Microstructural alterations of the arcuate fasciculus in schizophrenia patients with frequent auditory verbal hallucinations

• Published in: Schizophrenia research Vol. 130; no. 1; pp. 68 - 77
• Main Authors: de Weijer, A.D, Mandl, R.C.W, Diederen, K.M.J, Neggers, S.F.W, Kahn, R.S, Pol, H.E. Hulshoff, Sommer, I.E.C
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.08.2011; Elsevier
• Subjects: Adolescent; Adult; Adult and adolescent clinical studies; Analysis of Variance; Arcuate fasciculus; Auditory verbal hallucinations; Biological and medical sciences; Brain Mapping; Diffusion Tensor Imaging; Female; Fiber tracking; Frontal Lobe - pathology; Hallucinations - etiology; Humans; Image Processing, Computer-Assisted; Language network; Magnetization transfer imaging; Male; Medical sciences; Middle Aged; Neural Pathways - pathology; Psychiatric Status Rating Scales; Psychiatry; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Psychoses; Schizophrenia; Schizophrenia - complications; Schizophrenia - pathology; Temporal Lobe - pathology; Tract-based analysis; White matter; Young Adult; Fiber tracking; Language network; Arcuate fasciculus; Schizophrenia; Magnetization transfer imaging; Tract-based analysis; White matter; Auditory verbal hallucinations; Diffusion tensor imaging; Human; Auditory hallucination; Nuclear magnetic resonance imaging; Psychosis; Language; Imaging; Transfer; Medical imagery
• ISSN: 0920-9964; 1573-2509
• DOI: 10.1016/j.schres.2011.05.010

Abstract Auditory verbal hallucinations (AVH) is a common and stressful symptom of schizophrenia. Disrupted connectivity between frontal and temporo-parietal language areas, giving rise to the misattribution of inner speech, is speculated to underlie this phenomenon. Disrupted connectivity should be reflected in the microstructure of the arcuate fasciculi (AF); the main connection between frontal and temporo-parietal language areas. In this study we compared microstructural properties of the AF and three other fiber tracts (cortical spinal tract, cingulum and uncinate fasciculus), between 44 schizophrenia patients with chronic severe hallucinations and 42 control subjects using diffusion tensor imaging (DTI) and magnetic transfer imaging (MTI). The DTI scans were used to compute fractional anisotropy (FA) and to reconstruct the fiber bundles of interest, while the MTI scans were used to compute magnetic transfer ratio (MTR) values. The patient group showed a general decrease in FA for all bundles. In the arcuate fasciculus this decreased FA was coupled to a significant increase in MTR values. A correlation was found between mean MTR values in both arcuate fasciculi and the severity of positive symptoms. The combination of decreased FA and increased MTR values observed in the arcuate fasciculi in patients suggests increased free water concentrations, probably caused by degraded integrity of the axons or the supportive glia cells. This suggests that disintegrated fiber integrity in the connection between frontal and temporo-parietal language areas in the schizophrenia patients is associated with their liability for auditory verbal hallucinations.