CHAPTER 12

The Patient With Head, Ocular, or Facial Pain

Evaluation of Headache

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 history is the most important part of an evaluation for headache because results of the ocular examination are normal in the vast majority of such patients (Table 12-1).

Table 12-1

In addition to receiving a complete ophthalmic examination, the patient complaining of 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 function. Any reports of visual phenomena should prompt careful visual field testing.

The 1988 International Headache Society classification scheme for headaches includes primary headaches (eg, migraine, tension-type, and trigeminal autonomic cephalgias) and secondary headaches (ie, headaches resulting from other causes). The classification scheme was revised in 2004 to update the concepts regarding primary headache syndromes and include the new diagnostic category of chronic migraine for patients who have migraine for 15 or more days per month.

Several clinical features of headache may suggest the need for neuroimaging and additional diagnostic testing:

sudden onset of severe headache unexplained change in headache pattern headaches unresponsive to typical therapies

headaches related to physical exertion or to a change in body position

Migraine with aura (formerly classic migraine) comprises 30% of migraine cases and is heralded by neurologic symptoms that are usually visual. Imagery builds over minutes, with positive phenomena that typically have movement. The classic 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 mixing of positive and negative features is the hallmark of migraine aura. Typical visual auras have a hemianopic distribution but are frequently perceived by the patient as monocular (in the eye ipsilateral to the temporal defect). The aura lasts less than 60 minutes and is typically followed by a throbbing headache on the contralateral side of the head. 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.)

Basilar-type migraine (previously complicated migraine) is thought to result from transient ischemia within the distribution of the basilar artery and may be accompanied by bilateral vision loss, diplopia, vertigo, dysarthria, ataxia, and loss of consciousness.

Studies of the pathophysiology of migraine have found evidence for primary dysfunction involving the afferent sensory neurons of the trigeminal nerve and have emphasized genetic factors with a substantial familial incidence (eg, familial hemiplegic migraine, a rare autosomal dominant form of migraine). Activation of the trigeminal nucleus caudalis is thought to cause the release of vasoactive chemokines at the vascular endings of the trigeminal nerve. Such 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.

Studies have suggested that migraine is a type of channelopathy in which there is increased neuronal excitability. This condition may underlie the spreading depression in the occipital region thought to be responsible for the visual aura and the blood vessel changes resulting in pain and other symptoms of basilar-type migraine. The same studies also provided a basis for developing the family of triptans (serotonin receptor agonists) that function by inhibiting release of vasoactive neuromediators.

In basilar-type migraine, a focal neurologic deficit may be part of the aura, or it may occur with the headache and then persist. This neurologic deficit is usually transient, but permanent deficits consequent to intracranial infarction may occur.

Migraine without aura

Accounting for 65% of cases, migraine without aura (formerly common migraine) has no preceding neurologic symptoms. This type of headache may be global, not strictly unilateral, and it can last hours to days. Distinguishing between it and the very common tension-type headache (discussed later in the chapter) may be challenging.

Migraine aura without headache

Some patients may report only the visual symptoms of migraine aura without an associated headache. The occurrence of migraine aura without headache (acephalgic migraine; 5% of migraine) must be differentiated from transient ischemic attacks (TIAs). This form of migraine occurs mainly in adults with a prior history of migraine with aura. Manifestations of migraine aura include scintillating scotoma, transient homonymous hemianopia without positive visual phenomena, peripheral visual field constriction progressing to tunnel vision or complete vision loss, and episodic diplopia (usually vertical and accompanied by other neurologic symptoms). Symptoms typically last less than 60 minutes. A positive patient or family history of migraine with aura is helpful for the diagnosis, as is a description of the deficit. The classic scintillating scotoma with fortification spectrum is suggestive of migraine. Residual visual field defects may indicate another underlying process, such as cerebrovascular disease or a vascular malformation.

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 alternating hemicranial headaches suggests a benign etiology, but most patients with headaches that always occur on the same side of the head 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; also see Chapter 14). Such a finding underlines the importance of visual field testing in the evaluation of patients with presumed migraine. Referral of patients with suspicious headaches to a neurologist is prudent. The following findings may suggest the need for additional evaluation of patients presumed to have migraine:

headache or aura always occurring on the same side headache preceding the aura

neurologic deficit, including visual field defect, persisting after aura resolves

features of aura are atypical (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)

Figure 12-2 Occipital lobe arteriovenous malformation. A, Axial T2-weighted MRI showing 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.)

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. Available at: http://www.aan.com/professionals/practice/pdfs/gl0088.pdf. Accessed July 6, 2012.

Tension-type headache

Tension-type headaches are chronic, described as aching or viselike, typically worse at the end of the day, and often precipitated by stress. 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, red wine and other alcoholic beverages, aspartamebased 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