Nervus intermedius neuralgia (NIN) or geniculate neuralgia is a rare facial pain condition consisting of sharp, lancinating pain deep in the ear and can occur alongside trigeminal neuralgia (TN). Studies on the clinical presentation, intraoperative findings, and ultimately postoperative outcomes are extremely limited. The aim of this study was to examine the clinical presentation and surgical findings, and determine pain-free survival after sectioning of the nervus intermedius (NI).
The authors conducted a retrospective chart review and survey of patients who were diagnosed with NIN at one institution and who underwent neurosurgical interventions. Pain-free survival was determined through chart review and phone interviews using a modified facial pain and quality of life questionnaire and represented as Kaplan-Meier curves.
The authors found 15 patients with NIN who underwent microsurgical intervention performed by two surgeons from 2002 to 2016 at a single institution. Fourteen of these patients underwent sectioning of the NI, and 8 of 14 had concomitant TN. Five patients had visible neurovascular compression (NVC) of the NI by the anterior inferior cerebellar artery in most cases where NVC was found. The most common postoperative complaints were dizziness and vertigo, diplopia, ear fullness, tinnitus, and temporary facial nerve palsy. Thirteen of the 14 patients reportedly experienced pain relief immediately after surgery. The mean length of follow-up was 6.41 years (range 8 months to 14.5 years). Overall recurrence of any pain was 42% (6 of 14), and 4 patients (isolated NIN that received NI sectioning alone) reported their pain was the same or worse than before surgery at longest follow-up. The median pain-free survival was 4.82 years ± 14.85 months. The median pain-controlled survival was 6.22 years ± 15.78 months.
In this retrospective review, sectioning of the NI produced no major complications, such as permanent facial weakness or deafness, and was effective for patients when performed in addition to other procedures. After sectioning of the NI, patients experienced 4.8 years pain free and experienced 6.2 years of less pain than before surgery. Alone, sectioning of the NI was not effective. The pathophysiology of NIN is not entirely understood. It appears that neurovascular compression plays only a minor role in the syndrome and there is a high degree of overlap with TN.
ABBREVIATIONSAICA = anterior inferior cerebellar artery; BNI = Barrow Neurological Institute; BPI-Facial = Brief Pain Inventory–Facial instrument; CN = cranial nerve; GN = glossopharyngeal neuralgia; MVC = microvascular decompression; NI = nervus intermedius; NIN = NI neuralgia; NVC = neurovascular compression; PICA = posterior inferior cerebellar artery; QOL = quality of life; TN = trigeminal neuralgia.
LeeJY, ChenHI, UrbanC, HojatA, ChurchE, XieSX, : Development of and psychometric testing for the Brief Pain Inventory-Facial in patients with facial pain syndromes. 113:516–523, 201010.3171/2010.1.JNS0966920151778)| false
RogersCLShetterAGFiedlerJASmithKAHanPPSpeiserBL: Gamma knife radiosurgery for trigeminal neuralgia: the initial experience of The Barrow Neurological Institute. Int J Radiat Oncol Biol Phys47:1013–10192000
RogersCL, ShetterAG, FiedlerJA, SmithKA, HanPP, SpeiserBL: Gamma knife radiosurgery for trigeminal neuralgia: the initial experience of The Barrow Neurological Institute. 47:1013–1019, 200010.1016/S0360-3016(00)00513-710863073)| false
SakasDEPanouriasIGStranjalisGStefanatouMPMaratheftisNBontozoglouN: Paroxysmal otalgia due to compression of the intermediate nerve: a distinct syndrome of neurovascular conflict confirmed by neuroimaging. Case report. J Neurosurg107:1228–12302007
SakasDE, PanouriasIG, StranjalisG, StefanatouMP, MaratheftisN, BontozoglouN: Paroxysmal otalgia due to compression of the intermediate nerve: a distinct syndrome of neurovascular conflict confirmed by neuroimaging. Case report. 107:1228–1230, 20071807796310.3171/JNS-07/12/1228)| false
XuWZhangJWangYWangLWangX: Changes in the expression of voltage-gated sodium channels Nav1.3, Nav1.7, Nav1.8, and Nav1.9 in rat trigeminal ganglia following chronic constriction injury. Neuroreport27:929–9342016
XuW, ZhangJ, WangY, WangL, WangX: Changes in the expression of voltage-gated sodium channels Nav1.3, Nav1.7, Nav1.8, and Nav1.9 in rat trigeminal ganglia following chronic constriction injury. 27:929–934, 20162732715610.1097/WNR.0000000000000632)| false