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Smeele SJ, Adhia DB, De Ridder D. Feasibility and Safety of High-Definition Infraslow Pink Noise Stimulation for Treating Chronic Tinnitus—A Randomized Placebo-Controlled Trial. Neuromodulation 2022:S1094-7159(22)01339-3. [DOI: 10.1016/j.neurom.2022.10.049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 10/18/2022] [Accepted: 10/19/2022] [Indexed: 12/03/2022]
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A Preliminary Investigation Report on Using Probabilistic Fiber Tractography to Track Human Auditory Pathways. World Neurosurg 2019; 130:e1-e8. [DOI: 10.1016/j.wneu.2019.03.066] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 03/06/2019] [Accepted: 03/07/2019] [Indexed: 01/09/2023]
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Edlow BL, Chatelle C, Spencer CA, Chu CJ, Bodien YG, O'Connor KL, Hirschberg RE, Hochberg LR, Giacino JT, Rosenthal ES, Wu O. Early detection of consciousness in patients with acute severe traumatic brain injury. Brain 2017; 140:2399-2414. [PMID: 29050383 DOI: 10.1093/brain/awx176] [Citation(s) in RCA: 205] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 05/29/2017] [Indexed: 01/03/2023] Open
Abstract
See Schiff (doi:10.1093/awx209) for a scientific commentary on this article. Patients with acute severe traumatic brain injury may recover consciousness before self-expression. Without behavioural evidence of consciousness at the bedside, clinicians may render an inaccurate prognosis, increasing the likelihood of withholding life-sustaining therapies or denying rehabilitative services. Task-based functional magnetic resonance imaging and electroencephalography techniques have revealed covert consciousness in the chronic setting, but these techniques have not been tested in the intensive care unit. We prospectively enrolled 16 patients admitted to the intensive care unit for acute severe traumatic brain injury to test two hypotheses: (i) in patients who lack behavioural evidence of language expression and comprehension, functional magnetic resonance imaging and electroencephalography detect command-following during a motor imagery task (i.e. cognitive motor dissociation) and association cortex responses during language and music stimuli (i.e. higher-order cortex motor dissociation); and (ii) early responses to these paradigms are associated with better 6-month outcomes on the Glasgow Outcome Scale-Extended. Patients underwent functional magnetic resonance imaging on post-injury Day 9.2 ± 5.0 and electroencephalography on Day 9.8 ± 4.6. At the time of imaging, behavioural evaluation with the Coma Recovery Scale-Revised indicated coma (n = 2), vegetative state (n = 3), minimally conscious state without language (n = 3), minimally conscious state with language (n = 4) or post-traumatic confusional state (n = 4). Cognitive motor dissociation was identified in four patients, including three whose behavioural diagnosis suggested a vegetative state. Higher-order cortex motor dissociation was identified in two additional patients. Complete absence of responses to language, music and motor imagery was only observed in coma patients. In patients with behavioural evidence of language function, responses to language and music were more frequently observed than responses to motor imagery (62.5-80% versus 33.3-42.9%). Similarly, in 16 matched healthy subjects, responses to language and music were more frequently observed than responses to motor imagery (87.5-100% versus 68.8-75.0%). Except for one patient who died in the intensive care unit, all patients with cognitive motor dissociation and higher-order cortex motor dissociation recovered beyond a confusional state by 6 months. However, 6-month outcomes were not associated with early functional magnetic resonance imaging and electroencephalography responses for the entire cohort. These observations suggest that functional magnetic resonance imaging and electroencephalography can detect command-following and higher-order cortical function in patients with acute severe traumatic brain injury. Early detection of covert consciousness and cortical responses in the intensive care unit could alter time-sensitive decisions about withholding life-sustaining therapies.
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Affiliation(s)
- Brian L Edlow
- Center for Neurotechnology and Neurorecovery, Massachusetts General Hospital, 175 Cambridge Street, Boston, MA, 02114, USA.,Department of Neurology, Massachusetts General Hospital, Harvard Medical School, 175 Cambridge Street, Boston, MA, 02114, USA.,Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 149 13th Street, Charlestown, MA 02129, USA
| | - Camille Chatelle
- Center for Neurotechnology and Neurorecovery, Massachusetts General Hospital, 175 Cambridge Street, Boston, MA, 02114, USA.,Department of Neurology, Massachusetts General Hospital, Harvard Medical School, 175 Cambridge Street, Boston, MA, 02114, USA.,Coma Science Group, GIGA Consciousness, University and University Hospital of Liège, Liège, Belgium
| | - Camille A Spencer
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, 175 Cambridge Street, Boston, MA, 02114, USA
| | - Catherine J Chu
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, 175 Cambridge Street, Boston, MA, 02114, USA
| | - Yelena G Bodien
- Center for Neurotechnology and Neurorecovery, Massachusetts General Hospital, 175 Cambridge Street, Boston, MA, 02114, USA.,Department of Neurology, Massachusetts General Hospital, Harvard Medical School, 175 Cambridge Street, Boston, MA, 02114, USA.,Department of Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital, Harvard Medical School, 300 First Avenue, Charlestown, MA, 02129, USA
| | - Kathryn L O'Connor
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, 175 Cambridge Street, Boston, MA, 02114, USA
| | - Ronald E Hirschberg
- Department of Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital, Harvard Medical School, 300 First Avenue, Charlestown, MA, 02129, USA.,Department of Physical Medicine and Rehabilitation, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, Boston, MA, 02114, USA
| | - Leigh R Hochberg
- Center for Neurotechnology and Neurorecovery, Massachusetts General Hospital, 175 Cambridge Street, Boston, MA, 02114, USA.,Department of Neurology, Massachusetts General Hospital, Harvard Medical School, 175 Cambridge Street, Boston, MA, 02114, USA.,Department of Engineering, Brown University, 184 Hope St, Providence, RI, 02912, USA
| | - Joseph T Giacino
- Department of Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital, Harvard Medical School, 300 First Avenue, Charlestown, MA, 02129, USA.,Department of Physical Medicine and Rehabilitation, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, Boston, MA, 02114, USA
| | - Eric S Rosenthal
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, 175 Cambridge Street, Boston, MA, 02114, USA
| | - Ona Wu
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 149 13th Street, Charlestown, MA 02129, USA
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Bach JP, Lüpke M, Dziallas P, Wefstaedt P, Uppenkamp S, Seifert H, Nolte I. Auditory functional magnetic resonance imaging in dogs--normalization and group analysis and the processing of pitch in the canine auditory pathways. BMC Vet Res 2016; 12:32. [PMID: 26897016 PMCID: PMC4761139 DOI: 10.1186/s12917-016-0660-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 12/04/2015] [Indexed: 11/10/2022] Open
