What is Brodmann Area 25?

Brodmann Area 25 (BA 25) is a section of the brain's cerebral cortex. The region is also called the subgenual cingulate. BA 25 is the site of recent deep brain stimulation (DBS) experimentation studies in treating depression. The name for the area comes from Korbinian Brodmann, a German neurologist who originated the idea of mapping and numbering sections of the brain.

Brodmann's cytoarchitectonic map is a chart used to differentiate between different cellular tissue structures. The cytoarchitecture of the brain is determined by staining the tissue to reveal nerve cells. The different Brodmann areas generally correspond with certain psychological functions. The cytoarchitectonic brain section, Brodmann Area 25, is thought to relate to behavior and emotion.

Success with DBS in BA 25 was first shown in treating Parkinson's disease. Some studies in deep brain stimulation (DBS) that involve planting electrodes in Brodmann Area 25, have suggested promising treatments for depression. Patients with major depressive disorder who had treatment-resistant depression showed improvement after DBS in BA 25. In one study that used DBS in Brodmann Area 25, eight out of 12 patients with treatment-resistant depression responded favorably to the treatment. In another similar study, four out of six patients with treatment-resistant depression experienced a remission of their depression.

It should be noted that in some DBS treatments, a few patients did experience side effects. In one study, 9% of treatment-resistant depressive disorder patients experienced neuropyschiatric side effects that included a relapse in depression and changes in personality. Other risks associated with DBS include damage from slipping electrodes or bleeding in the brain.

The part of Brodmann Area 25 stimulated in deep brain stimulation is the white matter. White matter is whitish-colored nerve tissue found in the brain and spinal cord. This area is a relatively thin strip of the brain. Korbinian Brodmann first included BA25 in with Brodmann Area 24 (BA 24) in 1905, but then charted two separate sections, BA 25 and BA 24, in 1909.