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Academic Journal
TINNITUS
| Title: |
Contralateral versus ipsilateral rTMS of temporoparietal cortex for the treatment of chronic unilateral tinnitus: comparative study.
| | Date: | 2010 | | Author(s): |
Khedr EM, Abo-Elfetoh N, Rothwell JC, El-Atar A, Sayed E, Khalifa H.
| | Source: | Eur J Neurol. | | Keywords: |
neuroplasticity, repetitive transcranial magnetic stimulation, tinnitus, tinnitus handicap inventory
| | Abstract: |
Background: Repetitive transcranial magnetic stimulation (rTMS) applied over left temporoparietal cortex has been reported to have a long-term therapeutic effect on tinnitus. We compare the impact of 1 and 25 Hz rTMS delivered either contralateral or ipsilateral to symptoms in 62 patients with unilateral chronic tinnitus. Material and methods: Patients were randomly assigned to one of four treatment groups: with stimulation at 1 or 25 Hz applied either ipsilateral or contralateral to symptoms. Two thousand pulses per session were given daily for 2 weeks. Changes in tinnitus handicap inventory (THI), self-rating scores of loudness, awareness, and annoyance were measured monthly for 10 months. Duration of residual inhibition (RI) and psychiatric morbidity were evaluated monthly for 3 months. Results: There was a significant main effect of time (P < 0.0001) and a significant time x side interaction (P = 0.032) between groups. This was because of the fact that contralateral stimulation had a greater effect on THI than ipsilateral stimulation; it was also superior to left side stimulation (P = 0.027). Ratings of loudness improved more after contralateral rTMS (P = 0.037). Twenty patients had no remaining tinnitus after 3 months; the remainder had a significant increase in RI. Patients with the shortest history of tinnitus tended to respond better to rTMS. There was a significant correlation between changes in THI score and changes in Hamilton anxiety and depression scores. Conclusion: Ten daily treatments of 1 and 25 Hz rTMS contralateral to the side of tinnitus have a greater beneficial effect on symptoms than either ipsilateral or left side stimulation.
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| | Title: |
Left temporal low-frequency rTMS for the treatment of tinnitus: clinical predictors of treatment outcome - a retrospective study.
| | Date: | 2010 | | Author(s): |
Frank G, Kleinjung T, Landgrebe M, Vielsmeier V, Steffenhagen C, Burger J, Frank E, Vollberg G, Hajak G, Langguth B.
| | Source: | Eur J Neurol. | | Keywords: |
chronic tinnitus, inhibition, predictors, repetitive transcranial magnetic stimulation, treatment outcome
| | Abstract: |
Background: There is increasing evidence that repetitive transcranial magnetic stimulation (rTMS) can reduce chronic tinnitus. However, treatment results are characterized by high interindividual variability. Therefore, the identification of predictors for treatment response is of high clinical relevance. Methods: Clinical data of 194 patients with tinnitus were evaluated. All patients were treated with a standardized rTMS procedure (1 Hz, 10 days, 2000 stimuli/day, over the left temporal cortex). A potential influence on the outcome was analysed for the following parameters: age, gender, depression scores in Beck Depression Inventory (BDI) and tinnitus severity (TQ) before rTMS, lateralization, frequency and duration of tinnitus and extent of hearing loss. Results: An effect of tinnitus laterality was observed. In patients with left-sided or bilateral tinnitus, rTMS resulted in a statistically significant reduction of TQ scores, whereas patients with right-sided tinnitus did not show a significant improvement after rTMS treatment. However, in correlation analyses, we found a trend which did not reach statistical significance that in the subgroup of treatment responders tinnitus duration influenced rTMS outcome. In addition, a multiple regression analysis identified the TQ score at baseline as a significant predictor for treatment outcome. For all other investigated parameters, no statistically significant effects were found. Conclusions: This study suggests that left temporal low-frequency rTMS has beneficial effects in left-sided and bilateral tinnitus, but not in right-sided tinnitus. In line with the results from earlier studies involving smaller samples, tinnitus duration was found to influence rTMS outcome.
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| | Title: |
rTMS for the treatment of tinnitus: the role of neuronavigation for coil positioning.
| | Date: | 2010 | | Author(s): |
Langguth B, Kleinjung T, Landgrebe M, de Ridder D, Hajak G.
| | Source: | Neurophysiol Clin. | | Keywords: |
Transcranial magnetic stimulation, Functional imaging, Neuronavigation, Neuroplasticity, Auditory cortex, Neuromodulation
| | Abstract: |
Tinnitus affects 10% of the population, its pathophysiology remains incompletely understood, and treatment is elusive. Both animal models and functional imaging data in tinnitus patients suggest that tinnitus is associated with increased neuronal activity, increased synchronicity and functional reorganisation in the auditory cortex. Therefore, targeted modulation of auditory cortex has been proposed as a new therapeutic approach for chronic tinnitus. Repetitive transcranial magnetic stimulation (rTMS), a non invasive method for modulation of cortical activity, has been applied in different ways in patients with chronic tinnitus. Single sessions of high-frequency rTMS over the temporal cortex have been used to transiently interfere with the intensity of tinnitus. Repeated sessions of low-frequency rTMS have been investigated as a treatment for tinnitus. Here, we review data from clinical trials and discuss potential neurobiological mechanisms with special focus on the relevance of the stimulation target and the method of TMS coil positioning. Different functional neuroimaging techniques are used for detecting tinnitus-related changes in brain activity. They converge in the finding of increased neuronal activity in the central auditory system, but they differ in the exact localisation of these changes, which in turn results in uncertainty about the optimal target for rTMS treatment. In this context, it is not surprising that the currently available studies do not demonstrate clear evidence for superiority of neuronavigational coil positioning. Further development of rTMS as a treatment for tinnitus will depend on a more detailed understanding of both the neuronal correlates of the different forms of tinnitus and of the neurobiological effects mediating the benefit of TMS on tinnitus perception.
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