Visual memory deficits following uncomplicated intracranial surgery for aneurysm

Seventeen aneurysm patients demonstrating good recoveries following intracranial surgery for aneurysm were assessed with 17 neurosurgical control subjects on a battery of neuropsychological measures. The results of this study suggest that at least in the short-term, subtle cognitive deficits are part of the clinical picture following intracranial surgery for aneurysm. This is the case with aneurysm patients who demonstrate a relatively uncomplicated recovery with no obvious residual neurological deficits. The aneurysm group performed worse on all measures. The Rey Visual Design Learning Test was able to significantly differentiate between the groups with the aneurysm patients exhibiting a poor learning curve relative to controls. In addition, the Weschler Memory Scale - Revised Visual Paired Associates I and the Visual Reproduction II Subtests were able to discriminate between the groups. With the Rey Auditory Verbal Learning Test, only the first recall condition following an intervening task was significantly sensitive to differences between the groups. The results suggest that visual learning is more sensitive to subtle and mild brain impairment. A supraspan test of visual learning seems particularly sensitive. The results suggest that the aneurysm patients have a relatively normal immediate memory span for visual material yet find it difficult to exceed this span. These problems with the aquisition and retention of this material are made obvious under recognition and recall conditions. Statistical analyses indicate moderate to high correlations between the verbal and visual learning tests. Limitations of the present study are also discussed. These findings have significant clinical implications and form the foundation for future research.