no-go reaction time

Abstracts improved by 63%, 49.6%, 4.2% and 27.3% respectively. In the non-affected limb, HY ratings changed by 18.9% from 8.8 prior the first tDCS session to 7.14 after the 5th session of the first block. During following four blocks, HY ratings in the non-affected limb were as follows: decreased by 66%, increased by 13% (worsening), decreased by 31.1%, and 39.9% respectively. AL improved only after the 4th and 5th block, by 54.2% and 40.2% (from 7.2 to 3.3 and from16.7 to 10.0) respectively in the affected limb and by 63.9% and 27.2% in the contralateral limb. Conclusions: To our knowledge, this the first study assessing hyperalgesia and allodynia in a patient receiving tDCS treatment.

rTMS Poster Only 50

One year follow-up study of patients received left temproparietal rTMS for treatment of chronic tinnitus

Khedr E1, Rothwell J2, El Atar A1, 1Assiut University Hospital, Assiut, Egypt (Assiut, EG); 2Queen Square Hospital, (London, UK) Background: Although there are a number of positive reports of the therapeutic effects of repetitive transcranial magnetic stimulation (rTMS) for treatment of tinnitus, there are few details about the duration of treatment effects or the relative efficiency of different rTMS protocols. Methods: 66 patients with chronic tinnitus were divided into 4 groups, sham (occipital rTMS), 1, 10 and 25 Hz rTMS applied each day for 10 days over temporoparietal cortex. They were followed up at 4 months and 1 year using the tinnitus questionnaire (THI), self ratings of tinnitus loudness, annoyance, awareness as well as measures of residual inhibition. Results: A two factor ANOVA revealed a significant ‘‘rTMS’’ x ‘‘time’’ interaction indicating that real and sham rTMS had different effects on the THI scale, loudness, awareness and annoyance of tinnitus (P 5 0.02, 0.03, 0.02, and 0.003 respectively). After one year, the tinnitus was absent in one or both ears of 10 patients who had received real rTMS: 1 of these was in the 1 Hz group (both ears), 4 patients were in the 10 Hz group (2 unilateral and 2 both ears), and 5 patients were in the 25 Hz group (4 unilateral and one both ears). The duration of residual inhibition in the remaining ears was increased significantly more than sham in the 10 Hz and 25 Hz rTMS group while it had returned to base line in the 1 Hz group. Conclusion: Some patients show a lasting benefit at 1 year after 10 days of rTMS treatment. It appears that treatment at 10 or 25 Hz may be more beneficial than at 1 Hz, although more work is necessary to validate this conclusion.

TMS Poster Only 51

Interaction between left dorsal premotor and right primary motor cortex during a left hand visual go/no-go reaction time

Maruyama A1, Takahashi K2, Rothwell JC3, 1Kagoshima University (Kagoshima, JP); 2Kyusyu Institute of Technology (Kitakyusyu, JP); 3 Institute of Neurology (London, UK) Background: The left dorsal premotor cortex (PMd) plays a dominant role in the selection of movements by either hand. Koch et al (2006) recently showed that the connections between left PMd and right M1, which can be studied using a paired pulse TMS paradigm, were modulated during the reaction time of an auditory cued left/right choice reaction task. Here we examined the role of the connections in a visually cued left hand go/nogo task. Methods: Eight (6 males and 2 females aged 20-25 yrs) subjects participated. In experiment 1, the inhibitory connection between left PMd and right M1 was studied in a paired pulse paradigm by applying a conditioning TMS pulse to PMd (CS: 90/110% RMT, chosen to give maximum effect in each individual) and a test pulse to right M1 (TS: sufficient to produce an MEP of around 1mV peak-to-peak) at an interstimulus interval of 8ms. Subjects received a warning and then 1-3 s later a visual reaction signal (go, blue / no-

255 go, red) to press the left index finger as rapidly as possible. PMd-M1 connectivity was evaluated at 100, 120, 140, 160, 180 ms after the reaction signal. In experiment 2, SICI (2, 3ms) and ICF (10, 15ms) (Kujirai et al. 1993; CS of 80% AMT) in the right M1 together with PMd-M1 connectivity were evaluated at an interval of 160ms. Results: Experiment 1) Reaction times were around 225ms (EMG onset) in all conditions. Starting 140ms after the reaction signal, MEPs increased (to 200% control by 180ms) in the ‘‘go’’ task and slightly decreased in the nogo task (80% control by 180ms). Baseline PMd-M1 inhibition was minimal prior to the reaction signal (PMd conditioning suppressed the test MEP to around 90% control). It became facilitatory (105-110%) from 140180 ms in ‘‘go’’ trials and increased slightly to 85% in the ‘‘nogo’’ trials. Experiment 2) At 160ms, the test MEP was greatly facilitated. However the percent ICF was unchanged (110%) whereas SICI was reduced (from about 50% control to 80% control). As in the first experiment, PMd-M1 connectivity was excitatory (110% control) in the ‘‘go’’ task and inhibitory (85% control) in the ‘‘nogo’’ task. Conclusion: Interhemispheric left PMd-right M1 interactions may contribute to the selection or suppression of left hand movement in a visually cued reaction task.

Clinical Studies Poster Only 52

Tolerability and safety of theta-burst TMS in patients with major depression

Chistyakov A, Kaplan B, Robicsek O, Klein E, Rambam Health-Care Campus (Haifa, IL) Objective: The aim of this preliminary open study was to evaluate tolerability, safety and antidepressant effects of theta-burst transcranial magnetic stimulation (TBS) in patients with major depression (MD). Method: Nineteen subjects with MD were enrolled into the study. Initially, thirteen patients were assigned to receive either continuous TBS (cTBS) administered to the right dorsolateral prefrontal cortex (DLPFC) (n 5 6) or intermittent TBS (iTBS) administered to the left DLPFC (n 5 7). Each treatment session included 600 pulses of cTBS or iTBS at an intensity of 90% active motor threshold (aMT). Based on the results obtained from the first 13 subjects, the treatment protocol was amended, so that the following 6 patients received cTBS to the right DLPFC at an intensity of 100% aMT, 900 pulses per session. All patients received 2 daily treatment sessions for 10 consecutive work days. Severity of depression was assessed by the Hamilton depression scale. Result: Eighteen out of 19 patients completed two weeks treatment protocol without any adverse effects. Marked clinical improvement was observed in 9 patients (2 receiving left DLPFC 90% aMT iTBS; 4 receiving right DLPFC 90% aMT cTBS; and 3 receiving right DLPFC 100% aMT cTBS). One patient who received TBS at 100% aMT intensity dropped out after 4 treatment sessions due to local painful scalp sensations during stimulation. Conclusion: These preliminary results suggest that in MD patients, TBS as applied in our study has an antidepressant effect and is safe and well tolerated. cTBS administered to the right DLPFC seems to have more prominent antidepressant action compared to left sided iTBS. Randomized sham-controlled studies are required to further evaluate the therapeutic efficacy of TBS in major depression.

tDCS Poster Only 53

Towards unravelling task-related modulations of neuroplastic changes induced in the human motor cortex

Terney D, Antal A, Paulus W, Georg-August University (Go¨ttingen, DE) Stimulation with weak electrical direct current has been shown to be capable of inducing stimulation-polarity-dependent prolonged diminutions