National Institute of Health’s researchers conducted a diagnostic assay of 60 cerebral spinal fluid samples: 12 from people with Parkinson disease, 17 from people with dementia with Lewy bodies, and 31 controls, including 16 with Alzheimer disease. The test correctly excluded all the 31 controls and diagnosed both Parkinson disease and dementia with Lewy bodies with 93% accuracy.
Moreover, test results were available within 2 days compared with 13 days for related assays.
Like prion diseases, Parkinson disease and dementia with Lewy bodies cause progressive deterioration of brain functions. The diseases typically progress for years before symptoms appear; once they do, distinguishing one from another can be difficult. The NIH says early, accurate diagnoses are essential for developing treatments and identifying patients eligible for clinical trials.