External Acoustic Stimulation Research Articles

The Analogy between Tinnitus and Chronic Pain: A Phenomenological Approach.

Tinnitus is an auditory sensation without external acoustic stimulation or significance, which may be lived as an unpleasant experience and impact the subject's quality of life. Tinnitus loudness, which is generally low, bears no relation to distress. Factors other than psychoacoustic (such as psychological factors) are therefore implicated in the way tinnitus is experienced. The aim of this article is to attempt to understand how tinnitus can, like chronic pain, generate a 'crisis' in the process of existence, which may go as far as the collapse of the subject. The main idea put forward in the present article is that tinnitus may be compared to the phenomenon of pain from the point of view of the way it is experienced. Although the analogy between tinnitus and pain has often been made in the literature, it has been limited to a parallel concerning putative physiopathological mechanisms and has never really been explored in depth from the phenomenological point of view. Tinnitus is comparable to pain inasmuch as it is felt, not perceived: it springs up (without intention or exploration), abolishes the distance between the subject and the sensation (there is only a subject and no object), and has nothing to say about the world. Like pain, tinnitus is formless and abnormal and can alter the normal order of the world with maximum intensity. Finally, tinnitus and pain enclose the subject within the limits of the body, which then becomes in excess. Tinnitus may be a source of suffering, which affects not only the body but a person's very existence and, in particular, its deployment in time. Plans are thus abolished, so time is no longer 'secreted', it is enclosed in an eternal present. If the crisis triggered by tinnitus is not resolved, the subject may buckle and collapse (depression) when their resources for resisting are depleted. The path may be long and winding from the moment when tinnitus emerges to when it assaults existence and its eventual integration into a new existential norm where tinnitus is no longer a source of disturbance.

HEARING AID EFFECTIVENESS ON PATIENTS WITH CHRONIC TINNITUS AND ASSOCIATED HEARING LOSS : SYSTEMATICS REVIEW

Tinnitus, the perception of sound in the absence of an obvious external source, is even more frequent, affecting around ten percent of adults in the United States. Tinnitus is defined as the sense of sound in the absence of an obvious external source. Tinnitus is typically accompanied by hearing loss, but this is not always the case. It is conceivable for it to occur either by itself or in conjunction with a loss of hearing of any type. Tinnitus and hearing loss are both caused by a wide variety of conditions, the most frequent of which is age-related hearing loss. Other, less common causes include malignancies of the brain and skull base. Hearing loss can be broken down into three basic categories: sensorineural, conductive, or mixed (where both conductive and sensorineural components are present). The perception of sound in the absence of external acoustic stimulation for an extended length of time (more than three months) is the hallmark of chronic tinnitus. Tinnitus is quite common, with an estimated incidence of 10–15% in the adult population; however, prevalence estimates can vary widely from study to study. Tinnitus is characterized by a buzzing or ringing sound in the ear. A minority of people may experience severe psychological distress as a direct result of the situation, despite the fact that the majority of people are able to adapt to the perception and report very mild emotional distress as a result of it. Tinnitus Questionnaire (abbreviated as TQ), Tinnitus Handicap Inventory (abbreviated as THI), and Tinnitus Functional Index (abbreviated as TFI) are the three self-report questionnaires that are used the most frequently for quantifying tinnitus-related suffering. The total scores of these measures properly capture both the suffering associated with tinnitus and the change that is attributable to treatments. In patients who have tinnitus and chronic hearing loss, the use of hearing aids is successful in suppressing the symptoms; however, the usage of the device must be carried out for at least six months in order for the treatment to take effect.

Subaqueous free-standing 3D cell culture system for ultrafast cell compaction, mechano-inductive immune control, and improving therapeutic angiogenesis.

