Differential diagnosis

Headache disorders are classified by the ICHD-II as (1)

• primary headache disorders
  • migraine
  • tension type headache
  • cluster headache and other trigeminal autonomic cephalagias
  • other primary headache disorders
• secondary headache disorders
  • these include a new headache occurring with another lesion capable of causing it.( e.g., headache attributed to intracranial tumour)

The differential diagnosis of migraine is large, but includes:

• tension headaches
• depression
• sinusitis
• dental caries
• in the elderly, transient ischaemic attacks
• epilepsy
• temporal lobe tumours, e.g. angiomata
• arteriovenous malformations
• phaeochromocytoma

Consideration of secondary causes of headache (2):

• atypical aspects of the history should alert the clinician to exclude a secondary cause of headache
  • for example
    • onset of migraine after age 50 years is less common and is associated with an increased likelihood of secondary causes
    • combination of new-onset headache, jaw claudication, and nodular or tender temporal arteries is highly predictive of giant cell arteritis
    • disorders of intracranial pressure, such as idiopathic intracranial hypertension and spontaneous intracranial hypotension, often have symptoms that overlap those of migraine, such as headache, visual disturbance, and worsening of symptoms with exertion
      • therefore clinician enquiry relating to symptoms specific to these conditions may help to identify these patients who need urgent referral and treatment:
        • intracranial hypertension
          • transient binocular vision loss, double vision, and pulsatile tinnitus
        • intracranial hypotension
          • orthostatic symptoms for spontaneous intracranial hypotension

Reference:

• Headache classification subcommittee of the international headache society. The international classification of headache disorders.2nd edition. Cephalagia 2004; 1:24
• Niushen Zhang, Matthew S. Robbins. Migraine. Ann Intern Med. [Epub 10 January 2023]. doi:10.7326/AITC202301170