Association of cerebral metabolic activity changes with vagus nerve stimulation antidepressant response in treatment-resistant depression
CR Conway, JT Chibnall, MA Gebara, JL Price… - Brain stimulation, 2013 - Elsevier
CR Conway, JT Chibnall, MA Gebara, JL Price, AZ Snyder, MA Mintun, ME Cornell…
Brain stimulation, 2013•ElsevierBackground Vagus nerve stimulation (VNS) has antidepressant effects in treatment resistant
major depression (TRMD); these effects are poorly understood. This trial examines
associations of subacute (3 months) and chronic (12 months) VNS with cerebral metabolism
in TRMD. Objective 17 Fluorodeoxyglucose positron emission tomography was used to
examine associations between 12-month antidepressant VNS response and cerebral
metabolic rate for glucose (CMRGlu) changes at 3 and 12 months. Methods Thirteen TRMD …
major depression (TRMD); these effects are poorly understood. This trial examines
associations of subacute (3 months) and chronic (12 months) VNS with cerebral metabolism
in TRMD. Objective 17 Fluorodeoxyglucose positron emission tomography was used to
examine associations between 12-month antidepressant VNS response and cerebral
metabolic rate for glucose (CMRGlu) changes at 3 and 12 months. Methods Thirteen TRMD …
Background
Vagus nerve stimulation (VNS) has antidepressant effects in treatment resistant major depression (TRMD); these effects are poorly understood. This trial examines associations of subacute (3 months) and chronic (12 months) VNS with cerebral metabolism in TRMD.
Objective
17Fluorodeoxyglucose positron emission tomography was used to examine associations between 12-month antidepressant VNS response and cerebral metabolic rate for glucose (CMRGlu) changes at 3 and 12 months.
Methods
Thirteen TRMD patients received 12 months of VNS. Depression assessments (Hamilton Depression Rating Scale [HDRS]) and PET scans were obtained at baseline (pre-VNS) and 3/12 months. CMRGlu was assessed in eight a priori selected brain regions (bilateral anterior insular [AIC], orbitofrontal [OFC], dorsolateral prefrontal [DLPFC], and anterior cingulate cortices [ACC]). Regional CMRGlu changes over time were studied in VNS responders (decreased 12 month HDRS by ≥50%) and nonresponders.
Results
A significant trend (decreased 3 month CMRGlu) in the right DLPFC was observed over time in VNS responders (n = 9; P = 0.006). An exploratory whole brain analysis (Puncorrected = 0.005) demonstrated decreased 3 month right rostral cingulate and DLPFC CMRGlu, and increased 12 month left ventral tegmental CMRGlu in responders.
Conclusions/Limitations
VNS response may involve gradual (months in duration) brain adaptations. Early on, this process may involve decreased right-sided DLPFC/cingulate cortical activity; longer term effects (12 months) may lead to brainstem dopaminergic activation. Study limitations included: a) a small VNS nonresponders sample (N = 4), which limited conclusions about nonresponder CMRGlu changes; b) no control group; and, c) patients maintained their psychotropic medications.
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