Conventional 3D cell culture methods require a comprehensive complement in labor-intensive and time-consuming processes along with in vivo circumstantial mimicking. Here, we describe a subaqueous free-standing 3D cell culture (FS) device that can induce the omnidirectional environment and generate ultrafast human adipose-derived stem cells (hADSCs) that efficiently aggregate with compaction using acoustic pressure. The cell culture conditions were optimized using the FS device and identified the underlying molecular mechanisms. Unique phenomena in cell aggregation have led to extraordinary cellular behavior that can upregulate cell compaction, mechanosensitive immune control, and therapeutic angiogenesis. Therefore, we designated the resulting cell aggregates as "pressuroid." Notably, external acoustic stimulation produced by the FS device affected the pressuroids. Furthermore, the pressuroids exhibited upregulation in mechanosensitive genes and proteins, PIEZO1/2. CyclinD1 and PCNA, which are strongly associated with cell adhesion and proliferation, were elevated by PIEZO1/2. In addition, we found that pressuroids significantly increase angiogenic paracrine factor secretion, promote cell adhesion molecule expression, and enhance M2 immune modulation of Thp1 cells. Altogether, we have concluded that our pressuroid would suggest a more effective therapy method for future cell therapy than the conventional one.

Audiological biomarkers of tinnitus in an older Portuguese population.

Tinnitus is a phantom sound perceived in the absence of external acoustic stimulation. It is described in a variety of ways (e.g., buzzing, ringing, and roaring) and can be a single sound or a combination of different sounds. Our study evaluated associations between audiological parameters and the presence or severity of tinnitus, to improve tinnitus diagnosis, treatment, and prognosis. Our sample included 122 older participants (63 women and 59 men), aged 55–75 years from the Portuguese population, with or without sensory presbycusis and with or without tinnitus. All participants underwent a clinical evaluation through a structured interview, Ear, Nose, and Throat observation, and audiological evaluation (standard and extended audiometry, psychoacoustic tinnitus evaluation, auditory brainstem responses, and distortion product otoacoustic emissions). The Tinnitus Handicap Inventory was used to measure tinnitus symptom severity. Our data confirmed that the odds of developing tinnitus were significantly higher in the presence of noise exposure and hearing loss. Also, participants who had abrupt tinnitus onset and moderate or severe hyperacusis featured higher odds of at least moderate tinnitus. However, it was in the ABR that we obtained the most exciting and promising results, namely, in wave I, which was the common denominator in all findings. The increase in wave I amplitude is a protective factor to the odds of having tinnitus. Concerning the severity of tinnitus, the logistic regression model showed that for each unit of increase in the mean ratio V/I of ABR, the likelihood of having at least moderate tinnitus was 10% higher. Advancing knowledge concerning potential tinnitus audiological biomarkers can be crucial for the adequate diagnosis and treatment of tinnitus.

Cortical Auditory Evoked Potentials Recorded Directly Through the Cochlear Implant in Cochlear Implant Recipients: a Feasibility Study.