Abstract
Background Functional magnetic resonance imaging (fMRI) is an advanced and frequently used technique for studying brain functions in humans and increasingly so in animals. A key element of analyzing fMRI data is group analysis, for which valid spatial normalization is a prerequisite. In the current study we applied normalization and group analysis to a dataset from an auditory functional MRI experiment in anesthetized beagles. The stimulation paradigm used in the experiment was composed of simple Gaussian noise and regular interval sounds (RIS), which included a periodicity pitch as an additional sound feature. The results from the performed group analysis were compared with those from single animal analysis. In addition to this, the data were examined for brain regions showing an increased activation associated with the perception of pitch. Results With the group analysis, significant activations matching the position of the right superior olivary nucleus, lateral lemniscus and internal capsule were identified, which could not be detected in the single animal analysis. In addition, a large cluster of activated voxels in the auditory cortex was found. The contrast of the RIS condition (including pitch) with Gaussian noise (no pitch) showed a significant effect in a region matching the location of the left medial geniculate nucleus. Conclusion By using group analysis additional activated areas along the canine auditory pathways could be identified in comparison to single animal analysis. It was possible to demonstrate a pitch-specific effect, indicating that group analysis is a suitable method for improving the results of auditory fMRI studies in dogs and extending our knowledge of canine neuroanatomy.
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Affiliation(s)
- Jan-Peter Bach
- Klinik für Kleintiere, Stiftung Tierärztliche Hochschule Hannover, Bünteweg 9, 30559, Hannover, Germany.
| | - Matthias Lüpke
- Fachgebiet für Allgemeine Radiologie und Medizinische Physik, Stiftung Tierärztliche Hochschule Hannover, Bischofsholer Damm 15, 30173, Hannover, Germany.
| | - Peter Dziallas
- Klinik für Kleintiere, Stiftung Tierärztliche Hochschule Hannover, Bünteweg 9, 30559, Hannover, Germany.
| | - Patrick Wefstaedt
- Klinik für Kleintiere, Stiftung Tierärztliche Hochschule Hannover, Bünteweg 9, 30559, Hannover, Germany.
| | - Stefan Uppenkamp
- Medizinische Physik, Universität Oldenburg, 26111, Oldenburg, Germany.
| | - Hermann Seifert
- Fachgebiet für Allgemeine Radiologie und Medizinische Physik, Stiftung Tierärztliche Hochschule Hannover, Bischofsholer Damm 15, 30173, Hannover, Germany.
| | - Ingo Nolte
- Klinik für Kleintiere, Stiftung Tierärztliche Hochschule Hannover, Bünteweg 9, 30559, Hannover, Germany.
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5
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Bach JP, Lüpke M, Dziallas P, Wefstaedt P, Uppenkamp S, Seifert H, Nolte I. Functional magnetic resonance imaging of the ascending stages of the auditory system in dogs. BMC Vet Res 2013; 9:210. [PMID: 24131784 PMCID: PMC3854503 DOI: 10.1186/1746-6148-9-210] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Accepted: 10/11/2013] [Indexed: 11/21/2022] Open
Abstract
Background Functional magnetic resonance imaging (fMRI) is a technique able to localize neural activity in the brain by detecting associated changes in blood flow. It is an essential tool for studying human functional neuroanatomy including the auditory system. There are only a few studies, however, using fMRI to study canine brain functions. In the current study ten anesthetized dogs were scanned during auditory stimulation. Two functional sequences, each in combination with a suitable stimulation paradigm, were used in each subject. Sequence 1 provided periods of silence during which acoustic stimuli could be presented unmasked by scanner noise (sparse temporal sampling) whereas in sequence 2 the scanner noise was present throughout the entire session (continuous imaging). The results obtained with the two different functional sequences were compared. Results This study shows that with the proper experimental setup it is possible to detect neural activity in the auditory system of dogs. In contrast to human fMRI studies the strongest activity was found in the subcortical parts of the auditory pathways. Especially sequence 1 showed a high reliability in detecting activated voxels in brain regions associated with the auditory system. Conclusion These results indicate that fMRI is applicable for studying the canine auditory system and could become an additional method for the clinical evaluation of the auditory function of dogs. Additionally, fMRI is an interesting technique for future studies concerned with canine functional neuroanatomy.
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Affiliation(s)
| | - Matthias Lüpke
- Institute for General Radiology and Medical Physics, University of Veterinary Medicine Hannover, Foundation, Germany.
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Javad F, Warren JD, Micallef C, Thornton JS, Golay X, Yousry T, Mancini L. Auditory tracts identified with combined fMRI and diffusion tractography. Neuroimage 2013; 84:562-74. [PMID: 24051357 PMCID: PMC3898984 DOI: 10.1016/j.neuroimage.2013.09.007] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Revised: 08/16/2013] [Accepted: 09/09/2013] [Indexed: 01/08/2023] Open
Abstract
The auditory tracts in the human brain connect the inferior colliculus (IC) and medial geniculate body (MGB) to various components of the auditory cortex (AC). While in non-human primates and in humans, the auditory system is differentiated in core, belt and parabelt areas, the correspondence between these areas and anatomical landmarks on the human superior temporal gyri is not straightforward, and at present not completely understood. However it is not controversial that there is a hierarchical organization of auditory stimuli processing in the auditory system. The aims of this study were to demonstrate that it is possible to non-invasively and robustly identify auditory projections between the auditory thalamus/brainstem and different functional levels of auditory analysis in the cortex of human subjects in vivo combining functional magnetic resonance imaging (fMRI) with diffusion MRI, and to investigate the possibility of differentiating between different components of the auditory pathways (e.g. projections to areas responsible for sound, pitch and melody processing). We hypothesized that the major limitation in the identification of the auditory pathways is the known problem of crossing fibres and addressed this issue acquiring DTI with b-values higher than commonly used and adopting a multi-fibre ball-and-stick analysis model combined with probabilistic tractography. Fourteen healthy subjects were studied. Auditory areas were localized functionally using an established hierarchical pitch processing fMRI paradigm. Together fMRI and diffusion MRI allowed the successful identification of tracts connecting IC with AC in 64 to 86% of hemispheres and left sound areas with homologous areas in the right hemisphere in 86% of hemispheres. The identified tracts corresponded closely with a three-dimensional stereotaxic atlas based on postmortem data. The findings have both neuroscientific and clinical implications for delineation of the human auditory system in vivo.
