Table 1.
Demographic, clinical, and CSF biomarkers data of the patients with IRBD
| All patients | Positive α-synuclein | Negative α-synuclein | P value | |
|---|---|---|---|---|
| N (%) | 148a | 110 (75.3) | 36 (24.7) | – |
| Female, n (%) | 35 (23.6) | 27 (24.5) | 8 (22.2) | >0.99 |
| Age at LP, yrs | 69.1 ± 9.7 | 70.9 ± 6.5 | 65.4 ± 10.1 | 0.0002 |
| Age at IRBD diagnosis, yrs | 66.7 ± 7.6 | 67.8 ± 6.5 | 63.4 ± 9.7 | 0.0021 |
| Time from IRBD diagnosis to LP, yrs | 1.7 (0.5–4.2) | 2.1 (0.5–4.5) | 0.8 (0.4–3.4) | 0.126 |
| Prodromal PD rate at LP, % | 82.1 ± 28.3 | 89.0 ± 22.9 | 59.4 ± 32.3 | <0.0001 |
| DAT-SPECT abnormal/tested, n (%) | 84/145 (57.9) | 73/108 (67.6) | 9/35 (25.7) | <0.0001 |
| UPSIT-40 score | 19.0 (14.0–25.0) | 17.0 (13.0–22.0) | 27.0 (22.0–30.0) | <0.0001 |
| Mild cognitive impairment at LP, n (%) | 33 (22.3) | 26 (23.6) | 6 (16.7) | 0.488 |
| A + T + N + , n (%) | 13 (9.3) | 10 (9.4) | 3 (8.8) | >0.99 |
| A + T + , n (%) | 16 (11.4) | 12 (11.3) | 4 (11.8) | >0.99 |
| A + T-, n (%) | 16 (11.4) | 13 (12.3) | 3 (8.8) | 0.761 |
| Aβ42, pg/mL | 570 (405–808) | 573 (403–821) | 574 (415–822) | 0.761 |
| Aβ42/Aβ40 | 0.8 (0.6–0.9) | 0.8 (0.6–0.9) | 0.8 (0.6–0.9) | 0.653 |
| p-tau, pg/mL | 38 (27–49) | 39 (28–50) | 35 (25–44) | 0.271 |
| p-tau/Aβ42 | 0.6 (0.4–0.9) | 0.6 (0.4–0.9) | 0.6 (0.4–0.8) | 0.473 |
| t-tau, pg/mL | 280 (217–353) | 290 (219–380) | 257 (212–335) | 0.308 |
| NfL, pg/mL | 550 (405–761) | 620 (459–802) | 485 (344–665) | 0.0045 |
Data are expressed as mean ± SD, median (interquartile range), number, and percentage, as appropriate. Aβ positivity (A+) was defined by CSF Aβ42/Aβ440 ratio < 0.65; tau positivity (T+) by CSF p-tau181 > 60 pg/ml; and neurodegeneration positivity (N+) by CSF t-tau > 450 pg/ml.
p values indicating statistically significant differences between groups are highlighted in bold.
LP lumbar puncture, IRBD isolated REM sleep behavior disorder, PD Parkinson disease, Aβ42 42 amino acid isoform of amyloid-beta, Aβ40 40 amino acid isoform of amyloid-beta, p-tau phosphorylated tau protein, A amyloid-beta, T tau, N neurodegeneration, NfL neurofilament light chain, t-tau total tau protein.
aα-synuclein status was available in 146 patients while Alzheimer’s disease core biomarkers and NfL values were available in 142 individuals.