Background: Frequent oulomotricity problems with orthoptic testing were reported in patients with... more Background: Frequent oulomotricity problems with orthoptic testing were reported in patients with tinnitus. This study examines with objective recordings vergence eye movements in patients with somatic tinnitus patients with ability to modify their subjective tinnitus percept by various movements, such as jaw, neck, eye movements or skin pressure.
ObjectiveSmooth pursuit (SP), optokinetic nystagmus (OKN) and fixation were investigated in five ... more ObjectiveSmooth pursuit (SP), optokinetic nystagmus (OKN) and fixation were investigated in five subjects with somatic tinnitus modulated by eye movements, jaw or neck.
During the past decade, a large amount of work on transcranial magnetic stimulation (TMS) has bee... more During the past decade, a large amount of work on transcranial magnetic stimulation (TMS) has been performed, including the development of new paradigms of stimulation, the integration of imaging data, and the coupling of TMS techniques with electroencephalography or neuroimaging. These accumulating data being difficult to synthesize, several French scientific societies commissioned a group of experts to conduct a comprehensive review of the literature on TMS. This text contains all the consensual findings of the expert group on the mechanisms of action, safety rules and indications of TMS, including repetitive TMS (rTMS). TMS sessions have been conducted in thousands of healthy subjects or patients with various neurological or psychiatric diseases, allowing a better assessment of risks associated with this technique. The number of reported side effects is extremely low, the most serious complication being the occurrence of seizures. In most reported seizures, the stimulation parame...
Subjective (non-recordable) tinnitus is the conscious perception of a phantom sound, and a very f... more Subjective (non-recordable) tinnitus is the conscious perception of a phantom sound, and a very frequent, sometimes disabling, condition. Even if subjective tinnitus is often related to peripheral hearing loss, neurophysiological and functional imaging studies provide increasing evidence for an involvement both auditory and non-auditory central nervous pathways in the generation of tinnitus and related distress. Repetitive transcranial magnetic stimulation (rTMS)
Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive method used to induce elect... more Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive method used to induce electrical current in the brain through impulses of strong magnetic fields applied externally. The technique can relieve tinnitus by modulating the excitability of neurons in the auditory cortex to decrease the hyperexcitability that is associated with generating the neural activity that causes some form of tinnitus. This chapter will review clinical studies using rTMS for the treatment of tinnitus.
Subjective tinnitus (ST) is a frequent but poorly understood medical condition. Recent studies de... more Subjective tinnitus (ST) is a frequent but poorly understood medical condition. Recent studies demonstrated abnormalities in several types of eye movements (smooth pursuit, optokinetic nystagmus, fixation, and vergence) in ST patients. The present study investigates horizontal and vertical saccades in patients with tinnitus lateralized predominantly to the left or to the right side. Compared to left sided ST, tinnitus perceived on the right side impaired almost all the parameters of saccades (latency, amplitude, velocity, etc.) and noticeably the upward saccades. Relative to controls, saccades from both groups were more dysmetric and were characterized by increased saccade disconjugacy (i.e., poor binocular coordination). Although the precise mechanisms linking ST and saccadic control remain unexplained, these data suggest that ST can lead to detrimental auditory, visuomotor, and perhaps vestibular interactions.
Tinnitus is a common auditory symptom that interferes with activities of daily living and is ofte... more Tinnitus is a common auditory symptom that interferes with activities of daily living and is often associated with anxiety and depression. This study included consecutive patients with chronic intense tinnitus for more than six months who were treated with Tinnitus Retraining Therapy (TRT), a cognitive-behavioral therapy, after previous treatment failed and after a clinical evaluation based on standardized questionnaires, including the Tinnitus Handicap Questionnaire (THQ). One year after the end of the TRT, the treatment was evaluated by the same standardized questionnaires. This prospective study included 96 consecutive patients (49 women, 47 men, mean age: 48 years). Tinnitus improved significantly in 75%, where significant improvement was defined as a final THQ score of less than 500 after CBT. This improvement varied according to initial THQ scores and was seen in: all patients with moderate (THQ<500), 70.3% of the patients with intermediate (500<THQ>1001), and 34.8% o...
