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High Frequency Essay

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Most studies focus on the activation and deactivation TMS causes in the brains of depressed individuals. High-frequency stimulation, commonly measured as 20 Hz, has been found to have global activation (Teneback et. al, 1999; Speer et. al, 2000; Nahas et. al, 2001). High-frequency is measured as any frequency above 1 Hz as there was no change in blood flow with 5 Hz and 20 Hz (Teneback et. al, 1999; Nahas et. al, 2001). On the opposite end, a frequency of 1 Hz was found to decrease the blood flow (Speer et. al, 2000). At 20 Hz, blood flow increased in the prefrontal cortex, cingulate gyrus, left amygdala, bilateral insula, basal ganglia, uncus, hippocampus, parahippocampus, thalamus, and cerebellum (Teneback et. al, 1999; Speer et. al, …show more content…

At baseline, before stimulation, it was found that the more depressed an individual was, the less activation there was in the prefrontal cortex and caudate nucleus (Teneback et. al, 1999). Teneback et. al (1999) also noted that following high-frequency treatment, the people who responded to the treatment had increased inferior frontal gyrus activity compared to those who did not respond, and days later, they also had decreased medial temporal activity. The prediction is that while both the responders and non-responders showed changes in a Single-Photon Emission Computed Tomography (SPECT) image, the responders had more normalization of blood flow (Teneback et. al, 1999). These results support the idea that depression can be caused by either hyper-activation or hypo-activation, an imbalance within the brain. If it can be measured as to which causes an individual’s depression, the frequency needed for TMS to be effective can be predicted to further help the suffering individual. The FDA has approved TMS to treat TRD. Studies show that in comparison with control groups, done by sham stimulation, TMS effectively improves the symptoms of depression and even causes some people to go into remission following two weeks of daily treatment. George et. al (2000) compared sham stimulation with 5 Hz and 20 Hz. They found that there was no difference between 5 and 20 Hz with people from both

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