| Major OSAS symptoms | Headache with specific etiology | Nonspecific headache |
| n (%) | n (%) | |
| Snoring | ||
| Yes (n = 8) | 2 (25.0) | 6 (75.0) |
| No (n = 16) | 7 (43.8) | 9 (56.2) |
| Witnessed apnea | ||
| Yes (n = 1) | - (0) | 1 (100) |
| No (n = 23) | 9 (39.1) | 14 (60.9.8) |
| Excessive daytime sleepiness | ||
| Yes (n = 5) | 1 (20.0) | 4 (80.0) |
| No (n = 19) | 8 (42.1.0) | 11 (57.9) |
| Co-existence of major symptoms | ||
| None | 7 (46.7) | 8 (53.3.) |
| 1 major symptom | 2 (22.2) | 7 (77.8) |
| 2 major symptoms | 1 (25.0) | 3 (75.0) |
| 3 major symptoms | - (0) | 1 (100) |