| Vascular Risk Factors | All patients | Group I (n = 20) | Group II (n = 20) | Group III (n = 20) | F/χ2# | P value |
| Previous TIA attacks | 29 (48.3%) | 8 (40%) | 7 (35%) | 14 (70%) | 5.740 | 0.037* |
| Previous stroke | 19 (31.7%) | 5 (25%) | 6 (30%) | 8 (40%) | 1.078 | 0.583 |