Strakowski SM, Adler CM, Cerullo MA, Eliassen JC, Lamy M, Fleck DE, Lee JH, Delbello MP.
Division of Bipolar Disorders Research, Department of Psychiatry, and the Center for Imaging Research, University of Cincinnati, Cincinnati, OH, USA
Early Interv Psychiatry. 2008 Nov;2(4):225-233.

OBJECTIVES: Impulsivity is common in bipolar disorder, especially during mania. Understanding the functional neuroanatomy of response inhibition, one component of impulsivity, might clarify the neural substrate of bipolar disorder.
METHODS: Sixteen DSM-IV first-episode, manic bipolar patients and 16 matched healthy subjects were examined during a first manic episode using fMRI while performing a response inhibition task. All subjects were studied using a 4 T Varian INOVA whole body MRI system. The response inhibition task was presented using nonferromagnetic goggles and task performance was recorded during scan acquisition. Imaging data were analyzed using AFNI.

Group contrasts were made for the specific response inhibition measure.
RESULTS: The groups performed the task similarly, although both demonstrated relatively poor rates of target response, but high rates of successful ‘stops.’ Despite similar behavioral results, the groups showed significantly different patterns of fMRI brain activation. Specifically, during response inhibition the healthy subjects exhibited significantly greater activation in anterior and posterior cingulate, medial dorsal thalamus, middle temporal gyrus and precuneus. The bipolar patients exhibited prefrontal activation (BA 10) that was not observed in healthy subjects.
CONCLUSIONS: Bipolar and healthy subjects exhibit different patterns of brain activation to response inhibition; these differences may reflect different functional neuroanatomic approaches to response inhibition between the two groups.