Correlation between vestibular and cochlear function in newborns

Abstract

This paper examines the correlation between vestibular and cochlear responses, obtained in newborns immediately after birth, for the purpose of improving procedures of early detection of possible hearing and vestibular impairment. A group of reflexes which indicate whether the vestibular apparatus is already realizing its function were tested in 100 healthy, full-term newborns from regular pregnancies, on the third day upon birth. At the same time, hearing ability in all newborns was examined by transient otoacoustic emission (TEOAE). Testing each reflex in newborns, was carried out in three attempts by trained medical staff, whereas the examiner performed instructing, observation and data recording. The obtained data were recorded by means of a digital camera, then scored and statistically and descriptively processed. For each examinee in the sample, data on gender and body size on birth, body weigh (BW), body length (BL) and head circumference (HC), were recorded. Research results indicate that 91% of babies have normal TEOAE finding bilaterally, whereas in 9% of newborns TEOAE was absent on both sides or just on one ear (bilaterally 3%, on the left side 4% and on the right side 2%). In the examined sample, maximal presence of reflexes in total (MOR+ATRV+VOR+LRIG) was established in 7% of newborns, while minimal presence was recorded just in 1%. Absence of these four reflexes together, was not established in any of the newborns. Reflexes in total were significantly more developed in babies with normal TEOAE results bilaterally, then in babies whose TEOAE findings were bilaterally or unilaterally absent (p<0.01). It was also confirmed that a significant part of variance (13.8%) about presence of reflexes in total, can be established on the basis of TEOAE results. Absence of these four reflexes together, was not established in any of the newborns. BW, BL, HC and gender of infants, do not have significant influence on the presence of reflexes in total, regardless of the fact whether it is an isolated influence of the mentioned variables, their reciprocal interaction, or their interaction with TEOAE results. Giving instructions for recognition and further monitoring of newborns with delayed maturation of vestibular pathways is of special significance in practice. This is particularly important because of the possible associated disturbance of vestibular and cochlear function.

U radu se ispituje povezanost vestibularnih i kohlearnih odgovora dobijenih kod beba neposredno po rođenju, u cilju usavršavanja procedure rane detekcije mogućeg oštećenja slušne i vestibularne funkcije. Kod stotinu zdrave, terminske novorođenčadi iz urednih trudnoća, trećeg dana po rođenju, ispitana je grupa refleksa koji ukazuju da li vestibularno čulo već ostvaruje svoju funkciju. Istovremeno, funkcija kohlee kod novorođenčadi ispitana je putem tranzijentne otoakustičke emisije (TEOAE). Testiranje refleksa kod beba izvodilo je iz tri pokušaja obučeno medicinsko osoblje, dok je ispitivač vršio instruiranje, opservaciju i beleženje podataka. Dobijeni podaci su dokumentovani digitalnom kamerom, potom bodovani, statistički i deskriptivno obrađeni. Za svakog ispitanika iz uzorka, uzeti su podaci o polu kao i o telesnoj težini (TT), telesnoj dužini (TD) i obimu glave (OG) na rođenju. Rezultati istraživanja su ukazali da je obostrana prolaznost na TEOAE testu unutar ispitanog uzorka, utvrđena kod 91% novorođenčadi. Kod 3% beba TEOAE odgovor je obostrano izostao, dok je 6% ispitanika palo TEOAE test samo sa jedne strane (4% levo i 2% desno). Maksimalna prisutnost refleksa ukupno (MOR+ATRV+VOR+LRIG) utvrđena je kod 7% novorođenčadi, dok je samo 1% ispitanika ove reflekse imalo minimalno prisutne. Odsutnost sva četiri refleksa, nije utvrđena ni kod jednog novorođenčeta. Svi refleksi su značajno prisutniji kod beba koje su imale obostrano uredan nalaz TEOAE u odnosu na bebe kod kojih TEOAE odgovora obostrano ili samo sa jedne strane nije bilo (p<0.01). Takođe, utvrđeno je da se značajan deo varijanse (13.8%) o prisutnosti refleksa ukupno, može odrediti na osnovu rezultata TEOAE testa. Pol, TT, TD i OG novorođenčadi nemaju značajan uticaj na prisutnost ispitivanih refleksa, bilo da se radi o pojedinačnom uticaju tih varijabli, o njihovoj međusobnoj interakciji ili interakciji sa rezultatima TEOAE testa. Poseban značaj za praksu je u uputstvima prema kojima bi se novorođenčad sa zakasnelom maturacijom vestibularnih puteva, izdvajala i pratila zbog mogućnosti postojanja udružene smetnje vestibularne i kohlearne funkcije.