Papers by Magdalena Sereda
PloS one, 2015
Tinnitus is the perception of an internally generated sound that is postulated to emerge as a res... more Tinnitus is the perception of an internally generated sound that is postulated to emerge as a result of structural and functional changes in the brain. However, the precise pathophysiology of tinnitus remains unknown. Llinas' thalamocortical dysrhythmia model suggests that neural deafferentation due to hearing loss causes a dysregulation of coherent activity between thalamus and auditory cortex. This leads to a pathological coupling of theta and gamma oscillatory activity in the resting state, localised to the auditory cortex where normally alpha oscillations should occur. Numerous studies also suggest that tinnitus perception relies on the interplay between auditory and non-auditory brain areas. According to the Global Brain Model, a network of global fronto-parietal-cingulate areas is important in the generation and maintenance of the conscious perception of tinnitus. Thus, the distress experienced by many individuals with tinnitus is related to the top-down influence of this ...
International journal of audiology, Jan 3, 2014
Objective: Psychoacoustic measures of tinnitus, in particular dominant tinnitus pitch and its rel... more Objective: Psychoacoustic measures of tinnitus, in particular dominant tinnitus pitch and its relationship to the shape of the audiogram, are important in determining and verifying pathophysiological mechanisms of the condition. Our previous study postulated that this relationship might vary between different groups of people with tinnitus. For a small subset of participants with narrow tinnitus bandwidth, pitch was associated with the audiometric edge, consistent with the tonotopic reorganization theory. The current study objective was to establish this relationship in an independent sample. Design: This was a retrospective design using data from five studies conducted between 2008 and 2013. Study sample: From a cohort of 380 participants, a subgroup group of 129 with narrow tinnitus bandwidth were selected. Results: Tinnitus pitch generally fell within the area of hearing loss. There was a statistically significant correlation between dominant tinnitus pitch and edge frequency; hi...
PloS one, 2014
Previous studies of frequency discrimination training (FDT) for tinnitus used repetitive task-bas... more Previous studies of frequency discrimination training (FDT) for tinnitus used repetitive task-based training programmes relying on extrinsic factors to motivate participation. Studies reported limited improvement in tinnitus symptoms. To evaluate FDT exploiting intrinsic motivations by integrating training with computer-gameplay. Sixty participants were randomly assigned to train on either a conventional task-based training, or one of two interactive game-based training platforms over six weeks. Outcomes included assessment of motivation, tinnitus handicap, and performance on tests of attention. Participants reported greater intrinsic motivation to train on the interactive game-based platforms, yet compliance of all three groups was similar (∼ 70%) and changes in self-reported tinnitus severity were not significant. There was no difference between groups in terms of change in tinnitus severity or performance on measures of attention. FDT can be integrated within an intrinsically mot...
Ear and hearing, Jan 13, 2015
In many countries including the United Kingdom, hearing aids are a first line of audiologic inter... more In many countries including the United Kingdom, hearing aids are a first line of audiologic intervention for many people with tinnitus and aidable hearing loss. Nevertheless, there is a lack of high quality evidence to support that they are of benefit for tinnitus, and wide variability in their use in clinical practice especially for people with mild hearing loss. The aim of this study was to identify a consensus among a sample of UK clinicians on the criteria for hearing aid candidature and clinical practice in fitting hearing aids specifically for mild hearing loss with and without tinnitus. This will allow professionals to establish clinical benchmarks and to gauge their practice with that used elsewhere. The Delphi technique, a systematic methodology that seeks consensus amongst experts through consultation using a series of iterative questionnaires, was used. A three-round Delphi survey explored clinical consensus among a panel of 29 UK hearing professionals. The authors measur...
Noise and Health, 2013
The past decade has seen an escalating enthusiasm to comprehend chronic tinnitus from the perspec... more The past decade has seen an escalating enthusiasm to comprehend chronic tinnitus from the perspective of both scientific understanding and clinical management. At the same time, there is a significant interest and commercial investment in providing targeted and individualized approaches to care, which incorporate novel sound-based technologies, with standard audiological and psychological strategies. Commercially produced sound-based devices for the tinnitus market include Co-ordinated Reset Neuromodulation ® , Neuromonics © , Serenade ® , and Widex ® Zen. Additionally, experimental interventions such as those based on frequency-discrimination training are of current interest. Many of these interventions overtly claim to target the underlying neurological causes of tinnitus. Here, we briefly summarize current perspectives on the pathophysiology of tinnitus and evaluate claims made by the device supporters from a critical point of view. We provide an opinion on how future research in the field of individualized sound-based interventions might best provide a reliable evidence-base in this growing area of translational medicine.
