By Rita Rubin

The original Yellow Wiggle is back, but he’ll never be free of the disorder that forced him to stop Wiggling five years ago.

Greg Page, 40, a.k.a. Yellow Wiggle, left the "The Wiggles," the wildly popular kids’ singing group he helped found 21 years ago, because of symptoms related to orthostatic intolerance, a little-understood condition. In January, though, The Australia-based Wiggles announced Page had rejoined the group, set to tour the United States this summer.

And that was welcome news for Vanderbilt University cardiologist Dr. Satish Raj, a Wiggles aficionado who also happens to specialize in studying and treating the disorder that forced Page to pass his yellow "skivvy," or t-shirt, on to replacement Sam Moran.

"The Wiggles have not been the same with Sam since Greg left," says Raj, father of a 7-year-old daughter and 2 ½-year-old son. Raj has been known to sing Wiggles songs to his adult patients at the Vanderbilt Autonomic Dysfunction Center.( Autonomic refers to the autonomic nervous system, which controls automatic functions such as heart and breathing rate.) When he read of Page’s illness, Raj says, he emailed The Wiggles through their website to offer his services, but got a "no, thank you" in reply.

Page, who suffered from fainting spells, chronic fatigue and poor balance and coordination, according to The Wiggles website, was tested for a variety of conditions before doctors figured out he had orthostatic intolerance, "a beautifully vague term," Raj says, that describes anybody who has trouble standing up.

"What Greg had sounded more like what we call POTS," or "postural tachycardia syndrome," a type of orthostatic intolerance, Raj says. Page is unusual for a POTS patient, Raj says, because four out of five sufferers are women, and only about one in five have fainting spells.

When POTS patients stand for as little as five minutes, their heart rate can jump up to 30 beats per minute, Raj says. They often have high levels of norepinephrine, the stress hormone that underlies the "fight-or-flight" response. And most have decreased blood volume due to low levels of two hormones, regulated by the kidneys,that promote salt retention and increase plasma volume.

Patients frequently report that their symptoms began following stressors such as pregnancy or major surgery, Raj says, and Page has said his got worse after he underwent hernia surgery.

Treatments include small doses of beta-blockers and increased salt and water intake to increase blood volume. That's where a Wiggles song plays a role in Raj's practice. "Gulp, Gulp, Drink Some Water," he'll sing to patients to encourage them to chug the stuff, especially before they get out of bed in the morning.

Page apparently is practicing what he sings. "My health is much better now due to having a greater understanding of the disorder (Orthostatic Intolerance) and how to manage it appropriately. It is not a curable condition and will always be with me," he wrote on his website in February.

"There's no doubt about it," Raj says, "people have good days and bad days."

On top of a much-reduced quality of life, comparable to that of kidney failure patients on hemodialysis, POTS patients have to deal with disbelieving doctors, Raj says. "Doctors often think that they’re crazy."

One of his patients is a medical student who talks to undergraduates about her condition. Raj says the woman tells fellow students:  "The worst part of this is if I didn’t have it myself, I wouldn’t believe me."

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