Eye Signs in Stroke

Abstract

A large part of the central nervous system is involved in the normal functioning of the vision, and hence vision can be affected in a stroke patient. Transient visual symptoms can likewise be a harbinger of stroke and prompt rapid evaluation for the prevention of recurrent stroke. A carotid artery disease can manifest as transient monocular visual loss (TMVL), central retinal artery occlusion (CRAO), anterior ischemic optic neuropathy or ocular ischemic syndrome (OIS). Stroke posterior to the optic chiasm can cause sectoranopias, quadrantanopias, or hemianopias, which can be either congruous or incongruous. Any stroke involving the dorsal stream (occipito-parietal lobe), or ventral stream (occipito-temporal lobe) can manifest with visuospatial perception deficits. Similarly, different ocular motility abnormalities can result from a stroke affecting the cerebrum, cerebellum, or brainstem. Among these deficits, vision and perception disorders are more difficult to overcome. Clinical, experimental, and neuroimaging studies have helped us to understand the anatomical basis, physiological dysfunction, and the underlying mechanisms of these neuro-ophthalmic signs.

Keywords: Dorsal stream; neuro-ophthalmic signs; quadrantanopias; vision.

Figure 1

Algorithm for examining eye signs in a patient with stroke

Figure 2

Visual pathway from retina to occipital cortex. The visual field defects associated with damage to different parts of the visual pathway are shown

Figure 3

Alexia without agraphia localization and anatomy. (Adapted from: Alexia without Agraphia as a Manifestation of Posterior Reversible Encephalopathy Syndrome. Can J Neurol Sci. 2021 Sep; 48 (5):727-9.)[15]

Figure 4

Illustration of matching tasks in which agnostic patients depending on type of agnosia typically show deficits. (a) View-matching task: (b) Function-match task

Figure 5

A lesion circumscribed to area V4 in the inferior occipital cortex [area highlighted in red]. (5a) Loss of color vision perception in the contralateral homonymous visual field. (5b)

Figure 6

(a) Navon letter (b) lady cooking on challah. (Adapted from Prasad K, Dash D, Kumar A. Validation of the Hindi version of National Institute of Health Stroke Scale. Neurol India. 2012 Jan-Feb; 60 (1):40-4.)[23]

Figure 7

Neural pathway of horizontal eye movements. (Adapted from Alberstone CD, Benzel EC, Najm IM, Steinmetz MP, editors. Anatomic Basis of Neurologic Diagnosis. 1^st ed. New York, NY: Thieme Medical Publishers; 2009. p. 427.)[27]