LOS ANGELES, CA (Catholic Online) - Approximately one percent of the U.S. population has Chiari malformation. It's not just kids who are being diagnosed as adults in their 20s and 30s are being diagnosed incidentally.

"Essentially, what happens, the cerebellum tonsils are pushing through the bottom of the skull and potentially putting pressure on the spinal cord and the tissue of the spinal cord," Dr. Robert Keating, professor and chief of neurosurgery at Children's National Medical Center says.

Keating says that the symptoms, which are multiple and vary depending on the patients' age, include headaches and occipital headaches, neurological issues or double vision, including the feeling of pins and needles in the legs.

According to the National Institute of Neurological Disorders and Stroke, Chiari malformations can be caused by structural defects in the brain and spinal cord. It can also be caused if too much spinal fluid is drained from the back in cases of injury.

Not all Type I Chiari malformations present with symptoms, and there are at least three other types of malformations. Type II usually involves a form of spina bifida; Type III is the most serious and causes severe neurological defects and Type IV may have parts of the cerebellum missing and parts of the skull and spinal cord may be visible to the naked eye.

"Her brain stem was compressed and squished through the opening of the base of her skull, where the skull meets the spinal cord; it's supposed to be wide open," Stephanie Barone said. "When the spinal fluid couldn't get into her brain, that's why she had the headaches."

Her parents decided to go with Keating for what they thought would be a simple surgery. They checked into the hospital on Aug. 1.

Using ultrasound, Keating opened the covering to her brain. Under the microscope, he saw there were obstructions to the spinal fluid, so he cut those out too.

Allie began leaking spinal fluid from her incision about three or four days after that initial surgery, so Keating took her back into surgery.

After a trial of hit-and-miss, a fourth operation brought Allie back to normal, although she is restricted from certain activities.

Keating is pleased with Allie's overall outcome, and he stressed that most Chiari cases do not involve so many surgeries.

"She's quite a character," he said. "I'm looking forward to her long-term prognosis."

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