Subject: Re: Technique can pinpoint tinnitus From: Andrew Bell <andrew.bell@xxxxxxxx> Date: Wed, 7 Oct 2009 18:43:36 +1100 List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>Matt and list: Thanks for pointer to Ceranic et al (1998), a paper which gives clear evidence that spontaneous otoacoustic emissions (SOAEs) and tinnitus are closely related. If SOAEs sound like tinnitus and behave like tinnitus, isn't it likely that they are (in some respect) tinnitus? If we are aiming to pinpoint tinnitus, then SOAEs offer the most direct tool, and Ceranic et al. support this idea. Their Table 5 shows that patients with head injury and tinnitus displayed 4.4 SOAEs per ear, compared to 1.7 with normals and 0.25 with those having head injury without tinnitus. So did the head injury damage the cochlea and generate a tinnitus sensation (via afferent pathways), or did the injury damage the brain, which responded by sending a signal to the cochlea (via efferent pathways)? As you say, that question is still very much open, but it would definitely repay some attention. Andrew. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Andrew Bell Research School of Biology (RSB) The Australian National University Canberra, ACT 0200, Australia T: +61 2 6125 5145 F: +61 2 6125 3808 andrew.bell@xxxxxxxx ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > Further, tinnitus can also be induced by head injury [6]. In > this case, it is possible that the inner ear is damaged and > this causes a peripheral type of tinnitus, which again is a > cochlear amplifier dysfunction. Until we can successfully > trace this cause and develop methods such as cellular > regeneration possibly using stem cells - we can tinker and > experiment using all sorts of procedures to quash the > problem, but they will never be as sophisticated as actually > repairing the biology. > > > > [6] @xxxxxxxx{ceranic:1998, > author = {Ceranic, B.J. and Prasher, D.K. and Raglan, E. > and Luxon, L.M.}, > title = {{Tinnitus after head injury: evidence from > otoacoustic emissions}}, > journal = {Journal of Neurology, Neurosurgery \& Psychiatry}, > year = {1998}, > volume = {65}, > pages = {523--529}, > number = {4}, > publisher = {BMJ} > } >