Lateralized Tinnitus Studied With Functional Magnetic Resonance Imaging: Abnormal Inferior Colliculus Activation

2000 ◽  
Vol 83 (2) ◽  
pp. 1058-1072 ◽  
Author(s):  
J. R. Melcher ◽  
I. S. Sigalovsky ◽  
J. J. Guinan ◽  
R. A. Levine
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Inferior Colliculus ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Sound Stimulation ◽  
Percent Signal Change ◽  
Signal Change ◽  
The Right

Tinnitus, the perception of sound in the absence of external stimuli, is a common and often disturbing symptom that is not understood physiologically. This paper presents an approach for using functional magnetic resonance imaging (fMRI) to investigate the physiology of tinnitus and demonstrates that the approach is effective in revealing tinnitus-related abnormalities in brain function. Our approach as applied here included 1) using a masking noise stimulus to change tinnitus loudness and examining the inferior colliculus (IC) for corresponding changes in activity, 2) separately considering subpopulations with particular tinnitus characteristics, in this case tinnitus lateralized to one ear, 3) controlling for intersubject differences in hearing loss by considering only subjects with normal or near-normal audiograms, and 4) tailoring the experimental design to the characteristics of the tinnitus subpopulation under study. For lateralized tinnitus subjects, we hypothesized that sound-evoked activation would be abnormally asymmetric because of the asymmetry of the tinnitus percept. This was tested using two reference groups for comparison: nontinnitus subjects and nonlateralized tinnitus subjects. Binaural noise produced abnormally asymmetric IC activation in every lateralized tinnitus subject ( n = 4). In reference subjects ( n = 9), activation (i.e., percent change in image signal) in the right versus left IC did not differ significantly. Compared with reference subjects, lateralized tinnitus subjects showed abnormally low percent signal change in the IC contralateral, but not ipsilateral, to the tinnitus percept. Consequently, activation asymmetry (i.e., the ratio of percent signal change in the IC ipsilateral versus contralateral to the tinnitus percept) was significantly greater in lateralized tinnitus subjects as compared with reference subjects. Monaural noise also produced abnormally asymmetric IC activation in lateralized tinnitus subjects. Two possible models are presented to explain why IC activation was abnormally low contralateral to the tinnitus percept in lateralized tinnitus subjects. Both assume that the percept is associated with abnormally high (“tinnitus-related”) neural activity in the contralateral IC. Additionally, they assume that either 1) additional activity evoked by sound was limited by saturation or 2) sound stimulation reduced the level of tinnitus-related activity as it reduced the loudness of (i.e., masked) the tinnitus percept. In summary, this work demonstrates that fMRI can provide objective measures of lateralized tinnitus and tinnitus-related activation can be interpreted at a neural level.

scholarly journals Resting-State Functional Magnetic Resonance Imaging and Functional Connectivity Density Mapping in Patients With Optic Neuritis

2021 ◽  
Vol 15 ◽  
Author(s):  
Ke Song ◽  
Yong Wang ◽  
Mei-Xia Ren ◽  
Jiao Li ◽  
Ting Su ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Connectivity ◽  
Functional Magnetic Resonance Imaging ◽  
Optic Neuritis ◽  
Resting State ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Functional Connectivity Density ◽  
The Right

Background: Using resting-state functional connectivity (rsFC), we investigated alternations in spontaneous brain activities reflected by functional connectivity density (FCD) in patients with optic neuritis (ON).Methods: We enrolled 28 patients with ON (18 males, 10 females) and 24 healthy controls (HCs; 16 males, 8 females). All subjects underwent functional magnetic resonance imaging (fMRI) in a quiet state to determine the values of rsFC, long-range FCD (longFCD), and short-range FCD (IFCD). Receiver operating characteristic (ROC) curves were generated to distinguish patients from HCs.Results: The ON group exhibited obviously lower longFCD values in the left inferior frontal gyrus triangle, the right precuneus and the right anterior cingulate, and paracingulate gyri/median cingulate and paracingulate gyri. The left median cingulate and paracingulate gyri and supplementary motor area (SMA) were also significantly lower. Obviously reduced IFCD values were observed in the left middle temporal gyrus/angular gyrus/SMA and right cuneus/SMA compared with HCs.Conclusion: Abnormal neural activities were found in specific brain regions in patients with ON. Specifically, they showed significant changes in rsFC, longFCD, and IFCD values. These may be useful to identify the specific mechanism of change in brain function in ON.

scholarly journals Processing facial emotions in adults with velo-cardio-facial syndrome: functional magnetic resonance imaging

2006 ◽  
Vol 189 (6) ◽  
pp. 560-561 ◽  
Author(s):  
Therese Van Amelsvoort ◽  
Nicole Schmitz ◽  
Eileen Daly ◽  
Quinton Deeley ◽  
Hugo Critchley ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Emotional Processing ◽  
Brain Regions ◽  
Functional Neuroanatomy ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
The Right ◽  
Velo Cardio Facial Syndrome