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Affiliation(s)
- Faiza Javad
- Neuroradiological Academic Unit, Department of Brain Repair and Rehabilitation, UCL Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
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Langers DRM, Melcher JR. Hearing without listening: functional connectivity reveals the engagement of multiple nonauditory networks during basic sound processing. Brain Connect 2013; 1:233-44. [PMID: 22433051 DOI: 10.1089/brain.2011.0023] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The present functional magnetic resonance imaging (fMRI) study presents data challenging the traditional view that sound is processed almost exclusively in the classical auditory pathway unless imbued with behavioral significance. In a first experiment, subjects were presented with broadband noise in on/off fashion as they performed an unrelated visual task. A conventional analysis assuming predictable sound-evoked responses demonstrated a typical activation pattern that was confined to classical auditory centers. In contrast, spatial independent component analysis (sICA) disclosed multiple networks of acoustically responsive brain centers. One network comprised classical auditory centers, but four others included nominally "nonauditory" areas: cingulo-insular cortex, mediotemporal limbic lobe, basal ganglia, and posterior orbitofrontal cortex, respectively. Functional connectivity analyses confirmed the sICA results by demonstrating coordinated activity between the involved brain structures. In a second experiment, fMRI data obtained from unstimulated (i.e., resting) subjects revealed largely similar networks. Together, these two experiments suggest the existence of a coordinated system of multiple acoustically responsive intrinsic brain networks, comprising classical auditory centers but also other brain areas. Our results suggest that nonauditory centers play a role in sound processing at a very basic level, even when the sound is not intertwined with behaviors requiring the well-known functionality of these regions.
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Affiliation(s)
- Dave R M Langers
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, USA.
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8
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Perspective of functional magnetic resonance imaging in middle ear research. Hear Res 2013; 301:183-92. [PMID: 23291496 DOI: 10.1016/j.heares.2012.12.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Revised: 11/26/2012] [Accepted: 12/19/2012] [Indexed: 11/20/2022]
Abstract
Functional magnetic resonance imaging (MRI) studies have frequently been applied to study sensory system such as vision, language, and cognition, but have proceeded at a considerably slower speed in investigating middle ear and central auditory processing. This is due to several factors, including the intrinsic anatomy of the middle ear system and inherent acoustic noise during acquisition of MRI data. However, accumulating evidences have demonstrated that clarification of some fundamental neural underpinnings of audition associated with middle ear mechanics can be achieved using functional MRI methods. This mini review attempted to take a narrow snapshot of the currently available functional MRI procedures and gave examples of what may be learned about hearing from their application. It is hoped that with these technical advancements, many new high impact applications in audition would follow. In particular, because the fMRI can be used in humans and in animals, fMRI may represent a unique tool that should promote translational research by enabling parallel analyses of physiological and pathological processes in the human and animal auditory system. This article is part of a special issue entitled "MEMRO 2012".
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9
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Langguth B, De Ridder D. Tinnitus: therapeutic use of superficial brain stimulation. HANDBOOK OF CLINICAL NEUROLOGY 2013; 116:441-467. [PMID: 24112915 DOI: 10.1016/b978-0-444-53497-2.00036-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Tinnitus is a common disorder and traditional treatment approaches such as medication, active or passive sound enhancement, and cognitive behavioral therapy have limited efficacy. Thus, there is an urgent need for more effective treatment approaches. Functional imaging studies in patients with tinnitus have revealed alterations in neuronal activity of central auditory pathways, probably resulting as a consequence of sensory deafferentation. However, nonauditory brain areas are also involved. These nonauditory brain areas might represent both an "awareness" network involved in the conscious perception of the tinnitus signal as well as areas related to a nontinnitus-specific distress network consisting of the anterior cingulate cortex, anterior insula, and amygdala. Moreover, memory mechanisms involving the hippocampus and the parahippocampal region may play a role in the persistence of the awareness of the phantom percept, as well as in the reinforcement of the associated distress. All of these networks represent potential targets for treatment via pharmacological treatment or noninvasive and invasive brain stimulation. Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive method of applying electromagnetic fields to the brain that can induce alterations of neuronal activity that outlast the stimulation period. Single sessions of rTMS over the temporal or temporoparietal cortex have been successful in transiently reducing tinnitus perception. Repeated sessions of rTMS have resulted in tinnitus relief in a subgroup of patients, lasting from several days to several months. However, effect sizes of rTMS in the treatment of tinnitus are only moderate, and interindividual variability is high. Larger and longer lasting effects have been observed with direct electrical stimulation of the auditory cortex via implanted epidural electrodes. Transcranial direct current stimulation (tDCS) has also shown potential for the treatment of tinnitus. Both auditory and frontal tDCS have shown tinnitus reduction in a subgroup of patients. In spite of the promising results of the different brain stimulation approaches, further research is needed before these techniques can be recommended for routine clinical use.
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Affiliation(s)
- Berthold Langguth
- Interdisciplinary Tinnitus Clinic, Department of Psychiatry and Psychotherapy, University of Regensburg, Regensburg, Germany.