The use of objective measures in cochlear implant (CI) mapping, has greatly contributed to the refinement of the setting of audible and comfortable stimulation levels, which serve as the basis of the mapping process, especially in cases of infants and young children. In addition, objective measures can also confirm the integrity of the CI system. Current CI objective measures mainly reflect neural activity from the auditory nerve and brainstem site. An objective cortical CI measure that reflects directly central auditory activity is greatly needed, especially since it is closely related to CI outcomes in both children and adults. Recording the brain activity currently requires an external evoked potential (EP) system including scalp electrodes, rendering it impractical for widespread clinical use. This study aimed to assess the feasibility of recording cortical auditory evoked potentials (CAEPs) directly and solely through the cochlear implant in response to external acoustic stimulation in the non-implanted ear. A total of nine CI users (four females and five males) participated, including seven post-lingual adults (23 to 72 years), and two pediatric cases, one teenager (15 years), and one child (8 years)-both pre-lingual. All participants had a residual hearing in the ear contralateral to the ear with CI. CAEPs were recorded in the implanted ear in response to acoustic stimulation of the non-implanted ear, consisting of a brief tonal stimulus at comfortable listening levels. Recordings used an intracranial montage consisting of an intracochlear apical electrode (active) and one of the two ( case and ring ) extra-cochlear implanted electrodes serving as reference electrodes. The CI CAEPs were compared with a single-channel conventional CAEP recording obtained simultaneously via scalp electrodes (Fz-mastoid) using a standard EP system and an external trigger from the CI system. Statistical comparisons were made between the CI and the scalp recorded CAEPs and for differences between the CI CAEP measures acquired using the ring and the case as the reference electrode. CAEPs recorded directly and solely through the CI were equivalent to the standard scalp recorded CAEP responses. CAEP responses acquired using the case electrode as the reference were highly correlated in terms of morphology, latencies, and amplitudes of the CAEP components. The CI CAEP latencies of the two pediatric cases were consistent with their normal developed age group and delayed relative to adult CAEP latencies, as expected. This study demonstrated the feasibility of recording long latency CAEPs directly and solely through CI in adults with residual hearing, in response to acoustic stimulation of the non-implanted ear. The CI CAEPs closely resembled the CAEPs recorded simultaneously by an external EP system and via scalp electrodes. The ability to record directly from the implant, without the need of an external recording system, presents an innovative method with many clinical and research implications.

Numerical Modeling of Shockwave Treatment of Knee Joint.

Arthritis is a degenerative disease that primarily affects the cartilage and meniscus of the knee joint. External acoustic stimulation is used to treat this disease. This article presents a numerical model of the knee joint aimed at the computer-aided study of the regenerative effects of shockwave treatment. The presented model was verified and validated. A numerical analysis of the conditions for the regeneration of the tissues of the knee joint under shockwave action was conducted. The results allow us to conclude that to obtain the conditions required for the regeneration of cartilage tissues and meniscus (compressive stresses above the threshold value of 0.15 MPa to start the process of chondrogenesis; distortional strains above the threshold value of 0.05% characterized by the beginning of the differentiation of the tissues in large volumes; fluid pressure corresponding to the optimal level of 68 kPa to transfer tissue cells in large volumes), the energy flux density of therapeutic shockwave loading should exceed 0.3 mJ/mm2.

Three-dimensional vibration patterns of alto saxophone reeds measured on different mouthpieces under mimicked realistic playing conditions.

In single reed musical instruments, vibrations of the reed, in conjunction with the geometry of the mouthpiece and the acoustic feedback of the instrument, play an essential role in sound generation. Up until now, three-dimensional (3D) reed vibration patterns have only been studied under external acoustic stimulation, or at a single note and lip force. This paper investigates vibration patterns of saxophone reeds under imitated realistic playing conditions. On different notes displacement measurements on the entire optically accessible part of the reed are performed using stroboscopic digital image correlation. These vibration data are decomposed onto the harmonic frequencies of the generated note pitch and into the operational modes. Motion data as a function of time are shown on single points. All points on the reed predominantly move in phase, corresponding to the first flexural mode of the reed. At higher note harmonics very low amplitude higher vibration modes are superimposed on the fundamental mode. Mouthpiece characteristics and lip force influence the vibration patterns. Vibration patterns differ strongly from earlier measurements on free vibrating reeds. Results show that single-point measurements on the tip of the reed can give a good indication of the 3D vibration amplitude, also at higher note pitches.

The effects of transcutaneous auricular vagal nerve stimulation on pupil size

ObjectiveMechanisms of action and optimal stimulation parameters of transcutaneous auricular vagus nerve stimulation (taVNS) are currently unknown. Pupil size has gained attention as a promising biomarker of vagal activation in different studies on animal models. The aim of this study is to investigate the effects of taVNS on pupil diameter in healthy subjects. MethodsAll subjects received taVNS at the left external acoustic meatus and control stimulation at the left earlobe during the same experimental session. Different intensities (0.5 mA; 1.0 mA; 2.0 mA; 3.0 mA) for both conditions were tested. Tonic pupil size was recorded in both eyes at baseline and during each stimulation using an infrared-automated pupillometer in three different illuminance conditions (scotopic, mesopic, photopic). ResultsIn scotopic illuminance condition, a significant interaction between intensity and condition (real vs control) was found for the left eye. Post-Hoc analysis showed that during real taVNS at 2 mA, pupil size was significantly larger in comparison to baseline and 2 mA control stimulation. ConclusionsOur study demonstrates that taVNS induces pupil dilation under specific illuminance conditions and at specific stimulation intensity. SignificanceThe effects of taVNS are strictly dependent on technical aspects, such as stimulation parameters and experimental set-up.

