SCREENING NEONATES WITH MSSR TO SIMULTANEOUSLY PRESENTED BONE- AND AIR- CONDUCTED STIMULI

Pérez Abalo MC, Hernández MC,  Santos E, Rodríguez E, Hernández O, Torres A.

Cuban Neuroscience Center, La Habana, Cuba.

Background: With the rapid growth of universal neonatal hearing screening, the methods and technology for early detection of hearing impairments need to be continuously perfected. An important goal is to reduce the false positive rate in the initial screen due to transient conductive impairments.

Objectives: To evaluate the diagnostic efficiency and overall performance of an automatic MSSR screening device using simultaneous bone- and air- conducted stimulation.

Methods:  A sample of 24 infants (46 ears) with and without high risk factors was screened within 3 days of birth. Each infant (ear) was tested twice (in random order) with MSSR to simultaneous bone- and air-conducted stimuli and with automatic EOA (Accuscreen, Madsen). All babies (pass/fail) were followed up and re-evaluated within 1 month of age with: 1) standard MSSR and EOA; 2) Otoscopy and Impedance testing. The MSSR stimuli were two amplitude modulated (95% depth) carrier tones (500 & 2000 Hz) presented simultaneously through bone- (B71) and air- conducted (Eartone 5A) transducers. The intensities were fixed at 30 and 40 dB HL for BC and AC stimuli respectively. The pass/fail intensity criterion was previously established (100% response detectability) in control groups of 15 healthy infants.

Results: Both automatic screening devices performed adequately in the maternity ward, showing similar pass/fail results in most (77%) tested ears. The diagnostic  sensitivity and specificity rates were much better though for the MSSR (100% and 95%) than for the AOAE (50% and 83%) screening test. This was due to the MSSR correct identification of 9 of the 11 screen failures classified as ¨transient conductive impairments¨ and the detection of a sensorineural hearing loss than passed the OEA screen.

Conclusions: The automatic MSSR screening device performed adequately in the maternity ward identifying more efficiently transient and permanent impairments missed by an AOAE.

E-mail: mceciliapa@infomed.sld.cu