Hemianopsia, a Rare Associated Finding With Multiple Sclerosis

A case report demonstrates the importance of critical thinking in eye care.

By Mohammad Rafieetary, OD, FAAO; Jessica Haynes, OD, FAAO; and Kendrick Henderson, MD

We practice at a time when increasingly widespread use of ocular imaging techniques such as optical coherence tomography (OCT) allows us to obtain vast detail of ocular structures efficiently and with minimal patient discomfort. In the complete evaluation of the visual pathway, however, these imaging strategies are limited, as they provide information only about ocular structure.

The visual process is not limited to the eye alone. Often considered more tedious and unreliable, older testing strategies of visual function, such as visual field testing, can alert us to complications along the visual pathway in those experiencing vision loss from neurogenic etiologies. Visual field testing in the case described in this article proved to be crucial for obtaining an accurate diagnosis when fundus examination, OCT imaging, and fundus autofluorescence (FAF) did not uncover sufficient ocular structural abnormalities to account for the patient’s visual complaint.

CASE REPORT

A 40-year-old white man was referred as a new patient to our clinic with a tentative diagnosis of central serous retinopathy. He reported that he had an isolated and distinct hazy area of vision in his right eye only. This area affected his central vision and extended to the right of his central vision as well. The patient reported that his symptoms had been continuously present without change for 2 weeks. The patient articulated his complaint in a detailed and clear manner.

The patient had no personal or family ocular history. His medical history included medically diagnosed anxiety, for which he was taking venlafaxine 75 mg once daily, and hypertension, which he was controlling with diet and exercise. The patient reported being an everyday smoker. He had no known drug allergies.

Best corrected visual acuity (BCVA) was 20/30+2 in the right eye and 20/20 in the left. Intraocular pressure was 14 mm Hg in the right eye and 13 mm Hg in the left. Pupillary testing, extraocular motilities, and confrontation visual fields were normal. Anterior segment evaluation showed normal cornea and lens, both free of opacities or defects in both eyes.

Examination of the posterior segment revealed healthy optic nerves without edema or pallor and with positive spontaneous venous pulsation in both eyes. Mild pigment mottling was noted in both maculae. Retinal vessels and periphery were normal.

Additional ocular imaging was obtained with OCT and FAF using the Spectralis (Heidelberg Engineering). Radially oriented OCT scans overlying the optic nerve showed normal optic nerve structure without suggestion of nerve fiber layer loss or optic nerve edema (Figure 1). OCT scans of the retinal nerve fiber layer were symmetrical between the eyes, again without suggestion of retinal nerve fiber layer damage (Figure 2).

Figure 1. The patient’s optic nerve cross section on OCT was normal.

Figure 2. Retinal nerve fiber layer analysis was also normal.

Macular OCT scans showed normal structure (Figure 3). FAF showed finely scattered mixed hypo- and hyperautofluorescent areas throughout the macula in both eyes (Figure 4). FAF demonstrated structural disruption at the level of the retinal pigment epithelium, but this did not correlate with the OCT findings or with the patient’s chief complaint.

Figure 3. Macular scans were normal.

Figure 4. FAF demonstrated disruption of the retinal pigment, epithelium, shown with mottled autofluorescent signal in the macula.

Figure 5. Visual field testing revealed central defects extending to the right of midline in both eyes. There is reduction in both visual field index and mean deviation. The defect patterns on both total and pattern deviation suggest a partial right hemianopsia.

Based on these results, a Humphrey visual field 24-2 SITA-standard test was performed to investigate a potential neurologic source of the patient’s visual complaint. The results demonstrated decreased visual field sensitivity in both eyes with decline in both mean deviation (a measurement of overall deviation from normal) and visual field index (a measurement based more heavily on the patient’s central field sensitivity). The pattern of field loss on both total deviation and pattern deviation plots suggested a partial right hemianopsia with involvement of paracentral points (Figure 5). This finding indicated possible postchiasmal damage along the left side of the visual pathway.

Armed with these findings, the patient was referred for neurologic workup. The patient’s initial neurologic workup included magnetic resonance imaging (MRI) of the brain without contrast, including diffusion-weighted imaging. Diffusion-weighted imaging revealed no evidence of acute ischemia. T2-weighted and fluid-attenuated inversion recovery, or FLAIR, sequences both showed multiple round, focal white matter lesions involving both cerebral hemispheres. The largest of these lesions, measuring 20 mm by 27 mm, was located in the left occipital lobe, correlating with the pattern of field loss on Humphrey visual field. Initial differential diagnoses for these lesions included demyelinating lesions, nonspecific vasculitis, and metastatic disease (Figures 6 and 7).

Figure 6. Initial T2-weighted MRI brain scan showed a large hyperintensity in the left occipital region.