Vestibular functions in patients with tinnitus only

Objective: Tinnitus is the perception of sound in the ears or head without any external or internal acoustic stimulation, and it is usually associated with hearing loss. In addition, it has been reported that there is a relationship between vestibular problems and sensorineural hearing loss. The aim of this study was to evaluate the vestibular function in patients with tinnitus without hearing loss.Methods: A total of 32 patients who complained only of tinnitus without hearing loss and 30 control subjects without tinnitus or hearing loss were included in this study. Oculomotor and caloric tests were performed on all subjects with videonystagmography. The tinnitus handicap inventory questionnaire, side and duration of tinnitus were recorded in all patients.Results: The caloric test was abnormal in 13 of 32 (40.6%) patients in the tinnitus group and was normal in all of the control group. Abnormal caloric responses in patients with severe tinnitus were more frequent than in patients with mild or moderate tinnitus. There was a statistically significant difference in the optokinetic gain values between the tinnitus and control groups.Conclusion: A relationship between tinnitus and abnormal caloric responses was determined. Tinnitus may be the first symptom of vestibular dysfunction.

Transcranial direct current stimulation for the treatment of tinnitus: a review of clinical trials and mechanisms of action

BackgroundTinnitus is the perception of sound in the absence of any external acoustic stimulation. Transcranial direct current stimulation (tDCS) has shown promising though heterogeneous therapeutic outcomes for tinnitus. The present study aims to review the recent advances in applications of tDCS for tinnitus treatment. In addition, the clinical efficacy and main mechanisms of action of tDCS on suppressing tinnitus are discussed.MethodsThe study was performed in accordance with the PRISMA guidelines. The databases of the PubMed (1980–2018), Embase (1980–2018), PsycINFO (1850–2018), CINAHL, Web of Science, BIOSIS Previews (1990–2018), Cambridge Scientific s (1990–2018), and google scholar (1980–2018) using the set search terms. The date of the most recent search was 20 May, 2018. The randomized controlled trials that have assessed at least one therapeutic outcome measured before and after tDCS intervention were included in the final analysis.ResultsDifferent tDCS protocols were used for tinnitus ranging single to repeated sessions (up to 10) consisting of daily single session of 15 to 20-min and current intensities ranging 1–2 mA. Dorsolateral prefrontal cortex (DLPFC) and auditory cortex are the main targets of stimulation. Both single and repeated sessions showed moderate to significant treatment effects on tinnitus symptoms. In addition to improvements in tinnitus symptoms, the tDCS interventions particularly bifrontal DLPFC showed beneficial outcomes on depression and anxiety comorbid with tinnitus. Heterogeneities in the type of tinnitus, tDCS devices, protocols, and site of stimulation made the systematic reviews of the literature difficult. However, the current evidence shows that tDCS can be developed as an adjunct or complementary treatment for intractable tinnitus. TDCS may be a safe and cost-effective treatment for tinnitus in the short-term application.ConclusionsThe current literature shows moderate to significant therapeutic efficacy of tDCS on tinnitus symptoms. Further randomized placebo-controlled double-blind trials with large sample sizes are needed to reach a definitive conclusion on the efficacy of tDCS for tinnitus. Future studies should further focus on developing efficient disease- and patient-specific protocols.