Journal of the Association for Research in Otolaryngology, 2012
Tinnitus is an auditory phenomenon characterised by the perception of a sound in the absence of a... more Tinnitus is an auditory phenomenon characterised by the perception of a sound in the absence of an external auditory stimulus. Chronic subjective tinnitus is almost certainly maintained via central mechanisms, and this is consistent with observed measures of altered spontaneous brain activity. A number of putative central auditory mechanisms for tinnitus have been proposed. The influential thalamocortical dysrhythmia model suggests that tinnitus can be attributed to the disruption of coherent oscillatory activity between thalamus and cortex following hearing loss. However, the extent to which this disruption specifically contributes to tinnitus or is simply a consequence of the hearing loss is unclear because the necessary matched controls have not been tested. Here, we rigorously test several predictions made by this model in four groups of participants (tinnitus with hearing loss, tinnitus with clinically normal hearing, no tinnitus with hearing loss and no tinnitus with clinically normal hearing). Magnetoencephalography was used to measure oscillatory brain activity within different frequency bands in a 'resting' state and during presentation of a masking noise. Results revealed that low-frequency activity in the delta band (1-4 Hz) was significantly higher in the 'tinnitus with hearing loss' group compared to the 'no tinnitus with normal hearing' group. A planned comparison indicated that this effect was unlikely to be driven by the hearing loss alone, but could possibly be a consequence of tinnitus and hearing loss. A further interpretative linkage to tinnitus was given by the result that the delta activity tended to reduce when tinnitus was masked. High-frequency activity in the gamma band (25-80 Hz) was not correlated with tinnitus (or hearing loss). The findings partly support the thalamocortical dysrhythmia model and suggest that slow-wave (delta band) activity may be a more reliable correlate of tinnitus than high-frequency activity.
Hearing Research, 2009
In this review, we highlight the contribution of advances in human neuroimaging to the current un... more In this review, we highlight the contribution of advances in human neuroimaging to the current understanding of central mechanisms underpinning tinnitus and explain how interpretations of neuroimaging data have been guided by animal models. The primary motivation for studying the neural substrates of tinnitus in humans has been to demonstrate objectively its representation in the central auditory system and to develop a better understanding of its diverse pathophysiology and of the functional interplay between sensory, cognitive and affective systems. The ultimate goal of neuroimaging is to identify subtypes of tinnitus in order to better inform treatment strategies. The three neural mechanisms considered in this review may provide a basis for TI classification. While human neuroimaging evidence strongly implicates the central auditory system and emotional centres in TI, evidence for the precise contribution from the three mechanisms is unclear because the data are somewhat inconsistent. We consider a number of methodological issues limiting the field of human neuroimaging and recommend approaches to overcome potential inconsistency in results arising from poorly matched participants, lack of appropriate controls and low statistical power.
Hearing Research, 2013
Some forms of tinnitus are likely to be perceptual consequences of altered neural activity in the... more Some forms of tinnitus are likely to be perceptual consequences of altered neural activity in the central auditory system triggered by damage to the auditory periphery. Animal studies report changes in the evoked responses after noise exposure or ototoxic drugs in inferior colliculus and auditory cortex. However, human electrophysiological evidence is rather equivocal: increased, reduced or no difference in N1/N1m evoked amplitudes and latencies in tinnitus participants have been reported. The present study used magnetoencephalography to seek evidence for altered evoked responses in people with tinnitus compared to controls (hearing loss matched and normal hearing) in four different stimulus categories (a control tone, a tone corresponding to the audiometric edge, to the dominant tinnitus pitch and a tone within the area of hearing loss). Results revealed that amplitudes of the evoked responses differed depending on the tone category. N1m amplitude to the dominant tinnitus pitch and the frequency within the area of hearing loss were reduced compared to the other two categories. Given that tinnitus pitch is typically within the area of hearing loss, the differences in the evoked responses pattern in tinnitus participants seem to be related more to the hearing loss than to the presence of tinnitus.
International Journal of Audiology, 2011
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Papers by Magdalena Sereda