Table 2. Results of neuropsychological tests for AD dementia group, MCI due to AD group, normal preclinical AD group, and total participants.
| Neuropsychological test | AD dementia | MCI due to AD | Preclinical AD | Total | ||
|---|---|---|---|---|---|---|
| Mean±SD | Mean±SD | Mean±SD | Number | Mean±SD | ||
| Attention | ||||||
| Forward digit span | 5.2±1.6 | 6.0±1.4 | 6.1±1.8 | 249 | 5.6±1.6 | |
| Backward digit span | 3.0±1.4 | 3.8±1.1 | 4.1±1.5 | 246 | 3.4±1.3 | |
| Language | ||||||
| K-BNT | 34.0±13.5 | 41.9±10.6 | 48.5±6.3 | 238 | 38.5±12.8 | |
| Visuospatial function | ||||||
| RCFT: copying | 19.8±12.0 | 29.1±7.4 | 31.8±6.0 | 245 | 24.7±11.0 | |
| CDT | 2.0±0.9 | 2.5±0.8 | 2.8±0.5 | 193 | 2.3±0.9 | |
| Memory | ||||||
| SVLT: immediate recall | 10.9±5.3 | 14.4±4.2 | 20.9±5.0 | 249 | 13.2±5.6 | |
| SVLT: delayed recall | 0.7±1.3 | 1.6±2.1 | 7.2±2.1 | 249 | 1.6±2.5 | |
| SVLT: recognition | 15.5±2.9 | 18.1±2.6 | 21.2±1.5 | 249 | 17.1±3.2 | |
| RCFT: immediate recall | 3.0±3.4 | 6.2±4.9 | 14.4±6.2 | 244 | 5.3±5.4 | |
| RCFT: delayed recall | 1.8±3.0 | 5.5±4.9 | 14.0±5.9 | 244 | 4.4±5.4 | |
| RCFT: recognition | 15.4±2.8 | 17.8±2.5 | 19.4±2.8 | 244 | 16.7±3.0 | |
| Frontal/executive function | ||||||
| COWAT: animal | 8.4±4.5 | 12.0±4.5 | 14.4±5.1 | 249 | 10.4±5.0 | |
| COWAT: supermarket | 8.0±5.1 | 12.5±5.5 | 17.0±6.1 | 234 | 10.6±6.1 | |
| COWAT: phonemic | 15.0±10.9 | 22.1±10.9 | 24.2±13.5 | 220 | 18.8±11.7 | |
| Stroop test: color reading | 36.7±26.8 | 63.9±29.0 | 82.2±25.3 | 229 | 52.5±31.8 | |
| TMT-B | 188.6±107.1 | 92.5±86.9 | 66.9±39.0 | 184 | 134.2±106.4 | |
| DSC | 30.6±17.1 | 63.9±29.0 | 82.2±25.3 | 183 | 37.2±17.9 | |
Number represents number of patients whose data were available for analysis.
AD: Alzheimer's disease, MCI: mild cognitive impairment, SD: standard deviation, K-BNT: Korean version of the Boston Naming Test, RCFT: Rey-Osterrieth Complex Figure Test, CDT: Clock Drawing Test, SVLT: Seoul Verbal Learning Test, COWAT: Controlled Oral Word Association Test, TMT-B: part B of the Trail Making Test, DSC: Digit Symbol Coding.