Table 1.
Demographics, injury and imaging variables, and outcome by TBI severity groups (n = 463)
| Variable | Moderate-severe TBI (n = 305, 66%) | Mild TBI GCS score 14–15 (n = 158, 34%) | ||
|---|---|---|---|---|
| Severe TBI GCS score 3–8 (n = 176, 38%) | Moderate TBI (n = 129, 28%) | |||
| GCS score 9-12 (n = 74, 16%) | GCS score 13a (n = 55, 12%) | |||
| Age (median, IQR) | 27.2 (20.0–42.8) | 32.5 (19.3–46.8) | 31.1 (22.5–59.6) | 27.7 (21.7–42.5) |
| Sex (male/female, %) | 146/30 (83/17) | 56/18 (76/24) | 38/17 (69/31) | 103/55 (65/35) |
| Injury mechanism (%) | ||||
| Road traffic accident | 104 (59) | 32 (43) | 22 (40) | 42 (27) |
| Fall | 56 (32) | 30 (41) | 23 (42) | 67 (42) |
| Struck object | 4 (2) | 0 | 1 (2) | 17 (11) |
| Violence | 8 (5) | 2 (3) | 5 (9) | 22 (14) |
| Other/unknown | 4 (2) | 10 (14) | 4 (7) | 10 (6) |
| GCS score (median, IQR) (missing n) | 6 (4–7) (1) | 11 (10–12) (0) | 13 (13–13) (0) | 15 (15–15) (10) |
| Pupil dilatation at admission (n, %) | ||||
| Unilateral dilatation | 37 (21) | 1 (1) | 1 (2) | 0 |
| Bilateral dilatation | 9 (5) | 1 (1) | 0 | 0 |
| Secondary events (n, %) | ||||
| Any hypoxia | 64 (36) | 7 (9) | 1 (2) | 0 |
| Any hypotension | 48 (27) | 7 (9) | 0 | 0 |
| Alcohol intoxication at admissionb (n, %) (unknown n) | 58 (33) (13) | 26 (35) (0) | 14 (25) (1) | 72 (46) (2) |
| Worst Marshall CT score (n, %) | ||||
| No CT | 0 | 0 | 0 | 31 (19) |
| 1 | 11 (6) | 11 (15) | 13 (24) | 148 (94) |
| 2 | 77 (44) | 49 (66) | 25 (45) | 10 (6) |
| 3–4 | 43 (24) | 5 (6) | 4 (7) | 0 |
| 5–6 | 45 (26) | 9 (12) | 13 (24) | 0 |
| Evacuated haematoma (n, %) | 43 (24) | 9 (12) | 8 (15) | 0 |
| Days from injury to MRI (median, range) | 9 (0–41) | 7 (1–40) | 6 (1–38) | 2 (0–5) |
| TAI lesions on MRI (n, %) | 167 (95) | 55 (74) | 35 (64) | 9 (6) |
| Vol. TAI on FLAIR, cm3 (median, p75) | 1.33 (5.36) | 0.38 (1.76) | 0 (0.58) | 0 (0) |
| Vol. TAI on DWI, cm3 (median, p75) | 0.43 (2.27) | 0.10 (0.59) | 0 (0.16) | 0 (0) |
| No. TAI on T2*GRE/SWI (median, p75) | 15 (39) | 3.5 (21) | 3 (21) | 0 (0) |
| Contusions on MRI (n, %) | 140 (80) | 50 (68) | 39 (71) | 7(4) |
| Vol. Contusions, cm3 (median, p75) | 5.11 (29.8) | 3.02 (23.9) | 5.26 (37.1) | 0 (0) |
| Known preinjury disabilityc (n, %, (missing n)) | 31 (18) (3) | 16 (22) (2) | 4 (8) (1) | NA |
| Glasgow Outcome Scale Extended (GOSE) scoresd (n, %) | ||||
| 1–2 | 15 (9) | 0 | 0 | 0 |
| 3–4 | 44 (25) | 5 (7) | 1 (2) | 0 |
| 5–6 | 79 (45) | 30 (41) | 19 (35) | 16 (10) |
| 7–8 | 28 (16) | 34 (46) | 34 (62) | 131 (83) |
| Not possible to assess/missing | 10 (6) | 5 (7) | 1 (2) | 11 (7) |
TBI traumatic brain injury, n numbers, GCS Glasgow Coma Scale, IQR interquartile range, CT computer tomography, TAI traumatic axonal injury, Vol. volume, FLAIR fluid-attenuated inversion recovery, p75 75th percentile, DWI diffusion-weighted imaging, No. number, T2*GRE T2* gradient echo, SWI susceptibility-weighted imaging
a Patients with a GCS score of 13 were classified as moderate TBI
b Positive blood alcohol content and/or clinical suspicion
c Definition of preinjury disability: alcohol or/and drug abuse, psychiatric history, neurological disease (including epilepsy), developmental disorder or severe somatic disease (including cancer, severe heart- and lung disease)
d 6 months GOSE score for the moderate/severe TBI cohort and 3 months GOSE score for the mild TBI cohort