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Show ORIGINAL CONTRIBUTION Migraine- Like Visual Hallucinations in Occipital Lesions of Cysticercosis Kumudini Sharma, MD, J. Wahi, MS, R. V. Phadke, MD, A. Varma, MS, and V. K. Jain, MS, MCh Four Indian patients with occipital lesions of cysticercosis presented with visual hallucinations. Neuro- ophthalmic and systemic examinations were normal in all cases except for one patient who had a partial homonymous hemianopia. Electroencephalography was normal in all cases. Neuroim-aging revealed ring- enhancing lesions in the occipital lobe typical of neurocysticercosis. In endemic regions like India, neurocysticercosis should be suspected in patients presenting with visual hallucinations, even when there are no other clinical findings. ( JNeuro- Ophthalmol 2002; 22: 82- 87) Visual hallucination is the most common feature of aura of migraine ( 1). It may appear in many forms, including the scintillating scotoma, stationary flickering white or colored lights, stars, pinwheels, rings, or triangles. The hallucination typically lasts from 5 to 30 minutes and shows a marching or build- up phenomenon. It may be followed by a throbbing headache. Visual hallucinations may also be the presenting symptoms of an occipital seizure. The cause of the seizure may be a mass lesion ( tumor, abscess, chronic granulomatous lesion, intracranial parasites, arteriovenous malformation) or may be unknown ( 1- 5). Among the intracranial parasites, cysticercosis is the most common cause of seizures in endemic regions such as India and South America. Because they have similar features, the visual hallucinations associated with occipital lobe lesions maybe confused with the visual hallucinations of migraine ( 2,3). We describe four patients who had solitary occipital lobe lesions of cysticercosis and whose clinical presentation consisted of stereotyped episodes of visual hallucinations with occasional mild headache. Departments of Neurosurgery ( Neuro- Ophthalmology) and Radiology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Luck-now, India. Address correspondence to Kumudini Sharma, MD, Associate Professor, Department of Neurosurgery ( Neuro- Ophthalmology), Sanjay Gandhi Post Graduate Institute of Medical Sciences, Raebareli Road, Lucknow 226014, India CASE REPORTS Four patients were examined in a neuro- ophthal-mology clinic complaining only of seeing bright light on the lateral side of the field of vision. In two patients, this visual symptom was followed by a mild headache. Systemic examination was normal in all cases. Neuro- ophthalmic examination was normal in three patients, including visual fields, performed on a Topcon automated perimeter using the full- field screening program. Sixteen- channel scalp electroencephalography ( EEG) with photic stimulation was normal in all cases. Computerized tomography ( CT) or magnetic resonance imaging ( MRI) disclosed enhancing lesions in the occipital lobe consistent with cysticercosis in all cases ( Figs. 1- 4). All patients were treated for cysticercosis with oral albendazole 15 mg/ kg and oral prednisolone 1 mg/ kg for 28 days. Carbamazepine was given in a dose of 10 mg/ kg for 3 years as an anticonvulsant. Here are further details on each case ( Table 1). Case 1 An 18- year- old man complained of 2- minute episodes of seeing multiple, revolving, multicolored, round lights on the right side of his visual field. The lights started laterally in the right visual field and rapidly spread across the whole field. He described similar attacks three to four times per month for the previous 2 months. He was asymptomatic between attacks and had no complaints of headache, vomiting, convulsions, tingling and numbness, weakness in any part of the body, giddiness, or loss of consciousness. Systemic examination was normal. Visual acuity, color vision, ocular motility, pupillary reactions and fundus, and visual fields were normal. EEG with photic stimulation was normal. Brain CT revealed a 7- mm ring-enhancing lesion with perifocal edema in the left occipital region suggestive of a solitary degenerating cysticercus cyst ( Fig. \ A). Once treatment was begun, the patient had no further visual hallucinations. A follow- up CT 2 months later showed resolution of the lesion ( Fig. IB). Case 2 A 20- year- old man complained of 2- minute episodes of seeing a spinning, white, round, bright light with zigzag „ 82 . DDI: 10.1097/ 01. WNO. 000QP18223.83526, BB . J Neuro- Ophthalmol. Vol. 22, No. 2,. 2Q02 , Copyright © Lippincott Williams & Wifkins. Unauthorized reproduction oftnis article is prohibited. MIGRAINE- LIKE VISUAL HALLUCINATIONS FIG. 1. Case 1. A: Enhanced axial computed tomography ( CT) shows a ring- enhancing lesion with perifocal edema in the left occipital region consistent with a degenerating cys-ticercus cyst. B: Contrast enhanced axial CT after 2 months of treatment shows resolution of cyst. JNeuro- Ophthalmol, Vol. 22, No. 2, 2002 FIG. 2. Case 2. A: Enhanced computed tomography ( CT) shows a small ring- enhancing lesion in the left medial pa-rieto- occipital region with perifocal edema extending to the occipital region. B: Enhanced CT after 2 months of treatment shows resolution of the cyst. Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. JNeuro- Ophthalmol, Vol. 22, No. 2, 2002 Sharma et al. FIG. 3. Case 3. A: T2 axial magnetic resonance imaging ( MRI) shows a degenerating cyst that is hyperintense centrally with a peripheral hypointense rim in the left occipital region anteriorly { arrow). B: T2 axial MRI 1 year after treatment shows complete resolution of the cyst. edges on the right side of his visual field. It expanded rapidly to occupy the whole visual field. The episodes had occurred twice per week for 2 months. Between attacks, he was asymptomatic. Systemic examination was normal. Neuro- ophthalmic examination was normal, including visual fields. Scalp EEG was normal. Contrast enhanced CT showed a 8- mm ring- enhancing lesion in the left medial pa-rieto- occipital region with perifocal edema extending to the occipital region Fig. 2A). He remained asymptomatic on treatment, and a repeat scan after 2 months showed resolution of the cyst ( Fig. IB). Case 3 A 24- year- old man saw multiple, brightly colored, revolving spots of light on the right side of his visual field. They spread rapidly across the whole field. He had been having identical attacks once or twice a year for 2 years, with a marked increase in frequency within recent months. Each visual episode lasted less than 3 minutes and was followed by blurred vision for another 2 minutes. He also described a heavy sensation at the back of his head during the episodes. Systemic examination was normal. Neuro-ophthalmic examination was also normal, except that visual FIG. 4. Case 4. Enhanced axial T1 magnetic resonance imaging shows a ring- enhancing lesion with perifocal edema in the anteromedial occipital region on the right consistent with a degenerating cysticercus cyst. _ o4 . „ . © 2002 Lippincott Williams & WUkins , Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. MIGRAINE- LIKE VISUAL HALLUCINATIONS JNeuro- Ophthalmol, Vol. 22, No. 2, 2002 TABLE 1. Details of cases Age/ Case gender 1 18/ male 2 20/ male 3 24/ male 4 28/ male CT, computed Visual disturbance For past 2 months, three to four 2- minute episodes of seeing revolving red, green, blue circular spots of light in right hemifield, spreading rapidly across whole field. No headache For past 2 months, once or twice weekly 2- minute episodes of seeing a spinning, white, bright, circular spot of light with zigzag edges in right hemifield. It spread immediately across the whole field. No headache For past 2 years, twice- yearly 2- minute episodes of seeing multiple red, green, blue revolving spots of light in right hemifield. Followed by blurring of vision and heaviness on the back side of head for another 2 to 3 minutes. For last 3 months, episodes had become more frequent Gave history of seeing a circular flickering light on left side of visual field for last week. Light was stationary and colorless and did not spread to the whole field. It remained for 2 minutes. He experienced such attacks twice, and they were followed by mild headache Visual fields Normal Normal Right homonymous superior quadrantanopia confined to peripheral field Normal tomography; EEG, electroencephalography; MRI Imaging 7- mm ring- enhancing lesion with perifocal oedema in left occipital region on CT ( Fig. \ A) CT showed an 8- mm left medial parieto- occipital region- enhancing lesion with perifocal edema extending to the occipital lobe ( Fig. 2A) T2 MRI showed left anterior 5 x 8 mm occipital lesion that was hyperintense centrally with peripheral hypointense rim and perifocal edema ( Fig. 3A). Tl enhanced MRI showed a 5 mm ring- enhancing lesion with perifocal edema in right anterior occipital region ( Fig. 4) Scalp EEG Normal Normal Normal Normal , magnetic resonance imaging. Treatment Albendazole 15 mg/ kg, prednisolone 1 mg/ kg for 28 days; carbamazepine 10 mg/ kg for 3 years As above As above As above Outcome After starting treatment, the visual hallucinations disappeared. Repeat CT after 2 months showed resolution of cyst ( Fig. IB) After starting treatment, the visual hallucinations disappeared. Follow- up CT scan after 2 months showed resolution of cyst ( Fig. 2B) Two visual episodes while on treatment. After increasing the dose of carbamazepine, episodes ceased. Six months after treatment, visual fields improved. Twelve months after treatment, MRI showed complete resolution of cyst ( Fig. 35) Once treated, visual episodes ceased. Patient refused follow- up imaging Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited JNeuro- Ophthalmol, Vol. 22, No. 2, 2002 Sharma et al. fields showed a right homonymous superior quadrantano-pia. Scalp EEG was normal. Brain MRI revealed an oval 5 x 8 mm lesion in the left anterior occipital region that was hyperintense centrally with a peripheral hypointense rim ( Fig. 3A). While on treatment, he had two similar visual episodes. The carbamazepine dose was increased, and he became asymptomatic. After 6 months of treatment, visual fields had improved. A follow- up MRI after 1 year showed complete resolution of the cyst ( Fig. 3B). Case 4 A 28- year- old man reported 