Table 4 Types of putative biomarkers for disease progression investigated in the 183 included articles
From: A systematic review of biomarkers for disease progression in Parkinson’s disease
All studies (n=183) | Longitudinal studies (n=20) | Cross-sectional studies (n=163) | ||||
|---|---|---|---|---|---|---|
Biomarker modality | Number of studies examining biomarker | % | Number of studies examining biomarker | % | Number of studies examining biomarker | % |
Serum/plasma/blood | 51 | 27.9 | 0 | 0.0 | 51 | 31.3 |
Brain SPECT | 41 | 22.4 | 9 | 45.0 | 32 | 19.6 |
Brain PET | 31 | 16.9 | 8 | 40.0 | 23 | 14.1 |
CSF | 29 | 15.8 | 0 | 0.0 | 29 | 17.8 |
Brain MRI | 15 | 8.2 | 1 | 5.0 | 14 | 8.6 |
Cardiac 123I-MIBG scintigraphy | 9 | 4.9 | 0 | 0.0 | 9 | 5.5 |
Electrophysiology | 9 | 4.9 | 1 | 5.0 | 8 | 4.9 |
Ultrasound | 7 | 3.8 | 0 | 0.0 | 7 | 4.3 |
Urine | 5 | 2.7 | 0 | 0.0 | 5 | 3.1 |
Brain MRS | 2 | 1.1 | 0 | 0.0 | 2 | 1.2 |
Other | 3 | 1.6 | 1 | 5.0 | 2 | 1.2 |