| often | 6 | temporal |
| in combination with other factors | 4 | cause |
| ultimately | 3 | degree |
| brain → cause → headache | 45 |
| brain → lead to → headache | 34 |
| brain → result in → headache | 22 |
| brain → cause → severe headaches | 5 |
| brain → give → headache | 5 |
| brain → include → headache | 3 |
| brain → trigger → headache | 3 |
| negative | neutral | positive |
| 0.844 | 0.141 | 0.014 |
| Raw frequency | 117 |
| Normalized frequency | 0.587 |
| Modifier score | 0.567 |
| Perplexity | 220.538 |