CT features on admission in patients with a previous headache episode, compared with follow up CT of patients with a rebleed in hospital, without headaches before the presenting SAH
| Feature | Index SAH with previous headache (%) | At rebleed, no previous headache (%) |
Difference between proportions (%) 95% CI) |
| Number | 44 | 31 | |
| Hydrocephalus | 6 (14) | 5 (16) | 3 (−14 to 19) |
| Intracerebral haematoma | 18 (41) | 17 (55) | 14 (−9 to 37) |
| Intraventricular haemorrhage | 11 (25) | 17(55) | 30 (8 to 52) |
| Subdural haematoma | 2 (5) | 1 (3) | −1 (−10 to 7) |
| Amounts of cisternal blood | |||
| 0–10 | 14 (32) | 13 (42) | 10 (12 to 32) |
| 10–20 | 7 (16) | 11 (36) | 20 (0.4 to 40) |
| 20–30 | 23 (52) | 7 (23) | −30 (−51 to 9) |