Tinnitus - the perception of sound in one or both ears or in the head when no external sound is p... more Tinnitus - the perception of sound in one or both ears or in the head when no external sound is present - can be disabling and is especially difficult to treat. Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive technique for activating or inactivating specific areas of the cortex. The aim of this study was to assess the feasibility of magnetic neurostimulation of the primary and secondary auditory cortex in the treatment of disabling chronic tinnitus. Thirteen patients with tinnitus refractory to several conventional treatments underwent transcranial magnetic stimulation guided by functional magnetic resonance imaging (fMRI). We compared two types of stimulation of targets in the auditory cortex, identified by fMRI: 3-second pulses at high frequency (10 Hz) and 20-minute stimulations at a lower frequency (1 Hz). Brief high-frequency pulses of cortical magnetic stimulation (10 Hz) were not effective. On the other hand, prolonged low frequency (1 Hz) stimulation was...
Tinnitus is a considered to be an auditory phantom phenomenon, a persistent conscious percept of ... more Tinnitus is a considered to be an auditory phantom phenomenon, a persistent conscious percept of a salient memory trace, externally attributed, in the absence of a sound source. It is perceived as a phenomenological unified coherent percept, binding multiple separable clinical characteristics, such as its loudness, the sidedness, the type (pure tone, noise), the associated distress and so on. A theoretical pathophysiological framework capable of explaining all these aspects in one model is highly needed. The model must incorporate both the deafferentation based neurophysiological models and the dysfunctional noise canceling model, and propose a &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;tinnitus core&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; subnetwork. The tinnitus core can be defined as the minimal set of brain areas that needs to be jointly activated (=subnetwork) for tinnitus to be consciously perceived, devoid of its affective components. The brain areas involved in the other separable characteristics of tinnitus can be retrieved by studies on spontaneous resting state magnetic and electrical activity in people with tinnitus, evaluated for the specific aspect investigated and controlled for other factors. By combining these functional imaging studies with neuromodulation techniques some of the correlations are turned into causal relationships. Thereof, a heuristic pathophysiological framework is constructed, integrating the tinnitus perceptual core with the other tinnitus related aspects. This phenomenological unified percept of tinnitus can be considered an emergent property of multiple, parallel, dynamically changing and partially overlapping subnetworks, each with a specific spontaneous oscillatory pattern and functional connectivity signature. Communication between these different subnetworks is proposed to occur at hubs, brain areas that are involved in multiple subnetworks simultaneously. These hubs can take part in each separable subnetwork at different frequencies. Communication between the subnetworks is proposed to occur at discrete oscillatory frequencies. As such, the brain uses multiple nonspecific networks in parallel, each with their own oscillatory signature, that adapt to the context to construct a unified percept possibly by synchronized activation integrated at hubs at discrete oscillatory frequencies.
