title: Blunted prefrontal perfusion in depressed patients performing the Tower of London task.
abstract: Impairment of cognition is common in depression, and many tasks on which depressed patients are impaired are sensitive to frontal lobe dysfunction. Performance on the Tower of London (TOL) task, which includes setting up and maintaining multiple subgoals at the same time, has been shown to depend on intact prefrontal cortices. Single photon emission computed tomography (SPECT) with 99mTc-ethyl cysteinate dimer was used to compare cognitive activation in nine depressed patients and nine normal controls during performance of the TOL task. Planning times and accuracy were measured as performance parameters, and functional imaging data were analysed with statistical parametric mapping (SPM99) to determine significant voxel-wise differences in activation between the two groups. During activation, depressed patients were as accurate as controls but differed in that they spent more thinking time. These findings agree with the results of neuropsychological studies. Compared with the normal controls, depressed patients were characterized by a blunted perfusion response in the right middle frontal cortex [Brodmann area (BA) 6] and the left superior frontal gyrus (BA 9), and by increased perfusion in the right superior temporal gyrus (BA 21) and the insular cortex (BA 13). This study shows that a SPECT activation procedure using the TOL task under classical test conditions is feasible in depressed patients.
authors.affiliation: Division of Nuclear Medicine, Polikliniek 7, Ghent University Hospital, De Pintelaan 185, B-9000 Ghent, Belgium. ingeborg.goethals@ugent.be
authors.forename: Ingeborg
authors.initials: I
authors.lastname: Goethals
authors.forename: Kurt
authors.initials: K
authors.lastname: Audenaert
authors.forename: Filip
authors.initials: F
authors.lastname: Jacobs
authors.forename: Christophe
authors.initials: C
authors.lastname: Van de Wiele
authors.forename: Hamphrey
authors.initials: H
authors.lastname: Ham
authors.forename: Hanneke
authors.initials: H
authors.lastname: Pyck
authors.forename: André
authors.initials: A
authors.lastname: Vandierendonck
authors.forename: Cees
authors.initials: C
authors.lastname: Van Heeringen
authors.forename: Rudi
authors.initials: R
authors.lastname: Dierckx
mesh_terms: D000328:Adult; D003072:Cognition Disorders / Q000175:diagnosis* / Q000453:epidemiology*; D003865:Major Depressive Disorder / Q000453:epidemiology* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D049268:Positron-Emission Tomography; D017397:Prefrontal Cortex / Q000098:blood supply* / Q000503:physiopathology*; D015899:Tomography, Emission-Computed, Single-Photon