title: Equivalent brain SPECT perfusion changes underlying therapeutic efficiency in pharmacoresistant depression using either high-frequency left or low-frequency right prefrontal rTMS.
abstract: BACKGROUND
  Functional neuroimaging studies have suggested similar mechanisms underlying antidepressant effects of distinct therapeutics.
  
  
  OBJECTIVE
  This study aimed to determine and compare functional brain patterns underlying the antidepressant response of 2 distinct protocols of repetitive transcranial magnetic stimulation (rTMS).
  
  
  METHODS
  99mTc-ECD SPECT was performed before and after rTMS of dorsolateral prefrontal cortex in 61 drug-resistant right-handed patients with major depression, using high frequency (10Hz) left-side stimulation in 33 patients, and low frequency (1Hz) right-side stimulation in 28 patients. Efficiency of rTMS response was defined as at least 50% reduction of the baseline Beck Depression Inventory score. We compared the whole-brain voxel-based brain SPECT changes in perfusion after rTMS, between responders and non-responders in the whole sample (p<0.005, uncorrected), and separately in the subgroup of patients with left- and right-stimulation.
  
  
  RESULTS
  Before rTMS, the left- and right-prefrontal stimulation groups did not differ from clinical data and brain SPECT perfusion. rTMS efficiency (evaluated on % of responders) was statistically equivalent in the two groups of patients. In the whole-group of responder patients, a perfusion decrease was found after rTMS, in comparison to non-responders, within the left perirhinal cortex (BA35, BA36). This result was secondarily confirmed separately in the two subgroups, i.e. after either left stimulation (p=0.017) or right stimulation (p<0.001), without significant perfusion differences between these two subgroups.
  
  
  CONCLUSIONS
  These data show that distinct successful rTMS protocols induce equivalent brain functional changes associated to antidepressive efficiency, consisting to a remote brain limbic activity decrease within the left perirhinal cortex. However, these results will have to be confirmed in a double-blind randomized trial using a sham control group.
authors: Hôpital Sainte Marguerite, Pôle de Psychiatrie Universitaire, 13009 Marseille, France. raphaellemarie.richieri@ap-hm.fr
authors: Raphaëlle
authors: R
authors: Richieri
authors: Laurent
authors: L
authors: Boyer
authors: Romain
authors: R
authors: Padovani
authors: Marc
authors: M
authors: Adida
authors: Cécile
authors: C
authors: Colavolpe
authors: Olivier
authors: O
authors: Mundler
authors: Christophe
authors: C
authors: Lançon
authors: Eric
authors: E
authors: Guedj
mesh_terms: D061218:Depressive Disorder, Treatment-Resistant / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D059907:Functional Neuroimaging / Q000379:methods / Q000523:psychology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017397:Prefrontal Cortex / Q000502:physiology*; D013702:Temporal Lobe / Q000098:blood supply* / Q000000981:diagnostic imaging / Q000503:physiopathology; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods / Q000523:psychology*; D050781:Transcranial Magnetic Stimulation / Q000379:methods / Q000523:psychology*