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Show LETTERS TO THE EDITOR Retinal Migraine In this issue of the Journal, I am a coauthor of the manuscript on retinal migraine by Hill et al ( 1). I was somewhat responsible for " retinal migraine" remaining in the second edition of the International Headache Society ( IHS) Classification ( 2) and will relate how this transpired. Dr. Jes Olesen, Professor and Chairman of Neurology at the University of Copenhagen, was chair of the first Headache Classification Subcommittee, the results of which were published in 1988 ( 3). At the Migraine Trust International Symposium in London in 1994, I presented a paper on " The Eye and Headache" that included a brief mention of retinal migraine. Olesen told me that he doubted the existence of retinal migraine, because most patients did not have IHS- defmed migraine. I replied that I had seen at least one bona fide case when I was at the University of Miami ( 1968- 1980), and would try to locate my records. I wrote Olesen on September 21, 1994, as follows: Dear Jes: Since I always assumed that retinal migraine existed, I didn ' t keep records of the patients I had seen. However, in going over my Miami files, I came across two patients whose records are enclosed. 1. Case 1 had repetitive uniocular events and migraine headaches but only one episode of migraine associated with a monocular visual aura. The two follow- up notes indicate apparent resolution by propanolol. 2. Case 2, the wife of an ophthalmologist, is an absolutely unequivocal case as indicated in my enclosed 5- 11- 72 office note. Since taking the propanolol, she has stopped having episodes. I conclude that retinal ( anterior visual) migraine exists but is extremely rare ( if coexistent migraine headaches are required with more than a single episode). Sincerely yours, Bob Case 1 was not a " definite retinal migraine," but Case 2 seemed to be. Her relevant history, obtained on May 11, 1973, is as follows. She was the 26- year- old wife of a local ophthalmologist who had had her first migraine in 1967 at age 20. It consisted of a pulsating left temporal headache with nausea and vomiting. She was then asymptomatic until 1970, when she developed sudden visual loss in the left eye. She happened to be in the vicinity of the Bascom Palmer Eye Institute of the University of Miami School of Medicine and saw one of the neuro- ophthalmologists who confirmed a central scotoma in the left eye. An hour later, she developed a pulsating left temporal headache that lasted about 12 hours. The scotoma cleared about 3 hours after the onset of the headache. Subsequently, she had several left-sided headaches preceded by the left eye visual loss, the last occurring 3 weeks before her visit with me. I prescribed propanolol, and her episodes abated, at least until 1980, when I left Miami for Cleveland and lost contact with her. Olesen agreed that Case 2 was an " indisputable" example of retinal migraine. He later chaired the Second IHS Headache Classification Subcommittee, the results of which were published in 2004 ( 2), in which " retinal migraine" remained included. I have not seen a case of definite retinal migraine since leaving Miami in 1980. Several years ago, I asked four neuro- ophthalmologists in northeast Ohio how many patients they had seen with " IHS- defmed retinal migraine," and the response was zero. Monocular visual loss may be associated with migraine, but as indicated by Hill et al ( 1), it is exceptionally rare. Robert B. Daroff, MD Department of Neurology Case School of Medicine Cleveland, Ohio rbd2@ case. edu REFERENCES 1. Hill DL, Daroff RB, Ducros A, et al. Most cases labeled as " retinal migraine" are not migraine. JNeuroophthalmol 2007; 27: 000- 000 2. Headache Classification Subcommittee of the International Headache Society. The International Classification of Headache Disorders: 2nd edition. Cephalalgia 2004; 24( Suppl 1): 9- 160. 3. Headache Classification Committee of the International Headache Society. Classification and diagnostic criteria for headache disorders, cranial neuralgias, and facial pain. Cephalalgia 1988; 8( Suppl 7): 1- 96. Fluctuating Ptosis, Diplopia, and Normal Pupils With Intracavernous Aneurysm A 67- year- old woman was referred to the department of ophthalmology of our institution with a 4 month history of headache, intermittent vertical diplopia, and fluctuating left upper lid ptosis, which was often worse in the afternoon ( Fig. 1). She had a history of systemic hypertension. Best- corrected visual acuity was 20/ 60 in each eye. Ocular motility examination in the right eye was normal. In the left eye, there was a very variable and apparently J Neuro- Ophthalmol, Vol. 27, No. 1, 2007 83 J Neuro- Ophthalmol, Vol. 27, No. 1, 2007 FIG. 1. A. At presentation, left upper lid ptosis and frontalis over-action are evident. B. Later in the day, the left upper lid ptosis has increased. FIG. 2. A. Postcontrast T1 coronal MRI shows a 22.5 mm diameter mass in the left cavernous sinus with supracavernous extension. B. Shaded surface display magnetic resonance angiography shows that the aneurysm arises from the cavernous and supraclinoid segment of the left internal carotid artery. fatigable ptosis, with palpebral fissures measuring 6 mm on the left and 10 mm on the right. Abduction, adduction, and infraduction were normal in the left eye, but