Repeated transcranial magnetic stimulation (rTMS) of auditory cortex has been proposed to treat r... more Repeated transcranial magnetic stimulation (rTMS) of auditory cortex has been proposed to treat refractory chronic tinnitus, but the involved mechanisms of action remain largely unknown. The purpose of this pilot study was to evaluate the impact of rTMS on auditory cortex activity in a series of tinnitus patients, using for the first time both functional magnetic resonance imaging (fMRI) of the brain and auditory evoked potentials (AEPs). In six patients with chronic, lateralized refractory tinnitus, we performed five sessions of neuronavigated rTMS delivered at 1Hz over the secondary auditory cortex (defined on morphological MRI), contralateral to tinnitus side. The effects of rTMS were assessed on clinical scales, fMRI, and AEPs (N1 and P2 components). The clinical impact of rTMS on tinnitus was good for three patients (25-50% improvement of tinnitus severity compared to baseline), moderate for two patients (15% improvement), and null for one patient who had the most severe tinnitus at baseline. The changes induced by rTMS on fMRI data varied with the baseline level of auditory cortex activation before rTMS. This baseline level of activation was itself related to the severity of tinnitus. Thus, cortical stimulation increased auditory cortex activation in patients who had less severe tinnitus and low level of activation before rTMS, whereas it decreased auditory cortex activation in patients who had more severe tinnitus and higher level of activation before rTMS. Regarding AEPs, rTMS decreased N1 amplitude in all patients, except in the patient who had the most severe tinnitus at baseline and showed no improvement after rTMS. Conversely, P2 amplitude decreased after rTMS only in patients with severe tinnitus, at least for auditory stimulation contralateral to tinnitus, but increased in patients with less severe tinnitus. The changes produced by rTMS in auditory cortex activity, as assessed by fMRI and AEPs, appeared to depend on a process of disease-related homeostatic cortical plasticity, regardless of the therapeutic impact of rTMS on tinnitus.
Tinnitus affects 10% of the population, its pathophysiology remains incompletely understood, and ... more Tinnitus affects 10% of the population, its pathophysiology remains incompletely understood, and treatment is elusive. Functional imaging has demonstrated a relationship between the intensity of tinnitus and the degree of reorganization in the auditory cortex. Experimental studies have further shown that tinnitus is associated with synchronized hyperactivity in the auditory cortex. Therefore, targeted modulation of auditory cortex has been proposed as a new therapeutic approach for chronic tinnitus.
Background: Many patients show modulation of tinnitus by gaze, jaw or neck movements, reflecting ... more Background: Many patients show modulation of tinnitus by gaze, jaw or neck movements, reflecting abnormal sensorimotor integration, and interaction between various inputs. Postural control is based on multi-sensory integration (visual, vestibular, somatosensory, and oculomotor) and indeed there is now evidence that posture can also be influenced by sound. Perhaps tinnitus influences posture similarly to external sound. This study examines the quality of postural performance in quiet stance in patients with modulated tinnitus. Methods: Twenty-three patients with highly modulated tinnitus were selected in the ENT service. Twelve reported exclusively or predominately left tinnitus, eight right, and three bilateral. Eighteen control subjects were also tested. Subjects were asked to fixate a target at 40 cm for 51 s; posturography was performed with the platform (Technoconcept, 40 Hz) for both the eyes open and eyes closed conditions. Results: For both conditions, tinnitus subjects showed abnormally high lateral body sway (SDx). This was corroborated by fast Fourrier Transformation (FFTx) and wavelet analysis. For patients with left tinnitus only, medio-lateral sway increased significantly when looking away from the center. Conclusion: Similarly to external sound stimulation, tinnitus could influence lateral sway by activating attention shift, and perhaps vestibular responses. Poor integration of sensorimotor signals is another possibility. Such abnormalities would be accentuated in left tinnitus because of the importance of the right cerebral cortex in processing both auditorytinnitus eye position and attention.
Tinnitus affects 10% of the population, its pathophysiology remains incompletely understood, and ... more Tinnitus affects 10% of the population, its pathophysiology remains incompletely understood, and treatment is elusive. Functional imaging has demonstrated a relationship between the intensity of tinnitus and the degree of reorganization in the auditory cortex. Experimental studies have further shown that tinnitus is associated with synchronized hyperactivity in the auditory cortex. Therefore, targeted modulation of auditory cortex has been proposed as a new therapeutic approach for chronic tinnitus.
