Presbycusis

SensorLneural hcaring loss assoc iareci wirh phys iological
aging process in rhe ear is called presbycusls. It usually
lIlani(esls at: the age of 65 years bur may do so e.a.rly if
there is hereditary pred isposition) chronic noise exposure
or generalised vascu lar disease.
r our pathological types of presbyclls is ha ve been
identified.
1. Sensory. 'Ihis is characteri sed hy degeneration of
the organ of coni, starting at the hasal coil and progressing
gr aci lJ ~~ lly to the apex. Higher frequencies are affeCTed
bur speech discrimination remains good.
2. Neural. This i,s characterised by degeneration of
the ceLis of spiral ganglion. staning at the hl1.'iprogressin.g to the apex. Neurons of hieher cwdirory p,r(h~
ways may al::.o he tl ffecr.ed. Thi$ manifests Wilh high wnc
loss bllt speech di sc rimir'Hl1'joll is poor and Ollt of propor~
tion to the pure mne loss,
3. Strial or metj)bolie. This is charac terised byatro,
phy of stria vascularis tIl ali Lufns of coch lea. In this, t.he
physical ann chemiC-II processes of energy produc tion are
atfl~i.:ted. It runs in famili es. Audiogram ls flat hut speech
discrimin,nion is goud.
4. Cochlear conduct ive. This is due ro stiffening uf
the basilar memhrnne thus affecting its movements.
Audiogram is sloping Lype.
Pat ients of prcsbycusis hiJve great difficulty in hea ring
in thc presence of background noi se though (hey may
hear well in quiet surroundings. They may complain of
speech being heard but not understood. RecrLlinnent phe~
llomenon is pOSit ive and all the sounds suddenly become
iOLOierablc when volume is raised. Tinnitus is another
horhersome rrob lem and in some it is rhe only complaint.
Patients of presbycusis can be helped by a hearing aid.
They should also have lessons in speech reading through
visual cues. C unaitmenr. uf smoking and sriln lll nn(s like
tea and coffee Ulay help to decrease tinnitus.