[A reliable symptom in differential diagnosis of cochlear and retrocochlear neurosensory hypoacusis (study of sound lateralization in Weber's test and ultrasound)].
Sound laterality in Weber test occurs mainly in peripheral defects of the acoustic analyzer (lateral conduction or reception acoustic defects of the cochlea). In retrocochlear unilateral hypoacusis or loss of hearing, laterality in this test is absent in 80-90% of the cases (affection of the VIII nerve root, acoustic nuclei, stem and midbrain conductors). This symptom is most reliable in differentiation of cochlear with retrocochlear unilateral hypoacusis and deafness. In combination of retrocochlear hypoacusis of deafness with impaired sound conduction in the same ear, the sound in Weber test can show a paradoxical laterality in an absolutely deaf ear. This indicates that Weber test sound laterality definitely reflects changes in sound conduction. Ultrasound laterality occurs in the better hearing ear in any unilateral cochlear or retrocochlear lesions, thus complicating recognition of cochlear from retrocochlear affections. Laterality of ultrasound is a sensitive indicator of neurosensory abnormalities. Major trepanation bone defects of the parietotemporal skull did not influence sound laterality in Weber test.
Blagoveshchenskaia
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D003051:Cochlea / Q000000981:diagnostic imaging / Q000503:physiopathology*; D003937:Diagnosis, Differential; D005260:Female; D007839:Functional Laterality; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology; D006320:Hearing Tests; D006801:Humans; D008297:Male; D014463:Ultrasonography
Nadezhnyĭ simptom dlia differentsial'noĭ diagnostiki kokhlearnoĭ i retrokokhlearnoĭ neĭrosensornoĭ tugoukhosti (issledovanie lateralizatsii zvuka v opyte Vebera i ul'trazvuka).