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10
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Functional magnetic resonance imaging of sound pressure level encoding in the rat central auditory system. Neuroimage 2012; 65:119-26. [PMID: 23041525 DOI: 10.1016/j.neuroimage.2012.09.069] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Revised: 09/27/2012] [Accepted: 09/28/2012] [Indexed: 01/23/2023] Open
Abstract
Intensity is an important physical property of a sound wave and is customarily reported as sound pressure level (SPL). Invasive techniques such as electrical recordings, which typically examine one brain region at a time, have been used to study neuronal encoding of SPL throughout the central auditory system. Non-invasive functional magnetic resonance imaging (fMRI) with large field of view can simultaneously examine multiple auditory structures. We applied fMRI to measure the hemodynamic responses in the rat brain during sound stimulation at seven SPLs over a 72 dB range. This study used a sparse temporal sampling paradigm to reduce the adverse effects of scanner noise. Hemodynamic responses were measured from the central nucleus of the inferior colliculus (CIC), external cortex of the inferior colliculus (ECIC), lateral lemniscus (LL), medial geniculate body (MGB), and auditory cortex (AC). BOLD signal changes generally increase significantly (p<0.001) with SPL and the dependence is monotonic in CIC, ECIC, and LL. The ECIC has higher BOLD signal change than CIC and LL at high SPLs. The difference between BOLD signal changes at high and low SPLs is less in the MGB and AC. This suggests that the SPL dependences of the LL and IC are different from those in the MGB and AC and the SPL dependence of the CIC is different from that of the ECIC. These observations are likely related to earlier observations that neurons with firing rates that increase monotonically with SPL are dominant in the CIC, ECIC, and LL while non-monotonic neurons are dominant in the MGB and AC. Further, the IC's SPL dependence measured in this study is very similar to that measured in our earlier study using the continuous imaging method. Therefore, sparse temporal sampling may not be a prerequisite in auditory fMRI studies of the IC.
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Langguth B, Schecklmann M, Lehner A, Landgrebe M, Poeppl TB, Kreuzer PM, Schlee W, Weisz N, Vanneste S, De Ridder D. Neuroimaging and neuromodulation: complementary approaches for identifying the neuronal correlates of tinnitus. Front Syst Neurosci 2012; 6:15. [PMID: 22509155 PMCID: PMC3321434 DOI: 10.3389/fnsys.2012.00015] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Accepted: 03/01/2012] [Indexed: 11/13/2022] Open
Abstract
An inherent limitation of functional imaging studies is their correlational approach. More information about critical contributions of specific brain regions can be gained by focal transient perturbation of neural activity in specific regions with non-invasive focal brain stimulation methods. Functional imaging studies have revealed that tinnitus is related to alterations in neuronal activity of central auditory pathways. Modulation of neuronal activity in auditory cortical areas by repetitive transcranial magnetic stimulation (rTMS) can reduce tinnitus loudness and, if applied repeatedly, exerts therapeutic effects, confirming the relevance of auditory cortex activation for tinnitus generation and persistence. Measurements of oscillatory brain activity before and after rTMS demonstrate that the same stimulation protocol has different effects on brain activity in different patients, presumably related to interindividual differences in baseline activity in the clinically heterogeneous study cohort. In addition to alterations in auditory pathways, imaging techniques also indicate the involvement of non-auditory brain areas, such as the fronto-parietal "awareness" network and the non-tinnitus-specific distress network consisting of the anterior cingulate cortex, anterior insula, and amygdale. Involvement of the hippocampus and the parahippocampal region putatively reflects the relevance of memory mechanisms in the persistence of the phantom percept and the associated distress. Preliminary studies targeting the dorsolateral prefrontal cortex, the dorsal anterior cingulate cortex, and the parietal cortex with rTMS and with transcranial direct current stimulation confirm the relevance of the mentioned non-auditory networks. Available data indicate the important value added by brain stimulation as a complementary approach to neuroimaging for identifying the neuronal correlates of the various clinical aspects of tinnitus.
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Affiliation(s)
- Berthold Langguth
- Department of Psychiatry and Psychotherapy, University of Regensburg Regensburg, Germany
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12
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Lefaucheur JP, Brugières P, Guimont F, Iglesias S, Franco-Rodrigues A, Liégeois-Chauvel C, Londero A. Navigated rTMS for the treatment of tinnitus: A pilot study with assessment by fMRI and AEPs. Neurophysiol Clin 2012; 42:95-109. [DOI: 10.1016/j.neucli.2011.12.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Revised: 12/03/2011] [Accepted: 12/18/2011] [Indexed: 10/14/2022] Open
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Job A, Pons Y, Lamalle L, Jaillard A, Buck K, Segebarth C, Delon‐Martin C. Abnormal cortical sensorimotor activity during "Target" sound detection in subjects with acute acoustic trauma sequelae: an fMRI study. Brain Behav 2012; 2:187-99. [PMID: 22574285 PMCID: PMC3345361 DOI: 10.1002/brb3.21] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2011] [Revised: 08/18/2011] [Accepted: 08/31/2011] [Indexed: 11/26/2022] Open
Abstract
The most common consequences of acute acoustic trauma (AAT) are hearing loss at frequencies above 3 kHz and tinnitus. In this study, we have used functional Magnetic Resonance Imaging (fMRI) to visualize neuronal activation patterns in military adults with AAT and various tinnitus sequelae during an auditory "oddball" attention task. AAT subjects displayed overactivities principally during reflex of target sound detection, in sensorimotor areas and in emotion-related areas such as the insula, anterior cingulate and prefrontal cortex, in premotor area, in cross-modal sensory associative areas, and, interestingly, in a region of the Rolandic operculum that has recently been shown to be involved in tympanic movements due to air pressure. We propose further investigations of this brain area and fine middle ear investigations, because our results might suggest a model in which AAT tinnitus may arise as a proprioceptive illusion caused by abnormal excitability of middle-ear muscle spindles possibly link with the acoustic reflex and associated with emotional and sensorimotor disturbances.
