Preattentive dysfunction in patients with bipolar disorder as revealed by the pitch‐mismatch negativity: a magnetoencephalography (MEG) study. (8th May 2014)

• Record Type: Journal Article
• Authors: Shimano, Satomi; Onitsuka, Toshiaki; Oribe, Naoya; Maekawa, Toshihiko; Tsuchimoto, Rikako; Hirano, Shogo; Ueno, Takefumi; Hirano, Yoji; Miura, Tomofumi; Kanba, Shigenobu
• Is Part Of: Bipolar disorders. Volume 16:Number 6(2014)
• Page Start: 592
• Page End: 599
• Publication Date: 2014-05-08
• Subjects: Manic-depressive illness -- Periodicals; Depression, Mental -- Periodicals; 616.895
• DOI: 10.1111/bdi.12208
• Languages: English
• ISSNs: 1398-5647

Abstract

<abstract abstract-type="main" id="bdi12208-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="bdi12208-sec-0001" sec-type="section"> <title>Objectives</title> <p>Mismatch negativity (MMN) and its magnetic counterpart (MMNm) are thought to reflect an automatic process that detects a difference between an incoming stimulus and the sensory memory trace of preceding stimuli. In patients with schizophrenia, an attenuation of the MMN/MMNm amplitude has been repeatedly reported. Heschl's gyrus (HG) is one of the major generators of MMN and the functional alteration of HG has been reported in patients with bipolar disorder. The present study investigated the pitch‐MMNm in patients with bipolar disorder using whole‐head 306‐ch magnetoencephalography (MEG).</p> </sec> <sec id="bdi12208-sec-0002" sec-type="section"> <title>Methods</title> <p>Twenty‐two patients and 22 healthy controls participated in this study. Subjects were presented with two types of auditory stimulus sequences. One consisted of 1, 000 Hz standards (probability = 90%) and 1, 200 Hz deviants (probability = 10%), and the other consisted of 1, 000 Hz standards (90%) and 1, 200 Hz deviants (10%). These two tasks were each performed twice. Event‐related brain responses to standard tones were subtracted from responses to deviant tones.</p> </sec> <sec id="bdi12208-sec-0003" sec-type="section"> <title>Results</title> <p>Patients with bipolar disorder showed a significant bilateral reduction in magnetic global field power (mGFP) amplitudes (p = 0.02) and dipole moments of the MMNm (p = 0.04) compared with healthy controls. Patients with admission experience showed significantly reduced mGFP amplitudes of MMNm compared with patients without admission experience (p = 0.004). Additionally, patients with more severe manic symptoms had smaller mGFP amplitudes of MMNm (ρ = −0.50, p = 0.05).</p> </sec> <sec id="bdi12208-sec-0004" sec-type="section"> <title>Conclusions</title> <p>The results of this study suggest that patients with bipolar disorder may exhibit preattentive auditory dysfunction indexed by reduced pitch‐MMNm responses. Pitch‐MMNm could be a potential trait marker reflecting the global severity of bipolar disorder.</p> </sec> </abstract>