Headache is one of the most common neurological problems presented to GPs. People with headache and their healthcare professionals can be worried about possible serious underlying disease.20,21
Headaches disorders are classified as either primary or secondary and these are further divided into specific headache type.20,22
Primary headache disorders, including migraine, tension-type and cluster headaches, account for the majority of headaches.23The aetiology of primary headaches is poorly understood and they are differentiated by their clinical patterns.22
Investigations, including neuroimaging, do not contribute to the diagnosis of migraine or tension-type headache. Some guidelines, but not all, recommend brain MRI in patients with cluster headache due to the small possibility of a serious underlying structural lesion.24
Secondary headaches, are attributed to underlying disorders.20 The most common secondary headache is due to medication overuse, which occurs most commonly in those taking medication for a primary headache disorder.20 Headache may also be referred from the muscles, joints and ligaments of the upper three cervical segments due to the convergence of nociceptive afferent nerves from these segments with those of the trigeminal nerve.25
Serious causes of secondary headaches include tumour, infection, bleeding and arteritis.24,26 These warrant further investigation, which may include imaging. Note that MRI will not detect all serious causes of secondary headache, such as giant cell arteritis.6
For detailed explanations of headache classifications go to the
International Headache Society Classification page.
What findings increase the suspicion of intracranial pathology?
People with headache alone are unlikely to have serious underlying disease.22 Serious intracranial pathology as the cause of headache is rare (e.g. space-occupying lesion <1%, idiopathic intracranial hypertension <1%, chronic meningitis <1% and giant cell arteritis <1%).6
The SNOOP mnemonic is a useful reminder of clinical features that may indicate a secondary headache with serious underlying cause.27,28
History
Patients with increased intracranial pressure may report symptoms such as:
- a frontal headache that is worse after lying down, most notable in the morning and wakes the patient from sleep but improves during the day
- vomiting, particularly early morning and not associated with nausea
- blurred vision
- personality or behavioural changes.
In imaging studies, the following symptoms have been shown to increase the odds of finding a significant abnormality on neuroimaging: rapidly increasing headache frequency, history of dizziness or lack of coordination, history of subjective numbness or tingling, or history of headache causing awakening from sleep.21
Physical examination
Examination of patients presenting with headache should include:20,22
- blood pressure
- examination of temporal arteries
- neck examination, including palpation for posterior cervical tenderness
- fundoscopy (where the doctors is experienced in its use)
- cranial nerve assessment, especially pupils, visual fields, eye movements, facial power and sensation, and bulbar function (soft palate, tongue movement)
- assessment of tone, power, reflexes and coordination in all four limbs
- plantar responses
- assessment of gait, including heel–toe walking.
There should be more detailed assessment if prompted by the history. The examination should be tailored to include any focal neurological symptoms.20
An abnormal neurological examination significantly increases the likelihood of finding an abnormality on neuroimaging.21