This study was designed to investigate methods to help patients suffering from unilateral tinnitu... more This study was designed to investigate methods to help patients suffering from unilateral tinnitus synthesizing an auditory replica of their tinnitus. Two semi-automatic methods (A and B) derived from the auditory threshold of the patient and a method (C) combining a pure tone and a narrow band-pass noise centred on an adjustable frequency were devised and rated on their likeness over two test sessions. A third test evaluated the stability over time of the synthesized tinnitus replica built with method C, and its proneness to merge with the patient&amp;amp;#39;s tinnitus. Patients were then asked to try and control the lateralisation of this single percept through the adjustment of the tinnitus replica level. The first two tests showed that seven out of ten patients chose the tinnitus replica built with method C as their preferred one. The third test, performed on twelve patients, revealed pitch tuning was rather stable over a week interval. It showed that eight patients were able to consistently match the central frequency of the synthesized tinnitus (presented to the contralateral ear) to their own tinnitus, which leaded to a unique tinnitus percept. The lateralisation displacement was consistent across patients and revealed an average range of 29dB to obtain a full lateral shift from the ipsilateral to the contralateral side. Although spectrally simpler than the semi-automatic methods, method C could replicate patients&amp;amp;#39; tinnitus, to some extent. When a unique percept between synthesized tinnitus and patients&amp;amp;#39; tinnitus arose, lateralisation of this percept was achieved.
Presse médicale (Paris, France : 1983), Jan 13, 2002
A FREQUENTLY MISUNDERSTOOD AFFECTION: Because of its high prevalence and the considerable alterat... more A FREQUENTLY MISUNDERSTOOD AFFECTION: Because of its high prevalence and the considerable alteration it often provokes in quality of life, tinnitus aurium is an important public health problem. Current treatment of tinnitus aurium is limited by the lack of knowledge of the physiopathological processes that generate it. Analysis of the data in the literature and our recent works suggests that external ciliated cells of the cochlea are probably not a major source of tinnitus, but an important role is attributed to lateral efferent innervation and glutamatergic synapses situated beneath the internal ciliated cells. Experimental models of tinnitus are presently being developed in order to test these hypotheses, and pharmacological clinical trials should be set-up during the year to come, in order to apply these fundamental results to humans.
Background: Frequent oulomotricity problems with orthoptic testing were reported in patients with... more Background: Frequent oulomotricity problems with orthoptic testing were reported in patients with tinnitus. This study examines with objective recordings vergence eye movements in patients with somatic tinnitus patients with ability to modify their subjective tinnitus percept by various movements, such as jaw, neck, eye movements or skin pressure.
ObjectiveSmooth pursuit (SP), optokinetic nystagmus (OKN) and fixation were investigated in five ... more ObjectiveSmooth pursuit (SP), optokinetic nystagmus (OKN) and fixation were investigated in five subjects with somatic tinnitus modulated by eye movements, jaw or neck.
During the past decade, a large amount of work on transcranial magnetic stimulation (TMS) has bee... more During the past decade, a large amount of work on transcranial magnetic stimulation (TMS) has been performed, including the development of new paradigms of stimulation, the integration of imaging data, and the coupling of TMS techniques with electroencephalography or neuroimaging. These accumulating data being difficult to synthesize, several French scientific societies commissioned a group of experts to conduct a comprehensive review of the literature on TMS. This text contains all the consensual findings of the expert group on the mechanisms of action, safety rules and indications of TMS, including repetitive TMS (rTMS). TMS sessions have been conducted in thousands of healthy subjects or patients with various neurological or psychiatric diseases, allowing a better assessment of risks associated with this technique. The number of reported side effects is extremely low, the most serious complication being the occurrence of seizures. In most reported seizures, the stimulation parame...
Subjective (non-recordable) tinnitus is the conscious perception of a phantom sound, and a very f... more Subjective (non-recordable) tinnitus is the conscious perception of a phantom sound, and a very frequent, sometimes disabling, condition. Even if subjective tinnitus is often related to peripheral hearing loss, neurophysiological and functional imaging studies provide increasing evidence for an involvement both auditory and non-auditory central nervous pathways in the generation of tinnitus and related distress. Repetitive transcranial magnetic stimulation (rTMS)
Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive method used to induce elect... more Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive method used to induce electrical current in the brain through impulses of strong magnetic fields applied externally. The technique can relieve tinnitus by modulating the excitability of neurons in the auditory cortex to decrease the hyperexcitability that is associated with generating the neural activity that causes some form of tinnitus. This chapter will review clinical studies using rTMS for the treatment of tinnitus.
