Table 4 CAEP and laboratory investigations in PD patients and control subjects

CAEP

P1 latency (ms)

 RT

51.591 ± 11.560

45.576 ± 2.048

3.446

0.001*

 LT

49.347 ± 8.968

44.953 ± 2.828

3.163

0.002*

P1 amplitude (uv)

 RT

1.955 ± 0.567

2.249 ± 0.068

− 3.461

0.001*

 LT

2.101 ± 0.456

2.338 ± 0.054

− 3.469

0.001*

N1 latency (ms)

 RT

98.672 ± 18.342

90.089 ± 4.833

3.055

0.003*

 LT

99.638 ± 16.674

88.333 ± 5.304

4.375

 < 0.001*

N1 amplitude (uv)

 RT

− 3.729 ± 1.653

− 4.789 ± 0.855

3.912

 < 0.001*

 LT

− 3.699 ± 1.789

− 5.167 ± 0.693

5.205

 < 0.001*

P2 latency (ms)

 RT

195.931 ± 16.768

187.733 ± 5.683

3.140

0.002*

 LT

197.310 ± 18.118

183.244 ± 9.018

4.766

 < 0.001*

P2 amplitude (uv)

 RT

3.205 ± 1.698

4.106 ± 0.794

− 3.288

0.001*

 LT

2.800 ± 1.247

4.190 ± 0.950

− 6.208

 < 0.001*

N2 latency (ms)

 RT

258.310 ± 30.170

237.556 ± 21.808

3.891

 < 0.001*

 LT

255.241 ± 31.641

247.044 ± 17.242

1.566

0.121

P2 amplitude (uv)

 RT

− 3.000 ± 1.695

− 4.814 ± 1.409

5.790

 < 0.001*

 LT

− 2.874 ± 1.548

− 5.362 ± 1.402

8.426

 < 0.001*

P300 latency (ms)

 RT

293.397 ± 97.361

288.867 ± 8.220

0.311

0.757

 LT

284.914 ± 103.238

289.222 ± 15.158

− 0.277

0.782

P300 amplitude (uv)

 RT

2.422 ± 1.608

3.846 ± 0.825

− 5.409

 < 0.001*

 LT

2.668 ± 1.704

4.791 ± 0.855

− 7.639

 < 0.001*

Laboratory

IL-6 (pg/ml)

6.978 ± 2.027

5.100 ± 0.875

5.805

 < 0.001*

BDNF (ng/ml)

17.955 ± 11.561

27.298 ± 7.960

− 4.633

 < 0.001*

5-HT (ng/ml)

123.672 ± 57.050

134.089 ± 36.471

− 1.067

0.289

5-HIAA (mg/urinary 24 h)

4.488 ± 2.554

5.947 ± 1.515

− 3.394

0.001*

CT control

26.597 ± 0.921

25.835 ± 1.048

3.922

 < 0.001*

Ct miRNA

29.965 ± 3.673

26.813 ± 1.511

5.408

 < 0.001*

2-A Ct

0.765 ± 2.277

1.268 ± 2.380

− 1.091

0.278