Headache attributed to cerebrovascular diseases with clinical and diagnostic features
| Types | Headache features | Diagnostic features |
| SAH | Thunderclap, acute, severe, long-lasting | Non-contrast-enhanced CT: sensitivity 99% in the first 6 hours, CSF: erythrocytes or xanthochromia |
| PACNS | Chronic, moderate, diffuse, long-lasting | CSF: lymphocyte and protein increases, MRI: ischaemic lesions in subcortical and deep white matter and grey matter |
| CAD | Thunderclap, acute, unilateral | CT or MRA: long, irregular stenosis, an occlusion or a dissecting aneurysm |
| CVT | Acute or subacute, diffuse, long-lasting | MRI: detect brain parenchymal lesions; CT/CTV: high density consistent with the position of venous sinus |
| MELAS | Migrainous headaches, short-lasting, mild or moderate | MRI: lace sign or ribbon sign |
| CADASIL | Migraine with (atypical) aura | MRI: white matter hyperintensities in the anterior temporal pole, lacunes; genetic testing: NOTCH3 mutation |
| RCVS | Thunderclap, acute, severe, relapsing | Angiography: segmental narrowing of branches of cerebral arteries |
CAD, cervical artery dissection; CADASIL, cerebral autosomal dominant arteriopathy with subcortical infarcts and leucoencephalopathy; CSF, cerebrospinal fluid; CTV, CT venography; CVT, cerebral venous thrombosis; MELAS, mitochondrial encephalomyopathy, lactic acidosis and stroke-like episode syndrome; MRA, magnetic resonance angiography; PACNS, primary angiitis of the central nervous system; RCVS, reversible cerebral vasoconstriction syndrome; SAH, subarachnoid haemorrhage.