Article
Deep brain stimulation of the subgenual cingulate gyrus (Cg25) in treatment resistant depression
Tiefe Hirnstimulation des subgenualen Cingulum (Cg25) bei therapieresistenter Depression
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Published: | May 30, 2008 |
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Objective: About 5% of depressive patients do not respond satisfactorily to established treatment options with a suicide rate averaging 6–15%. Recent functional imaging studies in treatment resistant depression showed metabolic overactive structures of the limbo-cortical circuits like the subgenual cingulate gyrus (Cg25). Conventional antidepressant interventions modulate the activity of these structures. Hypothesizing that this would disrupt pathological activity of these circuit depressive patients were treated with deep brain stimulation (DBS) of the Cg25 (Mayberg et al 2006). Indeed, in this pilot study 66% of severely depressed patients showed a relevant treatment response. Based on these findings, we report on the – to our knowledge first European – case of antidepressant Cg25-DBS.
Methods: A 49-year-old female with severe therapy resistant depression was treated with bilateral Cg25 DBS. Psychometric and neuropsychological testing was performed throughout six weeks before surgery including Hamilton Depression Rating Scale (HAMD(28)), Montgomery Asberg Rating Scale, Beck Depression Inventory. After intraoperative macrostimulation with a stepwise advance of the electrode double-blind sequential testing of acute effects of electrode pairs (0+4, 1+5, 2+6, 3+7 and sham stimulation) as compared to baseline was performed: first at 9V for each of the five conditions (30 minutes on, separated by 1 hour off), in a second phase at 9V for 24 hours again for each of the five conditions. Afterwards the patient entered chronic stimulation for 6 weeks using the electrode pair with the largest acute effects.
Results: Acute antidepressant effects were neither reported intraoperatively nor after pair wise 30 minute stimulation. However, stimulation of 24 h duration of the electrodes 0+4 or 3+7 revealed modest, but substantial antidepressant effects as compared to baseline and placebo. The HAMD(28) score decreased from a preoperative 36 and postoperative stimulation-off 29 to 22 (0+4) or 21 (3+7), respectively. No positive effect of a 24 h stimulation of contacts 1+5 and 2+6 could be demonstrated vs. postoperative stimulation-off or placebo.
Conclusions: The present case shows that a Cg25 stimulation of only 24 hours may be capable for evoking acute antidepressant effects in some but not all electrodes. Effective contacts were adjacent to the cortex of the subgenual cingulum putatively indicating that stimulation of cortex may be more effective than of stimulation of white matter. No adverse events were found in any stimulation condition.