Use of Repetitive Transcranial Magnetic Stimulation (rTMS) in Chronic Posttraumatic Stress Disorder (PTSD)

Study Summary

Posttraumatic stress disorder occurs in patients who have experienced, witnessed or have been confronted with an event involving actual death or the threat of death, serious injury, or the threat to physical health and felt fear, helplessness, or horror. As a result, patients continue to re-experience, recollect, dream, or have flashbacks about the traumatic incident. Research on PTSD continues to show metabolic changes in specific areas of the brain in patients diagnosed with PTSD. For example, neuroimaging studies (functional MRI and PET scans) reveal that blood flow and glucose utilization increases in the right frontal, limbic, and paralimbic areas of the brain in patients with PTSD, particularly when they are recalling the traumatic event associated with their symptoms. One potential method for interfering with the neuronal circuitry associated with traumatic memories is through the use of repetitive transcranial magnetic stimulation (rTMS). This technique involves the placement of a cooled electromagnet with a figure-eight coil on the patient's scalp and rapidly turning on and off the magnetic flux. This permits non-invasive, relatively localized stimulation of the surface of the brain (cerebral cortex). The effect of magnetic stimulation varies, depending upon the location, intensity and frequency of the magnetic pulses. Preliminary clinical data shows that low frequency rTMS stimulation leads to a decrease in regional cerebral blood flow. This study is designed to determine if rTMS stimulation in patients diagnosed with PTSD leads to symptomatic improvement, reductions in blood flow to specific areas of the brain, and improvements in the regulation of the autonomic nervous system.