Brainstem stimulation a potential treatment solution for depression
Researchers at the University of Texas Health Science Center at Houston (UT Health Houston) have found deep brain stimulation (DBS) targeted towards a specific bundle of nerves in the brainstem to be a viable therapy for treatment-resistant depression. A small study revealed positive metabolic brain changes in patients who received the DBS treatment via implantation.
DBS has already been used to treat patients suffering from movement disorders such as Parkinson’s disease, tremours, and dystonia, and has been continuously studied as a possible treatment for patients with treatment-resistant depression.
In DBS, electrodes are implanted into certain brain areas, where they generate electrical impulses to affect brain activity – however, finding what part of the brain needs to be targeted to treat depression long term has been challenging.
UT Health Houston’s most recent study using DBS for psychiatric illnesses proved promising.
“We targeted a bundle of fibres that leave this small area [the superolateral branch of the medial forebrain bundle (MFB)] in the brainstem to travel to other areas throughout the brain,” said Dr. Christopher Conner, a former neurosurgery resident at McGovern Medical School at UTHealth Houston. MFB is associated with the gratifying sensation of reward and motivation.
“PET scans indicated that this small target area has very diffuse downstream effects. It’s not one single effect because there’s not one single area of the brain linked to depression. The whole brain needs to be changed and through this one small target, that’s what we were able to do.”
The researchers had initially performed a PET scan before the DBS procedure on 10 patients in the study for a baseline image. They performed additional PET scans at six months and one year to assess changes after treatment, for which scans of 8 of the 10 patients showed a response.
“Correlating with the PET image changes, our patients reported that their depression lessened after the treatment,” added Dr. João de Quevedo, professor in the Department of Psychiatry and Behavioral Sciences at McGovern Medical School. “So, for patients with severe chronic treatment-resistant depression, decreasing our symptoms by half is a lot. It’s the difference between being disabled to being able to do something.”