Cerebral function in posttraumatic stress disorder during verbal working memory updating: a positron emission tomography study

• Published in: Biological psychiatry (1969) Vol. 53; no. 6; pp. 474 - 481
• Main Authors: Clark, C.Richard, McFarlane, Alexander C, Morris, Philip, Weber, Darren L, Sonkkilla, Cynon, Shaw, Marnie, Marcina, Jackie, Tochon-Danguy, H.J, Egan, Gary F
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 15.03.2003; Elsevier Science
• Subjects: Adult and adolescent clinical studies; Anxiety disorders. Neuroses; Biological and medical sciences; cortical networks; Female; frontal-parietal axis; Humans; Male; Medical sciences; Memory Disorders - diagnosis; Memory Disorders - etiology; Middle Aged; Neuropsychological Tests; Parietal Lobe - blood supply; Parietal Lobe - metabolism; Parietal Lobe - physiopathology; positron emission tomography; Post-traumatic stress disorder; Posttraumatic stress disorder; Prefrontal Cortex - blood supply; Prefrontal Cortex - metabolism; Prefrontal Cortex - physiopathology; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Severity of Illness Index; Stress Disorders, Post-Traumatic - metabolism; Stress Disorders, Post-Traumatic - physiopathology; Stress Disorders, Post-Traumatic - psychology; Tomography, Emission-Computed; Tropical medicine; Visual Perception - physiology; working memory; cortical networks; Posttraumatic stress disorder; positron emission tomography; working memory; frontal-parietal axis; Case study; Human; Verbal memory; Posttraumatic syndrome; Cortical reaction; Behavioral analysis; Anxiety disorder; Clinical investigation; Working memory; Positron emission tomography; Stress
• ISSN: 0006-3223; 1873-2402
• DOI: 10.1016/S0006-3223(02)01505-6

This study examined cerebral function in posttraumatic stress disorder (PTSD) during the updating of working memory to trauma-neutral, verbal information. Ten PTSD and matched control subjects completed a visuoverbal target detection task involving continuous updating (Variable target condition) or no updating (Fixed target condition) of target identity, with updating activity estimated by condition comparison. Normal updating activity using this paradigm involved bilateral activation of the dorsolateral prefrontal cortex (DLPFC) and inferior parietal lobe. The PTSD group lacked this activation in the left hemisphere and was significantly different from control subjects in this regard, but showed additional activation in the superior parietal lobe, bilaterally. The pattern of parietal activation suggests a dependence on visuospatial coding for working memory representation of trauma-neutral, verbal information. Group differences in the relative involvement of the DLPFC indicate less dependence in PTSD on the executive role normally attributed to the left DLPFC for monitoring and manipulation of working memory content in posterior regions of the brain.