The primary objective of this study is to objectivate neural hyperactivity at the cortical level of chronic tinnitus sufferers compared to control subjects with the use of FDG-PET-scans.
ID
Source
Brief title
Condition
- Inner ear and VIIIth cranial nerve disorders
- Structural brain disorders
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
The main study parameter will be the cortical hyperactivity in tinnitus
patients compared to control subjects in FDG-PET, analysed with SPM5. Our
estimation is that this cortical hyperactivity is localised in the primary
auditory cortex and the associative auditory cortex, although other regions
might display some hyperactivity as well
Secondary outcome
Not applicable
Background summary
Approximately 10 to 15% of the general population complains about tinnitus, and
4-5% is severely affected by it. Subjective tinnitus is only perceived by the
patient, and can not be objectified by an external observer. It is believed to
be the result of plastic changes and reorganization processes in the auditory
pathway and brain structures, most likely caused by deprivation of input.
Several attempts have been made to register this change of activity in the CNS
with imaging studies.
Positron Emission Tomography (PET) scan is an excellent tool for assessment of
regional function of the human brain, in a quantitative manner. Until now 16
studies with PET-scanning in tinnitus patients have been performed, only 6 with
[18F]deoxyglucose (FDG). FDG-PET scanning reveals base-line metabolism in brain
tissue with a labeled biologically important compound without the need for
manipulation. Results have not been conclusive due to small sample size,
various manipulations or dependency on experimental interventions as a
comparison. Our hypothesis is that FDG-PET scanning can be used to determine
neural hyperactivity at the cortical level of chronic tinnitus sufferers. This
will then provide an objective measurement for subjective tinnitus.
Study objective
The primary objective of this study is to objectivate neural hyperactivity at
the cortical level of chronic tinnitus sufferers compared to control subjects
with the use of FDG-PET-scans.
Study design
Observational case-control study
Study burden and risks
According to the most recent publication of ICRP (ICRP 80) the total amount of
radiation for [18F]deoxyglucose in this scanning procedure is 3.8 mSv. The
estimated risk for this scanning procedure is categorised as IIb (ICRP 62),
minor to intermediate level of risk, 1-10 mSV. In comparison, according to the
*Rijksinstituut voor Mileuhygiëne (RIVM)*, the annual radiation dose in the
Netherlands is 1.7 mSv. The number of visits is once for the scanning
procedure. The audiometric analysis for control subjects will take place in 1
visit. No adverse or serious adverse events are to be expected during
FDG-PET-scanning. The physical discomfort during the scanning procedure is
minimal. The subject will be asked to lay quiet in the scanner for fifty
minutes in a quiet and dark surrounding with a head immobiliser.
Hanzeplein 1
9700 RB Groningen
Nederland
Hanzeplein 1
9700 RB Groningen
Nederland
Listed location countries
Age
Inclusion criteria
Chronic tinnitus, > 3 months, perceived in the head, not lateralized, constant in presence. Right-handed
Exclusion criteria
Presence of any major medical, neurological or psychiatric diagnoses now or in the past, specific epilepsy, severe head injury or previous cranial neurosurgery. Participation in a PET study in the year prior to this study. Radiological workers. Use of drugs or medications that reduce cortical excitation such as anticonvulsants, benzodiazepines or other sedatives. Pregnancy.
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
| Register | ID |
|---|---|
| CCMO | NL19448.042.07 |