Table 2.
Comparison of red flag signs and investigations.
| Nonserious intracranial headache (366 patients) | Serious intracranial headache (88 patients) | p value | |
|---|---|---|---|
| Red flag signs | |||
| Age >50 years | 231 (63.1) | 48 (54.5) | 0.174 |
| Abrupt onset | 58 (15.8) | 33 (37.5) | <0.001 |
| Positional provocation | 5 (1.4) | 4 (4.5) | 0.076 |
| Systemic symptoms | 26 (7.1) | 22 (25) | <0.001 |
| Secondary risk factors | 26 (7.1) | 21 (23.9) | <0.001 |
| Neurological deficit | 13 (3.6) | 29 (33) | <0.001 |
|
| |||
| Investigations | |||
| Performed CT brain | 70 (19.1) | 88 (100) | <0.001 |
|
| |||
| CT brain results | |||
| Subarachnoid hemorrhage | 0 (0) | 12 (13.6) | <0.001 |
| Intracerebral hemorrhage | 0 (0) | 15 (17.0) | <0.001 |
| Infarction | 0 (0) | 6 (6.8) | <0.001 |
| Tumor with/without complications | 0 (0) | 21 (23.9) | <0.001 |
| Venous sinus thrombosis | 0 (0) | 4 (4.5) | 0.001 |
| Hydrocephalus | 0 (0) | 1 (1.1) | 0.194 |
| Brain abscess | 0 (0) | 1 (1.1) | 0.194 |
| Within normal limits | 70 (19.1) | 28 (31.8) | 0.014 |
| Performed CTA | 0 (0) | 16 (18.2) | <0.001 |
|
| |||
| CTA results | |||
| AVM | 0 (0) | 6 (6.8) | <0.001 |
| Aneurysm | 0 (0) | 7 (8) | <0.001 |
| Within normal limits | 0 (0) | 3 (3.4) | 0.007 |
| Performed MRI | 0 (0) | 23 (26.1) | <0.001 |
|
| |||
| MRI results | |||
| Leptomeningeal enhancement | 0 (0) | 1 (1.1) | 0.194 |
| Focal meningoencephalitis | 0 (0) | 1 (1.1) | 0.194 |
| Brain tumor/metastasis | 0 (0) | 17 (19.3) | <0.001 |
| Cerebral infarction | 0 (0) | 2 (2.3) | 0.037 |
| Venous sinus thrombosis | 0 (0) | 1 (1.1) | 0.194 |
| AVM | 0 (0) | 1 (1.1) | 0.194 |
| Performed lumbar puncture | 5 (1.4) | 26 (29.5) | <0.001 |
|
| |||
| CSF findings | |||
| Bacterial meningitis | 0 (0) | 2 (2.3) | 0.037 |
| Viral meningitis | 0 (0) | 12 (13.6) | <0.001 |
| Fungal meningitis | 0 (0) | 6 (6.8) | <0.001 |
| Eosinophilic meningitis | 0 (0) | 1 (1.1) | 0.194 |
| Blood | 0 (0) | 1 (1.1) | 0.194 |
| Normal profile | 5 (1.4) | 4 (4.5) | 0.076 |
|
| |||
| Pathogens | |||
| Beta Streptococcus group B | 0 | 1 | |
| Pseudomonas aeruginosa | 0 | 1 | |
| Cryptococcus neoformans | 0 | 5 | |
| Human herpes virus | 0 | 2 | |
Data are presented as n (%) unless indicated otherwise. p values <0.05 are statistically significant. CT = computed tomography; CTA = computed tomographic angiography; AVM = arteriovenous malformation; MRI = magnetic resonance imaging.