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.