2B

Acute Painful Homonymous

Hemianopsia

CASE NO. 2B

A 37-year-old female was reaching up on a high shelf for a pack of cigarettes while at her job at a convenience store when she noted the acute onset of severe neck pain. Shortly after the pain developed, she noticed difficulty in seeing. She denied any periocular pain or headaches, weakness or photophobia. She could not recall any recent prior trauma. She went home “to sleep it off” but upon awakening the next day, she felt worse; she did not think that her vision was clear to the left side in both eyes.

Ocular examination showed a visual acuity of 20/20 in each eye. There was no relative afferent pupillary defect, ptosis or anisocoria. Ocular motility was full. Fundus examination was normal. Goldmann perimetry showed an almost complete, congruous, denser superiorly left homonymous hemianopia (Fig. 2B.1).

Dr. Lee. The localization of a homonymous hemianopia is a retrochiasmal lesion on the contralateral side. The absence of other neurologic symptoms suggests occipital rather than temporal or parietal lobe localization. The Goldmann visual field demonstrates an almost complete, congruous homonymous hemianopia without macular sparing or temporal crescent sparing. The acute onset suggests a vascular event (stroke or hemorrhage) rather than a neoplastic process or other etiology. In a young patient with neck pain, the major concerns would be vertebral arterial dissection with a

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Emergencies in Neuro-Ophthalmology: A Case Based Approach

Fig. 2B.1. Goldmann perimetry showed a left almost complete homonymous hemianopia.

posterior cerebral artery infarct or thromboembolic disease. The first study should be cranial imaging. Typically in the emergency room a non-contrast CT scan of the head would be the first line imaging study followed by an MRI if the CT was negative. Diffusion weighted imaging (DWI) that demonstrates restricted diffusion of water (bright signal on DWI with matched dark signal on apparent diffusion coefficient or ADC map) in an acute stroke might be useful. Concomitant MRA of the head and neck might be useful to evaluate vascular abnormalities at the same time as the MRI. Admission to the hospital would be recommended if the patient had imaging evidence for an acute stroke.

Dr. Brazis. The patient needs urgent neuroimaging. However, if the deficit is due to an acute ischemic infarction, the patient does not satisfy the criteria for the injection of tissue plasminogen activator (tPA) because she is already beyond the therapeutic window for the use of this agent.

Course. Cranial MRI/MRA (Fig. 2B.2) showed a subacute infarction of the right PCA territory on DWI. Subsequent catheter angiography

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Acute Painful Homonymous Hemianopsia

Fig. 2B.2. Diffusion weighted imaging (DWI) on MRI shows restricted diffusion (bright signal on right with dark signal on matched apparent diffusion coefficient (ADC) map consistent with a right posterior cerebral artery (PCA) distribution infarct.

showed a subtotal occlusion of the right vertebral consistent with a dissection. The patient was admitted to the stroke service and did well on antiplatelet therapy. The visual field loss, however, did not recover.

REFERENCES

Caplan LR. (2004) Thrombolysis 2004: The good, the bad and the ugly. Rev Neurolog Dis 1:16–26.

Pessin MS, Lathi ES, Cohen MB, et al. (1987) Clinical features and mechanism of occipital infarction. Ann Neurol 21:290–299.

National Institute of Neurologic Disorders and Stroke rt-PA Stroke Study Group. (1995) Tissue plasminogen activator for acute ischemic stroke. N Engl J Med 333:1581–1587.

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