Headache is a common complaint presented to the ophthalmologist. When pain extends to the orbits, the patient and referring physician may assume that the eyes are in some way responsible for the discomfort. Often the patient may have fears, perhaps unspoken, of a brain tumor.
The most important part of an evaluation for headache is the patient’s history, because in the vast majority of such patients, the results of the ocular examination are normal (Table 12-1).
In addition to receiving a complete ophthalmic examination, the patient reporting the headache should be screened systemically, including having measurements taken of blood pressure and pulse and undergoing neurologic examination for meningeal signs (eg, neck stiffness), focal tenderness, and integrity of cranial nerve (CN) function. Any reports of visual phenomena should prompt careful visual field testing.
The International Headache Society (IHS) classification scheme, which was designed in 1988 and revised in 2013, separates primary headaches (eg, migraine, tension-type, and trigeminal autonomic cephalgias) from secondary headaches (ie, headaches resulting from other causes).
Several clinical features of headache may suggest the need for neuroimaging and additional diagnostic testing. The “SNOOP” mnemonic is a useful tool for identifying the red flags of a potentially serious headache:
Table 12-2 summarizes the diagnosis and management of some common headache and related facial pain syndromes.
A sudden severe headache accompanied by neck stiffness, change in mentation, or focal neurologic signs suggests intracranial hemorrhage. Neuroimaging is urgently required in such cases.
Headache caused by meningitis may be chronic and not associated with focal neurologic deficits. Neck stiffness and pain on flexion, back pain, pain on eye movement, and photophobia may suggest meningeal inflammation.
Dodick DW. Clinical clues and clinical rules: Primary vs secondary headache. Adv Stud Med. 2003;3(6C):S550–S555.
Ducros A, Biousse V. Headache arising from idiopathic changes in CSF pressure. Lancet Neurol. 2015;14(6):655–668.
Friedman DI, Digre KB. Headache medicine meets neuro-ophthalmology: exam techniques and challenging cases. Headache. 2013;53(4):703–716.
Headache Classification Subcommittee of the International Headache Society. The International Classification of Headache Disorders, 3rd ed. Cephalalgia. 2013; 33(9):629–808.
Migraine and Tension-type Headache
Migraine is a common disabling primary headache disorder consisting of repetitive bouts of headache. Approximately 6%–8% of men and 15%–18% of women in North America and Europe experience migraine annually. A familial tendency for migraine is strong, and the patient may report having had motion sickness as a child. Onset of migraine may be linked to times of hormonal change, such as during puberty or young adulthood, and migraine episodes may decrease after menopause. Support for a diagnosis of migraine includes the unilaterality or pulsating character of the pain and associated symptoms such as nausea or vomiting, photophobia, phonophobia, and aggravation of pain with routine physical activity. Migraine may be exacerbated by menstruation, pregnancy, hunger, stress, certain foods (eg, chocolate or wine), and sleep deprivation.
Table 12-2 Diagnosis of Facial Pain
Migraine without aura
Migraine without aura, which comprises 65% of all migraine, has no preceding neurologic symptoms. This type of headache may be global, asymmetric bilateral, or unilateral and can last hours to days. Distinguishing between it and the very common tension-type headache (see the section “Tension-type headache”) may be challenging.
Migraine with aura
Migraine with aura, which comprises 30% of all migraines, is heralded by neurologic symptoms that are most commonly visual. Because they originate from the occipital lobes as a result of cortical spreading depression, visual symptoms in migrainous aura are always binocular (although the patient may report them as monocular in the eye that has the symptom in the temporal visual field). The aura builds over minutes, with positive visual phenomena that typically have movement. The classic scintillating scotoma with fortification spectrum commonly begins with a small scotoma that gradually expands into the peripheral vision (Fig 12-1). The scotoma is bounded by a zigzag, shimmering, colorful, or silvery image that moves temporally into the periphery and then breaks up. Loss of vision may occur, and the presence of both positive and negative phenomena is the hallmark of migraine aura. The aura typically lasts between 5 and 60 minutes and is usually followed by a contralateral throbbing headache. The aura always completely resolves. Most patients experience associated nausea, photophobia, and phonophobia. When untreated, migraine attacks typically last from 4 hours to 72 hours.
Figure 12-1 Visual aura of migraine. A, The aura commonly begins with a small scotoma near fixation that gradually expands into the peripheral vision (B–C) and then breaks up (D). The times shown represent minutes from the onset of the visual aura.
(Courtesy of Julie Falardeau, MD.)
Studies of migraine pathophysiology have found evidence for primary dysfunction involving the afferent sensory neurons of CN V. Activation of the trigeminal nucleus caudalis is thought to cause the release of vasoactive chemokines at the vascular endings of CN V. These neuropeptides are thought to cause dilation of the pial arteries, increase vascular permeability, and induce an inflammatory response that activates trigeminal afferent fibers within the walls of blood vessels.
Genetic factors with a substantial familial incidence (eg, familial hemiplegic migraine, a rare autosomal dominant form of migraine) have suggested that increased neuronal excitability is a primary event in migraine. This condition may underlie the spreading depression in the occipital region thought to be responsible for the visual aura and the blood vessel changes that result in pain, as well as the brainstem or bilateral hemispheric symptoms of basilar-type migraine.
Typical aura without headache
Some patients may report only the visual symptoms of migraine aura, without an associated headache. This typical aura without headache, previously termed acephalgic migraine comprises 5% of all migraines and must be differentiated from transient ischemic attacks (TIAs). Typical aura without headache mainly occur in adults with a prior history of migraine with aura. The typical manifestation of migraine aura is scintillating scotoma and, less commonly, transient homonymous hemianopia without positive visual phenomena or peripheral visual field constriction that progresses to tunnel vision or complete vision loss. Symptoms typically last 5–60 minutes and always completely resolve. A patient experiencing positive visual phenomena or a family history of migraine with aura is helpful for diagnosis, as is the presence of the classic scintillating scotoma with fortification spectrum. The absence of these features or the presence of residual visual field defects or a bruit should raise suspicion of another underlying process, such as cerebrovascular disease or a vascular malformation, and prompt urgent brain imaging.
