RETRACTED ARTICLE: Greater occipital nerve block in chronic migraine

Headache syndromes often involve occipital and neck symptoms suggesting a functional connectivity between nociceptive trigeminal and cervical afferents. Several studies have suggested that pain relief in migraine and other types of headache can be achieved by local injections of steroids, local anaesthetics or a mixture of both in the area of greater occipital nerve (GON). Usually greater occipital nerve block (GONB) is performed by using local anaesthetics alone or with steroid. The rationale of performing a GONB for the treatment of chronic headache states is on the anatomical connections between trigeminal and upper cervical sensory fibres at the level of the trigeminal nucleus caudalis. However, the reason for the improvement after GONB in primary headache is unknown. The objective of this study is to determine whether adding triamcinolone to local anaesthetics increased the efficacy of GONB and trigger point injections (TPIs) for chronic migraine (TM). Patients with TM were randomized to receive GONB and TPIs using lidocaine 2% and bupivacaine 0.5% + either saline or triamcinolone 40 mg. Particularly, a 10-ml syringe containing 4.5 ml of lidocaine 2%, 4.5 ml of bupivacaine 0.5% and 1 ml of either saline (group A) or triamcinolone 40 mg/ml (group B) was prepared for each patients. Patients were given bilateral GONB and TPIs in the cervical paraspinal and trapezius muscles bilaterally. 2 ml were injected into each GON at the medial third of the distance between the occipital protuberance and the mastoid process. In addition, 0.5 ml was injected into each of the 12 trigger points. The total injected volume was 10 ml. The primary outcome measure was the change in mean headache severity from before injection to 20 min after in the two groups. Secondary outcome measures were the change in mean neck pain, photophobia and phonofobia severity from before injection to 20 min after in the two groups. Patients documented headache and severity of associated symptoms for 4 weeks after injection. Changes in symptom severity were compared between the two groups. Thirty-seven patients were included. Twenty minutes after injection, mean headache severity decreased by 3.2 points in group A (p < 0.01) and by 3.1 points in group B (p < 0.01). Mean neck pain severity decreased by 1.5 points in group A (p < 0.01) and by 1.7 points in group B (p < 0.01). Mean duration of being headache-free was 2.7 ± 3.8 days in group A and 1.0 ± 1.1 days in group B (p = 0.67). None of the outcome measures differed significantly between the two groups. Both treatments were full tolerated. In our study, adding triamcinolone to local anaesthetic when perfoming GONB and TPIs was not associated with improved outcome in the sample of patients with TM. In both groups, the procedure resulted in significant and rapid relief of headache, neck pain, photophobia and phonofobia.