mind is very sharp, his brain works well. You can tell in his eyes he understands everything you're saying. He just has trouble translating it from the brain to his vocal cords."
Besides the famed countdown shows, Casey Kasem was also the voice of Shaggy in the cartoon "Scooby Doo" and an announcer for NBC. He was a popular DJ and occasional actor before "American Top 40" began in 1970.
CNN's Denise Quan and Todd Leopold contributed to this report.