[P300 in subjects with hearing loss].
BACKGROUND
behavioral and electrophysiological evaluations contribute to the understanding of the hearing system and to the intervention process.


OBJECTIVE
to investigate the occurrence of P300 in subjects with congenital severe to profound hearing loss, according to the variables of gender, age and hearing loss level.


METHODS
the design of this research is a descriptive transversal study. Twenty-nine subjects, 15 male and 14 female, ranging in age from 11 to 42 years, were evaluated. Inclusion criteria were: to have at least 11 years of age and no more than 45 years; to have the diagnosis of congenital severe to profound sensorineural hearing loss; to have no other disorder; and absence of central hearing loss or any other auditory conductive disorder. The first stage consisted of an auditory behavioral and physiological evaluation, including: pure tone audiometry (air and bone conduction measures), speech audiometry, SDT (Speech Detection Threshold) and functional gain measures for the subjects using hearing aids, and immittance measures--tympanometry and acoustic reflexes thresholds; transient evoked otoacoustic emissions (TEOAE); distortion product otoacoustic emissions (DPOAE). The electrophysiological evaluation was the fourth stage of the study and included: auditory brainstem response (ABR) and late latency response (P300).


RESULTS
P300 was obtained for 17 out of the 29 subjects. Mean latency and amplitude were 326.97 ms and 3.76 V, respectively. A statistical significant difference was observed for latency when considering the variable age (electrode CzA2 p < 0.003 and CzAI p < 0.02) and for amplitude when considering the variable hearing loss level (p < 0.0015).


CONCLUSIONS
P300 can be recorded in subjects with hearing loss.
Reis
Ana Cláudia Mirândola Barbosa
AC
Universidade Federal de São Paulo-Escola Paulista de Medicina. anacmbreis@yahoo.com.br
Iório
Maria Cecília Martinelli
MC
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D003430:Cross-Sectional Studies; D018913:Event-Related Potentials, P300; D016057:Evoked Potentials, Auditory, Brain Stem; D005260:Female; D006319:Hearing Loss, Sensorineural / Q000151:congenital / Q000503:physiopathology*; D006801:Humans; D008297:Male; D012720:Severity of Illness Index; D012737:Sex Factors; D013069:Speech Reception Threshold Test