Comparison of Lower Cranial Nerve Function Between Tympanojugular Paraganglioma Class C1/C2 With and Without Intracranial Extension: A Four-Decade Experience

Abstract

Objective: To compare preoperative and postoperative lower cranial nerve (LCN) function between Class C1 and C2 tympanojugular paraganglioma (TJP) with/without intracranial intradural (Di)/extradural (De) extensions, according to the experience of a single surgeon over four decades. Study Design: Retrospective review. Setting: Quaternary referral center for otology and skull base surgery. Material and Methods: A chart review was conducted of all the patients operated for C1/C2 TJPs from September 1983 to December 2018. The tumors were classified as: Limited-Group (C1/C2 without Di/De extensions) and Extended-Group (C1/C2 with Di/De extensions). Results: Of 159 patients, 107 (67.3%) were women; the mean age at surgery was 46.5 years. The Limited-Group (56.6%) comprised C1 (41.1%) and C2 (58.9%) tumors; the Extended-Group (43.4%) comprised C1+Di/De (14.5%) and C2+Di/De (85.5%) tumors. The prevalence of preoperative LCN palsy was 11.9 times higher in Extended than Limited tumors: 61.9% versus 4.9% (p < 0.05). The risk for postoperative LCN palsy was 4.7 times greater in Extended than Limited tumors: 29.2% versus 12.9%, p = 0.01. Conclusion: Especially in younger patients, complete removal of Limited C1/C2 tumors, before they extend intracranially, reduces the risk of dysfunctionality of LCNs and the burden of residual tumor. The incidence of new tumors increased over four decades. However, new-postoperative LCN palsy did not occur in any Limited C1/C2 tumors operated after the year 2000, and declined to less than 10% of Extended C1/C2 tumors.

Comparison of surgical outcomes between early and advanced class of jugular paragangliomas following application of our modified surgical techniques

“…Prasad et al noticed that the presence of intradural extension is usually associated with infiltration of the LCNs 3 . Grinblat et al reported that early and limited C1 and C2 tumors without medial wall invasion reduces the risk of dysfunctionality of LCNs 29 . Thus resection of early JPs (classes C1-C2), where the lateral aspect of the jugular bulb is involved and the medial wall is not infiltrated, makes preservation of the LCNs possible.…”

Paragangliomas of the Head and Neck: A Review of the Latest Diagnostic and Treatment Methods

“…For Fisch C1 and C2, with or without Di or De extensions, complete removal of the tumor is possible, preventing functional deficits for lower cranial nerves, with less than 10% of new postoperative nerve palsies in cases with Di/De, and none in those without extensions [ 74 ].…”