Investigating GABAergic inhibition in tinnitus with GABA-edited magnetic resonance spectroscopy and 11C-Flumazenil positron emission tomography.

Investigating GABAergic inhibition in tinnitus with GABA-edited magnetic resonance spectroscopy and 11C-Flumazenil positron emission tomography. - GABAergic inhibition in tinnitus

Status

Recruiting

Phases

Unknown

Study type

Observational

Source

NL-OMON

Registry ID

NL-OMON55068

Enrollment

Registered

2021-08-16

Start date

2021-10-07

Completion date

Unknown

Last updated

2024-09-23

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Ringing in the ears Tinnitus

Interventions

None listed

Eligibility

Age

18 Years to 99 Years

Inclusion criteria

Inclusion criteria: For all participants: • Adult, 18 to 75 years of age • Understanding the study and providing written informed consent In addition, depending on the group: • Group-1 (T+HL+): Having chronic tinnitus (for more than 2 months) and mild to moderate hearing loss (pure tone average for frequencies of 4 to 8kHz between 30 and 60dB for both ears). • Group-2 (T-HL+): Having mild to moderate hearing loss (as above) without tinnitus. • Group-3 (T-HL-): Having no tinnitus and normal hearing thresholds (pure tone average

Exclusion criteria

Exclusion criteria: • Not meeting the inclusion criteria of one of the 3 groups (T+HL+, T-HL+, or T-HL-) • Using hearing aids • Metal implants incompatible with the MRI scanner magnetic field (e.g., pacemaker, heart valves, vascular clips, cerebral implants, eye-implants, intra-uterine devices containing copper, non-removable piercing) • Any risk of having metal particles in the eyes • Tattoos containing iron oxide • Claustrophobia • History of neurological or neuropsychiatric illness (apart from tinnitus and hearing loss) • Being pregnant or at risk from being pregnant • Breastfeeding • Use of psycho-active medications (e.g., benzodiazepine, SSRI) • Alcohol or drug abuse • Refusal to be informed of structural brain abnormalities that could be detected during the experiment

Design outcomes

Primary

Measure	Time frame
The main study parameters are the GABA concentrations and GABA(A) receptors availability (binding potential) in the auditory pathway as measured with GABA-edited MR spectroscopy and with [11C]-flumazenil PET respectively.	—

Secondary

Measure	Time frame
Secondary study parameters include (1) the functional connectivity at rest and during sound stimulation as assessed with (partial-) correlations between activity time courses, (2) the level of activity in the auditory pathway at rest (i.e. spontaneous activity) and during sound perception, (3) the correlations between GABA levels and the functional connectivity as well as the spontaneous activity in the auditory pathway. We predict that compared to the other two groups, the tinnitus group will show enhanced spontaneous activity in nodes of the auditory pathway as well as decreased functional connectivity between these nodes.	—

Measure

Time frame

Secondary study parameters include (1) the functional connectivity at rest and during sound stimulation as assessed with (partial-) correlations between activity time courses, (2) the level of activity in the auditory pathway at rest (i.e. spontaneous activity) and during sound perception, (3) the correlations between GABA levels and the functional connectivity as well as the spontaneous activity in the auditory pathway. We predict that compared to the other two groups, the tinnitus group will show enhanced spontaneous activity in nodes of the auditory pathway as well as decreased functional connectivity between these nodes.

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Countries

Netherlands

Outcome results