Does IIH Alter Brain Microstructures? - A DTI-Based Approach.
BACKGROUND
To investigate the correlation of microstructural parameters with CSF pressure and macroscopic changes assessed by diffusion tensor imaging (DTI) in patients with idiopathic intracranial hypertension (IIH).


METHODS
Twenty-three patients with IIH as well as age-, sex-, and body mass index (BMI)-matched controls underwent high resolution MR imaging of the optic nerve sheaths (ONS), pituitary gland, and ventricles. For DTI data a voxelwise permutation analysis was performed for the whole brain and ROI analysis was performed for the optic nerve and optic radiation. DTI measurements were correlated to morphometric measurements, CSF opening pressure, and headache intensity. The reliability of diagnostic performance of DTI parameters was assessed using ROC analysis.


RESULTS
Analysis of DTI metrics revealed a significant reduction in the fractional anisotropy (FA) of the optic nerve in patients with IIH. In contrast, systematic regional variations between IIH patients and controls were neither observed in the whole brain analysis nor in the optic radiation. FA values of the optic nerve show significant correlations with the optic nerve sheath diameter (P = .003, r = -.589). The correlation of the alterations of the FA values of the optic radiation and the whole brain do not show a significant association to morphometric alterations in the ONS diameter and hypophysis height as well as to CSF opening pressure and headache intensity.


CONCLUSIONS
The results indicate that IIH is associated with microstructural changes in the optic nerve. These alterations may be the direct consequence of chronically elevated intracranial pressure.
Department of Neuroradiology, Charité - Universitätsmedizin Berlin, Berlin, Germany.
Christoph
C
Schmidt
Department of Neuroradiology, Charité - Universitätsmedizin Berlin, Berlin, Germany.
Edzard
E
Wiener
Department of Neuroradiology, Charité - Universitätsmedizin Berlin, Berlin, Germany.|Section for Medical Physics, Department of Radiation Therapy, Universitätsklinikum Essen, Essen, Germany.
Lutz
L
Lüdemann
MSB Medical School Berlin, Berlin, Germany.|Department of Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany.
Hagen
H
Kunte
Department of Neuroradiology, Charité - Universitätsmedizin Berlin, Berlin, Germany.|MSB Medical School Berlin, Berlin, Germany.|Department of Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany.
Katharina Maria
KM
Kreutz
Department of Neuroradiology, Charité - Universitätsmedizin Berlin, Berlin, Germany.|MSB Medical School Berlin, Berlin, Germany.|Department of Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany.
Nils
N
Becker
Department of Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany.
Lutz
L
Harms
Department of Neuroradiology, Charité - Universitätsmedizin Berlin, Berlin, Germany.|Department of Neuroradiology, Evangelisches Krankenhaus Bielefeld, Bielefeld, Germany.
Randolf
R
Klingebiel
Department of Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany.|Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
Jan
J
Hoffmann
D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging* / Q000473:pathology; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009900:Optic Nerve / Q000000981:diagnostic imaging* / Q000473:pathology; D011559:Pseudotumor Cerebri / Q000000981:diagnostic imaging* / Q000473:pathology; D055815:Young Adult
DTI; MRI; headache; idiopathic intracranial hypertension; pain