supraduction was reduced to approximately one- third of the normal range. There were no pupillary abnormalities. The rest of the ophthalmologic examination was unremarkable, as was the neurologic examination. Three days later, anisocoria was first noted, with the right pupil measuring 4 mm in dim illumination and reacting briskly to light and the left pupil measuring 6.5 mm and reacting sluggishly to light. There was no relative afferent pupillary defect. MRI and magnetic resonance angiography ( MRA) showed a 22.5 mm diameter saccular aneurysm arising from the cavernous and supraclinoid segment of the left internal carotid artery ( Fig. 2). The patient was offered coiling but declined. Aneurysmal third cranial nerve palsy is usually caused by aneurysms that arise from the junction of the internal carotid artery and posterior communicating artery ( 89%) but can be caused from aneurysms located in the intracavernous internal carotid artery ( 6.2%), as found in our patient, or in the basilar artery ( 3.4%), posterior cerebral artery, or superior cerebellar artery ( 1,2). In patients with aneurysmal third cranial nerve palsy, pupillary reactions are usually affected first, followed by ptosis, and finally extraocular muscle paralysis affecting the medial, superior, and inferior rectus and oblique muscles ( 2,3). Ptosis caused by aneurysmal third cranial nerve palsy is usually not variable ( 1). The marked fluctuation in ptosis seen in our patient has been reported only rarely ( 4). It has been attributed to intermittent hyperfunction of the muscles supplied by the third cranial nerve. Coexisting inappropriate neural discharge with blockage is the presumed mechanism ( 4). The presence of fluctuating unilateral ptosis in an elderly patient with minimal extraocular muscle dysfunction and pupil- sparing does not rule out intracavernous aneurysmal compression. Sonia Attia, MD Sonia Zaouali, MD Chahira Chourabi, MD Amel Boughammoura, MD Riadh Messaoud, MD Mahbouba Frih, MD Moncef Khairallah, MD Department of Ophthalmology ( SA, SZ, RM. MK) Department of Neurology ( AB, MF) Fattouma Bourguiba University Hospital Monastir, Tunisia moncefkhairallah@ rns. tn REFERENCES 1. Lee AG, Hayman LA, Brazis, PW. The evaluation of isolated third nerve palsy revisited: an update on the evolving role of magnetic resonance, computed tomography, and catheter angiography. Surv Ophthalmol 2002; 47: 137- 5. 2. Satyarthee GD, Mahapatra AK. Unusual neuro- ophthalmic presentation of anterior communicating artery aneurysm with third nerve paresis. J Clin Neurosci 2004; 11: 776- 8. 84 © 2007 Lippincott Williams & Wilkins Letters to the Editor J Neuro- Ophthalmol, Vol. 27, No. 1, 2007 3. Glombini S, Ferraresi S, Pluchino F. Reversal of oculomotor disorders after intracranial aneurysm surgery. Acta Neurochir 1991; 112: 19- 24. 4. Dayan MR, Elston JS. Fluctuating oculomotor hyperfunction and hypofunction caused by aneurysmal compression of the third cranial nerve. Br J Ophthalmol 1999; 83: 1204. Amiodarone and Ischemic Optic Neuropathy Since the original articles ( 1,2) about the occurrence of anterior ischemic optic neuropathy ( AION) during administration of amiodarone were published in 1987, many articles and case reports of a possible causal relationship between the neuropathy and amiodarone have emerged. I have closely followed these articles and case reports. They cover about 100 cases to date and probably underreport the actual incidence. As a coauthor of the initial study ( 2), I have been concerned that the higher incidence of AION in amiodarone users than in an age- matched group of nonusers, although statistically significant ( P = 0.001) in that report, could have been due to chance alone, because most of the amiodarone users were likely to have had substantially more vascular disease. Indeed, the purpose of the initial study was to determine the efficacy of amiodarone in saving the lives of patients with serious cardiac arrhythmias. Despite amiodarone use, 26% of the 447 patients in this study group died by the time the study was published. Because of the substantial morbidity and mortality, it would be ethically impossible to repeat such a study in a similar group of patients using a control group of untreated patients. Many of these untreated patients would die of cardiac arrhythmias. The lifesaving effect of amiodarone in serious cardiac arrhythmias is thus far unsurpassed ( 3), although in recent years, implanted cardiac pacemakers have been used more often, sometimes with amiodarone supplementation. To ascribe a cause- and- effect relationship to a drug and a presumed side effect, researchers would expect to see a substantial increase in the incidence of the side effect in the treated group compared with a similar group of untreated patients or patients treated with a different agent or device. A huge increase in the incidence of AION has not been seen in amiodarone users, despite the fact that thousands of patients have taken the drug. Thus, the occurrence of AION in patients taking amiodarone might be by chance alone. None of the literature describing the so- called entity of amiodarone optic neuropathy, including the article that I cowrote ( 2), provides a scientific basis for proving a cause-and- effect relationship by means of a prospective controlled study. Look at the design of such a study, with a few assumptions. The actual