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Randomized sham controlled trial of low frequency repetitive Transcranial Magnetic Stimulation (rTMS) to the Supplementary Motor Area (SMA) for treatment resistant Obsessive-Compulsive Disorder (OCD)
Abstracts tinnitus raises questions about the role of asymmetric cortical activity in tinnitus. The study demonstrates, for the first time, that maintenance rTMS can be used to achieve a lasting satisfactory result in a subset of patients with subjective tinnitus. Support: RR20146.
285 Method: The look and sound of active rTMS was replicated using a matched, air-cooled sham TMS coil (MagStim) that delivers 5% of stimulator output.
Clinical Studies Poster Only 145
Randomized sham controlled trial of low frequency repetitive Transcranial Magnetic Stimulation (rTMS) to the Supplementary Motor Area (SMA) for treatment resistant Obsessive-Compulsive Disorder (OCD)
Mantovani A1, Simpson HB1, Fallon BA1, Rossi S2, Lisanby SH1, 1 Columbia University (New York, US); 2Siena University (Siena, IT) Objective: In an open label trial of low-frequency repetitive Transcranial Magnetic Stimulation (rTMS) to Supplementary Motor Area (SMA) we found significant improvements in clinical symptoms and changes in cortical excitability of Obsessive-Compulsive Disorder (OCD) patients. Here we present data of the first double-blind study. Method: Twenty-one medication resistant OCD patients were assigned to 4 weeks of active or sham low-frequency rTMS to SMA. rTMS parameters consisted of 1200 stimuli/day, at 1-Hz and 100% of Motor Threshold (MT). Yale-Brown Obsessive Compulsive Scale (Y-BOCS) and Clinical Global Impression (CGI) were considered primary outcome measures. Patients received 4 additional weeks of active rTMS if during the double-blind phase they showed at least 25% change on the Y-BOCS. Result: There was significantly better improvement in OCD with active rTMS. Response rate defined as 25% change on the Y-BOCS was 67% with active and 22% with sham rTMS. At 4 weeks, patients receiving active rTMS showed 32% improvement compared with 11% with sham. After 8 weeks of active rTMS, OCD symptoms improved by 42%. Active rTMS led to significant reductions in depression and anxiety as well. Baseline MT on the right hemisphere was significantly lower in patients randomized to active and showed in this group a significant increase over time. At the end of 8 weeks of rTMS the abnormal hemispheric laterality found at baseline in the group randomized to active normalized. No significant changes in MT measures were detected in the group randomized to sham. Conclusion: These results are consistent with those found in our previous open trial. In both studies clinical improvements in OCD were associated with normalization of baseline cortical hyper-excitability. The response rate to active rTMS compares favorably with reported response rates to medications and Deep Brain Stimulation. The results of the first randomized sham-controlled study of SMA stimulation in the treatment of resistant OCD support further investigation into the potential therapeutic applications of rTMS in this disabling condition.
rTMS Poster Only 146
An advanced method of sham rTMS using electrical stimulation of the scalp
Mennemeier M1, Triggs W2, Chelette KC1, Woods AJ3, Myhill J1, Winham W1, Kimbrell T1, Dornhoffer J1, 1University of Arkansas for Med Scs (Little Rock, AR, US); 2University of Florida (Gainesville FL, US); 3 George Washington University (Washington D.C., US) Objective: Develop and validate a new method of sham, repetitive transcranial magnetic stimulation (rTMS) for use in a placebo-controlled study with subject crossover.
Stimulator output was set to 45% during sham TMS so the clicking sounds matched those of the active coil even at higher settings (87 dB versus 86 dB, respectively). Scalp muscle stimulation was replicated with large rubber electrodes placed directly over selected temporalis muscles. The intensity and pulse width of electrical stimulation necessary to match 1-Hz rTMS at both MT and 110% of MT was developed in one sample of 10 normal subjects. The sham technique was then validated in back-to-back comparisons with active rTMS in a new sample of 15 normal subjects who were either naive (n 5 10) or experienced (n 5 5) with rTMS. Result: Measured electrode impedances were always below 25. KOmega. A 500-msec pulse width was chosen because it felt less sharp than an 800 msec pulse width. Current intensities set to match MT and 110% of MT ranged from 6.7 to 17.0 mA, with a mean value of 12.7 mA (SE 5 .94).
Current intensity and MT were correlated at .68, p,.01. Naive subjects could not tell which type of stimulation was active or sham or which was electrical or magnetic. Naı¨ve subjects incorrectly picked sham stimulation as active when forced to choose (p,.05, Binomial Test) stating that electrical stimulation felt more focused than magnetic stimulation. Subjects experienced with rTMS could correctly identify the sham and the active stimulation. Experimenters could detect subtle differences in the equipment between conditions. Conclusion: This method of sham rTMS closely mimics the look, sound, and feel of active stimulation without creating a significant magnetic filed (5% of 45 5 only 2.25% of MS0). It is valid for use in crossover studies with naı¨ve subjects. A double-blind study would require further masking of equipment and a non-blinded assistant to set up equipment. The
285 Method: The look and sound of active rTMS was replicated using a matched, air-cooled sham TMS coil (MagStim) that delivers 5% of stimulator output.
