INTRODUCTION
Migraine is one of the primary headaches, manifested as headache attacks lasting for 4-72 hours, mostly localized to one half of the head, increasing in severity with physical activity, and affecting the individual’s daily living activities. Chronic migraine (CM) has been included as a subheading in the migraine classification due to its characteristics. According to the diagnostic criteria of the 2018 International Classification of Headache Disorders (ICHD-3 beta) [1], a migraine headache, present for more than three months, eight days or more in a month, and with intervals of less than 15 days, was defined as CM [2]. In a prevalence study conducted in Turkey, the prevalence of CM was reported as 0.066% without medication overuse and 0.56% in newly diagnosed patients [3].
It is known that the rate of benefiting from medical treatment is relatively low in chronic migraines, analgesics are extensively used besides frequent use of prophylactic drugs, and patients encounter disabilities because of pain. Recently, peripheral nerve blocks have been reported to be effective in particularly chronic migraine, and the greater occipital nerve (GON) block has started to be used in chronic migraine patients. It is known that in the GON block, low-concentration local anesthetics manifest their effects by selectively blocking sensory nerve fibers to provide improvement in painful conditions.
In the study conducted by Caputi et al., reductions in headache duration, frequency, and severity for six months were reported in patients in whom the supraorbital and GON blocks were performed [4]. Peripheral nerve blocks technically involve the blockage of trigeminal nerve branches such as supraorbital, supratrochlear, auriculotemporal nerves in addition to the greater and smaller occipital nerve blocks. In migraine patients, the GON block is the most preferred method, with studies most frequently conducted on its effectiveness [5]. The GON block’s effect is known to be via the trigeminovascular system. Conducted studies have emphasized a functional connection between the caudal trigeminal nucleus and the upper cervical segments [6, 7]. When the GON block is performed, the injected anesthetic substance creates modulation by blocking afferent stimuli at the field innervated by the nerve and preventing sensitization at the C2 and C3 dorsal horn convergence neurons [5].
This study aimed to evaluate the headache attack frequency, analgesic use, VAS (Visual Analog Scale) and MIDAS (Migraine Disability Assessment Scale) scores in the 3-month follow-up in patients in whom we had performed a GON block for chronic migraine refractory to medical treatment.