Subjective tinnitus (ST) is a frequent but poorly understood medical condition. Recent studies de... more Subjective tinnitus (ST) is a frequent but poorly understood medical condition. Recent studies demonstrated abnormalities in several types of eye movements (smooth pursuit, optokinetic nystagmus, fixation, and vergence) in ST patients. The present study investigates horizontal and vertical saccades in patients with tinnitus lateralized predominantly to the left or to the right side. Compared to left sided ST, tinnitus perceived on the right side impaired almost all the parameters of saccades (latency, amplitude, velocity, etc.) and noticeably the upward saccades. Relative to controls, saccades from both groups were more dysmetric and were characterized by increased saccade disconjugacy (i.e., poor binocular coordination). Although the precise mechanisms linking ST and saccadic control remain unexplained, these data suggest that ST can lead to detrimental auditory, visuomotor, and perhaps vestibular interactions.
Tinnitus is a common auditory symptom that interferes with activities of daily living and is ofte... more Tinnitus is a common auditory symptom that interferes with activities of daily living and is often associated with anxiety and depression. This study included consecutive patients with chronic intense tinnitus for more than six months who were treated with Tinnitus Retraining Therapy (TRT), a cognitive-behavioral therapy, after previous treatment failed and after a clinical evaluation based on standardized questionnaires, including the Tinnitus Handicap Questionnaire (THQ). One year after the end of the TRT, the treatment was evaluated by the same standardized questionnaires. This prospective study included 96 consecutive patients (49 women, 47 men, mean age: 48 years). Tinnitus improved significantly in 75%, where significant improvement was defined as a final THQ score of less than 500 after CBT. This improvement varied according to initial THQ scores and was seen in: all patients with moderate (THQ<500), 70.3% of the patients with intermediate (500<THQ>1001), and 34.8% o...
Tinnitus - the perception of sound in one or both ears or in the head when no external sound is p... more Tinnitus - the perception of sound in one or both ears or in the head when no external sound is present - can be disabling and is especially difficult to treat. Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive technique for activating or inactivating specific areas of the cortex. The aim of this study was to assess the feasibility of magnetic neurostimulation of the primary and secondary auditory cortex in the treatment of disabling chronic tinnitus. Thirteen patients with tinnitus refractory to several conventional treatments underwent transcranial magnetic stimulation guided by functional magnetic resonance imaging (fMRI). We compared two types of stimulation of targets in the auditory cortex, identified by fMRI: 3-second pulses at high frequency (10 Hz) and 20-minute stimulations at a lower frequency (1 Hz). Brief high-frequency pulses of cortical magnetic stimulation (10 Hz) were not effective. On the other hand, prolonged low frequency (1 Hz) stimulation was...