Tinnitus in Adults, a Health Problem: Implications for the Society and the Scientific Community

Tinnitus is a phantom sound perceived in the absence of external acoustic stimulation, which is only heard by the affected person. It is described in a variety of ways and can be a single sound or combination of different sounds. Tinnitus is related to many other conditions and has an impact in the quality of life of the affected person. However, pathophysiological mechanisms underlying tinnitus and their basic biological remains unknown. One of the major challenges, concerning the heterogeneity of the tinnitus condition, is the lack of standardization in research and clinical management. For this, the TINNET, a European Cost Action for research, has the main objective to developbetter strategies for diagnosis and management. The establishment of guidelines for clinical diagnosis, treatment, neuroimaging assessments and outcome assessment, through the identification of clinically meaningful tinnitus subtypes, provides an important basis for the standardization of clinical research and management of tinnitus.

Heidelberg Neuro-Music Therapy Restores Attention-Related Activity in the Angular Gyrus in Chronic Tinnitus Patients.

Background: Tinnitus is the perception of a phantom sound without external acoustic stimulation. Recent tinnitus research suggests a relationship between attention processes and tinnitus-related distress. It has been found that too much focus on tinnitus comes at the expense of the visual domain. The angular gyrus (AG) seems to play a crucial role in switching attention to the most salient stimulus. This study aims to evaluate the involvement of the AG during visual attention tasks in tinnitus sufferers treated with Heidelberg Neuro-Music Therapy (HNMT), an intervention that has been shown to reduce tinnitus-related distress.Methods: Thirty-three patients with chronic tinnitus, 45 patients with recent-onset tinnitus, and 35 healthy controls were tested. A fraction of these (21/21/22) were treated with the “compact” version of the HNMT lasting 1 week with intense treatments, while non-treated participants were included as passive controls. Visual attention was evaluated during functional Magnet-Resonance Imaging (fMRI) by a visual Continous Performance Task (CPT) using letter-based alarm cues (“O” and “X”) appearing in a sequence of neutral letters, “A” through “H.” Participants were instructed to respond via button press only if the letter “O” was followed by the letter “X” (GO condition), but not to respond if a neutral letter appeared instead (NOGO condition). All participants underwent two fMRI sessions, before and after a 1-week study period.Results: The CPT results revealed a relationship between error rates and tinnitus duration at baseline whereby the occurrence of erroneous “GO omissions” and the reaction time increased with tinnitus duration. Patients with chronic tinnitus who were treated with HNMT had decreasing error rates (fewer GO omissions) compared to treated recent-onset patients. fMRI analyses confirmed greater activation of the AG during CPT in chronic patients after HNMT treatment compared to treated recent-onset patients.Conclusions: Our findings suggest that HNMT treatment helps shift the attention from the auditory phantom percept toward visual cues in chronic tinnitus patients and that this shift in attention may involve the AG.

Polysomnography Applied to Patients with Tinnitus: A Review.

Introduction Tinnitus has been defined as an “auditory phantom perception,” meaning that tinnitus results from an abnormal activity within the nervous system, in the absence of any internal or external acoustic stimulation. About 10 to 15% of the adult population is affected by tinnitus, and a relevant percentage of tinnitus sufferers experience symptoms severe enough to significantly affect quality of life, including sleep disturbances, work impairment, and, in some cases, psychiatric distress. The self-rated complaints about tinnitus focus on emotional distress, auditory perceptual difficulties, and sleep disturbances. Objectives To evaluate the works that show sleep disorders in patients with tinnitus, and sleep disorders assessed by polysomnography. Data Synthesis We found four studies with polysomnography to assess sleep disorders in patients with tinnitus. The first study evaluated 80 patients who were military personnel without major psychiatric disturbances, and their tinnitus was associated with noise-induced permanent hearing. The second study was a prospective, case-control, nonrandomized study of 18 patients affected by chronic tinnitus who were compared with a homogeneous control group consisting of 15 healthy subjects. The last work evaluated questionnaires mailed to patients before their initial appointment at the Oregon Health Sciences University Tinnitus Clinic between 1994 and 1997. These questionnaires requested information pertaining to insomnia, tinnitus severity, and loudness. Follow-up questionnaires were mailed to 350 patients 1 to 4 years (mean 5 ± 2.3 years) after their initial appointment at the clinic. Conclusion There are few studies with polysomnography for the evaluation of patients with sleep disorders caused by tinnitus. This shows the need for more studies on this subject.