2- minute episodes of seeing a stationary, circular, flickering light on the left side of his visual field for the last week. It did not spread across the whole field. The visual symptoms were followed by a mild headache. He had no other complaints. Systemic and neuro- ophthalmic examination were normal, including visual fields. Scalp EEG was normal, while brain MRI showed a 5- mm ring- enhancing lesion with perilesional edema in the anterior occipital region on the right side ( Fig. 4). On treatment, he did not have further visual symptoms. He refused a follow- up MRI. DISCUSSION Visual hallucinations associated with seizures differ from those of migraine in that they 1) are of short duration, 2) lack a fortification spectrum, 3) are typically invariant from one episode to another, 4) lack a march or build- up of the visual disturbance across the visual field, and 5) always occur in the same hemifield ( contralateral to the lesion) ( 1,5- 8). Sometimes they show similarities with migraine visual hallucinations in that they may be colored and may spread across the whole field. We describe four patients whose only symptom was frequent episodes of seeing single or multiple, colored or white, circular spots of light that often rotated and that first appeared laterally in a hemifield and later spread across the whole field. Each episode was identical except that the duration varied from less than 2 minutes to 3 minutes. One patient had visual hallucinations with zigzag edges, but the edges were not black and white as described in migrainous hallucinations. In the study by Panayiotopoulos ( 6) of 50 patients with migraine and 20 patients with occipital lobe seizures, he observed that ictal visual hallucinations were predominantly multicolored spherical or circular spots of light and that none consisted of black and white zigzag lines. Others ( 9,10) have reported ictal visual hallucinations with similar features. Visual hallucinations of migraine are classically in the form of scintillating scotomas with a fortification spectrum. They start as hazy spots at or near the center of fixation and enlarge across the hemifield, lasting for 5 to 30 minutes, sometimes followed by headache and vomiting. The headache is typically unilateral and throbbing. The aura and headache change sides from episode to episode ( 11). Sometimes colored lines appear behind the advancing scintillation. Stars, spots, circles, rings, or triangles with or without colors may also be seen by some patients with migraine. Queiroz et al. ( 12) studied 100 patients with migraine with aura. The common visual phenomena observed by patients were small bright dots ( 42%). Flashes of light ( 39%), blind spots ( 32%), foggy vision ( 27%), and fortification ( 20%) were also reported. Most patients had a combination of phenomena. Three of our four patients had normal visual fields in spite of a lesion in occipital lobe. This finding may be explained by the fact that the lesions were relatively small and anteriorly located. The largest lesion was present in the single patient ( Case 3) who had visual field loss. Williamson et al. ( 3) studied 25 patients with occipital lobe epilepsy and found that none of the patients with lateral occipital lesions had visual field defects. Most patients with medial occipital lobe or occipital pole lesions had visual field defects, but two patients in this group showed normal visual fields ( 3). Focal seizures are common in parenchymal neuro-cysticercosis. They may be motor or sensory, depending on the location of the cyst in the brain. Seizures occur during the degenerative phase of the cyst, as the death of the cys-ticercus releases larval antigen that can stimulate or exacerbate an inflammatory host response ( 13,14). By imaging criteria, our four patients had degenerating cysts with perilesional edema. This inflammatory edema is responsible for the ictal phenomenon, as live cysts are asymptomatic ( 13). In this study, EEG was normal in all cases. This finding suggests that scalp EEG recording is incapable of detecting such focal seizures. Williamson et al. ( 3) and Svein-bjornsdottir et al. ( 15) also observed that intracranial EEG recording was more helpful than scalp EEG recording in identifying occipital lobe seizures in their cases. This study suggests that in an endemic region like India, cysticercosis should be suspected in patients presenting with visual hallucinations, particularly if these hallucinations have distinctive clinical features such as monotonous unilaterality, brief duration, and lack of build- up phenomena. REFERENCES 1. Hupp SL, Kline LB, Corbett JJ. Visual disturbances of migraine. Surv Ophthalmol 1989; 33: 221- 36. 2. Salanova V, Andermann F, Olivier A, et al. Occipital lobe epilepsy: electroclinical manifestation, electrocorticography, cortical stimulation and outcome in 42 patients treated between 1930 and 1991: surgery of occipital lobe epilepsy. Brain 1992; 115: 1655- 80. 3. Williamson PD, Thadani VM, Darcey TM, et al. Occipital lobe epi- _ 86 . „ . © 2002 Lippincott Williams & Wilkins , Copyright © Lippincott Williams & Wilkins. 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