Promontory Stimulation test

[Guest guest]

Thanks Dora

a

[Guest guest]

The discussion of the promontory Stimulation test keeps coming up on the

forums.I did have to have the test because I was profoundly deaf.I became

curious at the mention that it is no longer done so I contacted Cochlear

Americas.Here is the response that I received from Anne Beiter

M.S.,FAAA,CC-A,SLP

Global Clinical Coordinator ..Director ,Education and Training Cochlear

Americas.

Regarding your question regarding the validity of the promontory stimulation

test or " prom Stim " :Promontory stimulation is certainly a valid test.However,due

to changes in candidacy criteria it is no longer done on a routine

basis.Originally,the prom stim test was used primarily on individuals who were

profoundly deaf,and/or long termed deafened who did not exhibit any measureable

auditory responses.For these individuals,the promontory test was used to assess

the general viability of the auditory nerve for electrical

stimulation.Today,with current implant candidacy criteria,many candidates

including those in the profoundly deaf range have some measureable hearing that

is not just vibrotactile in nature.If the person has an auditory response then

we know that the nerve has some viability,therefore a promontory stim test is

typically not indicated.

Currently,promontory stimulation is reccomended for those individuals who do not

exhibit any auditory response across the frequency range and/or for those with

specific etiologies such as bone fracture{or very severe meningitis with no

auditory responses}where we are very concerned about viability of the nerve.It

is also worth noting that some of the other early promontory stimulation

units{not Cochlears}used sine waves{voltages} as opposed to to charge balanced

square waves{in current micro amps}to generate the stimulus.Using the sine wave

devices it was possible to generate nonauditory percepts{like facial

stimulation}before reaching an auditory threshold.Thus,it was possible for

individuals tested with sine waves to have no auditory response to the prom.stim

test,since their non auditory percept thresholds was reached before the auditory

response could be measured,yet have a positive result with the implant{meaning

they could hear with the implant}This is a major reason for the " poor "

reputation of the prom .stim test.However ,the bottom line is: with an

appropriate stimulus this is a valid test.It is just not needed as much as it

used to be given the expansion of candidacy criteria.

Dora Weber

Nucleus Volunteer Advocate

dora_weber@...

Bilateral

N22-96

N24C-01

Cochlear Otosclerosis