CT features of index SAH in patients with and without a previous headache
| Feature | With previous headache episode(%) | Without previous headache episode (%) |
Difference between proportions (%) (95% CI) |
| Number | 44 | 31 | 44v 31 |
| Hydrocephalus | 6 (14) | 3 (10) | 4 (−11 to 19) |
| Intracerebral haematoma | 18 (41) | 10 (32) | −9 (−31 to 13) |
| Intraventricular haemorrhage | 11 (25) | 10 (32) | 7 (−14 to 28) |
| Subdural haematoma | 2 (5) | 0 (0) | 5 ( −2 to 11) |
| Amount of cisternal blood: | |||
| 0–10 | 14 (32) | 14 (42) | 13 ( −9 to 36) |
| 10–20 | 7 (16) | 4 (13) | −3 (−19 to 13) |
| 20–30 | 23 (52) | 13 (42) | −10 (−33 to 13) |