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Affiliation(s)
- Agnès Job
- Institut de Recherche Biomédicale des Armées, antenne CRSSA, La Tronche, France
| | - Yoann Pons
- Hôpital d’instruction des Armées du Val‐de‐Grâce, 75 bld de Port‐Royal, Paris, France
| | | | | | - Karl Buck
- Institut franco‐allemand de recherche de Saint‐Louis, Saint Louis, France
| | - Christoph Segebarth
- INSERM U836, Grenoble Institut des Neurosciences, Grenoble, France
- Université Joseph Fourier, 38702 La Tronche, France
| | - Chantal Delon‐Martin
- INSERM U836, Grenoble Institut des Neurosciences, Grenoble, France
- Université Joseph Fourier, 38702 La Tronche, France
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Smits M, Visch-Brink EG, van de Sandt-Koenderman ME, van der Lugt A. Advanced Magnetic Resonance Neuroimaging of Language Function Recovery After Aphasic Stroke: A Technical Review. Arch Phys Med Rehabil 2012; 93:S4-14. [DOI: 10.1016/j.apmr.2011.02.023] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2010] [Revised: 02/18/2011] [Accepted: 02/22/2011] [Indexed: 10/14/2022]
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Joly O, Ramus F, Pressnitzer D, Vanduffel W, Orban GA. Interhemispheric Differences in Auditory Processing Revealed by fMRI in Awake Rhesus Monkeys. Cereb Cortex 2011; 22:838-53. [DOI: 10.1093/cercor/bhr150] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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16
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De Ridder D, van der Loo E, Vanneste S, Gais S, Plazier M, Kovacs S, Sunaert S, Menovsky T, van de Heyning P. Theta-gamma dysrhythmia and auditory phantom perception. J Neurosurg 2011; 114:912-21. [DOI: 10.3171/2010.11.jns10335] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Tinnitus is considered an auditory phantom percept analogous to phantom pain. Thalamocortical dysrhythmia has been proposed as a possible pathophysiological mechanism for both tinnitus and pain. Thalamocortical dysrhythmia refers to a persistent pathological resting state theta-gamma coupling that is spatially localized at an area where normally alpha oscillations predominate. Auditory cortex stimulation via implanted electrodes has been developed to treat tinnitus, targeting an area of activation on functional MR imaging elicited by tinnitus-matched sound presentation. The authors describe a case in which clinical improvement was correlated with changes in intracranial recordings. Maximal tinnitus suppression was obtained by current delivery exactly at the blood oxygen level–dependent activation hotspot, which colocalizes with increased gamma and theta activity, in contrast to the other electrode poles, which demonstrated a normal alpha peak. These spectral changes normalized when stimulation induced tinnitus suppression, both on electrode and source-localized electroencephalography recordings. These data suggest that thetagamma coupling as proposed by the thalamocortical dysrhythmia model might be causally related to a conscious auditory phantom percept.
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Affiliation(s)
- Dirk De Ridder
- 1Brai2n,
- 2Tinnitus Research Initiative,
- 3Department of Neurosurgery, and
| | - Elsa van der Loo
- 1Brai2n,
- 2Tinnitus Research Initiative,
- 3Department of Neurosurgery, and
| | - Sven Vanneste
- 1Brai2n,
- 2Tinnitus Research Initiative,
- 3Department of Neurosurgery, and
| | - Steffen Gais
- 4General and Experimental Psychology, Ludwig-Maximilians-Universität München, Germany
| | - Mark Plazier
- 1Brai2n,
- 2Tinnitus Research Initiative,
- 3Department of Neurosurgery, and
| | - Silvia Kovacs
- 5Department of Radiology, University Hospital Leuven, Belgium; and
| | - Stefan Sunaert
- 5Department of Radiology, University Hospital Leuven, Belgium; and
| | - Tomas Menovsky
- 1Brai2n,
- 2Tinnitus Research Initiative,
- 3Department of Neurosurgery, and
| | - Paul van de Heyning
- 1Brai2n,
- 2Tinnitus Research Initiative,
- 6Department of ENT, University Hospital Antwerp
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17
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De Ridder D, Vanneste S, Kovacs S, Sunaert S, Menovsky T, van de Heyning P, Moller A. Transcranial magnetic stimulation and extradural electrodes implanted on secondary auditory cortex for tinnitus suppression. J Neurosurg 2011; 114:903-11. [DOI: 10.3171/2010.11.jns10197] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Object
Tinnitus is a prevalent symptom, with clinical, pathophysiological, and treatment features analogous to pain. Noninvasive transcranial magnetic stimulation (TMS) and intracranial auditory cortex stimulation (ACS) via implanted electrodes into the primary or overlying the secondary auditory cortex have been developed to treat severe cases of intractable tinnitus.
Methods
A series of 43 patients who benefited transiently from 2 separate placebo-controlled TMS sessions underwent implantation of auditory cortex electrodes. Targeting was based on blood oxygen level–dependent activation evoked by tinnitus-matched sound, using functional MR imaging–guided neuronavigation.
Results
Thirty-seven percent of the patients responded to ACS with tonic stimulation. Of the 63% who were nonresponders, half benefited from burst stimulation. In total, 33% remained unaffected by the ACS. The average tinnitus reduction was 53% for the entire group. Burst stimulation was capable of suppressing tinnitus in more patients and was better than tonic stimulation, especially for noise-like tinnitus. For pure tone tinnitus, there were no differences between the 2 stimulation designs. The average pure tone tinnitus improvement was 71% versus 37% for noise-like tinnitus and 29% for a combination of both pure tone and noise-like tinnitus. Transcranial magnetic stimulation did not predict response to ACS, but in ACS responders, a correlation (r = 0.38) between the amount of TMS and ACS existed. A patient's sex, age, or tinnitus duration did not influence treatment outcome.
Conclusions
Intracranial ACS might become a valuable treatment option for severe intractable tinnitus. Better understanding of the pathophysiological mechanisms of tinnitus, predictive functional imaging tests, new stimulation designs, and other stimulation targets are needed to improve ACS results.
