Article
Transcranial magnetic stimulation of the auditory cortex in tinnitus therapy: Detection of dynamic structural neuroplasticity with voxel based morphometry
Transkranielle Magnetstimulation des auditorischen Cortex zur Tinnitustherapie: Nachweis strukturell neuroplastischer Prozesse mittels Voxel-basierter Morphometrie
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Published: | September 7, 2006 |
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Outline
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Introduction: Repetitive transcranial magnetic stimulation (rTMS) represents a new, minimal invasive tool for focal brain stimulation. Neuronavigated transcranial magnetic stimulation of the area of increased activity within the primary auditory cortex was able to reduce tinnitus perception. Some of these patients had long term improvement of their tinnitus complaints, which could be detected six months after stimulation [Ref. 1]. The therapeutical success might be reflected in an induction of dynamic neuroplastic processes. We used voxel-based morphometry (VBM), a sophisticated whole brain technique based on high-resolution, three-dimensional magnetic resonance imaging to detect subtle, region-specific changes in grey and white matter [Ref. 2].
Methods: Repetitive TMS to the left auditory cortex (110% motor threshold; 1 Hz; 2000 stimuli/ day over 10 days) was administered to patients suffering from chronic tinnitus. To detect dynamic neuroplastic changes a structural MRI scan (T1, MPRAGE) was performed before and after stimulation. The scans were evaluated based on principles of voxel-based morphometry.
Results: After 2 weeks of rTMS VBM was able to detect structural changes in central auditory regions (left temporal superior gyrus) and associated areas (right parietal region) compared to baseline measurement.
Conclusion: These results might indicate that rTMS is able to induce structural changes in the directly stimulated cortical regions as well as in functionally associated brain regions. These findings might explain the long-term effects of rTMS in therapeutical application, e.g. in tinnitus patients.
References
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- Kleinjung T, Eichhammer P, Langguth B, Jacob P, Marienhagen J, Hajak G, Wolf SR, Strutz J. Long-term effects of repetitive transcranial magnetic stimulation (rTMS) in patients with chronic tinnitus. Otolaryngol Head Neck Surg. 2005;132:566-9.
- 2.
- May A, Hajak G, Gänssbauer S, Steffens T, Langguth B, Kleinjung T, Eichhammer P. Structural brain alteration following 5 days of intervention: dynamic aspects of neuroplasticity. Cereb Cortex. 2006;Feb15[Epub ahead of print]