Sudden Hearing loss

Sudden Hearing loss
Ir is deft ned <.I~ st'nsorinemal hearing \o::;s that has devel,
oped over a period of hours or a few d8Y::i. Loss may he
parrh)1 or co mplete:. Mos rly ir is unilateral. It may be
accompani_ed by tinnitus or remporary spell of ve rtigo.
Aetiology. Most ofren the cause of sudden deafness
remains obscure, in which Ci.-'lSC it is called rhe idiopathic
vari e ty. In such cases, three aetiological fac((Jr~ are
consitkrccl- viral, vascular or the rupture of cochlear
membranes. SponG.H H':ouS perilymph fistu lae may /()rm
in the oval or round winJow. Other aetiological factors
which C(luse sudden deafness rind lIllist be excluded 8re
listed b~ low. Remember [he mnf':monic "In The Very Em
Too No Mfljor Patho logy)).
1.
2.
3.
Infections. Mumps, herpes zoster, meningitis,
enc~phalitis) <;yphilis, otitis media.
Trauma. Heacf injury, ear operations, no ise trauma,
ba rotr~uma, spontaneous ruprure of cochlear
me mbran<::~.
Vascu1ar. Hacmonha~~e (leuk8e rnia) , embo lism Or
rhrombos is of l<.Iby rinthinc or coc hlr.,u artery or rh~ i r
vrlsospasm. They may be a::.~ciJ.ted with dmhr:tcs,
hypencnsion, polyeythaemi8, macroglobinacmia or
sickle edl (fair.
4. Ear (otologic). Menicr~'s disease, Cogan's syndrome.
large vesnhular aquecfuct.
5. Toxic. Ototoxic drugs, inscct1cldes.
6. N eoplastic. Acoustic neuroma. Ml"t:ingle, carcino mllrolls ncuropal hy.
7. Miscellaneous. Multiple sclerosis, h ypothyroidlsm,
sarcoidosis.
8. Psychogenic.
Managemex1t. As far as possible, the aetio loJ;.:Y or."Iud,
den hearing loss shollid be Ji, covered by del " .Jed histO ry,
physical examinnrion and laboratory In vcstigatiLlP:". The
invesrigations l11r1y include ()udiomeuy, vestibular tes rs,
imaging studies of tL'mporal bonc:s , sedilDentation r8te,
rests for syphilis, di(lbe tc:s, h ypothyroidism , blood disor·
dets and lipid ptofiles. Some cases m(yrnpanotomy whcre perilymph fistula is st rongly sus'
pecreJ . Where the cause stH! remains obsc ure, treatment
lS empirical and conslsts of:
1. n ed rcst.
2. Steroid therapy. Prednisolone 40--60 mg in " single
mo rning dose for one wet!k anJ then raileJ off in
II period of 3 weeks. Stero ids ate anti,inflamlDatory
and re lieve ceduna. They have been found usef,J!
in iJiopathic sllJJcn hearing loss of moderate
Jegree .
3. Inhalation of carbogen (5% CO2 + 95% 0,) .
It increases cochlear hlood flow and improves
oxygenation.
4. Vasodilator drugs.
5. Low molecular weight dextran. It decrea,es blood
viscosiTY. Ir is conrra,indlCatecl in cardiac failure and
bleedlng disorders.
6. Hyperbaric oxygen therapy. G iven in the firs(
month of o nset of hearing loss, some benefits h~ve
he en claimed.
Prognosis. Fortuna tely, ahout half rhe pa(iems of idiopathic
sen~orineura l hearing loss recover spomaneously
within 15 cla)ls. Chances of recovery L month. Severe heming loss ;:Jnn rhal associated with vcr ~
tigo ha v(~ poor prognosis. Younger patient'S- below 40 and
those with mcx1erate losses have better prugnosis.