Brain size and brain/intracranial volume ratio in major mental illness

• Published in: BMC psychiatry Vol. 10; no. 1; p. 79
• Main Authors: Reite, Martin, Reite, Erik, Collins, Dan, Teale, Peter, Rojas, Donald C, Sandberg, Elliot
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 11-10-2010; BioMed Central; BMC
• Subjects: Accuracy; Adult; Age Factors; Analysis of Variance; Atrophy; Bipolar disorder; Bipolar Disorder - diagnosis; Bipolar Disorder - pathology; Brain; Brain - anatomy & histology; Brain - pathology; Cerebral Ventricles - anatomy & histology; Cerebral Ventricles - pathology; Diagnosis; Female; Humans; Image Processing, Computer-Assisted - statistics & numerical data; Intracranial pressure; Longitudinal Studies; Magnetic Resonance Imaging - methods; Magnetic Resonance Imaging - statistics & numerical data; Male; Medical imaging; Mental disorders; Mental Disorders - diagnosis; Mental Disorders - pathology; Mental illness; Organ Size; Physiological aspects; Psychiatry; Psychotic Disorders - diagnosis; Psychotic Disorders - pathology; Schizophrenia; Schizophrenia - diagnosis; Schizophrenia - pathology; Sex Factors; Size; Studies; Colorado
• ISSN: 1471-244X; 1471-244X
• DOI: 10.1186/1471-244x-10-79

This paper summarizes the findings of a long term study addressing the question of how several brain volume measure are related to three major mental illnesses in a Colorado subject group. It reports results obtained from a large N, collected and analyzed by the same laboratory over a multiyear period, with visually guided MRI segmentation being the primary initial analytic tool.
Intracerebral volume (ICV), total brain volume (TBV), ventricular volume (VV), ventricular/brain ratio (VBR), and TBV/ICV ratios were calculated from a total of 224 subject MRIs collected over a period of 13 years. Subject groups included controls (C, N = 89), and patients with schizophrenia (SZ, N = 58), bipolar disorder (BD, N = 51), and schizoaffective disorder (SAD, N = 26).
ICV, TBV, and VV measures compared favorably with values obtained by other research groups, but in this study did not differ significantly between groups. TBV/ICV ratios were significantly decreased, and VBR increased, in the SZ and BD groups compared to the C group. The SAD group did not differ from C on any measure.
In this study TBV/ICV and VBR ratios separated SZ and BD patients from controls. Of interest however, SAD patients did not differ from controls on these measures. The findings suggest that the gross measure of TBV may not reliably differ in the major mental illnesses to a degree useful in diagnosis, likely due to the intrinsic variability of the measures in question; the differences in VBR appear more robust across studies. Differences in some of these findings compared to earlier reports from several laboratories finding significant differences between groups in VV and TBV may relate to phenomenological drift, differences in analytic techniques, and possibly the "file drawer problem".