RT Book, Section A1 Simel, David L. A1 Rennie, Drummond SR Print(0) ID 3485143 T1 Parkinsonism T2 The Rational Clinical Examination: Evidence-Based Clinical Diagnosis YR 2016 FD 2016 PB McGraw-Hill Education PP New York, NY SN 9780071590303 LK jamaevidence.mhmedical.com/content.aspx?aid=3485143 RD 2024/03/28 AB Parkinson disease remains a clinical diagnosis. No accurate laboratory or radiologic test is currently available. An acute challenge with levodopa, followed by monitoring for improvement of symptoms, is not useful diagnostically.