title: White blood cell SPECT during active period of cluster headache and in remission.
abstract: OBJECTIVE
  Cluster headache (CH) is an episodic headache disorder characterized by recurrent, unilateral attacks of excruciating pain in the temporal/orbital region. The pathophysiology of CH is largely unknown although involvement of immunological mechanisms has been suggested. The aim of our study was to investigate whether patients with CH show signs of intracranial inflammation, when using white blood cell single-photon emission computer tomography (WBC-SPECT).
  
  
  METHODS
  We have examined 14 patients with CH, both in active period and in remission, and five control subjects at one occasion, with WBC-SPECT. To be able to precisely define regions of interest (ROI:s) in the brain, all patients with CH and control subjects underwent magnetic resonance imaging (MRI) of the brain.
  
  
  RESULTS
  We found no significant difference in (99m)Tc-labeled WBC uptake between patients with CH in active period and controls. Furthermore, patients with CH in active period were not significantly different in uptake compared with patients with CH in remission.
  
  
  CONCLUSIONS
  These results did not provide conclusive support for a hypothesis of a pathophysiological role of inflammation intracranially. Our conclusions are restricted to the advantages and limitations of the chosen method.
authors.affiliation: Department of Clinical Neuroscience, Division of Neurology, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden. anna.steinberg@karolinska.se
authors.forename: A
authors.initials: A
authors.lastname: Steinberg
authors.forename: R
authors.initials: R
authors.lastname: Axelsson
authors.forename: L
authors.initials: L
authors.lastname: Ideström
authors.forename: S
authors.initials: S
authors.lastname: Müller
authors.forename: A I M
authors.initials: AI
authors.lastname: Nilsson Remahl
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging*; D001931:Brain Mapping; D003027:Cluster Headache / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007249:Inflammation / Q000000981:diagnostic imaging; D007962:Leukocytes / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*