Table 3 Demographic features and results of longitudinal imaging analysis using MRI planimetry

Number

5

9

6

M: F ratio

5: 0

6: 3

6: 0

MRI number

3.0 ± 0.7 (2–4)

2.8 ± 1.0 (2–5) p = 0.422

3.2 ± 1.0 (2–5) p = 0.916

Age at MRI

69.2 ± 9.5 (56–86)

69.1 ± 10.3 (53–87) p = 0.970

69.3 ± 10.4 (53–87) p = 0.976

Disease duration at MRI (year)

6.5 ± 5.4 (1–21)

10.0 ± 8.5 (1–30) p = 0.175

11.4 ± 9.1 (1–30) p = 0.087

Interval between MRI (year)

3.2 ± 3.7 (0.0–10.8)

3.1 ± 4.0 (0.0–13.0) p = 0.842

3.6 ± 4.3 (0.0–13.0) p = 0.819

Midbrain area (mm²)

98.1 ± 14.5 (71.9–120.2)

114.1 ± 20.7 (82.7–149.8) p = 0.012^a

110.5 ± 20.3 (82.7–149.5) p = 0.047^a

Pons area (mm²)

526.0 ± 42.3 (455.2–604.9)

506.7 ± 34.0 (454.0–575.5), p = 0.121

507.6 ± 38.6 (454.0–575.5) p = 0.197

M/P area ratio

0.187 ± 0.026 (0.148–0.238)

0.224 ± 0.034 (0.176–0.306) p = 0.001^a

0.216 ± 0.026 (0.176–0.260) p = 0.003^a

Reduction ratio of midbrain area

0.898 ± 0.074 (0.773–0.995), n = 10

0.967 ± 0.046 (0.886–1.040), n = 16 p = 0.007^a

0.968 ± 0.043 (0.893–1.040), n = 13 p = 0.009^a

Reduction ratio of pons area

0.975 ± 0.062 (0.847–1.086), n = 10

0.979 ± 0.026 (0.943–1.033), n = 16 p = 0.859

0.976 ± 0.024 (0.943–1.017), n = 13 p = 0.985

Reduction ratio of M/P area ratio

0.922 ± 0.078 (0.820–1.085), n = 10

0.988 ± 0.049 (0.920–1.080), n = 16 p = 0.014^a

0.993 ± 0.051 (0.928–1.080), n = 13 p = 0.016^a