Table 3.
Results of Meta-analyses of Correlations of NSS and Neurocognitive Functions
| Number of Studies | Number of Subjects | Correlation (95% CI) | Q Value | |
| Correlation between NSS total score and cognitive abilities | 48 | 3789 | −0.331 (−0.362, −0.299) | 54.972 |
| NSS-MC subscale | 24 | 1816 | −0.332 (−0.378, −0.283) | 28.199 |
| NSS-SI subscale | 31 | 2435 | −0.374 (−0.409, −0.339) | 30.589 |
| NSS-Mseq subscale | 6 | 489 | −0.313 (−0.392, −0.23) | 3.253 |
| NSS-disinhib subscale | 17 | 1653 | −0.177 (−0.251, −0.101) | 37.535* |
| Correlation between NSS total score and verbal memory | 4 | 383 | −0.305 (−0.394, −0.21) | 0.955 |
| (WMS-R verbal pairs; paired associate learning; logical memory—immediate, delayed; CVLT) | ||||
| NSS-MC subscale | 5 | 423 | −0.296 (−0.397, −0.182) | 5.71 |
| NSS-SI subscale | 6 | 508 | −0.354 (−0.429, −0.274) | 2.687 |
| NSS-disinhib subscale | 4 | 338 | −0.058 (−0.166, 0.05) | 2.037 |
| Correlation between NSS total score and nonverbal memory | 6 | 608 | −0.374 (−0.485, −0.252) | 13.851* |
| (WMS-R visual reproduction—immediate, delayed; visual pairs; ROCFT) | ||||
| NSS-MC subscale | 4 | 338 | −0.396 (−0.483, −0.3) | 1.942 |
| NSS-SI subscale | 7 | 554 | −0.417 (−0.485, −0.345) | 1.748 |
| NSS-Mseq subscale | 1 | 85 | −0.3 (−0.482, −0.093) | NA |
| NSS-disinhib subscale | 4 | 338 | −0.117 (−0.241, 0.009) | 3.95 |
| Correlation between NSS total score and motor | 4 | 360 | −0.299 (−0.392, −0.291) | 0.363 |
| (Finger tapping test, Purdue pegboard task) | ||||
| Correlation between NSS total score and attention | 8 | 579 | −0.292 (−0.382, −0.197) | 9.892 |
| (TMT-A, B time; WAIS-R—digit span; reading span test; Stroop; Continuous Performance Test; SART) | ||||
| NSS-MC subscale | 2 | 82 | −0.274 (−0.6, 0.13) | 3.147 |
| NSS-SI subscale | 4 | 252 | −0.282 (−0.393, −0.161) | 2.058 |
| NSS-Mseq subscale | 1 | 85 | −0.26 (−0.448, −0.05) | NA |
| NSS-disinhib subscale | 1 | 51 | −0.015 (−0.289, 0.262) | NA |
| Correlation between NSS total score and IQ | 6 | 580 | −0.336 (−0.443, −0.218) | 10.952 |
| (WAIS-R—full scale, verbal, performance; WAIT-III; MWT-B, Ammons Quick Test) | ||||
| NSS-MC subscale | 4 | 353 | −0.26 (−0.474, −0.017) | 12.788* |
| NSS-SI subscale | 5 | 456 | −0.468 (−0.541, −0.388) | 4.306 |
| NSS-Mseq subscale | 1 | 79 | −0.18 (−0.386, 0.043) | NA |
| NSS-disinhib subscale | 2 | 246 | −0.35 (−0.456, −0.234) | 0 |
| Correlation between NSS total score and spatial ability | 5 | 233 | −0.268 (−0.386, −0.141) | 1.958 |
| (WAIS-R block design, picture arrangement, picture completion) | ||||
| NSS-MC subscale | 2 | 62 | −0.355 (−0.109, −0.56) | 0.017 |
| NSS-SI subscale | 1 | 85 | −0.36 (−0.532, −0.159) | 0 |
| Correlation between NSS total score and executive function | 10 | 641 | −0.361 (−0.428, −0.29) | 8.974 |
| (WCST categories achieved, preservative errors, total errors) | ||||
| NSS-MC subscale | 6 | 440 | −0.335 (−0.417, −0.248) | 1.427 |
| NSS-SI subscale | 4 | 246 | −0.209 (−0.328, −0.084) | 0.486 |
| NSS-Mseq subscale | 3 | 240 | −0.377 (−0.482, −0.261) | 0.213 |
| NSS-disinhib subscale | 4 | 431 | −0.289 (−0.141, 0.424) | 7.445 |
| Correlation between NSS total score and language function | 4 | 344 | −0.354 (−0.257, 0.445) | 2.597 |
| (WAIS-R vocabulary, WRAT-vocabulary, VF) | ||||
| NSS-MC subscale | 1 | 118 | −0.374 (−0.52, −0.207) | NA |
| NSS-SI subscale | 4 | 334 | −0.384 (−0.473, −0.288) | 1.748 |
| NSS-disinhib subscale | 1 | 118 | −0.147 (−0.204, −0.089) | NA |
Note: NSS = neurological soft signs; MC = motor coordination; SI = sensory integration; MSeq = complex motor sequencing; disinhib = disinhibition; WMS-R = Wechsler Memory Scale-Revised; CVLT = California Verbal Learning Test; ROCFT = Rey Auditory Verbal Learning Test; NA, not available; TMT-A, B = Trail-Making Test—A, B; WAIS-R = Wechsler Adult Intelligence Scale-Revised; WAIT-III = Wechsler Adult Intelligence Test-III; SART = Sustained Attention to Response Test; MWT-B = Mehrfachwahl-Wortschatz-Intelligenz Test; WCST = Wisconsin Card Sorting Test; WRAT = Wide Range Achievement Test; VF = verbal fluency from Controlled Word Association Test; NA = Not Available.
Q value heterogeneous, P < .05.