Contributions
Abstract: EP1570
Type: ePoster
Abstract Category: Pathology and pathogenesis of MS - 23 Neurophysiology
Background: Contrast vision is known to be more sensitive to detect optic neuritis (ON) in patients with multiple sclerosis (MS). Even in the absence of a history of ON or decrease of visual acuity (VA), low-contrast VA may appear to be abnormal. Thus, we investigated if VEPs using low contrast stimuli which can reflect low-contrast VA would help to identify optic nerve involvement.
Methods: We studied 9 patients with demyelinating diseases (5 male, 4 female; 15-51 years old). We included patients with demyelinating diseases which were ON, MS, or neuromyelitis optica spectrum disorders. Patients who had an episode of ON within the last 6 months were excluded to minimize the effect of optic disc swelling by acute ON. Clinical characteristics including disease duration, history of ON, number of ON episodes, and Expanded Disability Status Scale (EDSS) scores were obtained. Monocular VEPs were induced using pattern-reversal checkerboard stimuli with 100% and 10% contrast at check size of 33 minute. For 10% contrast VEPs, a prolonged absolute latency (more than 130 ms which was a limit obtained from the previous literature) or absence of the P100 component was considered abnormal.
Results: Eleven eyes with ON and seven eyes without ON were evaluated. VEP latencies were significantly increased in response to low-contrast stimuli compared with high-contrast stimuli in both groups; low-contrast and high-contrast VEPs were 136.1±19.5 ms and 115.3±14.4 ms in the eyes of ON (p=0.004) and 134.5±12.4 ms and 103.3±4.6 ms in the eyes without ON (p=0.001), respectively. Low-contrast and high-contrast VEPs were abnormal in 66.7% (n=12) and 27.8% (n=5), respectively in all eyes (n=18). Low-contrast and high-contrast VEPs were abnormal in 63.7% (n=7) and 45.5% (n=5) of ON eyes (n=11). In the eyes without ON (n=7), low-contrast VEPs detected subclinical involvement in 71.4% (n=5), but high-contrast VEP did not find any abnormalities. Thus, low-contrast VEPs proved to be more sensitive to detect optic nerve involvement than high-contrast VEPs (McNemar p=0.016) in the eyes of demyelinating diseases. Low-contrast VEPs latencies seems to be correlated with average RNFL thickness (ρ=-0.49, p=0.063), but not with VA (ρ=0.59, p=0.833).
Conclusions: In our study, we identified abnormal low-contrast VEPs in patients with demyelinating diseases, even when high-contrast VEPs is normal or no history of ON exists.
Disclosure:
Joong-Yang Cho: nothing to disclose
Soo-Hyun Park: nothing to disclose
Nam-Hee Kim: nothing to disclose
Abstract: EP1570
Type: ePoster
Abstract Category: Pathology and pathogenesis of MS - 23 Neurophysiology
Background: Contrast vision is known to be more sensitive to detect optic neuritis (ON) in patients with multiple sclerosis (MS). Even in the absence of a history of ON or decrease of visual acuity (VA), low-contrast VA may appear to be abnormal. Thus, we investigated if VEPs using low contrast stimuli which can reflect low-contrast VA would help to identify optic nerve involvement.
Methods: We studied 9 patients with demyelinating diseases (5 male, 4 female; 15-51 years old). We included patients with demyelinating diseases which were ON, MS, or neuromyelitis optica spectrum disorders. Patients who had an episode of ON within the last 6 months were excluded to minimize the effect of optic disc swelling by acute ON. Clinical characteristics including disease duration, history of ON, number of ON episodes, and Expanded Disability Status Scale (EDSS) scores were obtained. Monocular VEPs were induced using pattern-reversal checkerboard stimuli with 100% and 10% contrast at check size of 33 minute. For 10% contrast VEPs, a prolonged absolute latency (more than 130 ms which was a limit obtained from the previous literature) or absence of the P100 component was considered abnormal.
Results: Eleven eyes with ON and seven eyes without ON were evaluated. VEP latencies were significantly increased in response to low-contrast stimuli compared with high-contrast stimuli in both groups; low-contrast and high-contrast VEPs were 136.1±19.5 ms and 115.3±14.4 ms in the eyes of ON (p=0.004) and 134.5±12.4 ms and 103.3±4.6 ms in the eyes without ON (p=0.001), respectively. Low-contrast and high-contrast VEPs were abnormal in 66.7% (n=12) and 27.8% (n=5), respectively in all eyes (n=18). Low-contrast and high-contrast VEPs were abnormal in 63.7% (n=7) and 45.5% (n=5) of ON eyes (n=11). In the eyes without ON (n=7), low-contrast VEPs detected subclinical involvement in 71.4% (n=5), but high-contrast VEP did not find any abnormalities. Thus, low-contrast VEPs proved to be more sensitive to detect optic nerve involvement than high-contrast VEPs (McNemar p=0.016) in the eyes of demyelinating diseases. Low-contrast VEPs latencies seems to be correlated with average RNFL thickness (ρ=-0.49, p=0.063), but not with VA (ρ=0.59, p=0.833).
Conclusions: In our study, we identified abnormal low-contrast VEPs in patients with demyelinating diseases, even when high-contrast VEPs is normal or no history of ON exists.
Disclosure:
Joong-Yang Cho: nothing to disclose
Soo-Hyun Park: nothing to disclose
Nam-Hee Kim: nothing to disclose