Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
NEURO-OPHTHALMOLOGY Evaluating the Headache Patient in an Ophthalmic Practice Red flags, office testing, and neuroimaging. BY JOSHUA PASOL, MD P atients may initially present to their eye care provider with complaints of headaches or transient visual symptoms. Headaches are most commonly tension or migraine in type and are not associated with any ocular disease. Alternatively, headaches may be caused by more serious disorders with ocular manifestations such as giant cell arteritis or intracranial processes like tumors, aneurysms, and strokes. A full evaluation of patients’ symptoms may require in-office testing, neuroimaging studies, and referrals to other specialists. Recognizing headaches that are serious in nature can help identify and prevent sight- or life-threatening diseases. ASSESSING THE CLINICAL HISTORY Assessing the clinical history of patients with headaches is extremely important. Those with new-onset or worsening symptoms have a more urgent need for evaluation than patients who have had stable symptoms for many years. The three symptoms most frequently found in patients with abnormal neuroimaging studies in the emergency setting are (1) a headache of new onset or a change in the type of headache, (2) nausea or vomiting, (3) and the onset of the worst headache of their lives.1 Patients who have suffered from headaches for many years or who have stereotypical headaches (ie, tension and migraine) are less likely to suffer from an intracranial abnormality. Tension headaches are typically described as band-like pains around the front of the head extending posteriorly. Migraine headaches are typically unilateral, severe, throbbing pains with associated nausea or vomiting and sensitivity to light or sound. VISUAL SYMPTOMS ASSOCIATED WITH HEADACHES Up to 28% of migraine sufferers have associated visual auras. These typically last about 15 minutes and usually precede the headache.2 The aura is typically experienced in the center of both eyes and expands outward toward one hemifield, leaving a central scotoma. A few patients have migraine aura without a headache (acephalgic migraine), and others have a retinal (ocular) migraine, which is a monocular visual event followed by the typical migraine headache. Still other migraineurs experience reversible episodes of monocular visual loss without a headache, which likely represents retinal artery vasospasm. Visual symptoms also occur with more serious diseases. Transient blackouts or obscurations of vision are frequently experienced by patients with papilledema. Amaurosis fugax can result from temporal arteritis or other inflammatory vasculitides or carotid artery diseases. Sellar masses with chiasmal compression lead to a progressive loss of vision, but they can also cause a sudden loss of vision, as seen with pituitary apoplexy. All of these conditions can be associated with headaches. OCULAR SYMPTOMS ASSOCIATED WITH HEADACHES Headache patients may have associated ocular complaints. Ptosis, miosis, conjunctival injection, and tearing can occur with cluster-type headaches and with short-lasting unilateral neuralgiform headache with conjunctival injection and tearing, also called SUNCT. These headaches are generally more common in men and are due to changes in hypothalamic activity.3 Horner syndrome (ptosis, miosis, conjunctival injection, and at times, anhydrosis) can be present with carotid artery dissection. These patients usually have ipsilateral neck pain radiating upward toward the jaw and occasionally into the affected eye.4 Diplopia with associated headache symptoms can SEPTEMBER 2011 ADVANCED OCULAR CARE 65 NEURO-OPHTHALMOLOGY be due to numerous conditions, including orbital inflammatory disease, ischemic or inflammatory cranial neuropathies, Tolosa-Hunt syndrome, pituitary apoplexy, aneurysm, meningitis, intracranial hypertension, intracranial tumors, and basilar migraine. A careful history and examination are important when evaluating these patients to determine what type of testing is needed. Other associated neurological complaints or examination findings should prompt a neurological evaluation. (Cerebral angiogram courtesy of Ali Aziz-Sultan,MD,Neurosurgery at University of Miami Miller School of Medicine.) OFFICE TESTING CAN BE USEFUL Visual field testing is probably the most important in-office test for patients complaining of headaches. A B C D Abnormal results may lead to further neuroimaging or neurological evaluation. It is important to look for homonymous defects that would suggest a central nervous system lesion (Figure 1) or bitemporal field defects suggestive of a chiasmal process. In patients with eye pain, the visual field may demonstrate asymmetry, which could lead to the diagnosis of optic neuritis or a retro-orbital lesion such as an aneurysm. In patients with papilledema due to pseudotumor cerebri, visual fields along with the clinical examination guide treatment. Visual field testing assists in the evaluation of patients with transient visual loss and photopsias with or without associated headaches. In these cases, the visual fields may reveal homonymous defects that could be caused by a tumor or stroke. Rarely, migraines can lead to cerebral infarction, which could be detected with visual field testing if damage occurred within the visual pathway.5 Other useful in-office tests include fundus photography (Figure 2), fluorescein angiography, and ultrasonography. Photographs