title: Blood pool scintigraphy of the skull in relation to head-down tilt provocation in patients with chronic tension-type headache and controls.
abstract: OBJECTIVE
  To investigate the mechanisms behind the increase of chronic tension-type headache during head-down tilt.
  
  
  BACKGROUND
  The pathophysiology of chronic tension-type headache is unknown.
  
  
  METHODS
  Ten patients suffering from chronic tension-type headache and 10 age- and sex-matched controls were studied with respect to pain intensity and alterations in cranial blood volume using planar scintigraphy and radiolabeled autologous erythrocytes before, during, and after head-down tilt, a procedure known to increase chronic tension-type headache.
  
  
  RESULTS
  Four of 8 patients with chronic tension-type headache studied had increased cerebrospinal fluid pressure. During head-down tilt, the pain increased significantly in the group with chronic tension-type headache (P <.001) while the procedure did not cause headache in the controls. Blood volume significantly increased extracranially and decreased intracranially in both groups during head-down tilt. The extracranial nasal blood volume was significantly related to the pain experienced by the patients with chronic tension-type headache before and during head-down tilt.
  
  
  CONCLUSIONS
  Although the changes in blood volume and, presumably, the increase of intracranial pressure were similar in the patients with chronic tension-type headache and the controls, only the patients experienced pain and pain increase during head-down tilt. This indicates that the pre-head-down tilt conditions must be different in the 2 groups and should be related to increased cerebrospinal fluid pressure/intracranial venous pressure in patients with chronic tension-type headache compared with controls. A difference in central mechanisms may, however, also be of importance for the difference in headache provocation in the 2 groups during head-down tilt.
authors.affiliation: Departments of Neurology, Karolinska Hospital, Stockholm, Sweden.
authors.forename: Jan
authors.initials: J
authors.lastname: Hannerz
authors.forename: P-O
authors.initials: PO
authors.lastname: Schnell
authors.forename: Stig
authors.initials: S
authors.lastname: Larsson
authors.forename: Hans
authors.initials: H
authors.lastname: Jacobsson
mesh_terms: D000328:Adult; D001810:Blood Volume; D002908:Chronic Disease; D005260:Female; D015637:Gated Blood-Pool Imaging; D006257:Head / Q000098:blood supply*; D018475:Head-Down Tilt / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018781:Tension-Type Headache / Q000000981:diagnostic imaging / Q000503:physiopathology*