Made available in DSpace on 2014-12-17T15:28:51Z (GMT). No. of bitstreams: 1 MorganaMN_DISSERT.pdf: 8378987 bytes, checksum: 55d0d3823fa6d9c47865791e3edefa62 (MD5) Previous issue date: 2012-08-24 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Mirror therapy (MT) is being used as a rehabilitation tool in various diseases, including stroke. Although some studies have shown its effectiveness, little is known about neural mechanisms that underlie the rehabilitation process. Therefore, this study aimed at assessing cortical neuromodulation after a single MT intervention in ischemic stroke survivors, by means of by functional Magnetic Resonance Imaging (fMRI) and Transcranial Magnetic Stimulation (TMS). Fifteen patients participated in a single thirty minutes MT session. fMRI data was analyzed bilaterally in the following Regions of Interest (ROI): Supplementary Motor Area (SMA), Premotor cortex (PMC), Primary Motor cortex (M1), Primary Sensory cortex (S1) and Cerebellum. In each ROI, changes in the percentage of occupation and beta values were computed. Group fMRI data showed a significant decreased in the percentage of occupation in PMC and cerebellum, contralateral to the affected hand (p <0.05). Significant increase in beta values was observed in the following contralateral motor areas: SMA, Cerebellum, PMC and M1 (p<0,005). Moreover, a significant decrease was observed in the following ipsilateral motor areas: PMC and M1 (p <0,001). In S1 a bilateral significant decrease (p<0.0005) was observed.TMS consisted of the analysis of Motor Evoked Potential (MEP) of M1 hotspot. A significant increase in the amplitude of the MEP was observed after therapy in the group (p<0,0001) and individually in 4 patients (p <0.05). Altogether, our results imply that single MT intervention is already capable of promoting changes in neurobiological markers toward patterns observed in healthy subjects. Furthermore, the contralateral hemisphere motor areas changes are opposite to the ones in the ipsilateral side, suggesting an increase system homeostasis. / A Terapia Espelho (TE) vem sendo usada como ferramenta de reabilita??o para v?rias doen?as, incluindo o Acidente Vascular Cerebral (AVC). Embora alguns estudos tenham mostrado sua efic?cia cl?nica, pouco se sabe sobre os mecanismos neurais que levam ? melhora observada. Desse modo, este estudo teve como objetivo avaliar a neuromodula??o cortical promovida pela interven??o ?nica da TE em pacientes acometidos por AVC, por meio da Resson?ncia Magn?tica funcional (fMRI, do ingl?s Functional Magnetic Resonance Imaging) e da Estimula??o Magn?tica Transcraniana (TMS, do ingl?s Transcranial Magnetic Stimulation). Quinze pacientes participaram de sess?o ?nica de trinta minutos de TE. Os dados de fMRI foram analisados nas seguintes regi?es de interesse (ROI), bilateralmente: ?rea Motora Suplementar (AMS), c?rtex pr?-motor (PM), c?rtex motor prim?rio (M1), c?rtex sensorial prim?rio (S1) e Cerebelo. Em cada ROI, as mudan?as na porcentagem de ocupa??o e os valores de beta foram avaliados. Os resultados revelaram redu??o significativa no percentual de ocupa??o no PM e cerebelo contralateral ? m?o afetada (p <0,05). Al?m disso, foi observado aumento significativo nos valores de beta nas seguintes ?reas motoras contralaterais: AMS, Cerebelo, PM e M1 (p <0,005) e diminui??o significativa nas seguintes ?reas motoras ipsilaterais: PM e M1 (p < 0,001). Nas ?reas sensoriais foi observada redu??o em S1 bilateralmente (p <0,0005). Pela TMS foi analisado o Potencial Evocado Motor (PEM) sobre o hot spot de M1. Aumento significativo na amplitude do PEM foi observado ap?s a terapia no grupo (p<0,0001), e individualmente em 4 pacientes (p <0,05). Assim, nossos resultados indicam que interven??o ?nica da TE muda marcadores neurobiol?gicos em dire??o ao padr?o observado em indiv?duos saud?veis. Al?m disso, as altera??es nas ?reas motoras do hemisf?rio contralateral s?o opostas as do lado ipsilateral, sugerindo um aumento na homeostase do sistema.