The most common method for evaluation of language function at bedside is confrontation naming task. This is most often done with visually presented objects such as the naming page of the NIHSS questionnaire. Visual agnosia caused by a lesion in visual processing pathways might lead to mis-localization and delay in diagnosis and care for patients with acute stroke presenting with visual disturbances. Adding verbal/tactilely presented items for naming can distinguish difficulty with naming caused by language network dysfunction from visual agnosia.

We present a 69-year-old male who presented with speech difficulty and was transferred to us for consideration of intravascular intervention for his left ICA occlusion.

After further clinical assessment of his speech, we noted that he had difficulty with naming of visually presented items specially when they needed more visual processing suggestive of visual agnosia although his spontaneous speech was fluent. He also had alexia without agraphia and right sided homonymous hemianopia. He was disoriented and had pronounced difficulty with registration and delayed recall.

Further evaluation of his CTA showed a left P2 occlusion. Brain MRI confirmed left PCA territory infarct with involvement of left occipital lobe, temporo-occipital junction, partial involvement of splenium of corpus callosum and medial temporal lobe. 

In follow up evaluation, he had difficulty with delayed recall of verbally and visually presented items. Although his hemianopia had significantly improved, he still had associative visual agnosia.

Visual agnosia due to a PCA territory infarct can mimic aphasia and therefore result in false localization which in turn might impact treatment planning in the acute setting. Augmentation of our naming assessment with using verbal/ tactile stimulation can distinguish difficulty with naming caused by language network dysfunction from visual agnosia. Writing is another critical part of the exam in distinguishing visual processing deficit from a primary language deficit.