Lying down vs. sitting up: does position matter for bladder tests in MS and Parkinson's?

This study looks at whether the position a person is in during a urodynamic exam (a test that measures bladder function) affects the diagnosis of an overactive bladder in people with multiple sclerosis or Parkinson's disease. Researchers will compare results from tests done while lying down and while sitting in the same person. The goal is to see if lying down is a reliable alternative for those who cannot sit comfortably, which could lead to better testing guidelines for neurological patients.