By Mary Beth Nierengarten
CHICAGO -- May 1, 2008 -- When other treatments fail, deep-brain stimulation (DBS) may offer hope to patients suffering from chronic and severe depression, according to a study presented here at the 76th Annual Meeting of the American Association of Neurological Surgeons (AANS).
"Despite all therapies, 15% to 20% of patients with depression are treatment-resistant, so we need to explore surgical options for them," said lead author Ali R. Rezai, MD, Jane & Lee Seidman Chair in Functional Neurosurgery, and Director, Center for Neurological Restoration, The Cleveland Clinic, Cleveland, Ohio.
To evaluate the safety and efficacy of DBS in patients with depression, Rezai and colleagues from 3 study centres enrolled patients unresponsive to prior medical therapy to undergo bilateral DBS implantation in the ventral internal capsule/ventral striatum (VC/VS) between 2003 and 2007.
All patients had failed at least 7 documented treatment trials: 3 classes of antidepressants, 2 medication combination regimens, psychotherapy, and bilateral electroconvulsive therapy (ECT).
After DBS, patients were assessed at regular intervals to evaluate postoperative neurological, psychiatric, and neuropsychological functioning. A number of scales were used, including the Montgomery-Asberg Depression Rating Scale (MADRS), which was used as the primary measurement outcome. For the study, a formal clinical response was deemed as a decrease in the MADRS score of at least 50% compared with baseline.
Reporting on the first 17 patients enrolled in the ongoing study, Dr. Rezai said that 47.1% of patients responded to DBS at 6 months based on MADRS criteria, with an increase of up to 50% of the patients responding at 1 year. "This shows a progressive and durable response to treatment so far," he said.
The study also found improvements in quality-of-life measures, such as improvements in mood over time and in social and occupational functioning. According to Dr. Rezai, suicide scores dramatically decreased as well. Another interesting finding, he said, was a significant increase in memory in these patients after DBS.
Overall, the treatment was well tolerated, with no haemorrhages, infections, or other neurological deficits.
The authors concluded that in this cohort of patients, DBS led to progressive and durable improvements in psychiatric function in many patients, with no associated permanent adverse effects, warranting further evaluation in more studies.
As with the use of DBS for obsessive-compulsive disorder (OCD), DBS is considered an adjuvant to medical and behavioural treatment in these patients, said Dr. Rezai, since most if not all of these patients remain on the more conventional treatments after DBS.
Patients were excluded from this study if they were at imminent risk of suicide, were unable to sign an informed consent form, had a current or past psychotic disorder or associated neurological disorder, demonstrated any brain-imaging abnormality, had substance-abuse problems, or had any medical problem that would elevate the risk of surgery.
[Presentation title: Deep Brain Stimulation (DBS) for the Treatment of Intractable Major Depression: Long-Term Outcomes From a Prospective Multi-Center Trial. Abstract 703]
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