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Physiology of hearing and hearing loss

Question
3 out of 39
 

Stapedial reflex is mediated by: (LQ)



A V and VII nerves
B V and VIb nerves

C VII and VI nerves
D VII and VIII nerves

Ans. D VII and VIII nerves

Acoustic Reflex/Stapedial Reflex

It is based on the fact that a loud sound, 70-100 dB above the threshold of hearing of particular ear, causes bilateral contraction of the stapedial muscle which can be detected by tympanometry. This can be seen both in the stimulating ear (ipsilateral ear) and in the non stimulating ear (contralateral ear).

Note

I/L = Ipsilateral CIL = Contralateral

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Also know

Stapedial reflex can be used

As an objective method to test hearing in infants and young children

To detect malingers - as stapedial reflex is positive in people faking hearing loss

To detect

Lesion

Test response

a Cochlear pathology

B. VIII nerve lesion

C. VII nerve lesion

D. Brainstem lesion

Presence of stapedial reflex at lower intensities. 40-60 dB means recruitment is positive. cochlear pathology

It eliminates both the contralateral and ipsilateral acoustic reflex when the affected ear is stimulateD. But contralateral and ipsilateral reflex are present if normal side is stimulated

Absence of stapedial reflex in presence of normal hearing indicates lesion ofVllth nerve proximal to the nerve of stapedius

If ipsilateral reflex is present but contralateral reflex is absent, it indicates lesion in the area of crossed pathway in the brainstem

Physiology of hearing and hearing loss Flashcard List

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