SummaryWe studied the functional neuroanatomy of social behaviour in velo-cardio-facial syndrome (VCFS) using a facial emotional processing task and functional magnetic resonance imaging in adults with this syndrome and controls matched for age and IQ. The VCFS group had less activation in the right insula and frontal brain regions and more activation in occipital regions. Genetically determined abnormalities in pathways including those involved in emotional processing may underlie deficits in social cognition in people with VCFS.

scholarly journals Decreased frontal activation in schizophrenics during stimulation with the Continuous Performance Test - a functional magnetic resonance imaging study

1999 ◽  
Vol 14 (1) ◽  
pp. 17-24 ◽  
Author(s):  
H.-P. Volz ◽  
C. Gaser ◽  
F. Häger ◽  
R. Rzanny ◽  
J. Pönisch ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Performance Test ◽  
Continuous Performance Test ◽  
Continuous Performance ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Vast Number ◽  
The Right

SummaryThe Continuous Performance Test (CPT) has become an essential constituent of the neuropsychological investigation of schizophrenia. Also, a vast number of brain imaging studies, mostly PET investigations, have employed the CPT as a cognitive challenge and established a relative hypofrontality in schizophrenics compared to controls. The aim of the present investigation was to clarify whether this predescribed hypofrontality could also be verified using functional magnetic resonance imaging (fMRI). 20 healthy volunteers and 14 schizophrenics on stable neuroleptic medication were included. Imaging was performed using the CPT-double-T-version and a clinical 1.5 T MRI-scanner with a single slice technique and a T2*-weighted gradient-echo-sequence. The schizophrenics exhibited a decreased activation in the right mesial prefrontal cortex, the right cingulate and the left thalamus compared to controls. These results obtained by fMRI are discussed in relation to published findings using PET.

scholarly journals Cannabis affects people differently: inter-subject variation in the psychotogenic effects of Δ9-tetrahydrocannabinol: a functional magnetic resonance imaging study with healthy volunteers

2012 ◽  
Vol 43 (6) ◽  
pp. 1255-1267 ◽  
Author(s):  
Z. Atakan ◽  
S. Bhattacharyya ◽  
P. Allen ◽  
R. Martín-Santos ◽  
J. A. Crippa ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Healthy Volunteers ◽  
Temporal Cortex ◽  
Psychotic Symptoms ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Middle Temporal ◽  
The Right

BackgroundCannabis can induce transient psychotic symptoms, but not all users experience these adverse effects. We compared the neural response to Δ9-tetrahydrocannabinol (THC) in healthy volunteers in whom the drug did or did not induce acute psychotic symptoms.MethodIn a double-blind, placebo-controlled, pseudorandomized design, 21 healthy men with minimal experience of cannabis were given either 10 mg THC or placebo, orally. Behavioural and functional magnetic resonance imaging measures were then recorded whilst they performed a go/no-go task.ResultsThe sample was subdivided on the basis of the Positive and Negative Syndrome Scale positive score following administration of THC into transiently psychotic (TP; n = 11) and non-psychotic (NP; n = 10) groups. During the THC condition, TP subjects made more frequent inhibition errors than the NP group and showed differential activation relative to the NP group in the left parahippocampal gyrus, the left and right middle temporal gyri and in the right cerebellum. In these regions, THC had opposite effects on activation relative to placebo in the two groups. The TP group also showed less activation than the NP group in the right middle temporal gyrus and cerebellum, independent of the effects of THC.ConclusionsIn this first demonstration of inter-subject variability in sensitivity to the psychotogenic effects of THC, we found that the presence of acute psychotic symptoms was associated with a differential effect of THC on activation in the ventral and medial temporal cortex and cerebellum, suggesting that these regions mediate the effects of the drug on psychotic symptoms.

scholarly journals Within-Session and Between-Session Reproducibility of Cerebral Sensorimotor Activation: A Test–Retest Effect Evidenced with Functional Magnetic Resonance Imaging

2001 ◽  
Vol 21 (5) ◽  
pp. 592-607 ◽  
Author(s):  
Isabelle Loubinoux ◽  
Christophe Carel ◽  
Flamine Alary ◽  
Kader Boulanouar ◽  
Gérard Viallard ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Premotor Cortex ◽  
Memory Representation ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Fmri Signal ◽  
The Right ◽  
Flexion And Extension