can be used to document papilledema for future comparison in cases of pseudotumor cerebri. Autofluorescence is useful for documenting optic nerve head drusen in patients who may have an unrelated headache syndrome. Fluorescein angiography is useful in cases of suspected giant cell arteritis to assess choroidal perfusion as well as retinal and optic nerve involvement. Ultrasonography helps differentiate papilledema from pseudopapilledema due to buried drusen.6 Figure 1. Humphrey visual fields (Carl Zeiss Meditec, Inc., Dublin, CA), optic nerve photographs, and magnetic resonance imaging (MRI) of the brain and cerebral angiogram in a 49-year-old patient. New-onset headaches and visual loss are caused by a giant left internal carotid artery aneurysm that is compressing the left optic tract and the left optic nerve. Note the right homonymous visual field defect and inferior defect in his left eye due to compression (A). Optic nerve photographs reveal a normal right optic nerve, whereas the left optic nerve has trace temporal pallor (B). MRI and a cerebral angiogram reveal a giant left internal carotid artery aneurysm (C and D). 66 ADVANCED OCULAR CARE SEPTEMBER 2011 WHO NEEDS NEUROIMAGING AND WHAT TO ORDER Knowing when and which neuroimaging studies to order for patients with headaches is important. Those who have common migraines without aura and tension headaches with normal neurological examination are likely to have normal neuroimaging studies and, therefore, likely do not need them. Neuroimaging is also likely unnecessary for patients who have typical migraine aura with or without headaches and normal visual fields, especially if the aura is that of positive visual phenomenon (eg, zigzags, shimmering lights, kaleidoscopes, etc.). Those with a negative visual NEURO-OPHTHALMOLOGY with and without contrast can be performed if the patient is claustrophobic or if MRI cannot be obtained. Neurological visual field defects also require neuroimaging. Bitemporal defects, especially those that respect the vertical meridian, require imaging of the sella. MRI of the sella with and without contrast is preferred, but CT can also be performed. Homonymous hemianopic defects should be evaluated with CT or MRI, the latter’s being the test of choice. Contrast is useful if a tumor is suspected, but these field defects are usually due to infarct or trauma. Other types of headaches require more specific neuroimaging. Patients with trigeminal neuralgia require both MRI, with and without contrast, and MRA of the brain to evaluate for pathology along the trigeminal nerve. Practitioners may wish to obtain orbital imaging of patients with eye pain and a normal examination, but the yield in these cases is usually low. Orbital MRI with and without contrast is beneficial in cases of eye pain and objective findings such as ocular misalignment or visual loss. If there is pupillary involvement such as from a third nerve palsy, it is important to obtain MRA of the brain. Carotid artery studies, such as MRA or CT angiography of the neck, are required for patients with Horner syndrome and neck pain to look for carotid artery pathology. The history and clinical examination should guide eye care specialists on which neuroimaging study to order. CO N C LU S I O N In-office testing can be valuable when assessing patients with headaches or eye pain. Eye care specialists should order neuroimaging studies based on the clinical history and examination findings, and they should seek neurological evaluation if they encounter other symptoms or signs outside the ophthalmic examination. ■ Figure 2. Optic nerve photographs reveal optic nerve drusen in the right eye and blurred nasal disc margins in the left eye due to buried drusen in a patient with tension headaches. phenomenon (loss of vision) and no headaches generally need vascular studies (magnetic resonance angiography [MRA] or computed tomography [CT] angiography of the neck and brain) to look for arterial narrowing. They may also need cardiac evaluation and hematological testing for hypercoaguability. Patients who have papilledema with or without headaches always need neuroimaging. Preferred studies include MRI of the brain with and without contrast and a magnetic resonance venogram to look at the venous sinuses for possible obstruction. A CT scan of the brain Joshua Pasol, MD, is an assistant professor of ophthalmology at the Bascom Palmer Eye Institute, University of Miami Miller School of Medicine. He acknowledged no financial interest in the products or companies mentioned herein. Dr. Pasol may be reached at (305) 482-5219; [email protected]. 1. Sobri M,Lamont AC,Alias NA,Win MN.Red flags in patients presenting with headache:clinical indications for neuroimaging. Br J Radiol.2003;76(908):532-535. 2. Stewart WF,Linet MS,Celentano DD,et al.Age- and sex-specific incidence rates of migraine with and without visual aura. Am J Epidemiol.1991;134(10):1111-1120. 3. May A,Bahra A,Büchel C,et al.Hypothalamic activation in cluster headache attacks. Lancet. 1998;352(9124):275-278. 4. Stapf C,Elkind MS,Mohr JP.Carotid artery dissection. Annu Rev Med.2000;51:329-347. 5. Spector JT,Kahn SR,Jones MR,et al.Migraine headache and ischemic stroke risk:an updated meta-analysis. Am J Med.2010;123(7):612-624. 6. Kurz-Levin MM,Landau K.A comparison of imaging techniques for diagnosing drusen of the optic nerve head. Arch Ophthalmol.1999;117(8):1045-1049. SEPTEMBER 2011 ADVANCED OCULAR CARE 67