Occipital bending (Yakovlevian torque) in bipolar depression

Area of Science:

• Neuroscience
• Psychiatry
• Radiology

Background:

• Bipolar disorder (BD) is associated with structural brain differences, including occipital lobe asymmetry and enlarged lateral ventricles.
• Occipital bending (OB) is a proposed consequence of these differences, potentially impacting subcortical structures like the hippocampus.

Purpose of the Study:

• To investigate the prevalence of occipital bending (OB) in patients with bipolar disorder (BD) compared to healthy controls.
• To examine the relationship between OB, lateral ventricular volumes (LVVs), occipital lobe volumes (OLVs), and hippocampal volumes in BD patients.

Main Methods:

• A case-control study involving 35 patients with BD and 36 healthy controls.
• Volumetric analysis of lateral ventricles and occipital lobes using neuroimaging techniques.
• Assessment of occipital bending (OB) prevalence and its correlation with ventricular and hippocampal asymmetry.

Main Results:

• Occipital bending (OB) was significantly more prevalent in BD patients (34.3%) compared to controls (8.3%).
• BD patients exhibited larger lateral ventricular volumes (LVVs).
• OB correlated with specific left-to-right ratios of ventricular and occipital lobe volumes (OLVs) and was associated with reduced left-to-right hippocampal volume ratios.

Conclusions:

• Occipital bending (OB) is a more common finding in bipolar disorder (BD) patients, including those with BD Type I and Type II.
• Anomalies in neural pruning or ventricular enlargement may contribute to OB.
• Asymmetrical ventricular and occipital lobe volumes, potentially indicative of OB, may serve as a neuroimaging marker for psychiatric illness.