Datema, J. (2012) Invloed van een cochleair implantaat op de hersenactiviteit bij chronische tinnitus. thesis, Medicine.
Full text available on request.Abstract
Background: Patients with tinnitus perceive sounds without the involvement of an external sound source. Subjective tinnitus is a meaningless sound without association with a physical sound. The prevalence of tinnitus is 4-25,3%. The current hypothesis in the pathogenesis of subjective tinnitus is that it occurs as reaction of the central auditory system to peripheral hearing loss what causes increased activity at different brain regions. After implantation of a cochlear implant (CI) 42-93% of the people experience less tinnitus. Objectives: Establish the influences of a cochlear implant on the neural activity in people with chronic tinnitus with H2 15O positron emission tomography. Determine whether a relationship exists between the subjective perception of tinnitus and brain activity. Methods: Twelve subjects with unilateral implanted cochlear implants were included in this prospective patients study. Five subjects noticed a positive effect on the tinnitus after turning the CI on. The other subjects noticed no effect or worsening of the tinnitus after turning the CI on. Brain activity was measured by with H2 15O positron emission tomography. All participating subjects were scanned 12 times, six times with CI on and six times with CI off. After each scan the subjects were asked to indicate the loudness of the tinnitus at the time of scanning on a scale of 0 to 10 (0: no tinnitus, 10: very loud tinnitus). A questionnaire with questions about tinnitus and CI was completed by all participating individuals. Results: The subjective perception of the loudness of the tinnitus on a scale of 0 to 10 (0: no tinnitus, 10: very loud tinnitus) differed after turning the CI on in the ‘effect group’ en ‘no effect group’ significantly from each other (p=0.011). In 11 out of 12 tested subjects, after a comparison of the activated CI scans with the non-activated CI scans, an increase in brain activity of the auditory area were seen in the contralateral side of the implanted CI. The other subject showed an increase in brain activity on the ipsilateral side of the implanted CI. Brodmann’s areas 22, 41 and 42 showed more brain activity after analysing the scans with the CI on compared to the scans with the CI off. Conclusion: The auditory brain areas on the contralateral side of the implanted CI have an important role in hearing in patients with a CI and tinnitus. Brodmann area 22, primary and secondary auditory cortex are areas that show significantly more activity after determining the difference in brain activity between scans taken during and after switching the CI on and off. These areas may be involved in the suppression and/ or the onset of tinnitus. The hypothesis that less brain activity present in the ‘effect group’ after switching the CI on compared to the ‘no effect group’ could not be confirmed in this study. Further research with a larger group of subjects with a CI and tinnitus is needed to measure more precise the places in the brains with more activity.
| Item Type: | Thesis (Thesis) |
|---|---|
| Supervisor name: | Facultair Begeleider: and Kleine, Dr. ir. E. de and Dagelijkse Begeleider: and Kloostra, Drs. F.J.J. and Locatie: and KNO UMCG |
| Faculty: | Medical Sciences |
| Date Deposited: | 25 Jun 2020 11:03 |
| Last Modified: | 25 Jun 2020 11:03 |
| URI: | https://umcg.studenttheses.ub.rug.nl/id/eprint/2299 |
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