Such a possibility may seem inconsistent, because tinnitus is a sound, not a movement. However, movements of the tympano-ossicular chain are normally caused by sound. Thus, it would seem logical to us that illusory
movements of the same chain generated by abnormal fusimotor activity could be interpreted as sounds by the brain. It may seem paradoxical that we detected brain anomalies in AAT subjects only with “target” stimuli. We hypothesized that if the dysfunction is related to fine dysregulation of the acoustic reflex, a reflex activity such as found in “oddball task” (muscular Inhibitors,research,lifescience,medical responses when hearing targets) could reveal this type of dysfunction. It would be logical that the dysfunction as to reach a certain level to make the illusory percept clearly perceived (i.e., from occasional perception to permanent perception). In our study, subjects with AAT sequelae were nonclinical tinnitus subjects, frequent/permanent
tinnitus subjects had no severe handicap according to TRQ scores Inhibitors,research,lifescience,medical and consequently it might explain a nonmassive cortical overactivity in Broadman area 43 and 43/40, if it relates to tinnitus. Possibly, recordings of very fine parameters of acoustic reflex or Eustachian tube function should be of interest to support a middle ear hypothesis. In any case, direct experiments are clearly needed to test, for instance, whether specific vibrations applied to tendons of middle-ear Inhibitors,research,lifescience,medical muscle
do generate tinnitus and which of the muscles, the stapedius, the tensor tympani, or both are involved in the illusory percept. If confirmed, the identification Inhibitors,research,lifescience,medical of a proprioceptive origin for tinnitus could open a new field of therapeutic approaches to this distressing pathology. Furthermore, in the treatments of tinnitus, it could raised Inhibitors,research,lifescience,medical up the problem of middle-ear implants and their impacts on middle-ear muscle spindles activities. Depending on the location and the constraint applied to each of the middle-ear muscles, the illusory percept would be modified. Conclusion Our results actually illustrated the neuronal correlates DNA ligase of the hyperreactivity to auditory modality associated with AAT, and suggested associated sensorimotor anomalies affecting nonauditory pathways. Interestingly, our data also indicated abnormal overactivity in a brain region that corresponds to middle ear proprioception. We propose further investigations in this brain area because our results might suggest a model in which AAT tinnitus could arise as a proprioceptive learn more illusion, associated with (or caused by) widespread emotional and somatosensory dysfunctions. Acknowledgments We thank Dr Greg O’Beirne for comments on the English manuscript and Alain Roux, Denis Preté, and Alexandre Krainik for their helpful technical assistance. This study was supported by a grant from the French government (DGA/PEA 010809/project no. 05Co002-05).