If you haven’t heard about a fascinating spinal cord study at the University of Minnesota, that’s fine with the researchers.

Despite testing a treatment that could restore function in patients with chronic spinal cord injuries, Ann Parr and colleagues are tamping down word of the exciting research.

The university is enrolling six patients in the 12-center trial, funded by Stem Cell Inc., and will surgically inject an experimental stem cell treatment in half of them. The hope is these patients will gain mobility and show superior physical improvement compared to those who don’t receive the stem cells.

“There hasn’t been anything that has been this promising,” said Parr, the U’s director for spinal neurosurgery.

A bit of secrecy is needed to do the study right, though. In a typical drug trial, patients taking experimental medications are indistinguishable from comparison patients, because the former take real pills and the latter take placebos.

In this case, the comparison patients will undoubtedly know they didn’t have spinal surgery. So the study makes unusual demands on them to act is if they did.

Assessors at Courage Kenny in Golden Valley will regularly test the patients. To prevent them from knowing which patients received the treatment, the comparison patients will wear bandages covering the same body parts where the stem cell patients received incisions.

The patients can’t be chatty with the assessors, or discuss the project for a news story, Parr said. “There is a good chance the assessor would read that and know who [the patient] is.”

Even tweets are discouraged. The concern is that the assessors could be biased in their observations if they learn by accident which patients were treated.

An earlier trial focused on safety; this trial focuses on whether the stem cells work.

Volunteers must be dedicated, even if they don’t receive the stem cells. A 54-page consent document spells out the responsibilities and risks.

It’s a big deal asking paraplegic patients to show up for assessments and play the part even if they didn’t receive the stem cells, Parr said, but she expects many will want to participate in this search for a revolutionary treatment.

Just don’t tell your friends about it, she said. “Once we start enrolling patients, we really don’t want to talk about it.”