Masking Treatment and its Effect on Tinnitus Parameters.

Tinnitus is described as the perception of sound without any external acoustic stimulation. Any pathology of auditory pathways or any system of the human body may result with tinnitus. The pathophysiology of tinnitus accompanying the disorders of auditory system is not fully understood and there is not any particular effective treatment method has been specified. Tinnitus masking therapy has been reported as an effective treatment modality in the treatment of tinnitus. In this study, the results of tinnitus masking treatment on the parameters were evaluated prospectively. Patients with normal physical examination was enrolled in the study. Blood tests (complete blood count, biochemical analysis of lipid profile, and thyroid hormones), pure tone audiometry, tympanometric measurement of the middle ear pressure and stapedial reflexes were performed, Sixty six patients with normal results of blood tests and normal hearing thresholds with type A tympanogram were included. Tinnitus sufferers questionnaires (socio-demographics, clinical information, Tinnitus Handicap Inventory (THI), Beck Depression Inventory (BDI) was filled, audiological tests were performed, tinnitus parameters (frequency, intensity, minimal masking levels, residual inhibition) were measured. After four weeks of the treatment the questionnaires were repeated. Masking treatment for tinnitus patients resulted with significant decrease in Tinnitus Handicap Inventory and VAS scores. After four weeks of the masking treatment the questionnaire was repeated. Twenty patients did not respond to treatment. Masking therapy is one of the most effective methods of treatment for tinnitus patients. Masking therapy, that is not invasive and cost-effective has an important place in the treatment of tinnitus. Especially in a short time provides a significant reduction in tinnitus parameters.

Morphofunctional alterations in the olivocochlear efferent system of the genetic audiogenic seizure-prone hamster GASH:Sal.

The genetic audiogenic seizure hamster (GASH:Sal) is a model of a form of reflex epilepsy that is manifested as generalized tonic-clonic seizures induced by external acoustic stimulation. The morphofunctional alterations in the auditory system of the GASH:Sal that may contribute to seizure susceptibility have not been thoroughly determined. In this study, we analyzed the olivocochlear efferent system of the GASH:Sal from the organ of Corti, including outer and inner hair cells, to the olivocochlear neurons, including shell, lateral, and medial olivocochlear (LOC and MOC) neurons that innervate the cochlear receptor. To achieve this, we carried out a multi-technical approach that combined auditory hearing screenings, scanning electron microscopy, morphometric analysis of labeled LOC and MOC neurons after unilateral Fluoro-Gold injections into the cochlea, and 3D reconstruction of the lateral superior olive (LSO). Our results showed that the GASH:Sal exhibited higher auditory brain response (ABR) thresholds than their controls, as well as absence of distortion-product of otoacoustic emissions (DPOAEs) in a wide range of frequencies. The ABR and DPOAE results also showed differences between the left and right ears, indicating asymmetrical hearing alterations in the GASH:Sal. These alterations in the peripheral auditory activity correlated with morphological alterations. At the cochlear level, the scanning electron microscopy analysis showed marked distortions of the stereocilia from basal to apical cochlear turns in the GASH:Sal, which were not observed in the control hamsters. At the brainstem level, MOC, LOC, and shell neurons had reduced soma areas compared with control animals. This LOC neuron shrinkage contributed to reduction in the LSO volume of the GASH:Sal as shown in the 3D reconstruction analysis. Our study demonstrated that the morphofunctional alterations of the olivocochlear efferent system are innate components of the GASH:Sal, which might contribute to their susceptibility to audiogenic seizures. This article is part of a Special Issue entitled "Genetic and Reflex Epilepsies, Audiogenic Seizures and Strains: From Experimental Models to the Clinic".