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Affiliation(s)
- Dirk De Ridder
- 1Brai2n,
- 2Tinnitus Research Initiative,
- 3Department of Neurosurgery, and
| | - Sven Vanneste
- 1Brai2n,
- 2Tinnitus Research Initiative,
- 3Department of Neurosurgery, and
| | - Silvia Kovacs
- 4Department of Radiology, University Hospital Leuven, Belgium; and
| | - Stefan Sunaert
- 4Department of Radiology, University Hospital Leuven, Belgium; and
| | - Tomas Menovsky
- 1Brai2n,
- 2Tinnitus Research Initiative,
- 3Department of Neurosurgery, and
| | - Paul van de Heyning
- 1Brai2n,
- 2Tinnitus Research Initiative,
- 5Department of ENT, University Hospital Antwerp
| | - Aage Moller
- 6Callier Center for Communication Disorders, University of Texas at Dallas, Texas
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18
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Wildenberg JC, Tyler ME, Danilov YP, Kaczmarek KA, Meyerand ME. Sustained cortical and subcortical neuromodulation induced by electrical tongue stimulation. Brain Imaging Behav 2011; 4:199-211. [PMID: 20614202 DOI: 10.1007/s11682-010-9099-7] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
This pilot study aimed to show that information-free stimulation of the tongue can improve behavioral measures and induce sustained neuromodulation of the balance-processing network in individuals with balance dysfunction. Twelve balance-impaired subjects received one week of cranial nerve non-invasive neuromodulation (CN-NINM). Before and after the week of stimulation, postural sway and fMRI activation were measured to monitor susceptibility to optic flow. Nine normal controls also underwent the postural sway and fMRI tests but did not receive CN-NINM. Results showed that before CN-NINM balance-impaired subjects swayed more than normal controls as expected (p ≤ 0.05), and that overall sway and susceptibility to optic flow decreased after CN-NINM (p ≤ 0.005 & p ≤ 0.05). fMRI showed upregulation of visual sensitivity to optic flow in balance-impaired subjects that decreased after CN-NINM. A region of interest analysis indicated that CN-NINM may induce neuromodulation by increasing activity within the dorsal pons (p ≤ 0.01).
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Affiliation(s)
- Joseph C Wildenberg
- Neuroscience Training Program, University of Wisconsin-Madison, Madison, WI 53705, USA.
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19
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De Ridder D, Vanneste S, van der Loo E, Plazier M, Menovsky T, van de Heyning P. Burst stimulation of the auditory cortex: a new form of neurostimulation for noise-like tinnitus suppression. J Neurosurg 2010; 112:1289-94. [DOI: 10.3171/2009.10.jns09298] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Object
Tinnitus is an auditory phantom percept related to tonic and burst hyperactivity of the auditory system. Two parallel pathways supply auditory information to the cerebral cortex: the tonotopically organized lemniscal system, and the nontonotopic extralemniscal system, which fire in tonic and burst mode, respectively. Electrical cortex stimulation is a method capable of modulating activity of the human cortex by delivering stimuli in a tonic or burst way. Burst firing is shown to be more powerful in activating the cerebral cortex than tonic firing, and bursts may activate neurons that are not activated by tonic firing.
Methods
Five patients with an implanted electrode on the auditory cortex were asked to rate their tinnitus distress and intensity on a visual analog scale before and after 40-Hz tonic and 40-Hz burst (5 pulses at 500 Hz) stimulation. All patients presented with both high-pitched pure tone and white noise components in their tinnitus.
Results
A significantly better suppression for narrowband noise tinnitus with burst stimulation in comparison with tonic stimulation (Z = −2.03, p = 0.04) was found. For pure tone tinnitus, no difference was found between tonic and burst stimulation (Z = −0.58, p = 0.56). No significant effect was obtained for stimulation amplitude (Z = −1.21, p = 0.23) and electrical charge per pulse (Z = −0.67, p = 0.50) between tonic and burst stimulation. The electrical current delivery per second was significantly different (Z = −2.02, p = 0.04).
Conclusions
Burst stimulation is a new form of neurostimulation that might be helpful in treating symptoms that are intractable to conventional tonic stimulation. Further exploration of this new stimulation design is warranted.
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Affiliation(s)
- Dirk De Ridder
- 1BRAI2N (Brain Research Center Antwerp for Innovative and Interdisciplinary Neuromodulation); and
- 2Departments of Neurosurgery and
| | - Sven Vanneste
- 1BRAI2N (Brain Research Center Antwerp for Innovative and Interdisciplinary Neuromodulation); and
- 2Departments of Neurosurgery and
| | - Elsa van der Loo
- 1BRAI2N (Brain Research Center Antwerp for Innovative and Interdisciplinary Neuromodulation); and
- 2Departments of Neurosurgery and
| | - Mark Plazier
- 1BRAI2N (Brain Research Center Antwerp for Innovative and Interdisciplinary Neuromodulation); and
- 2Departments of Neurosurgery and
| | - Tomas Menovsky
- 1BRAI2N (Brain Research Center Antwerp for Innovative and Interdisciplinary Neuromodulation); and
- 2Departments of Neurosurgery and
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20
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Slabu LM. The effect of slice orientation on auditory FMRI at the level of the brainstem. Brain Topogr 2010; 23:301-10. [PMID: 20336360 DOI: 10.1007/s10548-010-0141-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2009] [Accepted: 03/12/2010] [Indexed: 10/19/2022]
Abstract
Although auditory information is processed in several subcortical nuclei, most fMRI studies focus solely on the auditory cortex and do not take brainstem responses into account. One common difficulty in obtaining clear functional brainstem recordings is due to heartbeat related motion, manifested in the rostro-caudal and in the ventro-dorsal directions in the contraction phase of the heart. The aim of this study was to investigate the effect of slice orientation on auditory functional magnetic resonance imagining (fMRI) measurements with respect to the pattern of brainstem oscillation. Fourteen healthy volunteers listened monaurally to modulated pink noise. Blood oxygenation level dependent (BOLD) contrast was performed with an echo-planar image (EPI) sequence using a 3T MRI system. Three different slice orientations were compared: approximately parallel, at 45 degrees , and orthogonal to the brainstem. The standard deviation of the residuals, the effect size, the median t-values, and the number of activated voxels were calculated to quantify variability in activation between orientations. The data for the inferior colliculi indicated that a slice orientation with a 45 degrees angle to the brainstem yielded the lowest sensitivity to motion (reflected in the standard deviation of the residuals). By contrast, the results did not suggest differences between the three imaging planes on the scanning of the auditory cortex. Findings indicate that the 45 degrees slice orientation is the optimum orientation for accurate measurement at the upper brainstem level.
