title: Phospholipase C activity increases in cerebrospinal fluid from migraineurs in proportion to the number of comorbid conditions: a case-control study.
abstract: BACKGROUND
  Migraineurs are more often afflicted by comorbid conditions than those without primary headache disorders, though the linking pathophysiological mechanism(s) is not known. We previously reported that phosphatidylcholine-specific phospholipase C (PC-PLC) activity in cerebrospinal fluid (CSF) increased during migraine compared to the same individual's well state. Here, we examined whether PC-PLC activity from a larger group of well-state migraineurs is related to the number of their migraine comorbidities.
  
  
  METHODS
  In a case-control study, migraineurs were diagnosed using International Headache Society criteria, and controls had no primary headache disorder or family history of migraine. Medication use, migraine frequency, and physician-diagnosed comorbidities were recorded for all participants. Lumbar CSF was collected between the hours of 1 and 5 pm, examined immediately for cells and total protein, and stored at -80°C. PC-PLC activity in thawed CSF was measured using a fluorometric enzyme assay. Multivariable logistic regression was used to evaluate age, gender, medication use, migraine frequency, personality scores, and comorbidities as potential predictors of PC-PLC activity in CSF.
  
  
  RESULTS
  A total of 18 migraineurs-without-aura and 17 controls participated. In a multivariable analysis, only the number of comorbidities was related to PC-PLC activity in CSF, and only in migraineurs [parameter estimate (standard error) = 1.77, p = 0.009].
  
  
  CONCLUSIONS
  PC-PLC activity in CSF increases with increasing number of comorbidities in migraine-without-aura. These data support involvement of a common lipid signaling pathway in migraine and in the comorbid conditions.
authors.affiliation: Molecular Neurology Program, Huntington Medical Research Institutes, 99 N El Molino Ave, Pasadena, CA 91101, USA. afonteh@hmri.org.
authors.forename: Alfred N
authors.initials: AN
authors.lastname: Fonteh
authors.forename: Janice M
authors.initials: JM
authors.lastname: Pogoda
authors.forename: Rainbow
authors.initials: R
authors.lastname: Chung
authors.forename: Robert P
authors.initials: RP
authors.lastname: Cowan
authors.forename: Michael G
authors.initials: MG
authors.lastname: Harrington
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D015897:Comorbidity; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008881:Migraine Disorders / Q000134:cerebrospinal fluid* / Q000201:enzymology* / Q000453:epidemiology; D010738:Type C Phospholipases / Q000134:cerebrospinal fluid*
chemical_list: D010738:Type C Phospholipases; C105598:phosphatidylcholine-specific phospholipase C