RESUMO
INTRODUCTION: Livedo reticularis (LR) refers to the violaceous netlike pattern of skin related to arteriopathy at the dermis-subcutis border. Livedo is associated with migraine, and among migraineurs, LR is more common in those with prior stroke. Other evidence of vascular perturbation in migraine comes from studies showing elevated von Willebrand factor (vWF). The purpose of this study is to evaluate global hemostasis in migraineurs, including the subset with LR, using a dynamic flow system simulating physiological conditions, and measuring vWF activity and antigen levels. MATERIALS AND METHODS: Patients with migraine were enrolled from the headache clinic and presence or absence of LR was noted. Age-matched healthy, non-migraine, LR-free individuals were recruited as controls. To evaluate hemostasis, we used the Clot Signature Analyzer (CSA) measuring platelet hemostasis time (PHT), collagen-induced thrombus formation (CITF), and clot time (CT). vWF activity and vWF antigen levels were also measured. RESULTS: The mean vWF activity level (142.7 vs. 103.4, p<0.01) and antigen level (132.1 vs. 104.5, p<0.05) were higher, and all three hemostasis parameters shorter in the episodic migraineurs than in the controls. The subset of migraineurs with LR had the highest vWF activity (155+/-59, p<0.05) and vWF antigen (141+/-43, p<0.05) levels, and the shortest PHT (3.7+/-1.6, p<0.05). In this subset there was a significant inverse correlation between vWF activity and PHT (r=-0.51, p=0.01). CONCLUSIONS: For migraineurs, the differences from controls in vWF and PHT are most robust in the LR subset, with the inverse correlation suggesting that endothelial perturbation may be causally related to the response of the platelets.