Evaluation of patients with migraine
If the patient has a typical history of migraine and the results of neurologic and ophthalmic examination are normal, neuroimaging studies are unlikely to show an intracranial abnormality. A history of visual phenomena and hemicranial headaches on both sides suggests a benign etiology. Although symptoms that occur strictly on one side are more worrisome, patients with this clinical presentation are also likely to have migraine. Occasionally, a mass lesion or a large vascular malformation is heralded by typical migraine symptoms, but in such cases, there are often residual visual field defects (Fig 12-2; see also Chapter 14). Such a finding underlines the importance of visual field testing in the evaluation of patients with presumed migrainous visual aura. Referral of patients with suspicious headaches to a neurologist is prudent. The following findings may suggest the need for additional evaluation of those patients presumed to have migraine:
Figure 12-2 Occipital lobe arteriovenous malformation. A, T2-weighted axial magnetic resonance imagery (MRI) shows an irregular hypointense mass (arrow) suggestive of a vascular lesion within the right occipital lobe. B, Lateral-projection cerebral arteriogram confirms that the lesion is an arteriovenous malformation (arrow).
(Courtesy of Rod Foroozan, MD.)
Headache or aura always occurring on the same side
Headache preceding the aura
Neurologic deficit, including visual field defect, persisting after aura resolves
Atypical aura (more than 1 aura occurring in a single day, lack of expansion of or change in aura, duration less than 5 minutes or more than 60 minutes)
Frishberg BM, Rosenberg JH, Matchar DB, et al; for the US Headache Consortium. Evidence-based guidelines in the primary care setting: neuroimaging in patients with nonacute headache. American Academy of Neurology website. Available at http://tools.aan.com/professionals/practice/pdfs/gl0088.pdf. Accessed January 13, 2017.
Tension-type headaches are chronic, described as aching or viselike, typically worse at the end of the day, and often precipitated by stress. They are not associated with typical auras. The specific pathophysiology and treatment of tension-type headaches remain unclear. Such headaches may be associated with depression.
Treatment of migraine and tension-type headache
The specific type of headache and the needs of the patient should guide treatment. Some patients, for example, need only reassurance that they do not have serious intracranial disease. Precipitating or contributing factors should be eliminated as much as possible. Certain foods provoke headaches in some people, and patients should consider avoiding the potential triggers of chocolate, nitrates, monosodium glutamate, aged cheese, caffeine, wine and other alcoholic beverages, aspartame-based sweeteners, nuts, and shellfish. The role of estrogens and oral contraceptives is uncertain, but a temporal relationship between initiation of hormone therapy and the development of migraine symptoms suggests a causal relationship.
Other environmental migraine triggers include stress or relief from stress, change in sleep patterns, fumes or strong scents such as perfumes and cigarette smoke, and exercise.
Migraine therapy consists of treatment for the acute symptoms as well as prophylactic management. For treatment of acute symptoms, various drugs can be used, including serotonin 5-HT1B/1D-receptor agonists (triptans), nonsteroidal anti-inflammatory drugs (NSAIDs), dihydroergotamine, and other combination drugs that include caffeine (long-term caffeine intake, however, worsens headaches). An antiemetic drug may also be necessary. The triptans (eg, sumatriptan, rizatriptan, zolmitriptan, frovatriptan, and almotriptan) are useful for symptomatic relief of the migrainous headache but should be used cautiously in patients with migraine with aura and only after the aura resolves to avoid vasoconstriction-induced infarct. Though rare, these drugs can also cause myocardial infarction and are typically not used for patients with suspected or known coronary artery disease.
Analgesic medications should be prescribed with caution, and narcotics should be avoided. The use of analgesic medications for more than 15 days per month can lead to analgesic rebound headache, characterized by a constant headache that is relieved only with the continuous use of pain medications. Therefore, obtaining a thorough medication history from patients with headache is important. Treatment of analgesic rebound headaches requires the withdrawal of analgesics, and hospitalization may be needed. Prophylactic treatment is warranted if headaches disrupt activities of daily living beyond what the patient is willing to tolerate. Topiramate, an antiepileptic c-aminobutyrate (gamma-aminobutyric acid, or GABA) agonist, has been increasingly prescribed for patients with migraine. However, a syndrome characterized by acute myopic shift, ciliochoroidal effusion, and acute bilateral angle-closure glaucoma can occur in some patients using topiramate (see BCSC Section 10, Glaucoma).
Alternatively, beta-blockers, calcium channel blockers, tricyclic antidepressants, selective serotonin reuptake inhibitors (SSRIs), sodium valproate, and gabapentin may be used as prophylactic drugs, as may NSAIDs if their potential for causing analgesic rebound headaches is kept in mind. Oral administration of magnesium and riboflavin can be effective for some patients, as well as pericranial botulinum toxin injections. Tension-type headaches are more likely to respond to treatment with tricyclic antidepressants, topiramate, gabapentin, muscle relaxants, and NSAIDs, although the overall rate of success with such drugs is not as high as for migraine. Various forms of biofeedback may be helpful.
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Monteith TS, Goadsby PJ. Acute migraine therapy: new drugs and new approaches. Curr Treat Options Neurol. 2011;13(1):1–14.
Excerpted from BCSC 2020-2021 series: Section 5 - Neuro-Ophthalmology. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.