Tinnitus is a considered to be an auditory phantom phenomenon, a persistent conscious percept of ... more Tinnitus is a considered to be an auditory phantom phenomenon, a persistent conscious percept of a salient memory trace, externally attributed, in the absence of a sound source. It is perceived as a phenomenological unified coherent percept, binding multiple separable clinical characteristics, such as its loudness, the sidedness, the type (pure tone, noise), the associated distress and so on. A theoretical pathophysiological framework capable of explaining all these aspects in one model is highly needed. The model must incorporate both the deafferentation based neurophysiological models and the dysfunctional noise canceling model, and propose a &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;tinnitus core&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; subnetwork. The tinnitus core can be defined as the minimal set of brain areas that needs to be jointly activated (=subnetwork) for tinnitus to be consciously perceived, devoid of its affective components. The brain areas involved in the other separable characteristics of tinnitus can be retrieved by studies on spontaneous resting state magnetic and electrical activity in people with tinnitus, evaluated for the specific aspect investigated and controlled for other factors. By combining these functional imaging studies with neuromodulation techniques some of the correlations are turned into causal relationships. Thereof, a heuristic pathophysiological framework is constructed, integrating the tinnitus perceptual core with the other tinnitus related aspects. This phenomenological unified percept of tinnitus can be considered an emergent property of multiple, parallel, dynamically changing and partially overlapping subnetworks, each with a specific spontaneous oscillatory pattern and functional connectivity signature. Communication between these different subnetworks is proposed to occur at hubs, brain areas that are involved in multiple subnetworks simultaneously. These hubs can take part in each separable subnetwork at different frequencies. Communication between the subnetworks is proposed to occur at discrete oscillatory frequencies. As such, the brain uses multiple nonspecific networks in parallel, each with their own oscillatory signature, that adapt to the context to construct a unified percept possibly by synchronized activation integrated at hubs at discrete oscillatory frequencies.
Repeated transcranial magnetic stimulation (rTMS) of auditory cortex has been proposed to treat r... more Repeated transcranial magnetic stimulation (rTMS) of auditory cortex has been proposed to treat refractory chronic tinnitus, but the involved mechanisms of action remain largely unknown. The purpose of this pilot study was to evaluate the impact of rTMS on auditory cortex activity in a series of tinnitus patients, using for the first time both functional magnetic resonance imaging (fMRI) of the brain and auditory evoked potentials (AEPs). In six patients with chronic, lateralized refractory tinnitus, we performed five sessions of neuronavigated rTMS delivered at 1Hz over the secondary auditory cortex (defined on morphological MRI), contralateral to tinnitus side. The effects of rTMS were assessed on clinical scales, fMRI, and AEPs (N1 and P2 components). The clinical impact of rTMS on tinnitus was good for three patients (25-50% improvement of tinnitus severity compared to baseline), moderate for two patients (15% improvement), and null for one patient who had the most severe tinnitus at baseline. The changes induced by rTMS on fMRI data varied with the baseline level of auditory cortex activation before rTMS. This baseline level of activation was itself related to the severity of tinnitus. Thus, cortical stimulation increased auditory cortex activation in patients who had less severe tinnitus and low level of activation before rTMS, whereas it decreased auditory cortex activation in patients who had more severe tinnitus and higher level of activation before rTMS. Regarding AEPs, rTMS decreased N1 amplitude in all patients, except in the patient who had the most severe tinnitus at baseline and showed no improvement after rTMS. Conversely, P2 amplitude decreased after rTMS only in patients with severe tinnitus, at least for auditory stimulation contralateral to tinnitus, but increased in patients with less severe tinnitus. The changes produced by rTMS in auditory cortex activity, as assessed by fMRI and AEPs, appeared to depend on a process of disease-related homeostatic cortical plasticity, regardless of the therapeutic impact of rTMS on tinnitus.
Tinnitus affects 10% of the population, its pathophysiology remains incompletely understood, and ... more Tinnitus affects 10% of the population, its pathophysiology remains incompletely understood, and treatment is elusive. Functional imaging has demonstrated a relationship between the intensity of tinnitus and the degree of reorganization in the auditory cortex. Experimental studies have further shown that tinnitus is associated with synchronized hyperactivity in the auditory cortex. Therefore, targeted modulation of auditory cortex has been proposed as a new therapeutic approach for chronic tinnitus.
