الفهرس 
MIGRAINEOnly 14 pages are availabe for public view
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Abstract
M
igraine is a common, multifactorial, neurovascular disorder with major individual and societal effects.
Migraine affects roughly 15% of people and is typically characterised by disabling episodes of severe headache accompanied by nausea, vomiting, and hypersensitivity to light, sound, and smell for up to 3 days (migraine without aura).
In a third of patients, attacks might be associated with transient focal neurological aura symptoms (migraine with aura); it has been suggested that migraine with and without aura are distinct disorders. Once a migraine attack has started, the mechanisms underlying migraine aura and headache are reasonably well understood. Aura is most likely caused by cortical spreading depression, and headache by activation of the trigeminovascular system and associated release of CGRP.
Migraine headache is caused by activation of the trigeminovascular system the trigeminovascular system consists of nociceptive trigeminal sensory afferents surrounding cranial blood vessels. Upon activation of these perivascular trigeminal afferents, the signal travels through the trigeminal ganglion to neurons in the trigeminocervical complex, using CGRP as the main neurotransmitter. The signals are then relayed to the thalamus; because all nociceptive inputs are integrated through this structure, it has been named the pain matrix of the brain (Noseda et al., 2013).
Modulation of the signal occurs through extensive connections with brainstem regions such as the periaqueductal gray and the locus coeruleus.
GON block intervention is found to substantially reduce pain intensity and analgesic medication consumption for migraine patients, with no increase in adverse events. GON block intervention should be recommended to be administrated in migraine patients.
Once the headaches become refractory to conventional pharmacologic management, minimally invasive techniques such as peripheral nerve blocks are feasible for pain relief, and help to decrease the frequency of the attacks. Various studies have demonstrated that peripheral nerve blocks are safe and effective for the treatment of a variety of headache disorders. These techniques not only provide adequate analgesia but can also help to decrease systemic side effects of pharmacological therapy.
Moreover it was found that The US guided GON injection technique has a higher success rate and might allow a more precise block of the nerve.
The aim of this study was to to assess the effect of ultrasound guided bilateral greater occipital nerve block on CGRP levels in peripheral blood and outcome in chronic migraine (CM).
Fourty patients diagnosed with chronic migraine were recruited in this study. All participants underwent GONB, CGRP levels were measured before and 1 month after block.
This study revealed female dominance in our sample and the duration of illness was about 7 years.
This study revealed that US guided GON injection showed good response rate than blind techniques
This study revealed that CGRP levels after ultrasound guided GONB were significantly lower as compared with CGRP levels obtained before GONB.
Moreover Pretreatment CGRP levels in non-responders were significantly higher than those seen in responders being in poor responders less than 50% improvement and good responders One month after treatment.
A number of demographic factors, clinical features, and comorbidities were not different in responders as compared with those of nonresponders.
At the end it was found that CGRP level before GONB may play a role as a predictor for response for the GONB although both responders and non responders showed significant reduction in CGRP levels and this may raise the importance of repeated GONB in non-responders while CGRP levels after injection didn’t show significant correlation raising the possibility that improvement may be non CGRP mechanism could be explained by limitations of this study, such as the absence of a control group, the fact that most of these patients remained on oral preventives, the relatively low numbers of nonresponders in our series, or the intrinsic and subjective variability of migraine, Our results might indicate that some patients with a “CM” phenotype could suffer from other headaches (eg, psychogenic, tension-type headache or other secondary headaches) in which CGRP does not seem to be involved.
The fact that we are the first study in the literature to assess the changes of CGRP levels with GONB gave us little chances to correlate our work with the others, hopefully in the future there will more studies regarding CGRP changes with peripheral intervention as they are feasible with less side effect and affordable.
RECOMMENDATIONS
Further studied enrolling larger sample size with control group for comparison.
Increase GONB frequency and to assess CGRP level for longer period and follow up patients clinically.
More studies to assess correlation between CGRP changes in response to treatment and to correlate CGRP levels and other CM biomarkers as VIP with GONB.
Studies to assess other peripheral injection blockades and effect on CGRP levels.
Use of US guided block to provide more accurate and precise localization of the nerve.