Bilateral transnasal sphenopalatine block for treating postdural puncture headache

puncture headache (PDPH) with great interest. The author has reviewed the literature and has very thoroughly discussed the diagnosis, risk factors, pathophysiology, prevention, and treatment of PDPH. In this letter, we want to mention another simple technique that can be performed at the bedside or in the outpatient department and is effective at relieving PDPH. The procedure is known as transnasal bilateral sphenopalatine ganglion block. In a review article published in the Korean Journal of Pain, we have reviewed the evidence for the efficacy of bilateral, transnasal sphenopalatine ganglion block at relieving PDPH [2]. The sphenopalatine ganglion (SPG), which is also known as the pterygopalatine ganglion, Meckel’s ganglion, or the nasal ganglion, is a triangular parasympathetic ganglion located superficially in the pterygopalatine fossa, posterior to the middle nasal turbinate and anterior to the pterygoid canal. It measures 5 mm in size with a 1 to 1.5 mm layer of connective tissue and mucous membrane surrounding the ganglion. Although essentially a parasympathetic ganglion, the SPG is a junction that has sympathetic, parasympathetic, and sensory innervation overlapping in a small area [3]. This is why postganglionic parasympathetic and sympathetic neurons and the somatic sensory afferents can all be blocked by an SPG block. Therefore, an SPG block is indicated in a variety of acute and chronic head and neck pain syndromes of varying etiologies, such as trigeminal neuralgia, complex regional pain syndrome I and II, temporomandibular joint pain, postherpetic neuralgia, cluster headaches, Sluder’s neuralgia, paroxysmal hemicranial pain, head and neck cancer pain, vasomotor rhinitis, atypical facial pain, and postoperative analgesia after head and neck cancer surgery [4]. Chronic pain physicians perform the SPG block via transnasal, transoral, subzygomatic, and lateral infratemporal approaches using radio-opaque contrast and a fluoroscope. These approaches are not only cumbersome but also require sufficient training to perform safely and accurately. However, the transnasal SPG block is very simple and does not need contrast or a fluoroscope. With the patient in the supine position and the neck extended, a sterile swab-stick soaked with lidocaine solution is inserted through the nostril after adequate lubrication until resistance is encountered. The resistance is due to the posterior pharyngeal wall, which is superior to the middle turbinate. The swab needs to be left there for 10–15 min. The procedure is repeated in the other nostril. The mucous membrane covering the Letter to the Editor