Background: Many patients show modulation of tinnitus by gaze, jaw or neck movements, reflecting ... more Background: Many patients show modulation of tinnitus by gaze, jaw or neck movements, reflecting abnormal sensorimotor integration, and interaction between various inputs. Postural control is based on multi-sensory integration (visual, vestibular, somatosensory, and oculomotor) and indeed there is now evidence that posture can also be influenced by sound. Perhaps tinnitus influences posture similarly to external sound. This study examines the quality of postural performance in quiet stance in patients with modulated tinnitus. Methods: Twenty-three patients with highly modulated tinnitus were selected in the ENT service. Twelve reported exclusively or predominately left tinnitus, eight right, and three bilateral. Eighteen control subjects were also tested. Subjects were asked to fixate a target at 40 cm for 51 s; posturography was performed with the platform (Technoconcept, 40 Hz) for both the eyes open and eyes closed conditions. Results: For both conditions, tinnitus subjects showed abnormally high lateral body sway (SDx). This was corroborated by fast Fourrier Transformation (FFTx) and wavelet analysis. For patients with left tinnitus only, medio-lateral sway increased significantly when looking away from the center. Conclusion: Similarly to external sound stimulation, tinnitus could influence lateral sway by activating attention shift, and perhaps vestibular responses. Poor integration of sensorimotor signals is another possibility. Such abnormalities would be accentuated in left tinnitus because of the importance of the right cerebral cortex in processing both auditorytinnitus eye position and attention.
Tinnitus affects 10% of the population, its pathophysiology remains incompletely understood, and ... more Tinnitus affects 10% of the population, its pathophysiology remains incompletely understood, and treatment is elusive. Functional imaging has demonstrated a relationship between the intensity of tinnitus and the degree of reorganization in the auditory cortex. Experimental studies have further shown that tinnitus is associated with synchronized hyperactivity in the auditory cortex. Therefore, targeted modulation of auditory cortex has been proposed as a new therapeutic approach for chronic tinnitus.
This study was designed to investigate methods to help patients suffering from unilateral tinnitu... more This study was designed to investigate methods to help patients suffering from unilateral tinnitus synthesizing an auditory replica of their tinnitus. Two semi-automatic methods (A and B) derived from the auditory threshold of the patient and a method (C) combining a pure tone and a narrow band-pass noise centred on an adjustable frequency were devised and rated on their likeness over two test sessions. A third test evaluated the stability over time of the synthesized tinnitus replica built with method C, and its proneness to merge with the patient&amp;amp;#39;s tinnitus. Patients were then asked to try and control the lateralisation of this single percept through the adjustment of the tinnitus replica level. The first two tests showed that seven out of ten patients chose the tinnitus replica built with method C as their preferred one. The third test, performed on twelve patients, revealed pitch tuning was rather stable over a week interval. It showed that eight patients were able to consistently match the central frequency of the synthesized tinnitus (presented to the contralateral ear) to their own tinnitus, which leaded to a unique tinnitus percept. The lateralisation displacement was consistent across patients and revealed an average range of 29dB to obtain a full lateral shift from the ipsilateral to the contralateral side. Although spectrally simpler than the semi-automatic methods, method C could replicate patients&amp;amp;#39; tinnitus, to some extent. When a unique percept between synthesized tinnitus and patients&amp;amp;#39; tinnitus arose, lateralisation of this percept was achieved.
Presse médicale (Paris, France : 1983), Jan 13, 2002
A FREQUENTLY MISUNDERSTOOD AFFECTION: Because of its high prevalence and the considerable alterat... more A FREQUENTLY MISUNDERSTOOD AFFECTION: Because of its high prevalence and the considerable alteration it often provokes in quality of life, tinnitus aurium is an important public health problem. Current treatment of tinnitus aurium is limited by the lack of knowledge of the physiopathological processes that generate it. Analysis of the data in the literature and our recent works suggests that external ciliated cells of the cochlea are probably not a major source of tinnitus, but an important role is attributed to lateral efferent innervation and glutamatergic synapses situated beneath the internal ciliated cells. Experimental models of tinnitus are presently being developed in order to test these hypotheses, and pharmacological clinical trials should be set-up during the year to come, in order to apply these fundamental results to humans.
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Papers by Alain Londero