MRI volumes, WAIS test scores, and correlation between IQ change and WMH measures
| Variable | Measured MRI and WAIS values | Correlations | ||||||
|---|---|---|---|---|---|---|---|---|
| Baseline | Follow up | Change | Baseline adjusted | Follow up adjusted | Increase | |||
| Adjusted | Non-adjusted | n | ||||||
| WMH volumes are median (range) and WAIS raw scores are mean (SD). | ||||||||
| For WMH increase, the table presents adjusted (partial) and non-adjusted (bivariate) correlations with cognitive decline between the two assessments. Partial correlations are adjusted for sex, education, and the corresponding 50 year test score; n number of subjects completing the test. | ||||||||
| *p<0.001; †p<0.01; ‡p<0.05; §p<0.1. | ||||||||
| MRI, magnetic resonance imaging; WAIS, Wechsler adult intelligence scale; WMH, white matter hyperintensities. | ||||||||
| WMH volume/ml | 4.7 (0 to 44.2) | 9.3 (0.1 to 49.3) | 2.6 (0.1 to 20.7)* | |||||
| Full IQ | 95.52 (16.12) | 90.39 (16.81) | −5.13(7.81)† | −0.23 | −0.40§ | −0.43§ | −0.35 | 23 |
| Verbal IQ | 97.73 (16.68) | 93.04 (16.54) | −4.69(8.46)† | −0.28 | −0.52† | −0.65* | −0.53† | 26 |
| Information | 19.62 (4.04) | 18.00 (4.53) | −1.62(2.37)† | −0.12 | −0.29 | −0.47‡ | −0.45‡ | 26 |
| Comprehension | 15.58 (4.27) | 15.50 (4.51) | −0.08(2.68) | −0.45‡ | −0.55† | −0.35 | −0.35 | 26 |
| Arithmetic | 11.00 (3.23) | 10.25 (3.19) | −0.75(1.92) | −0.33 | −0.42 | −0.38 | −0.34 | 20 |
| Similarities | 17.23 (4.60) | 16.00 (4.96) | −1.23(3.48) | −0.15 | −0.30 | −0.40§ | −0.27 | 26 |
| Digit span | 9.38 (1.88) | 9.19 (1.79) | −0.19(1.65) | −0.08 | −0.29 | −0.52† | −0.41‡ | 26 |
| Vocabulary | 56.58 (10.53) | 51.88 (12.66) | −4.69(5.92)* | 0.02 | −0.05 | −0.16 | 0.03 | 26 |
| Performance IQ | 93.30 (13.28) | 88.09 (15.05) | −5.22(9.18)‡ | −0.06 | −0.08 | −0.06 | −0.01 | 23 |
| Digit symbol | 34.38 (9.80) | 29.43 (9.95) | −4.95(5.45)* | −0.57† | −0.44§ | −0.11 | −0.01 | 21 |
| Picture completion | 12.39 (3.61) | 11.83 (3.26) | −0.57(2.74) | 0.07 | −0.02 | −0.18 | −0.19 | 23 |
| Block design | 30.64 (5.69) | 28.77 (6.27) | −1.86(4.16)‡ | 0.09 | 0.09 | 0.03 | 0.07 | 22 |
| Picture arrangement | 18.45 (6.48) | 15.80 (6.01) | −2.65(4.37)‡ | −0.21 | −0.01 | 0.37 | 0.13 | 20 |
| Object assembly | 28.68 (6.29) | 27.47 (7.69) | −1.21(6.80) | −0.20 | −0.13 | 0.08 | 0.08 | 19 |