A contrasted MRI of the brain was then performed. The large (20 mm by 27 mm) lesion described above did show peripheral nodular enhancement without mass effect. One other 5-mm enhancing lesion was seen in the right posterior supratentorial white matter. There was at least one T1-hypointense lesion suggestive of a T1 black hole. The findings were felt to be consistent with demyelinating disease—multiple sclerosis (MS)—and the larger lesion was suggestive of tumefactive MS (Figure 7).

DISCUSSION

MS, an immune-mediated demyelination disease of the central nervous system, is the leading cause of neurologic disability worldwide. It typically manifests in early adulthood as a relapsing-remitting condition, but it has a wide array of clinical presentations. Demyelinating lesions typical of MS appear on MRI as high T2 signals with ovoid shape. A single lesion is not diagnostic for MS, and neurologic imaging must be considered as part of the entirety of the patient’s clinical picture. Temporal evolution of the condition plays a key role in diagnosis, with dissemination of lesions over time and space being a criterion for diagnosis.1,2

Not all demyelinating lesions present in a typical fashion on neurologic imaging. Atypical features include lesions that are larger than 2 cm in size, have mass effect, or have a ring of edema or enhancement surrounding them. Such lesions are termed tumefactive lesions, as they can mimic a neoplasm. Biopsy of such lesions is sometimes necessary to confirm a diagnosis.3,4 This presentation is rare, and therefore there are limited data on the prognosis of patients with this type of lesion. However, it appears that these patients tend to follow a clinical course similar to those who are diagnosed with prototypical demyelinating lesions, the most common outcome being eventual diagnosis of MS.5

Figure 7. Initial T2 FLAIR MRI brain image with large left occipital hyperintensity (A). One-month follow-up T2 FLAIR MRI brain image, following intravenous methylprednisolone therapy (B). Six-month follow-up T2 FLAIR MRI brain image following 6 months of natalizumab therapy (C). Initial MRI T1 image with contrast showing large nodular enhancing lesion in the left occipital region (D). One-month follow-up MRI T1 with contrast showing some residual hypointensity but no evidence of contrast enhancement in the left occipital region (E).

Figure 8. Six-month visual field follow-up shows overall improvement.

The presentation of a partial hemianopic defect adds to the uniqueness of this case. The more common ocular complication of those who develop MS is retrobulbar optic neuritis, classically presenting with monocular central vision loss and pain on eye movement. Presentation of hemianopic defects from cerebral lesions is a much rarer finding, even though lesions frequently affect regions along the visual pathway.6

This 40-year-old man was treated initially with intravenous methylprednisolone and later with natalizumab (Tysabri; Biogen) with significant improvements in radiography, symptoms, and visual fields (Figures 7 and 8).

CONCLUSION

This case demonstrates the importance of critical thinking in eye care. Although FAF imaging demonstrated ocular structural abnormalities, those findings did not account for the specific complaint for which the patient presented. Because no oculogenic cause for the complaint could be found, visual field testing was performed in order to investigate the potential for a neurogenic etiology. This testing revealed a bilateral congruous pattern of right-sided field disruption and directed the ensuing course of care, eventually leading to an accurate diagnosis. n

1. Katdare A, Ursekar M. Systematic imaging review: multiple sclerosis. Ann Indian Acad Neurol. 2015;18(Suppl 1):S24-29.

2. McDonald WI, Compston A, Edan G, et al. Recommended diagnostic criteria for multiple sclerosis: guidelines from the international panel on the diagnosis of multiple sclerosis. Ann Neurol. 2001;50(1):121-127.

3. Qi W, Jia GE, Wang X, et al. Cerebral tumefactive demyelinating lesions. Oncol Lett. 2015;10(3):1763-1768.

4. Lucchinetti CF, Gavrilova RH, Metz I, et al. Clinical and radiographic spectrum of pathologically confirmed tumefactive multiple sclerosis. Brain. 2008;131(Pt 7):1759-1775.

5. Totaro R, Di Carmine C, Splendiani A, et al. Occurrence and long-term outcome of tumefactive demyelinating lesions in multiple sclerosis. Neurol Sci. 2016;37(7):1113-1117.

6. Hawkins K, Behrens MM. Homonymous hemianopia in multiple sclerosis. With report of bilateral case. Br J Ophthalmol. 1975;59(6):334-337.

Mohammad Rafieetary, OD, FAAO
• Consultative Optometric Physician, Charles Retina Institute, Germantown, Tennessee
mrafieetary@charlesretina.com
• Financial disclosure: consultant to Heidelberg Engineering and Genentech

Jessica Haynes, OD, FAAO
• Optometric Retina Fellow, Charles Retina Institute, Germantown, Tennessee
jhaynes@charlesretina.com
• Financial interest: none acknowledged

Kendrick Henderson, MD
• Neurologist at the Neurology Clinic, Cordova, Tennessee
khenderson@neuroclinic.org
• Financial interest: none acknowledged