A Phase II Study of Fornix Deep Brain Stimulation in Mild Alzheimer’s Disease

Abstract

Background: Deep brain stimulation (DBS) is used to modulate the activity of dysfunctional brain circuits. The safety and efficacy of DBS in dementia is unknown.

Objective: To assess DBS of memory circuits as a treatment for patients with mild Alzheimer’s disease (AD).

Methods: We evaluated active “on” versus sham “off” bilateral DBS directed at the fornix-a major fiber bundle in the brain’s memory circuit-in a randomized, double-blind trial (ClinicalTrials.gov NCT01608061) in 42 patients with mild AD. We measured cognitive function and cerebral glucose metabolism up to 12 months post-implantation.

Results: Surgery and electrical stimulation were safe and well tolerated. There were no significant differences in the primary cognitive outcomes (ADAS-Cog 13, CDR-SB) in the “on” versus “off” stimulation group at 12 months for the whole cohort. Patients receiving stimulation showed increased metabolism at 6 months but this was not significant at 12 months. On post-hoc analysis, there was a significant interaction between age and treatment outcome: in contrast to patients?<65 years old (n?=?12) whose results trended toward being worse with DBS ON versus OFF, in patients?65 (n?=?30) DBS-f ON treatment was associated with a trend toward both benefit on clinical outcomes and a greater increase in cerebral glucose metabolism.

Conclusion: DBS for AD was safe and associated with increased cerebral glucose metabolism. There were no differences in cognitive outcomes for participants as a whole, but participants aged?65 years may have derived benefit while there was possible worsening in patients below age 65 years with stimulation.

READ MORE: http://content.iospress.com/articles/journal-of-alzheimers-disease/jad160017