Adult patients with persistent headache following COVID-19 infection will be enrolled in the study. The patients will be randomised into three groups; bilateral SPG-block withto receive local anesthetic (lidocaine + ropivacaine), bilateral SPG-block with placebo (isotone NaCl) or bilateral sham-block with placebo (isotone NaCl).~Primary outcome is hyperactivity in the sphenopalatine ganglion assessed by pain intensity (0-100mm on a visual analogue scale, VAS) of the headache in standing position 30 minutes after block in the group Ropicavain-Lidocain and sham.
The purpose of this study is to evaluate the effect of the ganglion sphenopalatine block (SPG block) on persistent headache following acute COVID-19 infection.