eural reorganization in tinnitus: a high-field functional and antomical MRI study

Recruitment & Eligibility

Status: Withdrawn

Sex: Not specified

Target Recruitment: 30

Inclusion Criteria

The main inclusion criteria of the patient groups are:
* Male or female between 18 and 75 years
* Subjective tinnitus (i.e. not caused by an acoustic source inside the head, e.g., vascular abnormalities that cause pulsatile tinnitus)
* Stable tinnitus (i.e., present for at least 8 h per day since more than a year)
* Tinnitus that is dominant within one of three octaves (low: <750 Hz, middle: 750-3000 Hz, high: >3000 Hz; the exact frequency ranges will be determined empirically based on patient availability)
* Patient has not received medical care from an otolaryngologist and is able and willing to undergo the MRI measurements, as indicated by written informed consent.;The main inclusion criteria of the healthy subjects are:
* Male or female between 18 and 75 years
* No tinnitus
* Subject is able and willing to undergo the MRI measurements, as indicated by written informed consent.

Exclusion Criteria

Exclusion criteria of the patient groups are:
* Fletcher Index > 50 dB HL for both ears (i.e., mean of hearing loss in decibels for 1k, 2k and 4k Hz)
* Hyperacusis (oversensitivity to sound), phonophobia (defined as a persistent, abnormal, and unwarranted fear of sound), misophonia (dislike of certain sound),
* Neurological-, neurosurgical- and psychiatric history
* Use of dopaminergic drugs since this medication greatly influence the fMRI scans (Haslinger et al., 2001, Mattay et al., 2002)
* Morbid obesitas (BMI > 35) since it cannot be guaranteed that these subjects will fit in the scanner
* Current treatment of tinnitus and implanted devices or other metal objects that are not suitable for MRI. ;Exclusion criteria of the healthy subjects are:
* Fletcher Index > 50 dB HL for both ears (i.e. mean of hearing loss in decibels for 1k, 2k and 4k Hz)
* Hyperacusis (oversensitivity to sound), phonophobia (defined as a persistent, abnormal, and unwarranted fear of sound), misophonia (dislike of certain sound),
* Neurological-, neurosurgical- and psychiatric history
* Use of dopaminergic drugs since this medication greatly influence the fMRI scans (Haslinger et al., 2001, Mattay et al., 2002)
* Morbid obesitas (BMI > 35) since it cannot be guaranteed that these subjects will fit in the scanner
* Current treatment of tinnitus and implanted devices or other metal objects that are not suitable for MRI.

Study & Design

Study Type: Observational non invasive

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
<p>The hypothesized link between frequency tuning and tinnitus will be tested by<br /><br>comparing the size and response magnitude of the auditory cortex regions that<br /><br>show tuning to the patient*s specific tinnitus frequency vs. regions that show<br /><br>tuning to the other (non-tinnitus) frequencies. In this way, patients can serve<br /><br>as their own controls, in addition to matching healthy controls. Furthermore,<br /><br>anatomical features (measures of myelin content and cortical thickness) will be<br /><br>assessed in the same regions of interest.</p><br>

Secondary Outcome Measures