Table 1. Dementia and Pathologic Characteristics in Those Younger Than 40 Years Compared With Those 40 Years and Older.
| Characteristic | Individuals, No. (%) | P Value | |
|---|---|---|---|
| <40 y (n = 30)a | ≥40 y (n = 180)a | ||
| Dementia | 2 (6.7) | 120 (66.7) | <.001 |
| Chronic traumatic encephalopathy stage | |||
| I/II | 30 (100.0) | 35 (19.4) | <.001 |
| III/IV | 0 | 145 (80.6) | |
| Dorsolateral frontal cortex neurofibrillary tangle density rating | |||
| None or mild | 20 (66.7) | 50 (27.8) | <.001 |
| Moderate or severe | 10 (33.3) | 130 (72.2) | |
| Arteriolosclerosisb | |||
| None | 26 (86.7) | 54 (30.0) | <.001 |
| Mild | 4 (13.3) | 41 (22.8) | |
| Moderate | 0 | 67 (37.2) | |
| Severe | 0 | 18 (10.0) | |
| White matter rarefaction, mean (SD)b | |||
| None | 16 (53.3) | 22 (12.2) | <.001 |
| Mild | 7 (23.3) | 74 (41.1) | |
| Moderate | 4 (13.3) | 58 (32.2) | |
| Severe | 3 (10.0) | 26 (14.4) | |
| Remote microinfarcts | 1 (3.3) | 49 (27.2) | .002 |
a
Individuals who were younger than 40 years were excluded from analyses because of low pathologic burden and minimal presence of dementia (remote infarcts and microbleeds are not shown because of low burden in the overall sample). The final sample size of 180 individuals was finalized after exclusion of individuals for missing data and those younger than 40 years. Analyses were completed after exclusion of the 14 individuals who had missing data.
b
Ordinal regression was conducted for arteriolosclerosis and white matter rarefaction. Fisher exact tests were used to examine differences between the 2 groups for all other variables because of small cell sizes.