The Eden Prairie teenager who died during routine oral surgery in June suffered cardiac arrest but why she did “is undetermined,” the Hennepin County medical examiner’s office said Thursday.

The medical examiner added that medication she was receiving at the time could not be ruled out as playing a role in her death.

Upon receiving the examiner’s conclusions, Sydney Galleger’s mother wrote in a website posting Wednesday that the lack of a “clear-cut answer” has left her family “numb, in a fog, sad.”

The Eden Prairie High School junior went to the offices of Edina Oral and Maxillofacial Surgery on June 9 to have her wisdom teeth removed. On June 15, Galleger’s family announced her death on a CaringBridge page. The swim team diver and Alpine skier was 17 years old.

“The cause of death for [Galleger] is anoxic encephalopathy [oxygen being denied to the brain] due to cardiac arrest,” the medical examiner’s statement read.

Left unresolved, the medical examiner continued, is why Galleger was stricken. What “could not be excluded,” the examiner’s statement pointed out, was any “potential contributing role” of medication that Galleger was receiving during the oral surgery.

“We were just hoping for an answer,” Diane Galleger said Thursday morning in a telephone interview. She said she was unsure whether the family would seek further tests on its own in pursuit of a firm determination.

As for possibly taking legal action against the oral surgeon or his business, Galleger’s mother said, “No, I don’t see anything like that.”

Back in June, Diane Galleger explained on CaringBridge that everything was going well with the procedure “until the very end, when her blood pressure shot up and her pulse dropped and then she went into cardiac arrest.”

Sydney’s mother said the doctor started CPR and called 911. Paramedics quickly arrived and got her to a hospital. Once at the University of Minnesota Masonic Children’s Hospital, she was stabilized but continued to have seizures, Diane Galleger wrote.

In a CaringBridge note posted Wednesday, Diane Galleger wrote, “Today, I am numb, in a fog, sad, and not really sure what to think. After three months of the medical examiners trying to determine why Sydney had a cardiac arrest, there is no clear-cut answer.

“Without going into detail, Steve and I talked to the medical examiner [Wednesday] morning, and it appears to be ‘the perfect storm.’ She had a slight abnormality in her heart and signs of a viral infection on her brain. None on their own was felt to be enough to cause a cardiac arrest.

“Could she have had a slight reaction to the medications causing everything to misfire? Unlikely, but we will never know. We just wanted God to give us something, give us an answer why our healthy, happy daughter is no longer with us.”

Diane Galleger closed with “I really dislike the cliché even more now, ‘God needed another angel.’ It’s hard when that angel is yours. Thank you for all your continued prayers.”