London, United Kingdom 2013 Poster Session Blue Cerebrovasc Dis 2013; 35 (suppl 3)1-854 853 959 Recent news in stroke research Effects of low-frequency repetitive magnetic stimulation of the unaffected hemisphere on cor-tical excitability in the subacute phase after stroke A.B. CONFORTO1, E.A. MELLO2, S.M. ANJOS3, J. CONTI4, K.N. ANDRADE5, W. RO-DRIGUES JR.6, L.G. COHEN7 HOSPITAL DAS CLINICAS - UNIVERSIDADE DE SÃO PAULO, SÃO PAULO, BRAZIL1, HOSPITAL DAS CLINICAS - UNIVERSIDADE DE SÃO PAULO, SÃO PAULO, BRAZIL2, HOSPITAL DAS CLINICAS - UNIVERSIDADE DE SÃO PAULO, SÃO PAULO, BRAZIL3, HOSPITAL DAS CLINICAS - UNIVERSIDADE DE SÃO PAULO, SÃO PAULO, BRAZIL4, HOSPITAL DAS CLINICAS - UNIVERSIDADE DE SÃO PAULO, SÃO PAULO, BRAZIL5, HOSPITAL DAS CLINICAS - UNIVERSIDADE DE SÃO PAULO, SÃO PAULO, BRAZIL6, The Human Cortical Physiology and Stroke Rehabilitation Section, National Institutes of Neurological Disorders and Stroke, BETHESDA, USA7 Background: Low-frequency repetitive transcranial magnetic stimulation of the unaffected hemi-sphere (rTMS-UH) is a potential tool to enhance function of the paretic hand in patients with mild motor impairment. Our aim was to evaluate effects of rTMS-UH on excitability of the unaffected motor cortex in patients in the subacute phase after stroke. Methods: Eighteen patients were randomized to either active rTMS-UH at 1 Hz or sham rTMS, im-mediately before standard-of-care physical therapy, five days a week, for 2 weeks. The following cortical excitability measures were evaluated after stimulating the unaffected hemisphere and re-cording motor evoked potentials from the unaffected abductor pollicis brevis, before the first session (baseline) and after the last session of treatment: resting motor threshold (rMT), short-interval intra-cortical inhibition (SICI) and short-interval intracortical facilitation (SICF). Differences in changes in excitability measures (baseline - after treatment) between the active and sham groups were com-pared with unpaired t-tests. Results: There were no significant differences in baseline characteristics between the active and sham groups. There were no significant differences in changes in rMT or SICI, between the sham and active groups. There was a significant difference between changes in SICF between the two groups (p= 0.024). SICF increased in five patients in the active group and only in one patient in the sham group. Conclusion: The increase in SICF observed in the unaffected hemisphere after ten sessions of 1-Hz rTMS-UH was unexpected, and contrasts with the decrease in SICF reported after ten minutes of a single session of the same intervention in healthy subjects. The paradoxical result in patients may re-flect homeostatic mechanisms in the subacute phase after stroke, or may be related to differences in effects of ten repeated sessions of treatment compared to those of a single session. 960 Recent news in stroke research GENOTYPE AND MMP-9 / TIMP-1 LEVELS IN PATIENTS WITH ISCHEMIC STROKE PRESENTING DIFFERENT RANKIN SCORE B. Eccard1, I. Lemos2, C. Fernandes3, K. Fernandes4, P.P. Christo5, V. Sandrim6 Instituto de Ensino e Pesquisa Santa Casa de Belo Horizonte, Belo Horizonte, BRAZIL1-6 Matrix metalloproteinases form an enzyme family of which gelatinase B (MMP-9) that are zinc-de-pendent endopeptidases well known for their ability to regulate cellular matrix composition. In-creasingly, these extracellular proteases are recognized as playing critical roles in the pathophysiol-ogy of brain injury and neurodegeneration because may contribute to proteolysis of the blood brain barrier basal lamina, an important phase in the ischemic stroke. Tissue Inhibitor of Matrix Metallo-proteinases (TIMP-1), is known to bind MMP-9 with high affinity to block its enzymatic function. Because there are few studies of MMP-9/TIMP-1 about severity, but none in the Brazilian popula-tion, we correlated the plasmatic levels and genotypes of MMP-9/TIMP-1 among stroke severity that were evaluated using the modified Rankin Scale score. We conducted venous blood of patients admitted for post-stroke follow-up clinic of neurology at the Santa Casa de Belo Horizonte. Plasma MMP-9 and TIMP-1 was measured by ELISA in the plasma of 64 patients. Genotyping of MMP- 9 was through the method RFLP (Restriction fragment length polymorphism) and TIMP-1 with TaqMan. Statistical comparisons among groups were done using ANOVA and t-test. The differences genotype frequencies between groups were determined by chi-square. Statistical significance was set at P <0.05. We observed a significant increase in the expression of MMP-9 in patients with Rankin Scale >2 (529.7+81.05ng/mL, P=0,021, n=24) compared with Rankin Scale 0-1 (354.7+187.1ng/ mL, n=40). The classification >2 CC+CT genotype significantly increased plasma levels of TIMP- 1 (1462 ± 200.7 ng/mL, P= 0,0359, n=13) compared to genotype TT (935.5 ± 94.64ng/mL, n=11). These results suggest that patients with poor functional outcome have an elevation in expression of MMP-9, but unrelated with the polymorphism. This implies that this endopeptidase may be consid-ered as a future marked for disease prognosis.
Karger_ESC London_2013
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