Table 1.
Clinical and electrophysiological characteristics of the study population with and without PNP at baseline
| PNP( +) (n = 27) | PNP(–) (n = 14) | p | |
|---|---|---|---|
| Age at examination (years) | 66.33 ± 9.53 (27) | 59.36 ± 6.63 (14) | 0.019* |
| Female | 8 | 9 | |
| Disease duration (years) | 5.67 ± 4.76 (27) | 4.93 ± 3.73 (14) | 0.658 |
| Age at PD diagnosis (years) | 60.67 ± 7.75 (27) | 54.43 ± 7.27 (14) | 0.017* |
| H&Y (median, IQR) | 2 (IQR 1) (27) | 2,25 (IQR 1) (14) | 0.977 |
| MDS-UPDRS I | 10.73 ± 5.97 (26) | 11.43 ± 6.16 (14) | 0.898 |
| MDS-UPDRS II | 12.58 ± 9.04 (26) | 11.43 ± 7.17 (14) | 0.831 |
| MDS-UPDRS III | 32.59 ± 16.53 (27) | 18.79 ± 7.96 (14) | < 0.001** |
| MDS-UPDRS II.12 + III.12 | 1.65 ± 2.10 (26) | 1.14 ± 0.95 (14) | 0.941 |
| PDQ-39 | 22.38 ± 17.71 (26) | 24.19 ± 15.49 (14) | 0.533 |
| NMSQ | 9.04 ± 5.45 (26) | 9.14 ± 4.72 (14) | 0.921 |
| NMSQ (item 10—yes) | 4 (23) | 2 (13) | |
| NMSQ (item 21—yes) | 8 (24) | 0 (14) | |
| NSS | 5.46 ± 3.19 (26) | 3.43 ± 2.93 (14) | 0.065 |
| MoCA | 24.92 ± 3.63 (25) | 23.71 ± 3.52 (14) | 0.227 |
| LED (mg) | 610.15 ± 315.56 (27) | 586.32 ± 391.47 (14) | 0.834 |
| Levodopa (mg) | 329.63 ± 187.22 (27) | 323.21 ± 207.19 (14) | 0.921 |
| Vitamin B12 (pg/ml) | 421.08 ± 163.55 (26) | 434.85 ± 105.54 (13) | 0.753 |
| Holotranscobalamin (pmol/l) | 88.57 ± 34.89 (26) | 82.84 ± 24.82 (14) | 0.590 |
| Folic acid (ng/ml) | 13.03 ± 6.43 (26) | 8.24 ± 4.84 (13) | 0.037* |
| Methylmalonic acid (nmol/l) | 353.63 ± 293.93 (25) | 236.02 ± 71.60 (14) | 0.224 |
| Homocysteine (µmol/l) | 19.07 ± 7.83 (20) | 16.77 ± 5.70 (13) | 0.507 |
| Sural nerve (µV) | 0.69 ± 1.21 (27) | 6.92 ± 1.84 (14) | < 0.001** |
| Tibial nerve (mV) | 5.35 ± 3.79 (27) | 10.90 ± 3.35 (14) | < 0.001** |
| Median motor nerve (mV) | 6.40 ± 1.57 (25) | 6.27 ± 2.39 (13) | 0.834 |
| Median sensory nerve (µV) | 7.28 ± 5.53 (24) | 10.72 ± 7.59 (13) | 0.105 |
| Fibular motor nerve (mV) | 2.53 ± 2.36 (11) | 2.47 ± 1.98 (6) | 0.958 |
| Fibular sensory nerve (µV) | 1.28 ± 2.63 (11) | 3.08 ± 2.46 (6) | 0.091 |
| Radial nerve (µV) | 5.53 ± 1.72 (10) | 7.80 ± 4.71 (6) | 0.301 |
| Ulnar motor nerve (mV) | 7.88 ± 1.31 (12) | 8.54 ± 2.80 (7) | 0.569 |
| Ulnar sensory nerve (µV) | 6.06 ± 1.49 (12) | 5.70 ± 1.58 (7) | 0.627 |
PNP(+) PD patients with PNP, PNP(–) denotes PD patients without PNP. IQR interquartile ratio, H&Y Hoehn and Yahr Scale, MDS-UPDRS Movement Disorder Society Unified Parkinson’s Disease Rating Scale, NMSQ Non-Motor Symptom Questionnaire, NSS Neuropathy Symptom Score, MoCA Montreal Cognitive Assessment, LED levodopa equivalence dose
*p < 0.05; **p < 0.01. Clinical scores: mean values ± standard deviation (SD) are presented. H&Y scale: median value and IQR are presented