title: How coil-cortex distance relates to age, motor threshold, and antidepressant response to repetitive transcranial magnetic stimulation.
abstract: Repetitive transcranial magnetic stimulation (rTMS) is a tool with antidepressant potential that uses a coil placed on the scalp to produce a powerful magnetic field that directly stimulates only the outermost cortex. MRI scans were obtained in 29 depressed adults involved in an rTMS antidepressant clinical treatment. These scans were analyzed to investigate the effect of distance from coil to cortex on clinical parameters. Longer motor cortex distance, but not prefrontal distance, strongly correlated with increased motor threshold (P<0.01). Clinical antidepressant response did not correlate with either distance. The rTMS antidepressant responders, however, were significantly younger (t=-2.430, P<0.05), and there appears to be a maximum threshold of age and distance to prefrontal cortex for response.
authors.affiliation: Functional Neuroimaging Division and the Brain Magnetic Stimulation Laboratories, Department of Psychiatry, Medical University of South Carolina, Charleston 29425, USA. kozelfa@musc.edu
authors.forename: F A
authors.initials: FA
authors.lastname: Kozel
authors.forename: Z
authors.initials: Z
authors.lastname: Nahas
authors.forename: C
authors.initials: C
authors.lastname: deBrux
authors.forename: M
authors.initials: M
authors.lastname: Molloy
authors.forename: J P
authors.initials: JP
authors.lastname: Lorberbaum
authors.forename: D
authors.initials: D
authors.lastname: Bohning
authors.forename: S C
authors.initials: SC
authors.lastname: Risch
authors.forename: M S
authors.initials: MS
authors.lastname: George
mesh_terms: D000328:Adult; D000367:Age Factors; D000928:Antidepressive Agents / Q000627:therapeutic use*; D003866:Depressive Disorder / Q000175:diagnosis / Q000188:drug therapy*; D004311:Double-Blind Method; D055590:Electromagnetic Phenomena / Q000379:methods*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D017397:Prefrontal Cortex / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D011569:Psychiatric Status Rating Scales; D012886:Skull; D015899:Tomography, Emission-Computed, Single-Photon; D016896:Treatment Outcome
chemical_list: D000928:Antidepressive Agents