Neuroanatomy

Question 1

Thalamus station for relay of auditory information to temporal cortex

Answer 1

Medial Geniculate Body

Question 2

Conductive deafness

Answer 2

Problems of external ear (obstruction of canal, wax) or of middle ear (otitis media, otosclerosis)

Question 3

Sensorineural hearing loss (nerve deafness)

Answer 3

Disease involving the cochlea or cochlear portion of vestibulocochlear nerve

Central deafness: damage to cochlear nuclei or their central connections

Question 4

possible causes of hearing loss

Answer 4

Trauma - fracture of the petrous bone, demyelinating diseases, tumours, certain medications (streptomycin), or OCCLUSION OF THE LABRYINTHINE ARTERY.

Question 5

Weber Test

Answer 5

Tuning fork (512 Hz) applied to midline of forehead or apex of skull. Normal patient, sound conducted through skull bones, heard the SAME in each ear.
Nerve deafness(cochlea): sound best heard in NORMAL EAR
Conductive deafness: sound best heard in the ABNORMAL EAR

Question 6

Rinne Test

Answer 6

Tuning fork (512 Hz) placed against mastoid process
When sound is no longer perceived, prongs moved toward EAM, where sound is again heard. Normal (positive rinne tes)
In middle ear disease: sound not heard at eternal meautus after disappeared (negative rinne test)
Negative rinne test signifies conductive hearing loss in the ear tested. IN mild nerve deafness (cochlea or cochlear lesions) rinne test is positive, but in severe could also be negative.

Question 7

Affect on auditory path of a pontine lesion

Answer 7

Damage trapezoid body and nuclei. May diminish acuity, decrease ability to hear tones, or localise.

Question 8

Secondary auditory cortex temporal lobe damage

Answer 8

Difficulty in understanding and/or interpreting sounds (auditory agnosia)