Hemorheologic dysfunction in analgesic-induced chronic headache? Results of a pilot study

The aim of the present study was to investigate whether analgesic-induced chronic headache is associated with hemorheologic dysfunction. The viscoelastic properties of whole blood from 28 patients with chronic headache induced by regular use of analgesics were compared to the viscoelastic properties from 28 healthy control subjects matched with respect to age, sex, cigarette smoking, and intake of oral contraceptives. Fifteen of the investigated 28 patients originally suffered from migraine, 13 from tension-type headaches. Prior to analgesic drug-withdrawal, blood viscosity at shear rates 10/s and 50/s, blood elasticity at 50/s (each adjusted to a hematocrit of 45%), and the calculated shear resistance of erythrocytes in patients, originally suffering from tension-type headaches, were significantly higher than the corresponding values in control subjects. In contrast, most viscoelastic properties in migraine patients with the exception of blood elasticity at 50/s did not differ significantly from controls. A standardized analgesic drug-withdrawal therapy was administered for 10 days during hospitalization.Patients were re-examined 30 days after analgesic withdrawal. There were no relevant differences of viscoelastic properties in migraine and tension-type headache patients in comparison to the viscoelastic properties prior to drug-withdrawal therapy. The results of the present study indicate that hemorheologic dysfunction does not play a major role in the pathogenesis of analgesic-induced chronic headache.