Longitudinal neuropsychological outcomes of deep brain stimulation for treatment resistant depression : a retrospective review

Abstract

The purpose of this study was to review the neuropsychological outcomes of bed nucleus of the stria terminalis (BNST) deep brain stimulation (DBS) for treatment resistant depression (TRD). In addition, this study would report the mood outcomes of the treatment. Previous research endeavours have explored the safety and efficacy of available treatment methods for TRD as well as the clinical outcomes. Studies have observed antidepressant effects in patients treated with DBS for TRD. However, limited research exists regarding neuropsychological outcomes. In this study a brief history of the patient was provided. A battery of neuropsychological assessments were administered to one patient by a trained psychologist at baseline and at 6, 9 and 12 month s post-DBS in order to assess cognitive functioning. Neuropsychological testing covered the cognitive domains of attention, memory, executive functions, language, mental processing speed, verbal fluency and visuospatial/construction abilities. The results of these assessments were compared to available normative data and retrospectively reviewed. No adverse cognitive effects were observed following surgery, onset and maintenance of DBS when test results from baseline were compared to results at the 12 month interval. Areas of cognition that were impaired or below average at baseline improved at follow-up. However, attention and visuospatial/construction abilities, did not improve to normative levels at 12 months. Though no statistical analysis were conducted these results lend support for the cognitive safety of DBS of the bed nucleus of the stria terminalis for TRD.