"It's pretty common," said Cestari. For example, he has people who temporarily go blind, or patients who suffer "pseudoseizures" which look like epileptic seizures but have no physical basis in the brain.
"It can be hard because sometimes these patients come in with real experiences, they aren't making this up," said Cestari. "But the mind converted a conflict into a physical manifestation."
Yet, Mancuso, who managed Adler's treatment plan for four years, said doctors went down the mental conflict road.
"She's seen neurologists, she's had psychiatric assessment and nobody has been able to put their finger on it," said Mancuso.
Dr. William David, at clinician at Massachusetts General Hospital, is also perplexed by Adler's condition.
"There are all sorts of different types of disorders that can affect one's ability to open one's eyes," said David, who also listed blepharospasm and apraxia.
"But none of these things cycle in these three days on, three days off sort thing; one has to wonder at this point if there's real physiological reason for this," said David, who is also an associate professor of neurology at Harvard Med School in Boston.
In addition to the cycles, David said Adler's pain in her temple and neck do not conform to a diagnosis of blepharospasm, apraxia or other neurological disorders that cause the eyes to involuntarily shut.
"This picture is very curious and unusual," said David. "I've never seen or heard of anything like this."
Although doctors have not been able to diagnose Adler, Mancuso said she is receiving medical help as if she had blepharospasm.
"She's still continuing her [Botox] treatment," said Mancuso. "It seems to be the only treatment that we knew how to administer to Natalie."
Mancuso said the Botulinum toxin (Botox) treatment once mitigated Adler's cycles and helped with her pain, but Adler said the effects have since begun to fade.
"It meant that she could actually have a period of time where her eyes were open for longer," said Mancuso.
When they're closed, "My life is on hold -- I am unable to drive or work," said Adler. "In the beginning, I tried to ignore it but have now learnt to live with it."
Mancuso said she thinks Adler's sprit is a source of inspiration.
"She's a very positive young woman through this," she said.
Mario Conti in Syndey, Australia, contributed to this report.