Atlas of Ophthalmology

Homonymous Hemianopia after Posterior Cerebral Artery Territory Infarction (Colour Photography, OCT, ww-Perimetry, MRI)

Brain and Optical Pathway
Patient: 63 years of age, female, BCVA 0.8 at OD, 0.9 at OS; General Medical History: two months before, in Nov 2013 acute infarction of posterior cerebral artery, long standing arterial hypertension. Ocular Medical History: regular pseudophakia. Main Complaint: altered visual field to the left side. Purpose: to demonstrate complete visual field defect to the left side after posterior cerebral artery infarction. Methods: Colour Photography, SD-OCT (Heidelberg Engineering), ww-Perimetry (Octopus G1), MRT (Siemens, TimTrio). Colour Photography OD& OS: pale optic nerve head (OD>OS), no cupping. OCT OD& OS : minimal diffuse thinning of retinal nerve fiber layer. ww-Perimetry OD& OS : complete homonymus visual defect to the left side. MRI: in 11/2013 complete infarction of posterior cerebral artery (T1) (star). MRI-DTI: in 01/2014 decreased axonal integrity in posterior part of optic radiation (arrow). Discussion: Homonymous hemianopia is an anisotropic visual impairment with the binocular inability to see one side of the visual field. Patients with homonymous hemianopia often misperceive visual space and are not allowed to drive due to legal restrictions regarding the minimum size of the visual field. It is a common consequence of postchiasmic damage to the visual cortex due to cerebrovascular strokes on one side of the brain. Cardiac embolism and intrinsic PCA atherosclerotic disease has been shown to be the leading stroke mechanism of posterior cerebral artery (PCA) territory infarction. Lee et al. (1) reported that large artery atherosclerosis (LAA, 42.4%) was the most frequent etiology, followed by cardiogenic embolism (20%), small-vessel occlusion (20%), undetermined (18%) and other determined (3%) etiology. Finelli (2) commented, that the role of neuroimaging in acute posterior cerebral artery (PCA) territory infarction is less well appreciated compared with the anterior cerebral circulation because PCA infarction occurs less frequently and more often is associated with limited neurologic deficit not qualifying for thrombolytic therapy. However, visual field defect accompanies PCA infarction would warrant thrombolytic therapy. Literature: (1) Lee E, Kang DW, Kwon SU, Kim JS. Posterior cerebral artery infarction: diffusion-weighted MRI analysis of 205 patients. Cerebrovasc Dis. 2009;28(3):298-305. (2) Finelli PF. Neuroimaging in acute posterior cerebral artery infarction. Neurologist. 2008 May;14(3):170-80.

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