Organizational strategy influence on visual memory performance after stroke: cortical/subcortical and left/right hemisphere contrasts.

OBJECTIVE: To examine how organizational strategy at encoding influences visual memory performance in stroke patients.
DESIGN: Case control study.
SETTING: Postacute rehabilitation hospital. PARTICIPANTS: Stroke patients with right hemisphere damage (n = 20) versus left hemisphere damage (n = 15), and stroke patients with cortical damage (n = 11) versus subcortical damage (n = 19). MAIN OUTCOME MEASURES: Organizational strategy scores, recall performance on the Rey-Osterrieth Complex Figure (ROCF).
RESULTS: Results demonstrated significantly greater organizational impairment and less accurate copy performance (i.e., encoding of visuospatial information on the ROCF) in the right compared to the left hemisphere group, and in the cortical relative to the subcortical group. Organizational strategy and copy accuracy scores were significantly related to each other. The absolute amount of immediate and delayed recall was significantly associated with poor organizational strategy scores. However, relative to the amount of visual information originally encoded, memory performances did not differ between groups.
CONCLUSIONS: These findings suggest that visual memory impairments after stroke may be caused by a lack of organizational strategy affecting information encoding, rather than an impairment in memory storage or retrieval.