Auditory training program in subjects with tinnitus.

Tinnitus may be defined as the conscious perception of sound or noise, without the presence of external acoustic stimulation. Given the damage caused by tinnitus and the lack of effective treatment, alternatives are necessary to rehabilitate subjects with tinnitus. There is an assumption that auditory training (AT) could lead to a plastic reorganization of this system, thus promoting an improvement of the symptom. To verify the effect of an AT program in subjects with tinnitus in the perception of this symptom. Twelve subjects with tinnitus were included in the study and divided into two groups: Study Group (SG) and Control Group (CG). All of them underwent audiometric and electrophysiological assessments; acuphenometry; Tinnitus Handicap Inventory and auditory processing assessment (GIN - Gaps in Noise, Frequency Pattern Test and Speech-in-Noise). Afterward, trainings began and the SG was submitted to the formal AT, and the CG to the visual training. In the characterization of the groups, no statistically significant difference was found for the variables such as age, pitch, and loudness of tinnitus, or for hearing thresholds in conventional audiometry and high frequencies. Comparisons were performed between the groups, before and after the trainings, regarding electrophysiological, behavioral, and Tinnitus Handicap Inventory tests, and no statistically significant differences were found between them for any of the evaluations. Findings showed no statistically significant differences between groups in the comparison between the moments pre- and post-trainings (auditory or visual), nor for the electrophysiological findings or behavioral assessment of the auditory processing and for the Tinnitus Handicap Inventory, although some specific differences in the individual analysis have occurred.

Flufenamic acid prevents behavioral manifestations of salicylate-induced tinnitus in the rat.

IntroductionTinnitus is defined as a phantom auditory sensation, the perception of sound in the absence of external acoustic stimulation. Given that flufenamic acid (FFA) blocks TRPM2 cation channels, resulting in reduced neuronal excitability, we aimed to investigate whether FFA suppresses the behavioral manifestation of sodium salicylate (SSA)-induced tinnitus in rats.Material and methodsTinnitus was evaluated using a conditioned lick suppression model of behavioral testing. Thirty-one Wistar rats, randomly divided into four treatment groups, were trained and tested in the behavioral experiment: (1) control group: DMSO + saline (n = 6), (2) SSA group: DMSO + SSA (n = 6), (3) FFA group: FFA (66 mg/kg bw) + saline (n = 9), (4) FFA + SSA group: FFA (66 mg/kg bw) + SSA (400 mg/kg bw) (n = 10). Localization of TRPM2 to the plasma membrane of cochlear nucleus neurons was demonstrated by confocal microscopy.ResultsPavlovian training resulted in strong suppression of licking, having a mean value of 0.05 ±0.03 on extinction day 1, which is below the suppression training criterion level of 0.20 in control tinnitus animals. The suppression rate for rats having both FFA (66 mg/kg bw) and SSA (400 mg/kg bw) injections was significantly lower than that for the rats having SSA injections (p < 0.01).ConclusionsWe suggest that SSA-induced tinnitus could possibly be prevented by administration of a TRPM2 ion channel antagonist, FFA at 66 mg/kg bw.

Challenges in Managing the Side Effects of Oral Appliance Therapy

T is the perception of sound in the absence of external acoustic stimulation.1 Symptoms include ringing, buzzing, roaring, clicking, and hissing sounds. It may occur in one ear or both. Tinnitus is not a disease, but rather a symptom of an underlying condition such as age related hearing loss, exposure to loud noise, Meniere’s disease, acoustic neuroma, circulatory system disorder, or TMJ disorder.2 Complications of tinnitus include sleep interruption, fatigue, depression, memory lapses, anxiety, and irritability. A large number of patients with tinnitus suffer from sleep disorders. This perceived sound adversely impacts one’s quality of sleep. Patients become sleep deprived and exhibit signs of sleep apnea, including daytime sleepiness, fatigue, depression, and diminished quality of life.1,3 While some patients report success with CPAP and oral appliance therapy, others report an exacerbation of symptoms, possibly due to CPAP pressure, mask fitting, unequal pressure in the middle ear or TMJ problems.4

