Selected abnormalities on direct-access CT in patients with chronic headache that were likely to be incidental to the presenting symptoms
| Abnormality | n | Rate, % |
|---|---|---|
| Small vessel disease | 98 | 2.2 |
| Generalised atrophy | 67 | 1.5 |
| Established infarct | 48 | 1 |
| Lacunar infarct | 19 | 0.4 |
| Focal atrophy | 16 | 0.3 |
| Abnormal calcification | 15 | 0.3 |
| Tonsillar ectopia | 12 | 0.2 |
| Demyelination | 10 | 0.2 |
| Paranasal sinus thickening | 9 | 0.18 |
| Ventricular asymmetry | 8 | 0.16 |
| Cerebellar atrophy | 8 | 0.16 |
| Pineal cyst | 4 | 0.08 |
| Small ventricles | 4 | 0.08 |
| Frontal atrophy | 3 | 0.06 |
| Cavernous angioma | 2 | 0.04 |
| Small chronic subdural haematoma | 2 | 0.04 |
| Giant cisterna magna | 2 | 0.04 |
| Dandy Walker variant | 1 | 0.02 |
| Grey matter heterotopia | 1 | 0.02 |