title: Click-evoked otoacoustic emissions recorded from untreated congenital hypothyroid newborns.
abstract: Thyroid hormone plays an important role in hearing development. Both a genetic or non-genetic hypothyroidism is often associated with congenital hearing loss. The exact incidence of hearing impairment in untreated congenital hypothyroid (CH) patients is unknown. This paper will present the results of measuring of the transient-evoked otoacoustic emissions (TEOAE) in a population of 29 newborns, who tested positive on a screening test for hypothyroidism (CH group) and in 68 well babies (control group) randomly chosen from all the newborns, classified as PASS, included in the Hearing Screening Program of the San Raffaele Hospital in Milan. TEOAE were recorded in all newborns within 1 month after birth and before beginning L-thyroxine treatment with conventional commercial instrumentation. Both temporal and time-frequency analyses of the emitted responses were conducted by means of a wavelet transform. The comparison of the characteristics of the temporal and frequency content of the responses of the two groups (CH and control) showed no statistically significant difference. No correlation was found between outer hair cell dysfunction and hypothyroidism.
authors.affiliation: Department of Biomedical Engineering, Polytechnic of Milan, Piazza Leonardo da Vinci 32, Milan, Italy. marta.parazzini@polimi.it
authors.forename: Marta
authors.initials: M
authors.lastname: Parazzini
authors.forename: Paolo
authors.initials: P
authors.lastname: Ravazzani
authors.forename: Stefania
authors.initials: S
authors.lastname: Medaglini
authors.forename: Giovanna
authors.initials: G
authors.lastname: Weber
authors.forename: Carla
authors.initials: C
authors.lastname: Fornara
authors.forename: Gabriella
authors.initials: G
authors.lastname: Tognola
authors.forename: Maria Cristina
authors.initials: MC
authors.lastname: Vigone
authors.forename: Carlo
authors.initials: C
authors.lastname: Bianchi
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Comi
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Chiumello
authors.forename: Ferdinando
authors.initials: F
authors.lastname: Grandori
mesh_terms: D000161:Acoustic Stimulation; D016022:Case-Control Studies; D003409:Congenital Hypothyroidism; D016057:Evoked Potentials, Auditory, Brain Stem; D018072:Hair Cells, Auditory, Outer / Q000503:physiopathology; D034381:Hearing Loss / Q000151:congenital / Q000209:etiology / Q000503:physiopathology; D006801:Humans; D007037:Hypothyroidism / Q000209:etiology / Q000503:physiopathology*; D007231:Infant, Newborn; D017084:Otoacoustic Emissions, Spontaneous; D013963:Thyroid Hormones / Q000172:deficiency / Q000502:physiology
chemical_list: D013963:Thyroid Hormones