etiology of headache not apparent on noncontrast CT

Etiology

• vascular
  • saccular aneurysms
  • subarachnoid hemorrhage *a,b*
  • acute cerebral infarction
  • arteriovenous malformations *b,d*
  • dural arteriovenous fistula *b,d*
  • carotid artery dissection, vertebral artery dissection *d*
  • central nervous system vasculitis *a,b,d*
  • reversible cerebral vasoconstriction *d*
  • cerebral vein thrombosis, cortical vein thrombosis *e*
• structural
  • neoplasms, especially in the posterior fossa *c*
  • cerebral metastases *c*
  • meningeal carcinomatosis *a,c*
  • pituitary tumor, pituitary hemorrhage
  • foramen magnum lesions
  • Arnold-Chiari malformations
• infections
  • paranasal sinusitis
  • meningoencephalitis *a*
  • meningitis *a,c*
• disorders of intracranial pressure
  • cerebrospinal fluid leak *a,c*
  • idiopathic intracranial hypertension *a*

* see Special laboratory & Radiology below for meaning of *a* & *b* & *c*, *d* & *e*, respectively

Diagnostic procedures

• lumbar puncture may be required *a*
• conventional angiography may be required *b*

Radiology

• gadolinium-enhanced magnetic resonance imaging may be indicated *c*
• magnetic resonance angiography or CT angiography may be indicated *d*
• magnetic resonance veinography or CT veinography may be indicated *e*

Additional terms

• headache