TABLE 1.
Baseline characteristics
| Variable | iRBD (n = 25) | Control (n = 24) | P value |
|---|---|---|---|
| Age, y | 69.2 (5.3) | 69.5 (4.3) | 0.941 |
| Male sex, % | 12 (48%) | 7 (29%) | 0.270 |
| RBD duration, y | 4.5 (4.0) | − | − |
| MDS‐UPDRS score | |||
| Part I | 7.3 (3.8) | − | − |
| Constipation, % | 9 (36%) | − | − |
| Part II | 3.4 (3.5) | − | − |
| Part III | 5.1 (4.1) | − | − |
| Mild parkinsonian sign, % | 13 (52%) | − | − |
| K‐MMSE score | 27.4 (2.2) | 28.4 (1.5) | 0.176 |
| Neuropsychological test, z score | |||
| TMT‐A | −0.57 (1.05) | − | − |
| TMT‐B | −0.90 (1.80) | − | − |
| CWST (color reading) | −0.80 (0.83) | − | − |
| COWAT (semantic) | −0.29 (1.16) | − | − |
| COWAT (phonemic) | −0.65 (0.82) | − | − |
| RCFT (copy) | −2.02 (1.57) | − | − |
| SVLT (immediate recall) | −0.22 (0.98) | − | − |
| SVLT (delayed recall) | −0.60 (0.94) | − | − |
| SVLT (recognition) | −0.38 (1.03) | − | − |
| K‐BNT | −0.08 (1.15) | − | − |
| Mild cognitive impairment, % | 11 (44%) | − | − |
| Olfactory test | |||
| BTT score | 5.5 (2.6) | − | − |
| Hyposmia, % | 6 (24%) | − | − |
| DAT imaging, binding ratio | |||
| Caudate nucleus | |||
| More affected side | 3.40 (1.05) | 3.91 (0.82)a | 0.096 |
| Less affected side | 3.52 (1.00) | − | − |
| Anterior putamen | |||
| More affected side | 4.87 (1.20) | 5.59 (0.89)a | 0.041 |
| Less affected side | 5.01 (1.22) | − | − |
| Posterior putamen | |||
| More affected side | 4.18 (1.28) | 4.96 (0.87)a | 0.032 |
| Less affected side | 4.37 (1.34) | − | − |
| Reduced DAT availability, % | 5 (20%) | − | − |
Data are shown as n (%) and mean (standard deviation).
a
DAT imaging data were presented in a subgroup of 19 healthy controls. Their values are the average of left and right DAT binding ratios.
iRBD, isolated rapid eye movement (REM) sleep behavior disorder; y, year; MDS‐UPDRS, Movement Disorder Society Unified Parkinson's Disease Rating Scale; K‐MMSE, Korean version of the Mini‐Mental State Examination; TMT, Trail Making Test; CWST, Color Word Stroop Test; COWAT, Controlled Oral Word Association Test; RCFT, Rey−Osterrieth Complex Figure Test; SVLT, Seoul Verbal Learning Test; K‐BNT, Korean version of the Boston Naming Test; BTT, Butanol Threshold Test; DAT, dopamine transporter.