Sphenopalatine ganglion block for relieving postdural puncture headache: technique and mechanism of action of block with a narrative review of efficacy.

The sphenopalatine ganglion (SPG) is a parasympathetic ganglion, located in the pterygopalatine fossa. The SPG block has been used for a long time for treating headaches of varying etiologies. For anesthesiologists, treating postdural puncture headaches (PDPH) has always been challenging. The epidural block patch (EBP) was the only option until researchers explored the role of the SPG block as a relatively simple and effective way to treat PDPH. Also, since the existing evidence proving the efficacy of the SPG block in PDPH is scarce, the block cannot be offered to all patients. EBP can be still considered if an SPG block is not able to alleviate pain due to PDPH.