DBS for Depression

Question 1

Describe how DBS is delivered. That is, is it turned on once per hour, once per day?

Answer 1

Electrodes are implanted into the ACC and left in place, connected to a stimulator and battery pack implanted sc.
Pulsed stimulation is applied continuously (24/7).
PET studies done before and after stimulation found that DBS reduced the resting state activity of the ACC.

Question 2

What was the rationale for using DBS of the subgenual anterior cingulate cortex (subgenual ACC) as a treatment for MDD? That is, why did Mayberg think this would help?

Answer 2

Stimulation of ACC could disrupt the pathological activity of a network of neurons involved with mood regulation in patients with MDD.

Question 3

Imaging studies have shown that activation of the ACC is often associated with which one of the 6 basic emotions?

Answer 3

sadness

Question 4

Subgenual ACC includes Brodmann area 25 (BA25). Neurons here have direct projections to many other regions important for emotion and mood. Name some of the regions that receive input from BA25. Include two areas of the PFC and two areas of the midbrain in your answer.

Answer 4

OFC, other areas of ACC, nucleus accumbens (Acb), BST, amygdala, hypothalamus, VTA, PAG, monoamine cell groups (LC & raphe).

Question 5

DBS in other brain areas also has antidepressant effects. Name some of these areas. What do these areas have in common?

Answer 5

nucleus accumbens
lateral habenula
medial forebrain bundle

Question 6

DBS of the medial forebrain bundle (mfb) has been reported to relieve depression. The mfb carries axons that project from the ___________ to the nucleus accumbens and PFC.

Answer 6

mestelencephalic DA pathway