Multimodal assessments of the hippocampal formation in schizophrenia and bipolar disorder: evidences from neurobehavioral measures and functional and structural MRI.
A potential clinical and etiological overlap between schizophrenia (SZ) and bipolar disorder (BD) has long been a subject of discussion. Imaging studies imply functional and structural alterations of the hippocampus in both diseases. Thus, imaging this core memory region could provide insight into the pathophysiology of these disorders and the associated cognitive deficits. To examine possible shared alterations in the hippocampus, we conducted a multi-modal assessment, including functional and structural imaging as well as neurobehavioral measures of memory performance in BD and SZ patients compared with healthy controls. We assessed episodic memory performance, using tests of verbal and visual learning (HVLT, BVMT) in three groups of participants: BD patients (n = 21), SZ patients (n = 21) and matched (age, gender, education) healthy control subjects (n = 21). In addition, we examined hippocampal resting state functional connectivity, hippocampal volume using voxel-based morphometry (VBM) and fibre integrity of hippocampal connections using diffusion tensor imaging (DTI). We found memory deficits, changes in functional connectivity within the hippocampal network as well as volumetric reductions and altered white matter fibre integrity across patient groups in comparison with controls. However, SZ patients when directly compared with BD patients were more severely affected in several of the assessed parameters (verbal learning, left hippocampal volumes, mean diffusivity of bilateral cingulum and right uncinated fasciculus). The results of our study suggest a graded expression of verbal learning deficits accompanied by structural alterations within the hippocampus in BD patients and SZ patients, with SZ patients being more strongly affected. Our findings imply that these two disorders may share some common pathophysiological mechanisms. The results could thus help to further advance and integrate current pathophysiological models of SZ and BD.
Laboratory of Neurophysiology and Neuroimaging, Dept. of Psychiatry, Psychosomatic Medicine and Psychotherapy, Goethe Univ., Frankfurt/Main, Germany.
Christian
C
Knöchel
Laboratory of Neurophysiology and Neuroimaging, Dept. of Psychiatry, Psychosomatic Medicine and Psychotherapy, Goethe Univ., Frankfurt/Main, Germany.
Michael
M
Stäblein
Laboratory of Neurophysiology and Neuroimaging, Dept. of Psychiatry, Psychosomatic Medicine and Psychotherapy, Goethe Univ., Frankfurt/Main, Germany.
Helena
H
Storchak
Laboratory of Neurophysiology and Neuroimaging, Dept. of Psychiatry, Psychosomatic Medicine and Psychotherapy, Goethe Univ., Frankfurt/Main, Germany.
Britta
B
Reinke
Institute for Neuroradiology, Goethe Univ., Frankfurt/Main, Germany ; Center for Individual Development and Adaptive Education of Children at Risk, Frankfurt/Main, Germany.
Alina
A
Jurcoane
Laboratory of Neurophysiology and Neuroimaging, Dept. of Psychiatry, Psychosomatic Medicine and Psychotherapy, Goethe Univ., Frankfurt/Main, Germany.
David
D
Prvulovic
MRC Centre for Neuropsychiatric Genetics and Genomics, Institute of Psychological Medicine and Clinical Neurosciences, School of Medicine, Cardiff University, Cardiff, UK.
David E J
DE
Linden
Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands.
Vincent
V
van de Ven
Laboratory of Neurophysiology and Neuroimaging, Dept. of Psychiatry, Psychosomatic Medicine and Psychotherapy, Goethe Univ., Frankfurt/Main, Germany.
Denisa
D
Ghinea
Laboratory of Neurophysiology and Neuroimaging, Dept. of Psychiatry, Psychosomatic Medicine and Psychotherapy, Goethe Univ., Frankfurt/Main, Germany.
Sofia
S
Wenzler
Center for Alzheimer's Disease and Related Disorders, Universidade Federal, do Rio de Janeiro, Brazil.
Gilberto
G
Alves
Laboratory of Neurophysiology and Neuroimaging, Dept. of Psychiatry, Psychosomatic Medicine and Psychotherapy, Goethe Univ., Frankfurt/Main, Germany.
Silke
S
Matura
Laboratory of Neurophysiology and Neuroimaging, Dept. of Psychiatry, Psychosomatic Medicine and Psychotherapy, Goethe Univ., Frankfurt/Main, Germany.
Anne
A
Kröger
Laboratory of Neurophysiology and Neuroimaging, Dept. of Psychiatry, Psychosomatic Medicine and Psychotherapy, Goethe Univ., Frankfurt/Main, Germany.
Viola
V
Oertel-Knöchel
D000328:Adult; D001714:Bipolar Disorder / Q000175:diagnosis / Q000378:metabolism* / Q000523:psychology*; D005260:Female; D006624:Hippocampus / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D061212:Memory, Episodic; D008875:Middle Aged; D012559:Schizophrenia / Q000175:diagnosis / Q000378:metabolism*; D012565:Schizophrenic Psychology
Bipolar; DTI; Hippocampus; Resting state; Schizophrenia; VBM