MRI investigation of temporal lobe structures in bipolar patients

• Published in: Journal of psychiatric research 2003-07, Vol.37 (4), p.287-295
• Main Authors: Brambilla, Paolo, Harenski, Keith, Nicoletti, Mark, Sassi, Roberto B., Mallinger, Alan G., Frank, Ellen, Kupfer, David J., Keshavan, Matcheri S., Soares, Jair C.
• Format: Article
• Language: English
• Subjects: Adult; Adult and adolescent clinical studies; Amygdala; Amygdala - pathology; Biological and medical sciences; Bipolar disorder; Bipolar Disorder - pathology; Bipolar disorders; Case-Control Studies; Female; Functional Laterality; Hippocampus; Hippocampus - pathology; Humans; Magnetic Resonance Imaging; Male; Medical sciences; Middle Aged; Mood disorders; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Superior temporal gyrus; Temporal Lobe - pathology; Temporal lobes
• ISSN: 0022-3956; 1879-1379
• DOI: 10.1016/S0022-3956(03)00024-4

Previous anatomical MRI studies have suggested abnormalities in amygdala volumes in bipolar disorder, whereas hippocampus, temporal lobe (TL), and superior temporal gyri (STG) measures have been reported to be normal. This study further investigated the existence of anatomical abnormalities in these brain structures in bipolar subjects, to attempt to replicate previously reported findings. Twenty-four DSM-IV bipolar patients (mean age±S.D.=35±10 years) and 36 healthy controls (mean age±S.D.=37±10 years) were studied. 3D SPGR images were obtained with a 1.5T-GE Signa magnet (T R=25 ms, TE=5 ms, FOV=24 cm, slice-thickness=1.5 mm, matrix-size=256×192). Volumetric measurements of TL, hippocampus, amygdala, and STG were performed blindly, with a semi-automated software. Bipolar patients had significantly larger left amygdala volumes compared with controls (mean volumes±S.D.=2.57±0.69 vs. 2.17±0.58 ml, respectively; ANCOVA, age, gender, ICV as covariates; F=4.42, df=1/55, P=0.04). The volumes of the other temporal lobe structures did not differ significantly between the two groups (ANCOVA, age, gender, and ICV as covariates, P>0.05). Our findings of enlarged left amygdala in bipolar patients are in agreement with prior MRI studies, suggesting that abnormalities in this brain structure may be implicated in pathophysiology of the illness. Longitudinal studies in high-risk offspring and first-episode patients will be needed to examine whether such abnormalities precede the appearance of symptoms, or whether they may appear subsequently as a result of illness course.