title: Diffusion tensor imaging in episodic cluster headache.
abstract: BACKGROUND
  Cluster headache (CH) is a rare headache disorder with severe unilateral headache bouts and autonomic symptoms. The pathophysiology of CH is not completely understood. Using a voxel-based morphometric paradigm or functional imaging, a key role of the hypothalamus and the pain matrix could be demonstrated during CH episodes. However, there are no diffusion tensor imaging (DTI) data investigating the white matter microstructure of the brain in patients with CH. Therefore, we used DTI to delineate microstructural changes in patients with CH in a headache-free state.
  
  
  METHODS
  Seven male patients with episodic CH and 7 healthy subjects were included and examined with a routine 1.5 T magnetic resonance imaging scanner. Whole-head DTI scans measuring fractional anisotropy were analyzed without a priori hypotheses using track-based spatial statistics.
  
  
  RESULTS
  We found significant microstructural brain tissue changes bilaterally in the white matter of the brainstem, the frontal lobe, the temporal lobe, the occipital lobe, the internal capsule, and on the right side of thalamus and cerebellum. There were further lesions in the basal frontal lobe that were part of the olfactory system. Alterations of fractional anisotropy in the brainstem might indicate changes of the medial lemniscus and central sympathetic pathways.
  
  
  CONCLUSIONS
  Patients with episodic CH have microstructural brain changes in regions that belong to the pain matrix. Furthermore, we were able to detect structural changes suggesting an involvement of the olfactory system as well as lesions in the brainstem indicating an involvement of trigeminal and sympathetic systems.
authors.affiliation: Department of Neurology, Philipps-University of Marburg, Marburg, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Teepker
authors.forename: Katja
authors.initials: K
authors.lastname: Menzler
authors.forename: Marcus
authors.initials: M
authors.lastname: Belke
authors.forename: Johannes T
authors.initials: JT
authors.lastname: Heverhagen
authors.forename: Maximilian
authors.initials: M
authors.lastname: Voelker
authors.forename: Veit
authors.initials: V
authors.lastname: Mylius
authors.forename: Wolfgang H
authors.initials: WH
authors.lastname: Oertel
authors.forename: Felix
authors.initials: F
authors.lastname: Rosenow
authors.forename: Susanne
authors.initials: S
authors.lastname: Knake
mesh_terms: D000328:Adult; D000368:Aged; D016880:Anisotropy; D001921:Brain / Q000473:pathology*; D001931:Brain Mapping; D003027:Cluster Headache / Q000473:pathology*; D056324:Diffusion Tensor Imaging; D007839:Functional Laterality; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged