Table 2.

Correlation between gradient of z-scores in NAWM (difference of mean z-scores between the bands divided by distance between bands) and EDSS in patients with progressive multiple sclerosis (* indicates statistically significant values).

	Correlation coefficient for the z-score thresholds				p-values
Gradient between bands	0	1	2	3	0	1	2	3
1–2	0.325	0.331	0.374	0.390	0.019*	0.016*	0.006*	0.004*
1–5	0.287	0.315	0.341	0.379	0.039*	0.023*	0.014*	0.006*
1–10	0.229	0.301	0.326	0.378	0.103	0.030*	0.018*	0.006*
1–20	0.148	0.267	0.319	0.348	0.294	0.056	0.021*	0.011*
1–30	0.117	0.267	0.306	0.314	0.409	0.056	0.027*	0.023*

EDSS = expanded disability status scale, NAWM = normal appearing white matter.