Prevalence, clinical features and potential therapies for fibromyalgia in primary headaches.

Fibromyalgia (FM) syndrome is predominantly related to generation and persistence of central sensitization, which is an aggravating factor for chronic headaches. This review aims to examine the last 11 years of studies on FM and primary headache comorbidity, focusing on prevalence, clinical features and treatments. Chronic forms of migraine and tension-type headache show a high frequency of FM comorbidity. The symptoms characterizing headache patients presenting with FM comorbidity are high headache frequency, poor sleep quality, pericranial tenderness, anxiety and reduction of physical performances. The effects of headache-preventive drugs on factors favoring FM comorbidity were poorly evaluated. Nonpharmacological approaches such as transcranial magnetic stimulation may be an option for treatment of chronic migraine associated with FM.