7B. Secondary headaches

Secondary headaches are those headaches which occur as a feature of an underlying disease. The list of disorders which can cause secondary headaches is endless. It’s important to know the red flags of headache which may suggest a severe pathology, so that proper evaluation can be performed in patients presenting with these red flags.

Etiology

• Mass-occupying lesions
  • Epidural haemorrhage
  • Subdural haemorrhage
  • Subarachnoid haemorrhage
  • Intracerebral haemorrhage
  • Tumour
  • Brain abscess
• Other CNS pathology
  • Meningitis/encephalitis
  • Cerebral venous sinus thrombosis
  • Ischaemic stroke/TIA
  • Dissection of carotid/vertebral artery
  • Post head trauma
• Extracranial disorders
  • Infections near to the CNS (sinusitis, etc.)
  • Systemic infection
  • Hypertensive emergency
  • Acute glaucoma
  • Temporal arteritis and other vasculitides
  • Substance abuse (alcohol, etc.)
  • Substance withdrawal (caffeine, etc.)
  • Medication side effect
    • Nitrates
    • Analgesic overuse – overuse of analgesics can cause headache

Red flags/signs

• Non-specific symptoms like fever – rule out metastasis, infection
• Neurological symptoms – rule out stroke, CNS lesion, encephalitis
• Age > 50 at onset – rule out temporal arteritis, severe hypertension, tumour
• Hyperacute onset (esp. thunderclap) – rule out haemorrhagic stroke
• Papilloedema or precipitated by Valsalva or exertion – rule out raised ICP
• Positional – rule out intracranial hypotension
• Progressive worsening or significant change in symptom pattern of a known headache – rule out all secondary causes