Abnormalities of the Neonatal Ear: Otoscopic Observations, Histologic Observations, and a Model for Contamination of the Middle Ear by Cellular Contents of Amniotic Fluid

Abstract

It is unknown whether childhood ear disease could be present long before symptoms provoke an initial otoscopic examination. A newborn middle ear might or might not start in a pristine, privileged state. The clinician evaluating later infant and childhood ear disease is often unaware of the status of a patient's ear from the neonatal period, the earliest time at which the tympanic membrane can be evaluated. Adding to the physician's handicap, normative otoscopic and histologic data on the neonatal ear are incomplete. In order to test the hypothesis that disease in the neonatal middle ear may be more common than is generally appreciated, the population of critically ill neonates was selected for study since this group can provide both clinical as well as histologic data. This manuscript is divided into three parts. Clinically, otoscopic observations were analyzed on infants in an intensive care unit. Histologically, neonatal temporal bones were studied for normal anatomy and pathology of the middle ear and antrum. Experimentally, an animal study was performed to evaluate the potential effect of amniotic fluid cellular contents aspirated into the middle ear. I. Clinical Otoscopic Observations. Daily otoscopic examination was conducted on 44 neonates in an intensive care unit. Specific parameters of the otoscopic examination were evaluated to compare with the normal, translucent tympanic membrane of the older child. The otoscopic appearance was found to be abnormal in 97. 7% of neonatal ears. Of the otoscopic parameters evaluated, right ears averaged 2.6 abnormalities and left ears averaged 2.5 otoscopic abnormalities. The otoscopic appearance of the neonate in the neonatal intensive care unit is nearly universally abnormal. II. Temporal Bone Histologic Observations. One hundred eleven temporal bones from 56 neonates were collected for histologic study by light microscopy. Mesenchyme filling more than 60% of the middle ear space was found in 13 bones. Amniotic fluid cellular content was detected in 90 bones. Purulent otitis media was detected in 24 bones. Varying amounts of blood were found in the middle ear space of 34 bones. Only 7 of the bones had no significant middle ear abnormality. It is concluded that in the critically ill neonate, the middle ear and antrum usually contain cellular or fluid material, often in significant volume, that would not be considered normal in the older patient. III. An Animal Model Simulating Contamination of the Middle Ear by Cellular Contents of Amniotic Fluid. In human neonatal ears the histologic residue of refluxed amniotic fluid, keratinized epithelial cells and lanugo hair, initiates a foreign‐body giant‐cell reaction with granulation tissue formation. It was hypothesized that this residue might not be evacuated easily and potentially could persist as an inflammatory nidus. An animal model· was designed to determine if the human findings could be reproduced and to analyze the host reaction over 2 months. An aliquot of autologous, sterilized hair and keratinized epithelial cells...

Recém-nascidos gerados por mães com alto risco gestacional: estudo das emissões otoacústicas produtos de distorção e do comportamento auditivo

“…Podemos atribuir o elevado número de Falha na primeira etapa, na EOAPD a dois fatores: o grupos de RN prematuros, que fazem parte do GBI, são mais vulneráveis a afecções de orelha média, retardo na maturação coclear e na mielinização das vias auditivas 10,18,20,21,22,23 . Mesmo tomando-se o cuidado de não realizar a avaliação audiológica antes da 37ª semana de idade corrigida, não podemos deixar de considerar essa possibilidade.…”

“…Mesmo tomando-se o cuidado de não realizar a avaliação audiológica antes da 37ª semana de idade corrigida, não podemos deixar de considerar essa possibilidade. O segundo fator é a presença de vérnix, resíduos, descamação epitelial no MAE, alterações nas membranas timpânicas, alterações de orelha média, não absorção do líquido amniótico, oclusão parcial ou total do MAE por pequenas porções de resíduos até aproximadamente o sétimo dia de vida do RN 10,21,22,23 . Estes fatores podem ocasionar redução na intensidade ou abolição do sinal sonoro no MAE.…”

Wideband absorbance measures in neonates and young infants

“…Temporal bone studies have demonstrated that the condition of the middle ear in neonates is seldom pristine (Benner, 1940;Buch & Jorgensen, 1964;deSa, 1973deSa, , 1983Hemsath, 1936) with MEE present in up to 50% of ears (deSa, 1973;Eavey, 1993). The middle ear and antrum of a neonate have been reported to contain some amniotic fluid or residual mesenchyme and its cellular content.…”

“…have pointed out that otitis media with effusion may contribute up to 67% of the false positive newborn hearing screens. Amniotic fluid contents aspirated into the middle ear have been reported to contribute to conductive hearing loss in neonates (deSa, 1977;Eavey, 1993;Northrop et al, 1999).…”

“…Identification of MEE using otoscopy is not a reliable method in neonates due to difficulties in visualising and interpreting the tympanic membrane Zarnoch and Balkany, 1978;Eavey, 1993;. Although otomicroscopy is reported to improve the accuracy of diagnosing otitis media in children (Young et al, 2009;Lee, 2010), it needs to be performed by specialist otolaryngologists and often requires sedation or anaesthetisation of the child.…”