title: Normative data for vestibular evoked myogenic potential in different age groups among a heterogeneous Indian population.
abstract: To establish normative data of vestibular evoked myogenic potential in different age groups among a heterogeneous Indian population. Prospective study design using a sample of convenience. Eighty five normal controls ranging between the ages 7 and 71 years were asked to provide a written signed consent for the study. Demographic characteristics of the patients were summarized using descriptive statistical methods using SPSS-17 analysing software. The outcome variable (VEMP recording) was expressed in percentiles as function of age. In all patients the stimulus which gave the best response was 95 dB (97.7 %) and 100 dB (95 %). The mean of wave latencies (p1 & n1) for 95-VEMP were, 11.2 ± 3.2 and 17.3 ± 4.7 ms on the right and 11.0 ± 2.8 and 17.0 ± 4.2 ms on the left respectively. The amplitude was 45.1 ± 54 mV on right and 46.9 ± 61.6 mV on the left. The mean of latency difference was 0.87 ms. The VEMP is a relatively simple test. The VEMP response rate was maximum in the younger age group; the optimum intensity was 95 dB. The asymmetry ratio interpretation should be done according to the age specific values.
authors.affiliation: Department of ENT, Dr SMCSI Medical College, Karakkonam, Trivandrum, 695504 Kerala India.
authors.forename: Feroze K
authors.initials: FK
authors.lastname: Khan
authors.affiliation: Audiovestibular Unit, Christian Medical College, Vellore, India.
authors.forename: Achamma
authors.initials: A
authors.lastname: Balraj
authors.affiliation: Audiovestibular Unit, Christian Medical College, Vellore, India.
authors.forename: Anjali
authors.initials: A
authors.lastname: Lepcha
keywords: EMG; Electromyography; Normative data; Sacculo-colic reflex; VEMP; Vestibular evoked myogenic potential