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Affiliation(s)
- Lavinia M Slabu
- Department of Psychiatry & Clinical Psychobiology, Faculty of Psychology, Institute for Brain, Cognition and Behavior (IR3C), University of Barcelona, P. Vall d'Hebron 171, 08035, Barcelona, Spain.
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21
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van der Loo E, Gais S, Congedo M, Vanneste S, Plazier M, Menovsky T, Van de Heyning P, De Ridder D. Tinnitus intensity dependent gamma oscillations of the contralateral auditory cortex. PLoS One 2009; 4:e7396. [PMID: 19816597 PMCID: PMC2754613 DOI: 10.1371/journal.pone.0007396] [Citation(s) in RCA: 180] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2009] [Accepted: 09/15/2009] [Indexed: 11/18/2022] Open
Abstract
Background Non-pulsatile tinnitus is considered a subjective auditory phantom phenomenon present in 10 to 15% of the population. Tinnitus as a phantom phenomenon is related to hyperactivity and reorganization of the auditory cortex. Magnetoencephalography studies demonstrate a correlation between gamma band activity in the contralateral auditory cortex and the presence of tinnitus. The present study aims to investigate the relation between objective gamma-band activity in the contralateral auditory cortex and subjective tinnitus loudness scores. Methods and Findings In unilateral tinnitus patients (N = 15; 10 right, 5 left) source analysis of resting state electroencephalographic gamma band oscillations shows a strong positive correlation with Visual Analogue Scale loudness scores in the contralateral auditory cortex (max r = 0.73, p<0.05). Conclusion Auditory phantom percepts thus show similar sound level dependent activation of the contralateral auditory cortex as observed in normal audition. In view of recent consciousness models and tinnitus network models these results suggest tinnitus loudness is coded by gamma band activity in the contralateral auditory cortex but might not, by itself, be responsible for tinnitus perception.
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Affiliation(s)
- Elsa van der Loo
- Brain Research centre Antwerp for Innovative and Interdisciplinary Neuromodulation (BRAI(2)N), University Hospital Antwerp, Antwerp, Belgium.
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22
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Lanting C, de Kleine E, van Dijk P. Neural activity underlying tinnitus generation: Results from PET and fMRI. Hear Res 2009; 255:1-13. [PMID: 19545617 DOI: 10.1016/j.heares.2009.06.009] [Citation(s) in RCA: 216] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2009] [Revised: 06/15/2009] [Accepted: 06/15/2009] [Indexed: 10/20/2022]
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23
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Melcher JR, Levine RA, Bergevin C, Norris B. The auditory midbrain of people with tinnitus: abnormal sound-evoked activity revisited. Hear Res 2009; 257:63-74. [PMID: 19699287 DOI: 10.1016/j.heares.2009.08.005] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2009] [Revised: 07/24/2009] [Accepted: 08/05/2009] [Indexed: 11/19/2022]
Abstract
Sound-evoked fMRI activation of the inferior colliculi (IC) was compared between tinnitus and non-tinnitus subjects matched in threshold (normal), age, depression, and anxiety. Subjects were stimulated with broadband sound in an "on/off" fMRI paradigm with and without on-going sound from the scanner coolant pump. (1) With pump sounds off, the tinnitus group showed greater stimulus-evoked activation of the IC than the non-tinnitus group, suggesting abnormal gain within the auditory pathway of tinnitus subjects. (2) Having pump sounds on reduced activation in the tinnitus, but not the non-tinnitus group. This result suggests response saturation in tinnitus subjects, possibly occurring because abnormal gain increased response amplitude to an upper limit. (3) In contrast to Melcher et al. (2000), the ratio of activation between right and left IC did not differ significantly between tinnitus and non-tinnitus subjects or in a manner dependent on tinnitus laterality. However, new data from subjects imaged previously by Melcher et al. suggest a possible tinnitus subgroup with abnormally asymmetric function of the IC. The present and previous data together suggest elevated responses to sound in the IC are common among those with tinnitus and normal thresholds, while abnormally asymmetric activation is not, even among those with lateralized tinnitus.
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Affiliation(s)
- Jennifer R Melcher
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear Infirmary, Boston, MA 02114, USA.
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24
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Abstract
Advances in clinical magnetic resonance (MR) are discussed in this review in the context of publications from Investigative Radiology during 2006 and 2007. The articles relevant to this topic, published during this 2 year time period, are considered as organized by anatomic region. An additional final focus of discussion is in regards to those studies involving MR contrast media.
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25
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Smits M, Kovacs S, de Ridder D, Peeters RR, van Hecke P, Sunaert S. Lateralization of functional magnetic resonance imaging (fMRI) activation in the auditory pathway of patients with lateralized tinnitus. Neuroradiology 2007; 49:669-79. [PMID: 17404721 DOI: 10.1007/s00234-007-0231-3] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2006] [Accepted: 02/27/2007] [Indexed: 10/23/2022]
Abstract
INTRODUCTION Tinnitus is hypothesized to be an auditory phantom phenomenon resulting from spontaneous neuronal activity somewhere along the auditory pathway. We performed fMRI of the entire auditory pathway, including the inferior colliculus (IC), the medial geniculate body (MGB) and the auditory cortex (AC), in 42 patients with tinnitus and 10 healthy volunteers to assess lateralization of fMRI activation. METHODS Subjects were scanned on a 3T MRI scanner. A T2*-weighted EPI silent gap sequence was used during the stimulation paradigm, which consisted of a blocked design of 12 epochs in which music presented binaurally through headphones, which was switched on and off for periods of 50 s. Using SPM2 software, single subject and group statistical parametric maps were calculated. Lateralization of activation was assessed qualitatively and quantitatively. RESULTS Tinnitus was lateralized in 35 patients (83%, 13 right-sided and 22 left-sided). Significant signal change (P(corrected) < 0.05) was found bilaterally in the primary and secondary AC, the IC and the MGB. Signal change was symmetrical in patients with bilateral tinnitus. In patients with lateralized tinnitus, fMRI activation was lateralized towards the side of perceived tinnitus in the primary AC and IC in patients with right-sided tinnitus, and in the MGB in patients with left-sided tinnitus. In healthy volunteers, activation in the primary AC was left-lateralized. CONCLUSION Our paradigm adequately visualized the auditory pathways in tinnitus patients. In lateralized tinnitus fMRI activation was also lateralized, supporting the hypothesis that tinnitus is an auditory phantom phenomenon.
