Earlier this year neurosurgeon Jocelyne Bloch and Gregoire Courtine revealed that such an implant had enabled three paralysed people to walk again.
Both were also involved in the latest research, which tested a similar implant on a 48-year-old woman.
While the woman did not have Parkinson's, she had such similar symptoms -- including orthostatic hypotension -- that she was initially diagnosed with the disease.