Visual perceptual consequences of stroke.

PURPOSE: Perceptual consequences of stroke include agnosia, alexia, dyschromatopsia, inattention, and hallucinations. Our aim was to evaluate these perceptual consequences in terms of prevalence after stroke.
METHODS: Prospective multicenter cohort trial involving 14 recruiting centers (Vision in Stroke [VIS] group). Standardized referral and investigation protocol used by local investigators. Data presented from the first year of data collection, May 2006 to April 2007. Information obtained on visual acuity, ocular alignment and motility, visual field, visual inattention, and visual cognition/perception.
RESULTS: One hundred seventy-eight patients excluded (49% male, 51% female) mainly due to inability to consent because of cognitive difficulties. Three hundred twenty-three patients recruited (59% male, 41% female). Mean age at onset of stroke of 69 years (range 1-92). Median duration from onset to vision assessment of 22 days (range 0-2543 days). Type of stroke was an infarct in 79.5% and hemorrhagic in 20.5%. Six percent had had a previous stroke. Laterality of stroke was right sided in 48%, left sided in 40%, and bilateral in the remainder. Eight percent of patients had normal visual status; 68.4% had eye movement impairment, 46.1% had visual field impairment, and 25.1% had low vision; and 20.5% had perceptual difficulties. Of these, 14.2% had inattention, 1.3% had difficulty judging depth and distance, 0.3% had color detection problems, 2.5% complained of hallucinations, and 2.2% of agnosia.
CONCLUSIONS: A substantial proportion (92%) of patients referred with suspected visual difficulty had visual impairment. One fifth of patients referred had perceptual consequences to their stroke relating to inattention and cortical visual processing impairment.