Table 2.
VS defined by velocity thresholds—distribution by arteries involved.
| Variable | Patients |
|---|---|
| Artery in which VS was detected | |
| Distal BA | 24 (77.4%) |
| MCA | 12 (38.7%) |
| Proximal BA | 5 (16.1%) |
| ACA | 4 (12.9%) |
| PCA | 3 (9.6%) |
| VA | 2 (6.4%) |
| ICA | 0 |
| Number of arteries involved per patient | |
| 1 | 19 (61.4%) |
| 2 | 5 (16.1%) |
| 3 | 5 (16.1%) |
| 4 | 1 (3.2%) |
| 5 | 1 (3.2%) |
| Total | 31 (100%) |
| Average | 1.71 |
ICA: internal carotid artery; MCA: middle cerebral artery; ACA: anterior cerebral artery; PCA: posterior cerebral artery; VA: vertebral artery; BA: basilar artery; VS: vasospasm.