Gender-specific risk factors | |
Oral contraceptives | 54.3% |
Puerperium | 13.8% |
Pregnancy | 6.3% |
Hormonal replacement therapy | 4.3% |
Systemic conditions | |
Iron deficiency anaemia | 9.2% |
Malignancy | 7.4% |
Myeloproliferative diseases | 2.9% |
Dehydration | 1.9% |
Inflammatory bowel disease | 1.6% |
Systemic lupus erythematosus | 1% |
Behçet’s disease | 1% |
Thyroid disease | 1.7% |
Neurosarcoidosis | 0.2% |
Obesity | – |
Genetic/acquired prothrombotic condition (thrombophilia) | 22.4% / 15.7% |
Antiphospholipid antibody syndrome | 5.9% |
MTHFR gene mutation/hyperhomocysteinaemia | 4.5% |
Factor V Leiden mutation | – |
Prothrombin gene mutation | – |
Protein S/C deficiency | – |
Antithrombin deficiency | – |
Nephrotic syndrome | 0.6% |
Polycythaemia/thrombocythaemia | – |
Infections | |
Ears, sinuses, mouth, face, neck | 8.2% |
Other | 4.3% |
Central nervous system | 2.1% |
Mechanical factors | |
Surgery/neurosurgery | 2.7%/0.6% |
Lumbar puncture | 1.9% |
Head trauma | 1.1% |
Drugs | |
Cytotoxic | 0.8% |
Lithium | n.d. |
Vitamin A | n.d. |
Intravenous immunoglobulin | n.d |
Ecstasy | n.d |
Vascular abnormalities | |
Dural arteriovenous fistulae | 1.6% |
Arteriovenous malformations | 0.2% |
Other venous abnormalities | 0.2% |
MTHFR, methylenetetrahydrofolate reductase. n.d, not described