Influence of patient positioning on reported clinical outcomes after greater occipital nerve block for treatment of headache: Results from prospective single-centre, non-randomised, proof-of-concept study.

OBJECTIVE: Greater occipital nerve (GON) block is a treatment option applied for a variety of primary headache disorders. Although a patient's body position is known to have an impact on the effect of local anaesthetics, this has not before been investigated for patients undergoing GON block. Therefore, the clinical effectiveness of either a sitting or supine position was assessed.

PATIENTS AND METHODS: This evaluative prospective study took place in a single neurology department in the UK. Baseline and follow-up data were collated during standard clinic consultations for 95 consecutive patients who underwent GON block and follow-up consultations for treatment-refractory headache disorder. The GON block procedure was identical for all patients in terms of constitution of the applied medication and volume injected (lidocaine hydrochloride 20 mg and methylprednisolone acetate 80 mg in 2 ml vial). Directly afterwards, patients opted to either sit up (n = 34) or lie down (n = 61) for ten minutes.

RESULTS: Twenty-seven patients (44%) reported substantial benefit and 17 (28%) complete benefit (pain freedom) for a median duration of 70 days and 84 days in the 'supine' group, compared with 10 (29%) substantial and 6 (18%) complete benefit (pain freedom) for a median duration of 25 days (substantial) and 119 days (complete) in the 'sitting' group. Overall, a supine position results in a longer overall post-GON block headache-free period (p-value 0.007) and median relief score (p-value 0.017) compared to a sitting up position, as determined by Mann-Whitney U-test. Backward multiple linear regression analysis showed that the chronicity of the patient's condition is negatively associated (beta -0.24, p-value 0.024) and the post-GON block patient position is positively associated (beta 0.25, p-value 0.018) with the achieved headache-free period. Apart from variation in baseline headache characteristics, the 'sitting' and 'supine' cohorts did not significantly differ in terms of other clinical parameters and patient demographics.

CONCLUSIONS: Placing a patient in a supine position following a GON block procedure for headache may significantly improve the resulting clinical effectiveness of this treatment. Further research, through a prospective, multi-centre, randomised, controlled trial, is indicated to determine if the initial positive observations in this present pragmatic evaluation can be confirmed.