The Nasal NO Response To External Acoustic Energy: A Pilot Study

Acoustic stimulation (humming) facilitates NO diffusion from the paranasal sinuses into the nasal cavity. This acoustic response may be blunted in the presence of rhinosinusitis. To further standardize this test, we evaluated a prototype apparatus that applies external acoustic energy – as an alternative to humming – during negative pressure nasal NO sampling. Non-smoking, non-asthmatic volunteers underwent exhaled NO sampling, followed by nasal NO sampling under three conditions: 1) unstimulated / “quiet” (“Q”); 2) with 128 Hz external acoustic stimulation at low intensity (64 dBA at 30 cm – “S1”); and 3) with acoustic stimulation at moderate intensity (78 dBA at 30 cm – “S2”). Stimulated-to-quiet (S/Q) nasal NO ratios were calculated using mean NO values from the 10 seconds following the initial pressure transient in each recording. A total of 12 subjects (9 females; mean age, 43.7 years) completed the study. Seven subjects gave histories consistent with rhinitis. Individual mean nasal NO levels ranged from 66-182 ppb under quiet conditions, 106-386 ppb with low-amplitude acoustic stimulation, and 122-750 ppb with moderate amplitude. The corresponding values for S/Q ratio ranged from 1.07-2.70 (S1) and from 1.24-7.65 (S2). A paired analysis of nasal NO levels across subjects showed a significant upward trend with increasing applied acoustic energy (p < 0.01). Our results confirm the application of external acoustic stimulation as an alternative to humming in assessing acoustic mixing of gases between the paranasal sinuses and nasal cavity. Use of this procedure may form the basis for a screening test for sinusitis.

Ginkgo biloba for tinnitus

This is an update of a Cochrane review first published in The Cochrane Library in Issue 2, 2004 and previously updated in 2007 and 2009.Tinnitus can be described as the perception of sound in the absence of external acoustic stimulation. At present no specific therapy for tinnitus is acknowledged to be satisfactory in all patients. There are a number of reports in the literature suggesting that Ginkgo biloba may be effective in the management of tinnitus. However, there also appears to be a strong placebo effect in tinnitus management. To assess the effect of Ginkgo biloba in patients who are troubled by tinnitus. We searched the Cochrane Ear, Nose and Throat Disorders Group Trials Register; the Cochrane Central Register of Controlled Trials (CENTRAL); PubMed; EMBASE; AMED; Web of Science; BIOSIS Previews; Cambridge Scientific Abstracts; ICTRP and additional sources for published and unpublished trials. The date of the most recent search was 12 March 2012. Adults (18 years and over) complaining of tinnitus or adults with a primary complaint of cerebral insufficiency, where tinnitus forms part of the syndrome. Both original authors independently extracted data and assessed trials for quality. For the 2012 update two authors determined trial eligibility, extracted data, analysed data and updated the contents of the review. Four trials with a total of 1543 participants were included in the review; we assessed all the included studies as having a low risk of bias.Three trials (1143 participants) included patients with a primary complaint of tinnitus and one (400 participants) included patients with mild to moderate dementia, some of whom had tinnitus.There was no evidence that Gingko biloba was effective in patients with a primary complaint of tinnitus. In the study of patients with dementia, mean baseline levels of tinnitus were low (1.7 to 2.5 on a 10-point subjective symptom rating scale).A small but statistically significant reduction of 1.5 and 0.7 points was seen in patients taking Gingko biloba with vascular dementia and Alzheimer's disease respectively.The practical clinical significance of this is unclear.The incidence of side effects was low. The limited evidence does not demonstrate that Ginkgo biloba is effective for tinnitus when this is the primary complaint.