Clinical Studies Poster Only 145
Randomized sham controlled trial of low frequency repetitive Transcranial Magnetic Stimulation (rTMS) to the Supplementary Motor Area (SMA) for treatment resistant Obsessive-Compulsive Disorder (OCD)
Mantovani A1, Simpson HB1, Fallon BA1, Rossi S2, Lisanby SH1, 1 Columbia University (New York, US); 2Siena University (Siena, IT) Objective: In an open label trial of low-frequency repetitive Transcranial Magnetic Stimulation (rTMS) to Supplementary Motor Area (SMA) we found significant improvements in clinical symptoms and changes in cortical excitability of Obsessive-Compulsive Disorder (OCD) patients. Here we present data of the first double-blind study. Method: Twenty-one medication resistant OCD patients were assigned to 4 weeks of active or sham low-frequency rTMS to SMA. rTMS parameters consisted of 1200 stimuli/day, at 1-Hz and 100% of Motor Threshold (MT). Yale-Brown Obsessive Compulsive Scale (Y-BOCS) and Clinical Global Impression (CGI) were considered primary outcome measures. Patients received 4 additional weeks of active rTMS if during the double-blind phase they showed at least 25% change on the Y-BOCS. Result: There was significantly better improvement in OCD with active rTMS. Response rate defined as 25% change on the Y-BOCS was 67% with active and 22% with sham rTMS. At 4 weeks, patients receiving active rTMS showed 32% improvement compared with 11% with sham. After 8 weeks of active rTMS, OCD symptoms improved by 42%. Active rTMS led to significant reductions in depression and anxiety as well. Baseline MT on the right hemisphere was significantly lower in patients randomized to active and showed in this group a significant increase over time. At the end of 8 weeks of rTMS the abnormal hemispheric laterality found at baseline in the group randomized to active normalized. No significant changes in MT measures were detected in the group randomized to sham. Conclusion: These results are consistent with those found in our previous open trial. In both studies clinical improvements in OCD were associated with normalization of baseline cortical hyper-excitability. The response rate to active rTMS compares favorably with reported response rates to medications and Deep Brain Stimulation. The results of the first randomized sham-controlled study of SMA stimulation in the treatment of resistant OCD support further investigation into the potential therapeutic applications of rTMS in this disabling condition.
rTMS Poster Only 146
An advanced method of sham rTMS using electrical stimulation of the scalp
Mennemeier M1, Triggs W2, Chelette KC1, Woods AJ3, Myhill J1, Winham W1, Kimbrell T1, Dornhoffer J1, 1University of Arkansas for Med Scs (Little Rock, AR, US); 2University of Florida (Gainesville FL, US); 3 George Washington University (Washington D.C., US) Objective: Develop and validate a new method of sham, repetitive transcranial magnetic stimulation (rTMS) for use in a placebo-controlled study with subject crossover.
Stimulator output was set to 45% during sham TMS so the clicking sounds matched those of the active coil even at higher settings (87 dB versus 86 dB, respectively). Scalp muscle stimulation was replicated with large rubber electrodes placed directly over selected temporalis muscles. The intensity and pulse width of electrical stimulation necessary to match 1-Hz rTMS at both MT and 110% of MT was developed in one sample of 10 normal subjects. The sham technique was then validated in back-to-back comparisons with active rTMS in a new sample of 15 normal subjects who were either naive (n 5 10) or experienced (n 5 5) with rTMS. Result: Measured electrode impedances were always below 25. KOmega. A 500-msec pulse width was chosen because it felt less sharp than an 800 msec pulse width. Current intensities set to match MT and 110% of MT ranged from 6.7 to 17.0 mA, with a mean value of 12.7 mA (SE 5 .94).
Current intensity and MT were correlated at .68, p,.01. Naive subjects could not tell which type of stimulation was active or sham or which was electrical or magnetic. Naı¨ve subjects incorrectly picked sham stimulation as active when forced to choose (p,.05, Binomial Test) stating that electrical stimulation felt more focused than magnetic stimulation. Subjects experienced with rTMS could correctly identify the sham and the active stimulation. Experimenters could detect subtle differences in the equipment between conditions. Conclusion: This method of sham rTMS closely mimics the look, sound, and feel of active stimulation without creating a significant magnetic filed (5% of 45 5 only 2.25% of MS0). It is valid for use in crossover studies with naı¨ve subjects. A double-blind study would require further masking of equipment and a non-blinded assistant to set up equipment. The