rTMS Responders Research Articles

Theta, alpha and beta burst transcranial magnetic stimulation: brain modulation in tinnitus.

Some forms of tinnitus are considered to be auditory phantom phenomena related to reorganization and hyperactivity of the auditory central nervous system. Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive tool capable of modulating human brain activity, using single pulse or burst stimuli. Burst rTMS has only been performed in the theta range, and has not been used clinically. The authors analyze whether burst TMS at theta (5 Hz), alpha (10 Hz) and beta (20 Hz) frequencies can temporarily suppress narrow band noise/white noise tinnitus, which has been demonstrated to be intractable to tonic stimulation. rTMS is performed both in tonic and burst mode in 46 patients contralateral to the tinnitus side, at 5, 10 and 20 Hz. Fourteen placebo negative rTMS responders are further analyzed. In 5 patients, maximal tinnitus suppression is obtained with theta, in 2 with alpha and in 7 with beta burst stimulation. Burst rTMS suppresses narrow band/white tinnitus much better than tonic rTMS t(13)=6.4, p<.000. Women experience greater suppression of their tinnitus with burst stimulation than men, t(12)=2.9, p<.05. Furthermore left sided tinnitus is perceived as more distressing on the TQ than right sided tinnitus, t(12)=3.2, p<.01. The lower the tinnitus pitch the more effectively rTMS suppresses tinnitus(r=-0.65, p<0.05). Burst rTMS can be used clinically, not only theta burst, but also alpha and beta burst. Burst rTMS is capable of suppressing narrow band/white noise tinnitus very much better than tonic rTMS. This could be due the simple fact that burst neuromodulation is more powerful than tonic neuromodulation or to a differential effect of burst and tonic stimulation on the lemniscal and extralemniscal auditory system. In some patients only alpha or beta burst rTMS is capable of suppressing tinnitus, and theta burst not. Therefore in future rTMS studies it could be worthwhile not to limit burst stimulation to theta burst rTMS.

Effects of antidepressant pharmacotherapy after repetitive transcranial magnetic stimulation in major depression: an open follow-up study

An increasing number of clinical studies demonstrates antidepressant effects of repetitive transcranial magnetic stimulation (rTMS). However, limited data are available so far concerning the stability of these effects and the efficacy of subsequent maintenance therapy. Therefore, we examined whether antidepressant pharmacotherapy can stabilize clinical improvement after rTMS monotherapy. Twenty-six drug-free patients suffering from a major depressive episode (DSM-IV criteria) participated in an open rTMS trial over two weeks (10–13 sessions, 10 Hz, left prefrontal stimulation at 100% motor threshold intensity). Subsequently, the patients were followed up during standardized antidepressant pharmacotherapy with mirtazapine for a further 4 weeks. The interval between the last rTMS and the first day of pharmacotherapy varied between one and five days. After two weeks of rTMS monotherapy 39% of the patients responded to rTMS by at least 50% reduction in their Hamilton Rating Scale for Depression (HRSD) scores. Treatment interruption after rTMS resulted in a significant increase in the HRSD score of rTMS responders. The degree of the deterioration was dependent on the length of interval without treatment. However, this deterioration was reverted and the further clinical course stabilized by subsequent mirtazapine treatment. The overall response rate after rTMS and mirtazapine treatment (alone or in combination) was 77%. Our results suggest that (1) antidepressant pharmacotherapy is able to further improve the clinical response to rTMS and (2) that responders to rTMS monotherapy should receive subsequent psychopharmalogical treatment without interruption in order to avoid a deterioration of symptoms.