Results: Treatment with TMS was successful in 6/9 patients with anaverage improvement in responders of 35% on the Y-BOCS. 2/9 patientsresponded to sham (Mantovani et al., 2010). In the active group INC cor-related positively with Y-BOCS improvements (r = 0.7, p = 0.035), whileHA showed a negative correlation with changes in Y-BOCS (r = � 0.8,p = 0.009). The severity of NJREs showed no significant correlationwith clinical improvement. In the sham group correlations of INCand HA components with Y-BOCS were not significant.

Conclusion: According to our preliminary results, low-frequencyTMS to the pre-SMA might be more effective on INC. Consideringthe assumption that INC experiences primarily impair patients’ abil-ity to stop ritualizing, an inhibitory form of TMS directed to the pre-SMA, which has been found to be hyperactive in OCD (Yücel et al.,2007), may normalize a deficient response inhibition characteristicof OCD (de Wit et al., 2012).

This study was supported by an International Obsessive Compul-sive Foundation Award granted to Dr. Mantovani.

References

Ecker W, Gönner S. Incompleteness and harm avoidance in OCD symptom dimen-sions. Behav Res Ther 2008;46:895–904.

Mantovani A, Simpson HB, Fallon BA, Rossi S, Lisanby SH. Randomized sham-controlled trial of repetitive transcranial magnetic stimulation in treatment-resistant obsessive-compulsive disorder. Int J Neuropsychopharmacol2010;13:217–27.

Yücel M, Harrison BJ, Wood SJ, Fornito A, Wellard RM, Pujol J, et al. Functional andbiochemical alterations of the medial frontal cortex in obsessive-compulsivedisorder. Arch Gen Psychiatry 2007;64:946–55.

de Wit SJ, de Vries FE, van der Werf YD, Cath DC, Heslenfeld DJ, Veltman EM, et al.Presupplementary motor area hyperactivity during response inhibition: a candi-date endophenotype of obsessive-compulsive disorder. Am J Psychiatry2012;169:1100–8.

doi:10.1016/j.clinph.2013.04.323

P 248. Cortical inhibition by Retigabine in epilepsy patients:Assessment by transcranial magnetic stimulation—M.A.M. Mun-neke a, M.J. Zwarts b, D.F. Stegeman a, H.J. Schelhaas b, B.U. Kleine b

(a Donders Institute for Brain, Cognition and Behaviour, RadboudUniversity Nijmegen Medical Centre, Neurology/Clinical Neuro-physiology, Nijmegen, The Netherlands, b Epilepsy Centre, Kem-penhaeghe, Heeze, The Netherlands)

Introduction: Transcranial magnetic stimulation (TMS) has beenused to investigate the mechanism of action of several drugs.Sodium-channel blocking drugs elevate the threshold, while drugsthat act on GABAergic transmission improve intracortical inhibitionor prolong the silent period. While these basic studies are designedto investigate physiology and pharmacology, TMS can be suitable asbiomarker in individual patients. A prospective study in newly diag-nosed epilepsy demonstrated that TMS responses measured shortlyafter the application of an antiepileptic drug can predict long-termseizure control. * Retigabine is a first-in-class antiepileptic drug thatacts on potassium channels. Indirectly, changes in GABAergic synap-tic transmission may contribute to its efficacy. In-vivo studies of thephysiological effect of Retigabine on motor cortex excitability inpatients with epilepsy could deepen our understanding of theinvolved mechanisms. The results of such a study may be comparedwith the literature on TMS-effects of classical anti-epileptic andother drugs acting on the central nervous system.

Objectives: The study aims to investigate the effect of Retigabineon cortical excitability measured by TMS in patients with partialonset epilepsy. If there is a change in the TMS variables after startingRetigabine, we would like to see whether this correlates with thetherapeutic effect.

Materials and methods: This is an observational neurophysiologi-cal/neuropharmacological study. Fifteen patients with uncontrolledpartial onset epilepsy, with or without secondary generalizationthat have an indication to initiate adjuvant treatment with Retiga-bine will participate. Doses of conconcurrent medication are keptconstant during the study. TMS is performed before starting Reti-gabine, on 600 mg/day (post1), on 900/dag (post2) or after anyother different maintenance dose is reached (post3). In each ses-sion resting motor threshold, short interval (2 and 5 ms) intracor-tical inhibition, intracortical facilitation (10 and 15 ms), longinterval intracortical inhibition (250 and 300 ms) en silent periodare measured.

Results and conclusion: At the conference preliminary results andconclusions will be presented.

doi:10.1016/j.clinph.2013.04.324

P 249. Effects of repetitive transcranial magnetic stimulation onmotor and gait improvement in incomplete spinal cord injurypatients—M.C. Flores, H. Kumru, J. Benito, N. Murillo, J.M. Tormos,J. Vidal (Institu Guttmann, Badalona, Spain)

Objective: Incomplete spinal cord injury (SCI) patients have thepotential to regain some ambulatory function and optimalreorganization of remaining circuits can contribute to this recovery.We hypothesized that repetitive transcranial magnetic stimulation(rTMS) may promote more active recovery of motor function atthe beginning of gait training using electromechanical system.

Methods: Seventeen incomplete SCI patients were randomized toreceive active rTMS or sham stimulation coupled with rehabilita-tion therapy, when patients began gait training using electrome-chanical system. Active rTMS consisted of 20 daily sessions overthe leg motor area (at 20 Hz). We compared lower extremitymotor score (LEMS), ten meter walking test (10MWT) for walkingspeed, timed up and go (TUG), Walking Index for SCI (WISCI II)scale, Modified Ashworth Scale (MAS) and Spinal Cord Injury Spas-ticity Evaluation Tool (SCI-SET) at baseline, after the last sessionand 4 weeks later, in the active rTMS and sham stimulationgroups.

Results: A significant improvement was observed after last rTMSsession in the active group for LEMS and spasticity, but not for gaitscales. Sham stimulation, did not induce any improvement in LEMS,gait assessment, neither in spasticity after last session.

Conclusion: Twenty daily sessions of high-frequency rTMS canimprove motor score and spasticity, but not walking speed in thelower limbs in incomplete SCI. The study provides evidence for thetherapeutic potential of rTMS in the lower extremities in the earlyphase SCI rehabilitation.

doi:10.1016/j.clinph.2013.04.325

P 250. Inhibitory andexcitatory changes in corticospinal excit-ability after repetitive peripheral magnet stimulation—H. Kum-ru a, M.C. Flores a, E. Opisso a, J. Valls-Sole b, J.M. Tormos a, D.Leon a, J. Vidal a (a Institu Guttmann, Badalona, Spain, b HospitalClinic, Barcelona, Spain)

Introduction: Single pulse transcranial magnetic stimulation (TMS)combined with electrical stimulation of a peripheral nerve induceschanges in the excitability as a result of the so-called paired associa-tive stimulation or PAS (Stefan et al., 2000; Castel-Lacanal et al.,2007). Based on this information, we studied the effect of doublemagnetic stimulation (TMS combined with repetitive peripheral

Society Proceedings / Clinical Neurophysiology 124 (2013) e39–e187 e183