Cognitive potential--P300 in patients with right hemisphere ischemic lesion.

BACKGROUND Cognitive potential--P300 assessment in individuals with right hemisphere ischemic lesion due to ischemic stroke. AIM To characterize the cognitive potential--P300 in right-handed individuals with right hemisphere ischemic lesion, and to compare such data to those obtained in normal individuals. METHOD Anamnesis, conventional audiologic assessment and cognitive potential (P300) were carried out in 17 subjects with right hemisphere lesions (research group) and in 25 normal individuals (control group), aged between 20 and 70 years. RESULTS In the qualitative analysis of the P300 data, there was no statistically significant difference between groups for the normal result. In the quantitative analysis, there was a statistically significant difference between groups in terms of P300 wave latency, with the research group presenting higher latencies. In addition, there was a trend for a statistically significant difference between the right and left ears in the research group--increased P300 wave latency in the right ear. CONCLUSION Right-handed individuals with right hemisphere lesion and normal hearing presented electrophysiological hearing results indicative of central auditory nervous system deficits. Alterations were observed in regions generating this potential (cortical and subcortical areas). Hearing difficulties were not perceived by these individuals, suggesting that this signal can probably be related to an auditory heminegligence. Further studies that evaluate the central auditory pathway of individuals with right hemisphere ischemic lesion are needed in order to better characterize the electrophysiological findings.