Table 2 Secondary headaches that mimic chronic benign headache syndromes

Headache associated with vascular disorders

Cerebrovascular disease including carotid artery dissection and arteriovenous malformation

Arteritis including giant cell arteritis

Headache associated with non-vascular intracranial disorders

Low CSF pressure syndrome (spontaneous or post-traumatic CSF “leak”)

High CSF pressure without papilloedema

Intracranial: Lyme disease, human immunodeficiency virus, encephalitis, fungal meningitis, etc.

Headache associated with substances or their withdrawal

Overuse of acute headache medications (rebound or toxic drug overuse syndromes)

Headache associated with cranium, neck, eyes, ears, nose, sinuses, teeth, mouth or other facial or cranial structures

Otolaryngologic disease, including chronic sphenoid sinusitis (or other sinus disease)

Nasopharyngeal disorders, including carcinoma

Disorders of the trigeminal nerve, including dental and oral disease, jaw pathology

Subacute angle closure glaucoma, optic neuritis and other ocular disorders

Occipitocervical disease, including Arnold-Chiari Malformation Type I; upper cervical joint, root or nerve (neuralgic) syndromes

Headache associated with non-cephalic infection, metabolic or systemic disturbances

Hepatitis, renal disease, B12 deficiency, anaemia, exposure to carbon monoxide and other toxins

Hormonal disturbances/endocrinologic disease (oestrogen, thyroid disease, hyperprolactinaemia, etc.)

Vasculitis/rheumatic/connective tissue disorders

Miscellanea

Mediastinal and thoracic processes including angina, mass lesions, superior vena cava syndrome