Sphenopalatine Neuralgia: An Independent Neuralgia Entity. Pooled Analysis of a Case Series and Literature Review

Background Structural damage or demyelization of the sphenopalatine ganglion may cause sphenopalatine neuralgia (SN). The current International Classification of Headache Disorders, third edition (ICHD-3) regards SN as a phenotype of cluster headache. Whether SN is an independent neuralgia entity has been debated for years. Methods This article presents a case series of SN, a review of all published cases, and a pooled data analysis of the identified cases. Results Seven patients were identified, with a median age at symptom onset of 59 years. Six cases were secondary to structural lesions surrounding the ipsilateral sphenopalatine ganglion, and all of them experienced significant clinical improvements after removing the primary causes. In the seventh patient, no evidence of underlying disease was found. The literature review showed that SN affected patients spanning a wide range of ages and both sexes. The clinical characteristics of SN might mimic cluster headache with the exception of cluster pattern and treatment response to oxygen. The typical duration of pain episodes in SN was several hours to several days; and in some cases, pain was persistent. Sixty-seven percent (59/88) of patients with SN had structural lesions around the sphenopalatine ganglion. Conclusion SN could possibly be regarded as a different clinical entity from cluster headache. Based on our patients and literature review, SN can be categorized as idiopathic SN and secondary SN. Craniofacial structural lesions should be highly rating and taken into account when SN is suspected.