39 MANIC DISTRACTIBILITY AND FRONTOSUBCORTICAL PROCESSING

• Published in: Journal of investigative medicine Vol. 55; no. 2; p. S354
• Main Authors: Fleck, D. E., Eliassen, J. C., Durling, M., Adams, J., Lamy, M., Williams, K., Strakowski, S. M.
• Format: Journal Article
• Language: English
• Published: London Sage Publications Ltd 01-03-2007
• Subjects: Attention Deficit Hyperactivity Disorder; Bipolar disorder; Hypotheses; Information processing
• ISSN: 1081-5589; 1708-8267
• DOI: 10.1136/jim-55-02-39

The aim of this research was to examine state-related neurocognitive changes to advance understanding of the neurophysiology and treatment of bipolar disorder. Specifically, we examined the temporal (time limited) brain dynamics of sustained attention in relation to mood state. The central hypothesis was that the dorsolateral prefrontal cortex is “recruited” to maintain sustained attention in bipolar disorder owing to subcortical brain abnormalities. Sustained attention decrements were predicted when distractibility was increased by mania, which interferes with limited channel capacity (executive) control processes of prefrontal cortex. To test this hypothesis, we examined differences in the temporal dynamics of prefrontal-striatal-thalamic brain circuit activation during a continuous performance test (CPT) using high-field (4 Tesla) functional magnetic resonance imaging (fMRI). We examined chronometric changes during the simultaneous acquisition of fMRI and CPT data in three separate groups of manic bipolar, euthymic bipolar, and demographically similar healthy comparison subjects. Preliminary data suggest that manic distractibility has a mediating influence between the neurophysiologic consequences of bipolar disorder and information processing efficiency. Clinically, the results indicate that neural reorganization may allow patients with bipolar disorder to learn or enhance compensatory strategies in support of efficient information processing and better functional recovery. Although neuropsychological and anecdotal evidence suggests that this is indeed the case, to our knowledge, these are the first corroborating neuroimaging data pertaining to the spatial and temporal dynamics of neural reorganization in bipolar diorder.