NILAI NORMAL LATENSI DAN AMPLITUDO GELOMBANG VISUAL EVOKED POTENTIAL PADA USIA DEWASA

Introduction: Visual evoked potentials (VEP) is used to assess the visual pathway through the optic nerves and brain. VEP wave can be affected by physiological and non-physiological factors; some of which can be controlled, while others cannot. Thus, each VEP laboratory needs its own set of normative values. A normal VEP response to a stimulus is a positive occipital peak that occurs at a mean latency of 100ms. Most of the published normal value originated from abroad where demographical and environment condition are considered less appropriate with Indonesian population. Aims: To established normal value of adult VEP latency and amplitude in Clinical Naeurophysiology Laboratori- um, Neurology Clinic Dr. Cipto Mangunkusumo Hospital, Jakarta. Method: A cross-sectional study on healthy subject between 18 to 55 years old. The anthropometric parameters including age, height, weight, body mass index and head circumference were recorded in all the subjects. VEP was record- ed with a Caldwell Sierra Summit machine and standard silver-silver chloride disc electrodes. A VEP monitor displaying checker board was used to give the pattern reversal stimulus. The VEP parameters recorded were latencies to P100 waves. Results: P100 latencies on 110 subjects, 55 male, and 55 female upon recording at 32’ check size were 117ms in male and 119 ms in female. Upper normal limit of interocular latency difference values in recording at the same size were 10,96ms in male and 10,2ms in female. No significant differences of P100 latencies between male and female were found, but there were significant differences in amplitudes. Discussion: In our population, gender is an important factor affecting P100 amplitudes but not P100 latencies.