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