incidence of optic neuropathy in patients taking amiodarone is not known. If researchers use the widely quoted figure of 1.79%, which was determined in patients who had preexisting cardiac dysrhythmias ( 2), a study would have to have a substantial number of patients in both a treated group ( about 900) and an untreated group ( well over 1,000). Also, patients would need to be observed prospectively for a sufficiently long period to determine the incidence of clinically significant side effects with only 80% power. Given these numbers, as well as the better- known rates of side effects of amiodarone on other systems, investigators would expect to see these side effects, some of which are serious and clinically significant, develop in a certain percentage of the treated patients. Among amiodarone users, 2.5% would have peripheral neuropathy, 39% ataxia, 37% staggering, 4%- 25% liver function abnormalities, and 2%- 17% pulmonary infiltrates ( some of which may be lethal). During the study, about 26% of the treated group might die of cardiac disease. Consider the control group. To be representative, the control group would have to have the same characteristics as the treatment group, including clinically significant cardiac dysrhythmias, many of which are life- threatening. If the patients need alleviation of their dysrhythmias, a technique or agent other than amiodarone would have to be used. However, that use would make the control group different from the treatment group. Investigators might expect that in the untreated group, a higher percentage of patients would die of cardiac disease- perhaps as many as 50%. Getting approval for such a " high- risk" study by an institutional review board would be highly unlikely because the study would be unethical. This study design would be the equivalent of studying patients who have insulin-dependent diabetes by treating half the patients with insulin and not giving insulin to the other half as a way to measure a difference in disease complications. Many ophthalmologists have seen patients who present with bilateral simultaneous AION. They have also seen patients in whom visual loss has occurred in one eye because of acute AION and the other eye is already pale, indicating bilateral disease that is as yet unknown to the patient. If patients with AION are evaluated soon after one eye has been affected, some optic disc swelling may be seen eventually and before the onset of visual loss in the fellow eye ( 4). A recent Israeli prospective study of 23 patients who had optic disc edema without initial visual loss ( 5) points out that optic disc edema can be present for some time in the absence of visual loss. In 64% of this study group, the edema resolved without development of AION and in a mean of 15.5 weeks. Although the four patients in the small group taking amiodarone did not have AION, this 85 J Neuro- Ophthalmol, Vol. 27, No. 1, 2007 sample size is too small to be meaningful. The findings of the study illustrate how difficult it is to delineate a clinical difference between " typical" AION and AION associated with amiodarone use. Because some clinical features in patients who have AION associated with amiodarone use have differed from those in patients with spontaneous AION ( 6,7)- a higher incidence of simultaneous bilateral AION, a less severe effect on vision, and a higher incidence in men- several researchers have concluded that there must be a cause- and-effect relationship. I agree that this is possible, but the proof is lacking. Until a study can be designed that poses no additional risk to the patients being studied and given that both a control group and a group of patients with cardiac disease would need to be studied, there is no justification to assert that a cause- and- effect relationship exists between amiodarone and AION. Nonetheless, it is prudent to advise the treating cardiologist and the patient of possible adverse effects on vision with amiodarone use. If an amiodarone user experiences a change in vision, that patient should seek immediate attention from an ophthalmologist. If disc swelling or visual loss or both occur, cessation of amiodarone treatment should be seriously considered and a switch to a different agent or a pacemaker should be made. Even so, the consequences of stopping an effective antiarrhythmic treatment such as amiodarone should be considered on a case- by- case basis, taking into account the best interests of the patient. Brian R. Younge, MD Mayo Clinic Rochester, Minnesota byounge@ mayo. edu REFERENCES 1. Gittinger JW Jr, Asdourian GK. Papillopathy caused by amiodarone. Arch Ophthalmol 1987; 105: 349- 51. 2. Feiner LA, Younge BR, Kazmier FJ, et al. Optic neuropathy and amiodarone therapy. Mayo Clin Proc 1987; 62: 702- 17. 3. Schmidt D. Amiodarone treatment and visual prognosis [ in German]. Klin Monatsbl Augenheilkd 2003; 220: 774- 86. 4. Hayreh SS. Anterior ischemic optic neuropathy. V Optic disc edema an early sign. Arch Ophthalmol 1981; 99: 1030^ 0. 5. Almog Y, Goldstein M. Visual outcome in eyes with asymptomatic optic disc edema. JNeuroophthalmol 2003; 23: 204- 7. 6. Chen D, Hedges TR. Amiodarone optic neuropathy: review. Semin Ophthalmol 2003; 18: 169- 73. 7. Macaluso DC, Shults WT, Fraunfelder FT. Features of amiodarone-induced optic neuropathy. Am J Ophthalmol 1999; 127: 610- 2. 86 © 2007 Lippincott Williams & Wilkins |