The aim of the current study was to assess the reproducibility of functional magnetic resonance imaging (fMRI) brain activation signals in a sensorimotor task in healthy subjects. Because random or systematic changes are likely to happen when movements are repeated over time, the authors searched for time-dependent changes in the fMRI signal intensity and the extent of activation within and between sessions. Reproducibility was studied on a sensorimotor task called “the active task” that includes a motor output and a sensory feedback, and also on a sensory stimulation called “the passive task” that assessed the sensory input alone. The active task consisted of flexion and extension of the right hand. The subjects had performed it several times before fMRI scanning so that it was well learned. The passive task consisted of a calibrated passive flexion and extension of the right wrist. Tasks were 1 Hz-paced. The control state was rest. Subjects naïve to the MRI environment and non–MRI-naïve subjects were studied. Twelve MRI-naïve subjects underwent 3 fMRI sessions separated by 5 hours and 49 days, respectively. During MRI scanning, they performed the active task. Six MRI-naïve subjects underwent 2 fMRI sessions with the passive task 1 month apart. Three non–MRI-naïve subjects performed twice an active 2-Hz self-paced task. The data were analyzed with SPM96 software. For within-session comparison, for active or passive tasks, good reproducibility of fMRI signal activation was found within a session (intra-and interrun reproducibility) whether it was the first, second, or third session. Therefore, no within-session habituation was found with a passive or a well-learned active task. For between-session comparison, for MRI-naïve or non–MRI-naïve subjects, and with the active or the passive task, activation was increased in the contralateral premotor cortex and in ispsilateral anterior cerebellar cortex but was decreased in the primary sensorimotor cortex, parietal cortex, and posterior supplementary motor area at the second session. The lower cortical signal was characterized by reduced activated areas with no change in maximum peak intensity in most cases. Changes were partially reversed at the third session. Part of the test–retest effect may come from habituation of the MRI experiment context. Less attention and stress at the second and third sessions may be components of the inhibition of cortical activity. Because the changes became reversed, the authors suggest that, beyond the habituation process, a learning process occurred that had nothing to do with procedural learning, because the tasks were well learned or passive. A long-term memory representation of the sensorimotor task, not only with its characteristics (for example, amplitude, frequency) but also with its context (fMRI), can become integrated into the motor system along the sessions. Furthermore, the pattern observed in the fMRI signal changes might evoke a consolidation process.

scholarly journals Neural correlates of tactile simultaneity judgement: a functional magnetic resonance imaging study

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Takahiro Kimura ◽  
Hiroshi Kadota ◽  
Tsuyoshi Kuroda ◽  
Tomomi D. Funai ◽  
Makoto Iwata ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Neural Correlates ◽  
Time Range ◽  
Statistical Criterion ◽  
Time Interval ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
The Right

AbstractSimultaneity judgement (SJ) is a temporal discrimination task in which the targets span an ultimately short time range (zero or not). Psychophysical studies suggest that SJ is adequate to probe the perceptual components of human time processing in pure form. Thus far, time-relevant neural correlates for tactile SJ are unclear. We performed functional magnetic resonance imaging (fMRI) to investigate the neural correlates of tactile SJ using tactile number judgement as a time-irrelevant control task. As our main result, we demonstrated that the right inferior parietal lobule (IPL) is an SJ-specific region. The right IPL was detected by both parametric and non-parametric statistical analyses, and its activation intensity fulfilled a strict statistical criterion. In addition, we observed that some left-dominant regions (e.g., the striatum) were specifically activated by successive stimuli during SJ. Meanwhile, no region was specifically activated by simultaneous stimuli during SJ. Accordingly, we infer that the neural process for tactile SJ is as follows: the striatum estimates the time interval between tactile stimuli; based on this interval, the right IPL discriminates the successiveness or simultaneity of the stimuli. Moreover, taking detailed behavioural results into account, we further discuss possible concurrent or alternative mechanisms that can explain the fMRI results.

scholarly journals Cortical representation of experimental periodontal pain: a functional magnetic resonance imaging study

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Angelika Maurer ◽  
Damian Verma ◽  
Annika Reddehase ◽  
Lukas Scheef ◽  
Alexander Radbruch ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Imaging Study ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Pain Ratings ◽  
Tooth Clenching ◽  
The Right ◽  
First Time

AbstractThe aim of this study was to investigate central pain representations during loading of the periodontium induced by orthodontic and occlusal stress. Nineteen healthy male volunteers (25.7 ± 2.8 years) were tested on two consecutive days: after phenotyping (questionnaires) and determination of warmth (WPT) and heat (HPT) pain thresholds, functional magnetic resonance imaging was performed as event-related paradigm including 36 tooth clenchings of 3 s duration, alternating with rest periods varying between 20–30 s. The task was performed in absence (T1) and 24 h after placement of an elastic separator between the second bicuspid and the first molar on the right side of the lower jaw (T2). No significant changes in WPT and HPT were observed but pain ratings were significantly elevated at T2. Significantly elevated activation at T2, as compared to T1, was found in bilateral sensorimotor cortex, bilateral secondary sensory cortex, supplementary motor area, right rolandic operculum, and bilateral insula. Our data show for the first time in humans that periodontal stimulation, as tested by tooth clenching in the presence of an elastic separator, goes along with specific expressions of pain at behavioral and neuronal network levels. Findings supplement the existing neuroimaging literature on odontogenic pain.

Sign in / Sign up

Export Citation Format

Share Document