Migraine is an intermittent and recurrent, usually familial headache. Migraine may be subclassified as migraine without aura or migraine with aura. The clinical features of migraine without aura are listed in Table 15.1.

The aura may come before, during, or after the headache or may not be associated with headache at all. The aura is regarded as a reversible neurological deficit, lasting less than 60 minutes. The deficit is cortically based and may include visual, motor, somatosensory, or language symptoms, and the diagnosis of migraine is made because the symptoms progress, or march, in an extremity over time. Thus “pins and needles” or numbness in an arm could start in the hand and march up the limb to the shoulder over approximately 10 to 15 minutes. The visual aura (shimmering or scintillating light, scotomas, fortification spectra) will gradually spread across the visual field; the language deficit will change over minutes. Weakness will spread in a fashion similar to a sensory march.

Before or simultaneously with the aura, regional cortical cerebral blood flow is decreased in the somatic cortical area corresponding to the body part involved (e.g., occipital area for a visual aura). The spread of dysfunction is currently usually equated with the experimentally induced spreading depression of Leão. If potassium is dripped onto the cortex, it causes local depolarization, which leads to further potassium egress from the depolarized cell that in turn depolarizes its neighbor, setting up a chain reaction that spreads over the cortex at a rate of approximately 3 mm per minute. This spread correlates with the migraine march. The aura is distinct from the headache and has a different pathophysiology.

The headache of migraine is typically throbbing; aggravated by coughing, straining, and stooping; and relieved by lying still in a dark room. It is regarded as a neurovascular phenomenon associated with neurally mediated inflammation and activation of deep pain pathways. The periaqueductal gray in the brainstem is activated during the headache.

Triggers for migraine attacks include emotional upsets or stress, irregular sleep habits, missing meals, and hormonal changes. Curiously, patients will cope well during a stressful episode, but have a migraine once the stress passes. Migraine related to the menstrual period is called catamenial migraine—the trigger is estrogen withdrawal. Some patients report that specific foods may trigger an attack—common foods are red wine, chocolate, and Chinese food. The basic pathophysiological connection between any particular trigger and an attack of migraine remains obscure. During pregnancy, migraine usually improves, only to return after delivery.

Hemiplegia as part of migraine is rare but may be familial or sporadic. Familial hemiplegic migraine (FHM) has been tracked to mutations in the CACNA1A gene on chromosome 19
(FHM1) and to mutations in the ATP1A2 gene on chromosome 1 (FHM2). In FHM1, basilar symptoms are common, headache is almost always present, and disturbances of consciousness, fever, and cerebrospinal fluid (CSF) pleocytosis can occur. In approximately 50% of families with FHM1, chronic progressive cerebellar ataxia occurs.

If a migraine headache is very severe and lasts without remission for more than 72 hours, the label status migrainosus is warranted.

Tension-type headache (TTH), also known as tension headache, muscle contraction headache, psychomyogenic headache, stress headache, and psychogenic headache is classified as:

These classifications are further subdivided in the International Classification Impairments, Disabilities, and Handicaps (ICDH-2) into those with and those without pericranial tenderness.

The prevalence of TTH in the general population ranges from 30% to 78%, but, as in migraine, the figures quoted are likely on the low side.

Diagnostic criteria for infrequent episodic TTH are listed in Table 15.2.

Infrequent headaches by definition occur less frequently than 1 day per month, frequent headaches occur on more than 1 but fewer than 15 days per month for at least 3 months, and chronic headache implies that the occurrence of headache occurs on more than 15 days per month.

These patients describe their headaches variously as pressure, a band around the head, a bursting sensation, or tight scalp. The posterior cervical muscles are usually tight and tender, and there may be tenderness to pressure over the temporalis and masseter. Likely the headache is pain referred from extracranial muscle in spasm. In young patients the social background is almost always of stress, and in older individuals the root cause is likely to be cervical spondylosis diagnosed by restricted neck movement, cervical root signs, or long tract signs.