title: Long-term habituation of the smile response with deep brain stimulation.
abstract: Human and animal research has shown that the ventral striatum, including the nucleus accumbens, may play a critical role in mediating positive emotions. Recently we described a subject with obsessive-compulsive disorder who intra-operatively exhibited the acute onset of an asymmetric smile and acute positive emotional change with contralateral deep brain stimulation (DBS) in either the right or left nucleus accumbens and anterior limb of the internal capsule region. The purpose of the present study was to examine the stability of the stimulation-induced smile(s) over a 12-month period. Custom computer software objectively quantified left and right facial movement during DBS. Although stimulation-induced smiles were elicited at one and two months post-surgery, they were no longer present from 3-12 months following chronic high frequency DBS. The smiles could not be elicited even with long washout periods. These findings imply potential long-term habituation and changes in the neural chemistry (possibly neuroplasticity) induced by chronic DBS.
authors.affiliation: Clinical and Health Psychology, McKnight Brain Institute, University of Florida, Gainsville, Florida 32610-0165, USA. uspring@ufl.edu
authors.forename: Utaka S
authors.initials: US
authors.lastname: Springer
authors.forename: Dawn
authors.initials: D
authors.lastname: Bowers
authors.forename: Wayne K
authors.initials: WK
authors.lastname: Goodman
authors.forename: Nathan A
authors.initials: NA
authors.lastname: Shapira
authors.forename: Kelly D
authors.initials: KD
authors.lastname: Foote
authors.forename: Michael S
authors.initials: MS
authors.lastname: Okun
mesh_terms: D000328:Adult; D046690:Deep Brain Stimulation / Q000379:methods; D003865:Major Depressive Disorder / Q000503:physiopathology* / Q000601:surgery*; D004644:Emotions / Q000502:physiology / Q000528:radiation effects; D019277:Entropy; D005069:Evaluation Studies as Topic; D005260:Female; D006185:Habituation, Psychophysiologic; D006801:Humans; D009068:Movement / Q000502:physiology / Q000528:radiation effects; D013997:Time Factors