Headache
Headache is common. Almost everyone has a headache at some time in life. Headache accounts for 2% of general practice visits and 20% of neurological outpatients. Headaches are only very rarely sinister. However, it is important to recognize certain dangerous headaches, and the major types of safe but unpleasant headaches (Table 1).
History
The different features of the common but unpleasant and the rare but dangerous headaches are summarized in Figures 1 and 2.
Dangerous headaches
These headaches are single episodes of headache that develop in seconds to weeks. All are uncommon.
Subarachnoid haemorrhage
These patients classically present with a sudden severe headache: ‘like being hit by a baseball bat’ (Fig. 1a). There may be associated loss of consciousness and focal neurological signs. The subarachnoid blood provokes neck stiffness. Currently up to 50% of patients who present with subarachnoid haemorrhage are misdiagnosed by the first doctor who sees them. A high threshold of suspicion is needed (p. 72).
Meningitis
Meningitis is characterized by progressive headache developing over hours or days (Fig. 1b). There is an associated fever and neck stiffness, and there may be a rash and impaired consciousness. As early treatment favours a good prognosis, a high threshold of suspicion is needed (p. 98).
Temporal arteritis (or giant cell arteritis)
The headache is insidious in onset and may be unilateral or more generalized, though it usually produces bitemporal pain (Fig. 1c). The scalp is often tender. A specific symptom is ‘jaw claudication’, the development of pain in the muscles of mastication on chewing. Twenty-five per cent of patients also have generalized joint and muscle aching typical of polymyalgia rheumatica.
Raised intracranial pressure
The ‘classical’ headaches of raised intracranial pressure (ICP; p. 48) are generalized and made worse or brought on by manoeuvres that increase ICP such as coughing, bending or lying down (Fig. 1d