Although rTMS has proven to be an effective treatment for depression, the underlying mechanisms of how rTMS affects the brain are not well understood. Now, in a new study published this week in the American Journal of Psychiatry, Dr. Fidel Vila-Rodriguez and his team have, for the first time, mapped the changes occurring in the brain during rTMS treatment in patients with depression.
By delivering one round of rTMS to patients while measuring brain activity inside a magnetic resonance imaging (MRI) scanner, the team was able to examine the areas of the brain being activated in real time. The team found that by stimulating the dorsolateral pre-frontal cortex, several other regions of the brain involved in multiple functions, from managing emotional responses to memory and motor control, were also activated.
The participants then underwent another four weeks of rTMS treatment and the team assessed whether the activated regions were associated with patients having fewer symptoms of depression when their treatment ended.
“We found that regions of the brain that were activated during the concurrent rTMS-fMRI were significantly related to good outcomes… By demonstrating this principle and identifying regions of the brain that are activated by rTMS, we can now try to understand whether this pattern can be used as a biomarker” says Dr. Vila-Rodriguez.
With this new map of how rTMS stimulates different areas of the brain, Dr. Vila-Rodriguez hopes the findings could be used to determine how well a patient is responding to rTMS treatments.