Mean kurtosis alterations of cerebral white matter in patients with bipolar and major depressive disorders revealed by diffusion kurtosis imaging

2019 Fiscal Year Final Research Report

• Project/Area Number: 19K21204
• Project/Area Number (Other): 18H06081 (2018)
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund (2019); Single-year Grants (2018)
• Review Section: 0704:Neuroscience, brain sciences, and related fields
• Research Institution: Hokkaido University
• Principal Investigator: Hisashi Narita 北海道大学, 大学病院, 助教 (50779874)
• Project Period (FY): 2018-08-24 – 2020-03-31
• Keywords: MRI / 双極性障害 / 大うつ病性障害

Outline of Final Research Achievements

In this study, we aimed to examine the differences of mean kurtosis (MK) and fractional anisotropy (FA) values between the patients with bipolar and depressive disorders using voxel-based analysis (VBA). Additionally, we examined the correlation between these values and severity of clinical symptoms in the patients. Compared to FA values, significant decreases in MK values were widely and extensively observed throughout the brains of patients with bipolar disorders. The MK values of frontal lobe were significantly negatively correlated with the severity of depressive symptoms. Thus, the diffusion kurtosis indices are suitable for evaluating altered WM structures in the human brain as they may detect white matter alterations of crossing fibers in mood disorders and assess the clinical state of patients.

Free Research Field

精神医学

Academic Significance and Societal Importance of the Research Achievements

北海道大学病院精神科に通院もしくは入院中の躁うつ病および大うつ病の患者さんを対象として、頭部MRIの撮像と同時に、対象患者の年齢、性別、発症時の年齢、罹病期間、使用中の向精神薬を調査した。最終的に躁うつ病 7名、大うつ病性障害　12名のリクルートが終了した。症例数が予定より少ないため、暫定的な解析になるが躁うつ病の患者さんにおいて、前頭部の一部で、MRIの指標が優位に低下している可能性が認められた。
今回の研究の結果により、やはり躁うつ病と大うつ病の患者さんの一部には、大脳白質構造の差異が確認され、今後の診断確定および治療選択の予測につながることが期待された。