Nivedita Agarwal MD, Presenter: Nothing to Disclose

Giuseppe Como MD, Abstract Co-Author: Nothing to Disclose

Giovanni Brondani MD, Abstract Co-Author: Nothing to Disclose

Paolo Brambilla MD, PhD, Abstract Co-Author: Nothing to Disclose

Monica Baiano MD, PhD, Abstract Co-Author: Nothing to Disclose

Massimo Bazzocchi MD, Abstract Co-Author: Nothing to Disclose

Matteo Balestrieri MD, Abstract Co-Author: Nothing to Disclose

Laura Perini, Abstract Co-Author: Nothing to Disclose

Riccardo Zuliani, Abstract Co-Author: Nothing to Disclose

Rossana Ciano MD, Abstract Co-Author: Nothing to Disclose

Marta Maieron, Abstract Co-Author: Nothing to Disclose

Chiara Zuiani MD, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

functional Magnetic Resonance Imaging (fMRI) technique called BOLD (Blood-Oxygen-Level-Dependent) detects signal intensity changes caused by increased paramagnetic deoxygenated haemoglobin in activated brain structures. The prefrontal cortex (PFC) exercises a cognitive control over memories processed by the hippocampus including traumatic memories through a mechanism known as memory suppression. We hypothesized that this is dysfunctional in patients with psychiatric disorders such as Major Depression (MD) and Borderline Personality Disorder (BPD), suffering recurrent early sexual/physical abuse or difficult relationship.

10 patients (5 with MD and 5 with BPD; mean age: 40.9±11.5 years; 3M/7F; all right-handed; 10 Caucasians) and 11 healthy controls (HC) (mean age: 34.2±13.9 years; 3M/8F; 10 right-handed/1 left-handed; 10 Caucasians/1 Indian) underwent a specific think/no-think test (suppression and retrieval phase; Anderson test) using a 1.5T MR scanner. A qualitative cluster analysis, based on Talairach and Tourneaux parameters, was performed by visually detecting the activation of PFC and hippocampus.

While PFC was bilaterally activated in both HC and patients during both the suppression phase (SP) and the retrieval phase (RP), significantly reduced activation was found among patients. A trend towards greater activation during the SP was seen in the hippocampus of patients while HC showed greater activation during the RP.

These preliminary data suggest a dysfunctional cognitive memory suppression mechanism primarily due to alteration in the PFC in patients with stress related disorders. Also, altered memory retrieval process in patients would account for memory problems in patients. fMRI-BOLD permits investigation of transient cognitive functions in small brain areas.

These preliminary data suggest that the PFC-hippocampus neural circuitry dysfunction may play a key role in supporting cognitive symptoms of stress related psychiatric disorders

Agarwal, N, Como, G, Brondani, G, Brambilla, P, Baiano, M, Bazzocchi, M, Balestrieri, M, Perini, L, Zuliani, R, Ciano, R, Maieron, M, Zuiani, C, et al, , Mechanisms of Memory Suppression in Stress-related Psychiatric Disorders: A Functional Magnetic Resonance Study.  Radiological Society of North America 2008 Scientific Assembly and Annual Meeting, February 18 - February 20, 2008 ,Chicago IL. http://archive.rsna.org/2008/6007940.html