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Affiliation(s)
- Marion Smits
- Department of Radiology, Hs 224, Erasmus MC - University Medical Center Rotterdam, 's Gravendijkwal 230, 3015 CE Rotterdam, The Netherlands.
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26
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Tieleman A, Vandemaele P, Seurinck R, Deblaere K, Achten E. Comparison between functional magnetic resonance imaging at 1.5 and 3 Tesla: effect of increased field strength on 4 paradigms used during presurgical work-up. Invest Radiol 2007; 42:130-8. [PMID: 17220731 DOI: 10.1097/01.rli.0000251579.05052.08] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
OBJECTIVES We sought to evaluate the benefit of 3 T compared with 1.5 T during presurgical functional magnetic resonance imaging. MATERIALS AND METHODS Six participants performed a motor, a visual, and 2 language paradigms both at 1.5 and 3 T. The number of activated voxels, mean t-value, and assessment of language dominancy were compared between both field strengths. Group analysis was performed to evaluate the influence of field strength on the cortical language activation patterns. RESULTS The number of activated voxels and mean t-values were significantly higher at 3 T for all paradigms. Using the same statistical threshold, language activation was significantly less lateralized, and more activation zones were depicted at 3 T compared with 1.5 T. CONCLUSIONS Sensitivity associated with visual, motor and language functional magnetic resonance imaging increased significantly at 3 T. Additional cortical areas were depicted during language processing at 3 T. For assessment of language dominancy, usage of more stringent statistical thresholds at 3 T is suggested.
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Affiliation(s)
- Ann Tieleman
- Department of Radiology, Ghent Institute for functional Magnetic Resonance Imaging, GIfMI, Labaratory for Neuropsychology, Neurology Section, Ghent University Hospital, Ghent, Belgium.
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27
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Abstract
Advances in the field of magnetic resonance (MR) as it pertains to clinical diagnostic radiology are examined in this review on the basis of publications in Investigative Radiology over the past 2 years (2005-2006). The articles published during that timeframe are discussed, organizationally wise, by anatomic region with an additional focus on studies involving MR contrast media.
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Affiliation(s)
- Val M Runge
- Department of Radiology, Scott and White Clinic and Hospital, Temple, Texas 76508, USA.
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28
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Nielsen K, Rostrup E, Frederiksen JL, Knudsen S, Mathiesen HK, Hanson LG, Paulson OB. Magnetic resonance imaging at 3.0 tesla detects more lesions in acute optic neuritis than at 1.5 tesla. Invest Radiol 2006; 41:76-82. [PMID: 16428976 DOI: 10.1097/01.rli.0000188364.76251.28] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE We sought to assess whether magnetic resonance imaging (MRI) at 3.0 T detects more brain lesions in acute optic neuritis (ON) than MRI at 1.5 T. MATERIALS AND METHODS Twenty-eight patients with acute ON were scanned at both field-strengths using fast-fluid-attenuated inversion recovery (FLAIR), proton density and T2-weighted turbo spin echo, and T1-weighted spin echo after contrast. In addition, magnetization-prepared rapid acquisition gradient echo (MPRAGE) was obtained after contrast at 3.0 T. Lesion number and volumes were assessed by an observer blind to patient identity and field strength. RESULTS Scans at 3.0 T showed a significantly increase in number of lesions detected on FLAIR images (P = 0.002) relative to scanning at 1.5 T. MPRAGE proved to be suitable for detecting enhancing lesions in ON. CONCLUSION The MRI protocol at 3.0 T was more sensitive to hyperintense brain lesions in ON than the standard MRI protocol at 1.5 T.
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Affiliation(s)
- Kirsten Nielsen
- Danish Research Centre for Magnetic Resonance, Copenhagen University Hospital, Hvidovre, Denmark.
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29
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De Ridder D, De Mulder G, Verstraeten E, Van der Kelen K, Sunaert S, Smits M, Kovacs S, Verlooy J, Van de Heyning P, Moller AR. Primary and secondary auditory cortex stimulation for intractable tinnitus. ORL J Otorhinolaryngol Relat Spec 2006; 68:48-54; discussion 54-5. [PMID: 16514263 DOI: 10.1159/000090491] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
INTRODUCTION Recent research suggests tinnitus is a phantom phenomenon based on hyperactivity of the auditory system, which can be visualized by functional neuroimaging, and transiently modulated by transcranial magnetic stimulation (TMS). We present the results of the first implanted electrodes on the primary and secondary auditory cortex after a successful TMS suppression. METHODS AND MATERIALS Twelve patients underwent an auditory cortex implantation, 10 for unilateral and 2 for bilateral tinnitus, based on >50% suppression applying TMS. Results were analyzed for pure tone tinnitus and white noise tinnitus. RESULTS TMS results in 77% pure tone tinnitus and 67% white noise reduction. Electrical stimulation via an implanted electrode results in a mean of 97% pure tone tinnitus and 24% white noise suppression. Mean Visual Analogue Scale score decreases from 9.5 to 1.5 for pure tone and from 8.8 to 6.8 for white noise postoperatively. DISCUSSION Pure tone tinnitus might be the conscious percept of focal neuronal hyperactivity of the auditory cortex. Once visualized, this hyperactivity can be modulated by neurostimulation. CONCLUSION The preliminary results of the first implantations suggest that patients with unilateral pure tone tinnitus are good surgical candidates for electrode implantation and permanent electrical stimulation of the auditory cortex, provided that the tinnitus is of recent origin and can be suppressed by TMS.
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Affiliation(s)
- Dirk De Ridder
- Department of Neurosurgery and Otorhinolaryngology, University Hospital Antwerp, Antwerp, Belgium
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