Sphenopalatine Ganglion Stimulation in Neurovascular Headaches

Abstract

The interest for the sphenopalatine ganglion (SPG) in neurovascular headaches dates back to 1908 when Sluder presented his work on the role of the SPG in 'nasal headaches', which are now part of the trigeminal autonomic cephalalgias and cluster headache (ICHD-III-beta). Since then various interventions with blocking or lesional properties have targeted the SPG (transnasal injection of lidocaine and other agents, alcohol or steroid injections, radiofrequency lesions, or even ganglionectomy); success rates vary, but benefit is usually transient. Here we briefly review some anatomophysiological characteristics of the SPG and hypotheses about its pathophysiological role in neurovascular headaches before describing recent therapeutic results obtained with electrical stimulation of the SPG. Based on results of a prospective randomized controlled study, SPG stimulation appears to be an effective treatment option for patients with chronic cluster headaches; efficacy data indicate that acute electrical stimulation of the SPG provides significant attack pain relief and in many cases pain freedom compared to sham stimulation. Moreover, in some patients SPG stimulation has been associated with a significant and clinically meaningful reduction in cluster headache attack frequency; this preventive effect of SPG stimulation warrants further investigation. For migraine attacks, the outcome of a proof-of-concept study using a temporary electrode implanted in the pterygopalatine fossa was less encouraging; however, an ongoing multicenter trial is evaluating the efficacy of long-term SPG stimulation against sham stimulation for acute and preventive treatment in patients with frequent migraine.

PACAP Induces Light Aversion in Mice by an Inheritable Mechanism Independent of CGRP

“…It is one of the most incapacitating neurological disorders in the world (Collaborators, 2018). One diagnostic criterion for migraine is photophobia, autonomic symptoms of migraine since it can increase cerebral blood flow, intracranial and extracranial vasodilation, and dural plasma protein extravasation (Schoenen, 2015). Interestingly, PACAP can also induce release of CGRP from trigeminal neurons (Jansen-Olesen et al, 2014), which suggests the possibility of crosstalk between the sphenopalatine and trigeminal systems.…”

Cortical and subcortical changes following sphenopalatine ganglion blocks in chronic migraine with medication overuse headache: a preliminary longitudinal study

“…It is now widely known that disruption of neural signals generated by the SPG can modulate the output of the autonomic nerve fibers involved in headache. This disruption can be induced via electrical stimulation, or as is more commonly the case, through the administration of local anesthetics to the areas in close vicinity of SPG [1][2][3][4][5][6][7]. While some of the currently available approaches are either invasive (involving penetration of the mucosa on the lateral nasal wall) or expensive (requiring fluoroscopic guidance), SPG block using local anesthesia is a novel treatment option with great clinical potential and is both non-invasive and relatively inexpensive [8].…”

Peripheral Neuromodulation for the Management of Headache

“…These side-effects decreased significantly over several months, yet the positive effects have remained over time in longer-term studies (49). Trials employing a temporary electrode placed in the pterygopalatine fossa for migraine attacks appear less promising (50).…”