Scientific Poster

The Efficacy of Newly Designed Hemi-field Pattern Visual Evoked Potentials (VEPs) in Patients with Homonymous Hemianopsia by Jin-Ho Joo, Sang Woong Moon, South Korea

Jin-Ho Joo, Sang Woong Moon, South Korea

Purpose:
To investigate the usefulness of newly designed hemi-field pattern VEPs through the patients with homonymous hemianopsia due to brain damage.

Methods:
A retrospective review was conducted of patients with hemianopsia due to brain unilateral hemisphere damage. Full field pattern VEP and hemi-field pattern VEP with conventional system (occipito-frontal electrode placement, ISCEV standard for clinical VEP) and newly designed pattern VEP (occipito-occipital electrode placement) were examined for visual function in these patients. The main outcome measures included the latencies and amplitudes of N75, P100, and N135. And the ratio of exact lateralization were measured.

Results:
24 patients were included. 14 patients were injured in the right hemisphere and 10 patients in the left hemisphere. Conventional pattern VEP parameters did not show any statistically significant difference between ipsilateral and contralateral occipital electrode. And, paradoxical lateralization of this group was measured at 39.58% (19/48). On the other hand, some parameters of newly designed pattern VEP, P100 and N135 latency, showed a significant difference between ipsilateral and contralateral occipital electrode (P<0.05). Paradoxical lateralization of newly designed pattern VEP was measured at 14.6% (7/48). The false negative result was also statistically significantly lower than the previous test (P=0.014).

Conclusions:
The data of the present study suggest that newly designed pattern VEP with occipito-occipital electrode placement showed good lateralization in patients with hemianopsia due to brain damage hemisphere damage because of low frequency of paradoxical lateralization. This test was statistically significantly superior to the conventional pattern VEP for evaluation of hemianopsia. There was a limitation of low amplitude, but this test was well designed test for check the activity of visual cortex.

Contact Details:
Jin-Ho Joo
Kyung Hee University Hospital at Gangdong

South Korea
Cell Phone : 82-10-8901-3142
Work Phone : 82-2-440-7751
Email : mamoru23@gmail.com