Comorbidity with fibromyalgia predicted poorer outcomes in patients with chronic migraine on flunarizine: Prospective proof-of-concept study.

AimFibromyalgia (FM) and chronic migraine (CM) are commonly comorbid. Clinical observations suggest patients with chronic migraine comorbid with fibromyalgia (CMFM) seem less responsive to migraine preventive treatment; however, evidence is still lacking. This study examined the responsiveness to migraine preventive treatment in patients with CM and CMFM.MethodsPatients with CM and CMFM were prospectively recruited. None of them received migraine prevention prior to participation. Both groups were administered with flunarizine as migraine prevention and were asked to keep headache diaries. The CMFM group received additional standard treatment for FM concomitantly, predominately pregabalin. Treatment response was defined as ≧50% reduction in monthly headache days (MHDs) at the third month post-treatment compared with baseline.ResultsEighty-four patients with CM (38.3 ± 11.5 years old, 93% female) and 38 with CMFM (40.2 ± 11.3 years old, 87% female) finished the study for final analyses. CMFM had more MHD and higher levels of depression and anxiety at baseline. After treatment, CM demonstrated better treatment outcomes (50% responder rate 52% vs. 32%, p = 0.033). The presence of FM in patients with CM increased the odds of non-converter to EM after controlling for baseline MHD using a logistic regression model (OR: 2.8 [1.1-7.1], p = 0.027). Comorbid FM in patients with CM showed limited improvement despite receiving standard treatments for both conditions.ConclusionThis proof-of-concept research underscores the importance of clinicians recognizing FM in patients with CM since they are prone to poor responses to treatment.